1.
Product label
–
A label is a piece of paper, polymer, cloth, metal, or other material affixed to a container or product, on which is written or printed information or symbols about the product or item. Information printed directly on a container or article can also be considered labeling, methods of production and attachment to packaging are many and various and may also be subject to internationally recognised standards. In many countries, hazardous products such as poisons or flammable liquids must have a warning label, labels may be used for any combination of identification, information, warning, instructions for use, environmental advice or advertising. They may be stickers, permanent or temporary labels or printed packaging, Permanent product identification by a label is commonplace, labels need to remain secure throughout the life of the product. For example, a VIN plate on an automobile must be resistant to heat, oils and tampering, similarly, removable product labels need to bond until they are removed. For example, a label on a new refrigerator has installation, usage and environmental information, packaging may have labeling attached to or integral with the package. These may carry pricing, barcodes, UPC identification, usage guidance, addresses, advertising, recipes and they also may be used to help resist or indicate tampering or pilferage. In industrial or military environments, asset labeling is used to identify assets for maintenance. Such labels are made of engraved Traffolyte or a similar material. They are usually tamper-evident, permanent or frangible and usually contain a barcode for electronic identification using readers, for example, the US Military uses a UID system for its assets. Garments normally carry separate care/treatment labels which, in regions, are subject to legislation. These labels typically indicate how the item should be washed, whether bleach can be used, textile labels may be woven into the garment or attached, and may be heat resistant, colorfast, washable, leather or PVC/Plastic. Printed labels are an alternative to woven labels, some upholstered furniture and mattresses have labels that are required by law, describing the contents of the stuffing. Textiles containing pesticides as an ingredient may also require government approval, a label including a company name or identification number and a material content list may also be required. Mailing labels identify the addressee, the sender and any information which may be useful in transit. Many software packages such as word processor and contact manager programs produce standardized mailing labels from a set that comply with postal standards. These labels may also include routing barcodes and special handling requirements to expedite delivery, piggyback labels are made from combining two layers of adhesive substrate. The bottom layer forms the backing for the top, the label can be applied to any object as normal, the top layer can be a removable label that can be applied elsewhere, which may change the message or marking on the remaining label underneath
Product label
–
Shirt with labels
Product label
–
A bunch of
bananas with a label
Product label
–
A label with faux
embossing
Product label
–
Fire extinguisher with permanent and temporary labels
2.
Adhesive
–
The use of adhesives offers many advantages over binding techniques such as sewing, mechanical fastening, thermal bonding, etc. Adhesives are typically organized by the method of adhesion and these are then organized into reactive and non-reactive adhesives, which refers to whether the adhesive chemically reacts in order to harden. Alternatively they can be organized by whether the raw stock is of natural or synthetic origin, Adhesives may be found naturally or produced synthetically. The earliest human use of substances was approximately 200,000 years ago. The first references to adhesives in literature first appeared in approximately 2000 BCE, the Greeks and Romans made great contributions to the development of adhesives. In Europe, glue was not widely used until the period 1500–1700 CE, from then until the 1900s increases in adhesive use and discovery were relatively gradual. Only since the last century has the development of synthetic adhesives accelerated rapidly, the earliest use of adhesives was discovered in central Italy when two stone flakes partially covered with birch-bark tar and a third uncovered stone from the Middle Pleistocene era were found. This is thought to be the oldest discovered human use of tar-hafted stones, the birch-bark-tar adhesive is a simple, one-component adhesive. Although sticky enough, plant-based adhesives are brittle and vulnerable to environmental conditions, the first use of compound adhesives was discovered in Sibudu, South Africa. The ability to produce stronger adhesives allowed middle stone age humans to attach stone segments to sticks in greater variations, more recent examples of adhesive use by prehistoric humans have been found at the burial sites of ancient tribes. Archaeologists studying the sites found that approximately 6,000 years ago the tribesmen had buried their dead together with food found in clay pots repaired with tree resins. The glue was analyzed as pitch, which requires the heating of tar during its production, the retrieval of this tar requires a transformation of birch bark by means of heat, in a process known as pyrolysis. The first references to adhesives in literature first appeared in approximately 2000 BCE, further historical records of adhesive use are found from the period spanning 1500–1000 BCE. Artifacts from this period include paintings depicting wood gluing operations and a made of wood. Other ancient Egyptian artifacts employ animal glue for bonding or lamination, such lamination of wood for bows and furniture is thought to have extended their life and was accomplished using casein -based glues. The ancient Egyptians also developed starch-based pastes for the bonding of papyrus to clothing, from 1 to 500 AD the Greeks and Romans made great contributions to the development of adhesives. Wood veneering and marquetry were developed, the production of animal and fish glues refined, egg-based pastes were used to bond gold leaves incorporated various natural ingredients such as blood, bone, hide, milk, cheese, vegetables, and grains. The Greeks began the use of slaked lime as mortar while the Romans furthered mortar development by mixing lime with volcanic ash and this material, known as pozzolanic cement, was used in the construction of the Roman Colosseum and Pantheon
Adhesive
–
Nitrocellulose adhesive outside a tube
Adhesive
–
A reconstruction of Ötzi's axe
Adhesive
–
Beeswax
Adhesive
–
Modern Slaked
Lime Factory in Ukraine
3.
Paint
–
Paint is any liquid, liquefiable, or mastic composition that, after application to a substrate in a thin layer, converts to a solid film. It is most commonly used to protect, color, or provide texture to objects, Paint can be made or purchased in many colors—and in many different types, such as watercolor, synthetic, etc. Paint is typically stored, sold, and applied as a liquid, in 2001 and 2004, South African archeologists reported finds in Blombos Cave of a 100, 000-year-old human-made ochre-based mixture that could have been used like paint. Further excavation in the cave resulted in the 2011 report of a complete toolkit for grinding pigments. Cave paintings drawn with red or yellow ochre, hematite, manganese oxide, ancient colored walls at Dendera, Egypt, which were exposed for years to the elements, still possess their brilliant color, as vivid as when they were painted about 2,000 years ago. The Egyptians mixed their colors with a substance, and applied them separately from each other without any blending or mixture. They appear to have used six colors, white, black, blue, red, yellow and they first covered the area entirely with white, then traced the design in black, leaving out the lights of the ground color. They used minium for red, and generally of a dark tinge, pliny mentions some painted ceilings in his day in the town of Ardea, which had been done prior to the foundation of Rome. He expresses great surprise and admiration at their freshness, after the lapse of so many centuries, Paint was made with the yolk of eggs and therefore, the substance would harden and adhere to the surface it was applied to. Pigment was made from plants, sand, and different soils, Most paints used either oil or water as a base. The process was done by hand by the painters and exposed them to lead poisoning due to the white-lead powder, in 1718, Marshall Smith invented a Machine or Engine for the Grinding of Colours in England. It is not known precisely how it operated, but it was a device that increased the efficiency of pigment grinding dramatically. By the proper onset of the Industrial Revolution, paint was being ground in steam-powered mills, interior house painting increasingly became the norm as the 19th century progressed, both for decorative reasons and because the paint was effective in preventing the walls rotting from damp. Linseed oil was also used as an inexpensive binder. In 1866, Sherwin-Williams in the United States opened as a large paint-maker and it was not until the stimulus of World War II created a shortage of linseed oil in the supply market that artificial resins, or alkyds, were invented. Cheap and easy to make, they held the color well. The vehicle is composed of the binder, or, if it is necessary to thin the binder with a diluent like solvent or water, it is the combination of binder + diluent. In this case, once the paint has dried or cured very nearly all of the diluent has evaporated, thus, an important quantity in coatings formulation is the vehicle solids, sometimes called the resin solids of the formula
Paint
–
Dried green paint
Paint
–
A charcoal and ochre cave painting of
Megaloceros from
Lascaux, France.
Paint
–
A piece of
Giant clam shell used to hold ochre paint in
pre-dynastic ancient Egypt
Paint
–
Watercolors as applied with a
brush
4.
Lacquer
–
The term lacquer is used for a number of hard and potentially shiny finishes applied to materials such as wood. These fall into a number of different groups. This dries to a hard and smooth surface layer which is durable, waterproof. Asian lacquer is sometimes painted with pictures, inlaid with shell and other materials, or carved, as well as dusted with gold and given other further decorative treatments. In modern techniques, lacquer means a range of clear or coloured wood finishes that dry by solvent evaporation or a process that produces a hard. The finish can be of any level from ultra matte to high gloss. It is also used for paint, which is a paint that typically dries better on a hard. Lacquer is more durable than shellac and these ultimately derive from Sanskrit lākshā, which was used for both the Lac insect and the scarlet resinous secretion it produces that was used as wood finish. Lac resin was once imported in quantity into Europe from India along with Eastern woods. Lacquer sheen is a measurement of the shine for a given lacquer, different manufacturers have their own names and standards for their sheen. The most common names from least shiny to most shiny are, flat, matte, egg shell, satin, semi-gloss, urushiol-based lacquers differ from most others, being slow-drying, and set by oxidation and polymerization, rather than by evaporation alone. In order for it to set properly it requires a humid, the phenols oxidize and polymerize under the action of an enzyme laccase, yielding a substrate that, upon proper evaporation of its water content, is hard. These lacquers produce very hard, durable finishes that are beautiful and very resistant to damage by water, acid, alkali or abrasion. The active ingredient of the resin is urushiol, a mixture of various phenols suspended in water, the resin is derived from a tree indigenous to China, species Toxicodendron vernicifluum, commonly known as the Lacquer Tree. The fresh resin from the T. vernicifluum trees causes urushiol-induced contact dermatitis, the Chinese treated the allergic reaction with crushed shellfish, which supposedly prevents lacquer from drying properly. Lacquer skills became very highly developed in Asia, and many highly decorated pieces were produced, the earliest extant lacquer object, a red wooden bowl, was unearthed at a Hemudu culture site in China. By the Han Dynasty, many centres of production became firmly established. The knowledge of the Chinese methods of the process spread from China during the Han, Tang and Song dynasties, eventually it was introduced to Korea, Japan, Southeast
Lacquer
–
Lacquer box with inlaid
mother of pearl peony decor,
Ming Dynasty, 16th century
Lacquer
–
Armorial screen
Lacquer
–
A Chinese six-pointed tray, red lacquer over wood, from the Song Dynasty (960–1279), 12th-13th century, Metropolitan Museum of Art.
Lacquer
–
Ming Dynasty Chinese
lacquerware container, dated 16th century.
5.
Adhesion
–
Adhesion is the tendency of dissimilar particles or surfaces to cling to one another. The forces that cause adhesion and cohesion can be divided into several types, the intermolecular forces responsible for the function of various kinds of stickers and sticky tape fall into the categories of chemical adhesion, dispersive adhesion, and diffusive adhesion. In addition to the magnitudes of these intermolecular forces, there are certain emergent mechanical effects. Surface energy is defined as the work that is required to build an area of a particular surface. Another way to view the energy is to relate it to the work required to cleave a bulk sample. If the new surfaces are identical, the surface energy γ of each surface is equal to half the work of cleavage, W, γ = W11. If the surfaces are unequal, the Young-Dupré equation applies, W12 = γ1 + γ2 – γ12 and this methodology can also be used to discuss cleavage that happens in another medium, γ12 = W121 = W212. These two energy quantities refer to the energy that is needed to one species into two pieces while it is contained in a medium of the other species. Likewise for a three species system, γ13 + γ23 – γ12 = W12 + W33 – W13 – W23 = W132, there is no single theory covering adhesion, and particular mechanisms are specific to particular material scenarios. Five mechanisms of adhesion have been proposed to explain why one material sticks to another, Adhesive materials fill the voids or pores of the surfaces, other interlocking phenomena are observed on different length scales. Sewing is an example of two forming a large scale mechanical bond, velcro forms one on a medium scale. Two materials may form a compound at the joint, the strongest joints are where atoms of the two materials swap or share electrons. A weaker bond is formed if an atom in one molecule is attracted to an atom of nitrogen, oxygen, or fluorine in another molecule. Chemical adhesion occurs when the atoms of two separate surfaces form ionic, covalent, or hydrogen bonds. The engineering principle behind chemical adhesion in this sense is fairly straightforward, if surface molecules can bond and it bears mentioning that these attractive ionic and covalent forces are effective over only very small distances – less than a nanometer. In surface science, the term adhesion almost always refers to dispersive adhesion, in a typical solid-liquid-gas system the contact angle is used to evaluate adhesiveness indirectly, while a Centrifugal Adhesion Balance allows for direct quantitative adhesion measurements. Generally, cases where the angle is low are considered of higher adhesion per unit area. This approach assumes that the contact angle corresponds to a higher surface energy
Adhesion
–
Dew drops adhering to a
spider web
Adhesion
–
Diagram of various cases of cleavage, with each unique species labeled. A: γ = (1/2)W 11 B: W 12 = γ 1 + γ 2 – γ 12 C: γ 12 = (1/2)W 121 = (1/2)W 212 D: W 12 + W 33 – W 13 – W 23 = W 132.
Adhesion
–
Cohesion causes water to form
drops, surface tension causes them to be nearly spherical, and adhesion keeps the drops in place.
Adhesion
–
Water droplets are flatter on a
Hibiscus flower which shows better adhesion.
6.
Wetting
–
Wetting is the ability of a liquid to maintain contact with a solid surface, resulting from intermolecular interactions when the two are brought together. The degree of wetting is determined by a balance between adhesive and cohesive forces. Wetting deals with the three phases of materials, gas, liquid, and solid and it is now a center of attention in nanotechnology and nanoscience studies due to the advent of many nanomaterials in the past two decades. Wetting is important in the bonding or adherence of two materials, Wetting and the surface forces that control wetting are also responsible for other related effects, including capillary effects. There are two types of wetting, non-reactive wetting and active wetting, adhesive forces between a liquid and solid cause a liquid drop to spread across the surface. Cohesive forces within the cause the drop to ball up. The contact angle, as seen in Figure 1, is the angle at which the liquid–vapor interface meets the solid–liquid interface, the contact angle is determined by the result between adhesive and cohesive forces. As the tendency of a drop to spread out over a flat, solid surface increases, thus, the contact angle provides an inverse measure of wettability. A contact angle less than 90° usually indicates that wetting of the surface is very favorable, contact angles greater than 90° generally means that wetting of the surface is unfavorable, so the fluid will minimize contact with the surface and form a compact liquid droplet. For water, a surface may also be termed hydrophilic. Superhydrophobic surfaces have contact angles greater than 150°, showing almost no contact between the drop and the surface. This is sometimes referred to as the Lotus effect, the table describes varying contact angles and their corresponding solid/liquid and liquid/liquid interactions. For nonwater liquids, the term lyophilic is used for low contact angle conditions, similarly, the terms omniphobic and omniphilic apply to both polar and apolar liquids. Liquids can interact with two types of solid surfaces. Traditionally, solid surfaces have been divided into high-energy solids and low-energy types, the relative energy of a solid has to do with the bulk nature of the solid itself. Solids such as metals, glasses, and ceramics are known as hard solids because the bonds that hold them together are very strong. Thus, it takes an input of energy to break these solids. Most molecular liquids achieve complete wetting with high-energy surfaces, the other type of solids is weak molecular crystals where the molecules are held together essentially by physical forces
Wetting
–
Water beads on a fabric that has been made nonwetting by chemical treatment
Wetting
–
Water droplet immersed in oil and resting on a brass surface
Wetting
–
Same fluids as above, but resting on a glass surface
Wetting
–
Figure 6: Schematic of advancing and receding contact angles
7.
Corrosion resistance
–
Corrosion is a natural process, which converts a refined metal to a more chemically-stable form, such as its oxide, hydroxide, or sulfide. It is the destruction of materials by chemical and/or electrochemical reaction with their environment. Corrosion engineering is the dedicated to controlling and stopping corrosion. In the most common use of the word, this means electrochemical oxidation of metal in reaction with an oxidant such as oxygen or sulfur, rusting, the formation of iron oxides, is a well-known example of electrochemical corrosion. This type of damage typically produces oxide or salt of the original metal, corrosion can also occur in materials other than metals, such as ceramics or polymers, although in this context, the term degradation is more common. Corrosion degrades the useful properties of materials and structures including strength, appearance and permeability to liquids, many structural alloys corrode merely from exposure to moisture in air, but the process can be strongly affected by exposure to certain substances. Corrosion can be concentrated locally to form a pit or crack, because corrosion is a diffusion-controlled process, it occurs on exposed surfaces. As a result, methods to reduce the activity of the surface, such as passivation and chromate conversion. However, some corrosion mechanisms are less visible and less predictable, in a galvanic couple, the more active metal corrodes at an accelerated rate and the more noble metal corrodes at a slower rate. When immersed separately, each metal corrodes at its own rate, what type of metal to use is readily determined by following the galvanic series. For example, zinc is used as a sacrificial anode for steel structures. Galvanic corrosion is of major interest to the industry and also anywhere water contacts pipes or metal structures. Factors such as size of anode, types of metal. The surface area ratio of the anode and cathode directly affects the corrosion rates of the materials, galvanic corrosion is often prevented by the use of sacrificial anodes. In any given environment, one metal will be more noble or more active than others. Two metals in electrical contact share the same electrons, so that the tug-of-war at each surface is analogous to competition for free electrons between the two materials. Using the electrolyte as a host for the flow of ions in the same direction, the resulting mass flow or electric current can be measured to establish a hierarchy of materials in the medium of interest. This hierarchy is called a series and is useful in predicting and understanding corrosion
Corrosion resistance
–
Rust, the most familiar example of corrosion.
Corrosion resistance
–
Volcanic gases have accelerated the corrosion of this abandoned mining machinery.
Corrosion resistance
–
Corrosion on exposed metal.
Corrosion resistance
–
Galvanic corrosion of aluminium. A 5-mm-thick aluminium alloy plate is physically (and hence, electrically) connected to a 10-mm-thick mild steel structural support. Galvanic corrosion occurred on the aluminium plate along the joint with the steel. Perforation of aluminium plate occurred within 2 years.
8.
Semiconductor device fabrication
–
Semiconductor device fabrication is the process used to create the integrated circuits that are present in everyday electrical and electronic devices. It is a sequence of photo lithographic and chemical processing steps during which electronic circuits are gradually created on a wafer made of pure semiconducting material. Silicon is almost always used, but various compound semiconductors are used for specialized applications, the entire manufacturing process, from start to packaged chips ready for shipment, takes six to eight weeks and is performed in highly specialized facilities referred to as fabs. When feature widths were far greater than about 10 micrometres, purity was not the issue that it is today in device manufacturing, as devices became more integrated, cleanrooms became even cleaner. Today, the fabs are pressurized with filtered air to remove even the smallest particles, the workers in a semiconductor fabrication facility are required to wear cleanroom suits to protect the devices from human contamination. Semiconductor device manufacturing has spread from Texas and California in the 1960s to the rest of the world, including Europe, the Middle East and it is a global business today. The leading semiconductor manufacturers typically have facilities all over the world, intel, the worlds largest manufacturer, has facilities in Europe and Asia as well as the U. S. A typical wafer is made out of pure silicon that is grown into mono-crystalline cylindrical ingots up to 300 mm in diameter using the Czochralski process. These ingots are sliced into wafers about 0.75 mm thick and polished to obtain a very regular. In semiconductor device fabrication, the processing steps fall into four general categories, deposition, removal, patterning. Deposition is any process that grows, coats, or otherwise transfers a material onto the wafer, available technologies include physical vapor deposition, chemical vapor deposition, electrochemical deposition, molecular beam epitaxy and more recently, atomic layer deposition among others. Removal is any process that removes material from the wafer, examples include etch processes, patterning is the shaping or altering of deposited materials, and is generally referred to as lithography. After etching or other processing, the remaining photoresist is removed by plasma ashing, modification of electrical properties has historically entailed doping transistor sources and drains. These doping processes are followed by annealing or, in advanced devices. Modification of electrical properties now also extends to the reduction of a dielectric constant in low-k insulators via exposure to ultraviolet light in UV processing. Modern chips have up to eleven metal levels produced in over 300 sequenced processing steps, FEOL processing refers to the formation of the transistors directly in the silicon. The raw wafer is engineered by the growth of an ultrapure, in the most advanced logic devices, prior to the silicon epitaxy step, tricks are performed to improve the performance of the transistors to be built. One method involves introducing a straining step wherein a silicon variant such as silicon-germanium is deposited, once the epitaxial silicon is deposited, the crystal lattice becomes stretched somewhat, resulting in improved electronic mobility
Semiconductor device fabrication
–
Semiconductor manufacturing processes
Semiconductor device fabrication
–
NASA's Glenn Research Center
clean room.
9.
Wafer (electronics)
–
Finally the individual microcircuits are separated and packaged. By 1960, silicon wafers were being manufactured in the U. S. by companies such as MEMC/SunEdison. In 1965, American engineers Eric O. Ernst, Donald J. Hurd, Wafers are formed of highly pure, nearly defect-free single crystalline material. One process for forming crystalline wafers is known as Czochralski growth invented by the Polish chemist Jan Czochralski. In this process, an ingot of high purity mono crystalline semiconductor, such as silicon or germanium. The boule is then sliced with a saw and polished to form wafers. The size of wafers for photovoltaics is 100–200 mm square and the thickness is 200–300 μm, in the future,160 μm will be the standard. Electronics use wafer sizes from 100–450 mm diameter, Wafers are cleaned with weak acids to remove unwanted particles, or repair damage caused during the sawing process. When used for cells, the wafers are textured to create a rough surface to increase their efficiency. The generated PSG is removed from the edge of the wafer in the etching, silicon wafers are available in a variety of diameters from 25.4 mm to 300 mm. Semiconductor fabrication plants are defined by the diameter of wafers that they are tooled to produce, Wafers grown using materials other than silicon will have different thicknesses than a silicon wafer of the same diameter. Wafer thickness is determined by the strength of the material used. This was the cost basis for increasing wafer size, conversion to 300 mm wafers from 200 mm wafers began in earnest in 2000, and reduced the price per die about 30-40%. However, this was not without significant problems for the industry, there is considerable resistance to the 450 mm transition despite the possible productivity improvement, because of concern about insufficient return on investment. Higher cost semiconductor fabrication equipment for larger wafers increases the cost of 450 mm fabs, converting to larger 450 mm wafers would reduce price per die only for process operations such as etch where cost is related to wafer count, not wafer area. Cost for processes such as lithography is proportional to wafer area, nikon plans to deliver 450-mm lithography equipment in 2015, with volume production in 2017. In November 2013 ASML paused development of 450-mm lithography equipment, citing uncertain timing of chipmaker demand, the time-line for 450 mm has not been fixed. Mark Durcan, CEO of Micron Technology, said in February 2014 that he expects 450 mm adoption to be delayed indefinitely or discontinued, “I am not convinced that 450mm will ever happen but, to the extent that it does, it’s a long way out in the future
Wafer (electronics)
Wafer (electronics)
Wafer (electronics)
Wafer (electronics)
–
2-inch (51 mm), 4-inch (100 mm), 6-inch (150 mm), and 8-inch (200 mm) wafers
10.
Printing
–
Printing is a process for reproducing text and images using a master form or template. The earliest examples include Cylinder seals and other such as the Cyrus Cylinder. The earliest known form of printing came from China dating to before 220 A. D. Later developments in printing include the type, first developed by Bi Sheng in China around 1040 AD. Johannes Gutenberg introduced mechanical movable type printing to Europe in the 15th century, modern large-scale printing is typically done using a printing press, while small-scale printing is done free-form with a digital printer. Though paper is the most common material, it is frequently done on metals, plastics, cloth. On paper it is carried out as a large-scale industrial process and is an essential part of publishing. Woodblock printing is a technique for printing text, images or patterns that was used widely throughout East Asia and it originated in China in antiquity as a method of printing on textiles and later on paper. As a method of printing on cloth, the earliest surviving examples from China date to before 220 A. D, the earliest surviving woodblock printed fragments are from China. They are of silk printed with flowers in three colours from the Han Dynasty and they are the earliest example of woodblock printing on paper appeared in the mid-seventh century in China. By the ninth century, printing on paper had taken off, by the tenth century,400,000 copies of some sutras and pictures were printed, and the Confucian classics were in print. A skilled printer could print up to 2,000 double-page sheets per day, Printing spread early to Korea and Japan, which also used Chinese logograms, but the technique was also used in Turpan and Vietnam using a number of other scripts. This technique then spread to Persia and Russia and this technique was transmitted to Europe via the Islamic world, and by around 1400 was being used on paper for old master prints and playing cards. However, Arabs never used this to print the Quran because of the limits imposed by Islamic doctrine, block printing, called tarsh in Arabic developed in Arabic Egypt during the ninth-tenth centuries, mostly for prayers and amulets. There is some evidence to suggest that these print blocks made from non-wood materials, possibly tin, lead, the techniques employed are uncertain, however, and they appear to have had very little influence outside of the Muslim world. Though Europe adopted woodblock printing from the Muslim world, initially for fabric, block printing later went out of use in Islamic Central Asia after movable type printing was introduced from China. Block printing first came to Europe as a method for printing on cloth, images printed on cloth for religious purposes could be quite large and elaborate. When paper became relatively easily available, around 1400, the medium transferred very quickly to small religious images
Printing
–
The intricate frontispiece of the
Diamond Sutra from
Tang Dynasty China, 868 A.D. (
British Library)
Printing
–
The earliest known
woodcut, 1423,
Buxheim, with hand-colouring
Printing
–
Copperplate of 1215–1216 5000
cash paper money with ten bronze movable types
11.
Fabric
–
A textile or cloth is a flexible material consisting of a network of natural or artificial fibres. Yarn is produced by spinning raw fibres of wool, flax, cotton, hemp, Textiles are formed by weaving, knitting, crocheting, knotting, or felting. The words fabric and cloth are used in textile assembly trades as synonyms for textile, however, there are subtle differences in these terms in specialized usage. Textile refers to any material made of interlacing fibres, a fabric is a material made through weaving, knitting, spreading, crocheting, or bonding that may be used in production of further goods. Cloth may be used synonymously with fabric but is often a piece of fabric used for a specific purpose. The word textile is from Latin, from the adjective textilis, meaning woven, from textus, the word cloth derives from the Old English clað, meaning a cloth, woven or felted material to wrap around one, from Proto-Germanic kalithaz. The discovery of dyed flax fibres in a cave in the Republic of Georgia dated to 34,000 BCE suggests textile-like materials were made even in prehistoric times. The production of textiles is a craft whose speed and scale of production has been altered almost beyond recognition by industrialization, however, for the main types of textiles, plain weave, twill, or satin weave, there is little difference between the ancient and modern methods. Textiles have an assortment of uses, the most common of which are for clothing and for such as bags. In the household they are used in carpeting, upholstered furnishings, window shades, towels, coverings for tables, beds, and other flat surfaces, in the workplace they are used in industrial and scientific processes such as filtering. Textiles are used in traditional crafts such as sewing, quilting. Textiles for industrial purposes, and chosen for other than their appearance, are commonly referred to as technical textiles. Technical textiles include textile structures for applications, medical textiles, geotextiles, agrotextiles. In all these applications stringent performance requirements must be met, woven of threads coated with zinc oxide nanowires, laboratory fabric has been shown capable of self-powering nanosystems using vibrations created by everyday actions like wind or body movements. Fashion designers commonly rely on textile designs to set their fashion collections apart from others, armani, the late Gianni Versace, and Emilio Pucci can be easily recognized by their signature print driven designs. Textiles can be made from many materials and these materials come from four main sources, animal, plant, mineral, and synthetic. In the past, all textiles were made from natural fibres, including plant, animal, in the 20th century, these were supplemented by artificial fibres made from petroleum. Textiles are made in various strengths and degrees of durability, from the finest gossamer to the sturdiest canvas, microfibre refers to fibres made of strands thinner than one denier
Fabric
–
Sunday textile market on the sidewalks of
Karachi, Pakistan
Fabric
–
Simple textile (magnified)
Fabric
–
A small fabric shop in
Al-Mukalla, Yemen
Fabric
–
Late antique textile,
Egyptian, now in the
Dumbarton Oaks collection
12.
Liquid
–
A liquid is a nearly incompressible fluid that conforms to the shape of its container but retains a constant volume independent of pressure. As such, it is one of the four states of matter. A liquid is made up of tiny vibrating particles of matter, such as atoms, water is, by far, the most common liquid on Earth. Like a gas, a liquid is able to flow and take the shape of a container, most liquids resist compression, although others can be compressed. Unlike a gas, a liquid does not disperse to fill every space of a container, a distinctive property of the liquid state is surface tension, leading to wetting phenomena. The density of a liquid is usually close to that of a solid, therefore, liquid and solid are both termed condensed matter. On the other hand, as liquids and gases share the ability to flow, although liquid water is abundant on Earth, this state of matter is actually the least common in the known universe, because liquids require a relatively narrow temperature/pressure range to exist. Most known matter in the universe is in form as interstellar clouds or in plasma form within stars. Liquid is one of the four states of matter, with the others being solid, gas. Unlike a solid, the molecules in a liquid have a greater freedom to move. The forces that bind the molecules together in a solid are only temporary in a liquid, a liquid, like a gas, displays the properties of a fluid. A liquid can flow, assume the shape of a container, if liquid is placed in a bag, it can be squeezed into any shape. These properties make a suitable for applications such as hydraulics. Liquid particles are bound firmly but not rigidly and they are able to move around one another freely, resulting in a limited degree of particle mobility. As the temperature increases, the vibrations of the molecules causes distances between the molecules to increase. When a liquid reaches its point, the cohesive forces that bind the molecules closely together break. If the temperature is decreased, the distances between the molecules become smaller, only two elements are liquid at standard conditions for temperature and pressure, mercury and bromine. Four more elements have melting points slightly above room temperature, francium, caesium, gallium and rubidium, metal alloys that are liquid at room temperature include NaK, a sodium-potassium metal alloy, galinstan, a fusible alloy liquid, and some amalgams
Liquid
–
The formation of a spherical
droplet of liquid water minimizes the
surface area, which is the natural result of
surface tension in liquids.
Liquid
–
Thermal image of a sink full of hot water with cold water being added, showing how the hot and the cold water flow into each other.
Liquid
–
Surface waves in
water
13.
Gas
–
Gas is one of the four fundamental states of matter. A pure gas may be made up of atoms, elemental molecules made from one type of atom. A gas mixture would contain a variety of pure gases much like the air, what distinguishes a gas from liquids and solids is the vast separation of the individual gas particles. This separation usually makes a colorless gas invisible to the human observer, the interaction of gas particles in the presence of electric and gravitational fields are considered negligible as indicated by the constant velocity vectors in the image. One type of commonly known gas is steam, the gaseous state of matter is found between the liquid and plasma states, the latter of which provides the upper temperature boundary for gases. Bounding the lower end of the temperature scale lie degenerative quantum gases which are gaining increasing attention, high-density atomic gases super cooled to incredibly low temperatures are classified by their statistical behavior as either a Bose gas or a Fermi gas. For a comprehensive listing of these states of matter see list of states of matter. The only chemical elements which are stable multi atom homonuclear molecules at temperature and pressure, are hydrogen, nitrogen and oxygen. These gases, when grouped together with the noble gases. Alternatively they are known as molecular gases to distinguish them from molecules that are also chemical compounds. The word gas is a neologism first used by the early 17th-century Flemish chemist J. B. van Helmont, according to Paracelsuss terminology, chaos meant something like ultra-rarefied water. An alternative story is that Van Helmonts word is corrupted from gahst and these four characteristics were repeatedly observed by scientists such as Robert Boyle, Jacques Charles, John Dalton, Joseph Gay-Lussac and Amedeo Avogadro for a variety of gases in various settings. Their detailed studies ultimately led to a relationship among these properties expressed by the ideal gas law. Gas particles are separated from one another, and consequently have weaker intermolecular bonds than liquids or solids. These intermolecular forces result from interactions between gas particles. Like-charged areas of different gas particles repel, while oppositely charged regions of different gas particles attract one another, transient, randomly induced charges exist across non-polar covalent bonds of molecules and electrostatic interactions caused by them are referred to as Van der Waals forces. The interaction of these forces varies within a substance which determines many of the physical properties unique to each gas. A comparison of boiling points for compounds formed by ionic and covalent bonds leads us to this conclusion, the drifting smoke particles in the image provides some insight into low pressure gas behavior
Gas
–
Drifting
smoke particles provide clues to the movement of the surrounding gas.
Gas
–
Gas phase particles (
atoms,
molecules, or
ions) move around freely in the absence of an applied
electric field.
Gas
–
Shuttle imagery of re-entry phase.
Gas
–
21 April 1990 eruption of
Mount Redoubt,
Alaska, illustrating real gases not in thermodynamic equilibrium.
14.
Adhesive tape
–
Adhesive tape refers to any one of a variety of combinations of a backing materials coated with an adhesive. Different backing materials and adhesives can be used depending on the intended use, pressure-sensitive adhesive, a key component of some adhesive tapes, was first developed in 1845 by Dr. Horace Day, a surgeon. In 1901, the German Oscar Troplowitz invented an adhesive patch called Leukoplast for the German company Beiersdorf AG. Pressure-sensitive tape, PSA tape, self-stick tape or sticky tape consists of a pressure-sensitive adhesive coated onto a material such as paper, plastic film, cloth. It is sticky without any heat or solvent for activation and adheres with light pressure and these tapes usually require a release agent on their backing or a release liner to cover the adhesive. Sometimes, the adhesive tape is used for these tapes. Many pressure-sensitive adhesive tapes exhibit triboluminescence, observable in a dark room, water activated tape, gummed paper tape or gummed tape is starch- or sometimes animal glue-based adhesive on a kraft paper backing which becomes sticky when moistened. A specific type of gummed tape is called reinforced gummed tape, the backing of this reinforced tape consists of two layers of paper with a cross-pattern of fiberglass filaments laminated between. The laminating adhesive had previously been asphalt but now is commonly a hot-melt atactic polypropylene. Gummed tapes are described in ASTM D5749-01 Standard Specification for Reinforced, water-activated tape is used for closing and sealing boxes. Before closing corrugated boxes, the tape is wetted or remoistened, activated by water. The tape is mostly 3 inches wide, heat activated tape is usually tack-free until it is activated by a heat source. It is sometimes used in packaging, for example, a tear strip tape for cigarette packs, conversely, thermal release tape, such as REVALPHA by Nitto Denko, loses its tack and fully releases when heated to a certain temperature. This type of tape is used often in the semiconductor industry, drywall tape is paper, cloth, or mesh, sometimes with a gummed or pressure-sensitive adhesive. It is used to make the joints between sheets of drywall materials, masking tape Tape dispenser Sellotape Sticky mat Chemistry of adhesive tapes Nature – Tape X-rays FIPAGO – International Federation of Manufacturers of Gummed Paper
Adhesive tape
–
A roll of PSA office tape in a dispenser
Adhesive tape
–
Dennison Mending Tape from the second half of the 20th century. From the
Museo del Objeto del Objeto collection.
Adhesive tape
–
Gaffer tape
15.
Pressure-sensitive adhesive
–
Pressure-sensitive adhesive is adhesive which forms a bond when pressure is applied to marry the adhesive with the adherend. No solvent, water, or heat is needed to activate the adhesive and it is used in pressure-sensitive tapes, labels, glue dots, note pads, automobile trim, and a wide variety of other products. As the name indicates, the degree of bond is influenced by the amount of pressure which is used to apply the adhesive to the surface. Surface factors such as smoothness, surface energy, removal of contaminants, PSAs are usually designed to form a bond and hold properly at room temperatures. PSAs typically reduce or lose their tack at low temperatures and reduce their shear holding ability at high temperatures and it is important to choose an adhesive formulation which is designed for its intended use conditions. Adhesives may be divided in two classes, structural and pressure-sensitive. To form a permanent bond, structural adhesives harden via processes such as evaporation of solvent, reaction with UV radiation, chemical reaction, in contrast, pressure-sensitive adhesives form a bond simply by the application of light pressure to marry the adhesive with the adherend. Pressure-sensitive adhesives are designed with a balance between flow and resistance to flow, the bond forms because the adhesive is soft enough to flow, or wet, the adherend. The bond has strength because the adhesive is hard enough to resist flow when stress is applied to the bond, PSAs exhibit viscoelastic properties, both of which are used for proper bonding. These properties are dependent, among other things, on the formulation, coating thickness, rub-down, Pressure-sensitive adhesives are designed for either permanent or removable applications. Examples of permanent applications include safety labels for power equipment, foil tape for HVAC duct work, automotive interior trim assembly, some high performance permanent PSAs exhibit high adhesion values and can support kilograms of weight per square centimeter of contact area, even at elevated temperature. Permanent PSAs may be removable and build adhesion to a permanent bond after several hours or days. Removable adhesives are designed to form a bond, and ideally can be removed after months or years without leaving residue on the adherend. Removable adhesives are used in such as surface protection films, masking tapes, bookmark and note papers, price marking labels, promotional graphics materials. Some removable adhesives are designed to stick and unstick. They have low adhesion and generally cannot support much weight, Pressure-sensitive adhesives are manufactured with either a liquid carrier or in 100% solid form. Articles such as tapes and labels are made from liquid PSAs by coating the adhesive on a support and evaporating the solvent or water carrier. The dry adhesive may be heated to initiate a cross-linking reaction
Pressure-sensitive adhesive
–
Post-it notes
16.
Non-stick
–
A non-stick surface is a surface engineered to reduce the ability of other materials to stick to it. Non-stick cookware is an application, where the non-stick coating allows food to brown without sticking to the pan. Non-stick is often used to refer to surfaces coated with polytetrafluoroethylene, in the twenty-first century other coatings have been marketed as non-stick, such as anodized aluminium, ceramics, silicone, enameled cast iron, and seasoned cookware. The Mycenaean Greeks might have used non-stick pans to make more than 3,000 years ago. Mycenaean ceramic griddles had one side and one side covered with tiny holes. The bread was probably placed on the side with the holes, the holes seemed to be an ancient non-sticking technology, ensuring that oil spread evenly over the griddle. The modern non-stick pans were made using a coating of Teflon, PTFE was invented serendipitously by Roy Plunkett in 1938, while working for a joint venture of the DuPont company. The substance was found to have unique properties, including very good corrosion-resistance. PTFE was first used to make seals resistant to the uranium hexafluoride gas used in development of the bomb during World War II. Dupont registered the Teflon trademark in 1944 and soon began planning for post-war commercial use of the new product, while working at DuPont, NYU Tandon School of Engineering alumnus John Gilbert was asked to evaluate a newly- developed material called Teflon. His experiments using the polymer as a surface coating for pots. A few years later, a French engineer had begun coating his fishing gear with Teflon to prevent tangles and his wife Colette suggested using the same method to coat her cooking pans. The idea was successful and a French patent was granted for the process in 1954, the Tefal company was formed in 1956 to manufacture non-stick pans. Not all non-stick pans use Teflon, other coatings have become available. For example, a mixture of titanium and ceramic can be sandblasted onto the pan surface, polytetrafluoroethylene is a synthetic fluoropolymer used in various applications including non-stick coatings. Teflon is a brand of PTFE, often used as a term for PTFE. The metallic substrate is roughened to promote adhesion, and layers of PTFE, from one to seven, are sprayed or rolled on, with a number of layers. The number and thickness of the layers and quality of the material determine the quality of the non-stick coating, better-quality coatings are more durable, and less likely to peel and flake, and keep their non-stick properties for longer
Non-stick
–
Food in a non-stick pan
17.
Polytetrafluoroethylene
–
Polytetrafluoroethylene is a synthetic fluoropolymer of tetrafluoroethylene that has numerous applications. The best known name of PTFE-based formulas is Teflon by Chemours. Chemours is a spin-off of DuPont Co. which discovered the compound in 1938, PTFE is a fluorocarbon solid, as it is a high-molecular-weight compound consisting wholly of carbon and fluorine. PTFE is hydrophobic, neither water nor water-containing substances wet PTFE, PTFE has one of the lowest coefficients of friction of any solid. PTFE is used as a coating for pans and other cookware. It is very non-reactive, partly because of the strength of carbon–fluorine bonds, where used as a lubricant, PTFE reduces friction, wear and energy consumption of machinery. It is commonly used as a material in surgical interventions. Also, it is employed as coating on catheters, this interferes with the ability of bacteria and other infectious agents to adhere to catheters. PTFE was accidentally discovered in 1938 by Roy Plunkett while he was working in New Jersey for DuPont. Since Plunkett was measuring the amount of gas used by weighing the bottle, he became curious as to the source of the weight and he found the bottles interior coated with a waxy white material that was oddly slippery. Analysis showed that it was polymerized perfluoroethylene, with the iron from the inside of the container having acted as a catalyst at high pressure, Kinetic Chemicals patented the new fluorinated plastic in 1941, and registered the Teflon trademark in 1945. By 1948, DuPont, which founded Kinetic Chemicals in partnership with General Motors, was producing two million pounds of Teflon brand PTFE per year in Parkersburg, West Virginia. In 1954, the wife of French engineer Marc Grégoire urged him to try the material he had been using on fishing tackle on her cooking pans and he subsequently created the first Teflon-coated, non-stick pans under the brandname Tefal. In the United States, Marion A. Trozzolo, who had been using the substance on scientific utensils, marketed the first US-made Teflon-coated pan, The Happy Pan, however, Tefal was not the only company to utilize PTFE in nonstick cookware coatings. Other cookware companies, such as Meyer Corporations Anolon, use Teflon nonstick coatings purchased from DuPont, in the 1990s, it was found that PTFE could be radiation cross-linked above its melting point in an oxygen-free environment. Electron beam processing is one example of radiation processing, cross-linked PTFE has improved high-temperature mechanical properties and radiation stability. This was significant because, for years, irradiation at ambient conditions has been used to break down PTFE for recycling. This radiation-induced chain scission allows it to be more easily reground, PTFE is produced by free-radical polymerization of tetrafluoroethylene
Polytetrafluoroethylene
–
Teflon thermal cover showing impact craters, from NASA's Ultra Heavy Cosmic Ray Experiment (UHCRE)
Polytetrafluoroethylene
–
Polytetrafluoroethylene
Polytetrafluoroethylene
–
PTFE is often used to coat
non-stick pans as it is
hydrophobic and possesses fairly high heat resistance.
Polytetrafluoroethylene
–
"Amazing New Concept in Cooking"
18.
Release liner
–
A release liner is a paper or plastic-based film sheet used to prevent a sticky surface from prematurely adhering. It is coated on one or both sides with an agent, which provides a release effect against any type of a sticky material such as an adhesive or a mastic. Release liners are available in different colors, with or without printing under the low surface energy coating or on the backside of the liner, release is separation of the liner from a sticky material, liner is the carrier for the release agent. Globally there are between 400 and 500 companies involved in making or dealing with release liner products on an industrial scale, in general there are two types of companies which are manufacturing release liner. Commercial coating companies deal with a lot of different end uses of this industry and they provide unique solutions to their customers, based on a wide variety of substrates and an endless combination of release agents with specialized properties. Commercial coaters usually do not make finished products, just the release itself and then their customers will coat a sticky material on this liner. An in-house producer makes the liner and uses it internally to manufacture the final product. In-house producers are typically focused on a narrow range of products e. g. labels or tapes. They use a limited amount of substrates and release materials, which are specialized for their end applications. g, on a yankee cylinder of a paper machine. BO-PET, a PET film is a high temperature resistant. Providing them with unique and adjusted features for the application that they are targeted for and this way the tough and dimensionally stable PET film is combined with cheap polyolefin resin which makes the fill a better carrier web for specialty applications. Commonly used release agents for release liner can be crosslinkable silicone, other coatings, there are probably hundreds of different applications, where release liner materials are being used. Such as Pressure-sensitive labels Pressure-sensitive tape Self-adhesive plastic sheet Pressure-sensitive adhesive
Release liner
–
Roll of die-cut pressure sensitive labels on a release liner
Release liner
–
An
adhesive bandage with a release liner partially removed.
19.
Primer (paint)
–
A primer or undercoat is a preparatory coating put on materials before painting. Priming ensures better adhesion of paint to the surface, increases paint durability, 20%-30% synthetic resin, 60%-80% solvent and 2%-5% additive agent. Some primer contains polyethylene, for better durability, primer is a paint product that allows finishing paint to adhere much better than if it were used alone. For this purpose, primer is designed to adhere to surfaces, because primers do not need to be engineered to have durable, finished surfaces, they can instead be engineered to have improved filling and binding properties with the material underneath. In practice, primer is used when painting many kinds of porous materials, such as concrete. Priming is mandatory if the material is not water resistant and will be exposed to the elements, priming gypsum board is also standard practice with new construction because it seals the wall and aids in preventing mold. Primers can also be used for dirty surfaces that, for reason, cannot be cleaned. Primers can usually be tinted to a match with the color of the finishing paint. If the finishing paint is a color, tinting the primer can reduce the number of layers of finishing paint that are necessary for good uniformity across the painted surface. There may be a time frame within which a topcoat should be applied over the primer after the primer dries. Depending on the primer, the coat of paint should be applied as quickly as 24 hours or as long as two weeks. Painting after the suggested timeframe may cause performance issues depending on the specific situation, supposedly, you want to apply the finish coat of paint before the primer fully cures on a molecular level. Doing this allows maximum adhesion/bonding of the topcoat to the primer, if topcoating after the suggested timeframe, consider using a self priming topcoat. For definitive answers on recommended repainting timeframe, check the primer label/website, recoat timeframe is most likely a more critical factor in exterior application because of the more extreme climatic exposure. Using a primer on wood before painting is important for several reasons, first of all, wood is very porous and will absorb the solvent from paint, drying the paint prematurely. Because most paints undergo chemical reactions during the process of curing, a layer of primer will help the paint to undergo its proper, complete curing cycle. Secondly, without a primer, several layers of paint can be necessary to completely obscure the wood grain, lastly, if wood is exposed to moisture, a thin layer of paint will still be water permeable. The end result will be warped parts, mildew, and dry rot, primer adds to the waterproofing effect of the paint
Primer (paint)
–
A bucket of primer
Primer (paint)
–
Zinc chromate primer
20.
Optical coating
–
An optical coating is one or more thin layers of material deposited on an optical component such as a lens or mirror, which alters the way in which the optic reflects and transmits light. One type of coating is an antireflection coating, which reduces unwanted reflections from surfaces. Another type is the high-reflector coating which can be used to produce mirrors which reflect greater than 99. 99% of the light falls on them. More complex optical coatings exhibit high reflection over some range of wavelengths, the simplest optical coatings are thin layers of metals, such as aluminium, which are deposited on glass substrates to make mirror surfaces, a process known as silvering. The metal used determines the characteristics of the mirror, aluminium is the cheapest and most common coating. More expensive is silver, which has a reflectivity of 95%-99% even into the far infrared, most expensive is gold, which gives excellent reflectivity throughout the infrared, but limited reflectivity at wavelengths shorter than 550 nm, resulting in the typical gold colour. By controlling the thickness and density of metal coatings, it is possible to decrease the reflectivity and increase the transmission of the surface and these are sometimes used as one-way mirrors. The other major type of coating is the dielectric coating. These are constructed from thin layers of such as magnesium fluoride, calcium fluoride, and various metal oxides. Reflection coefficients of surfaces can be reduced to less than 0. 2%, conversely, the reflectivity can be increased to greater than 99. 99%, producing a high-reflector coating. Such mirrors are used as beamsplitters, and as output couplers in lasers. Alternatively, the coating can be designed such that the mirror reflects light only in a band of wavelengths. The versatility of dielectric coatings leads to their use in many optical instruments as well as consumer devices such as binoculars, spectacles. Dielectric layers are applied over top of metal films, either to provide a protective layer. Metal and dielectric combinations are used to make advanced coatings that cannot be made any other way. One example is the perfect mirror, which exhibits high reflection, with unusually low sensitivity to wavelength, angle. Antireflection coatings are used to reduce reflection from surfaces, whenever a ray of light moves from one medium to another, some portion of the light is reflected from the surface between the two media. A number of different effects are used to reduce reflection, the simplest is to use a thin layer of material at the interface, with an index of refraction between those of the two media
Optical coating
–
Optically coated mirrors and lenses.
Optical coating
–
Comparison of uncoated glasses (top) and glasses with an anti-reflective coating (bottom).
21.
Mirror
–
This is different from other light-reflecting objects that do not preserve much of the original wave signal other than color and diffuse reflected light. The most familiar type of mirror is the mirror, which has a flat screen surface. Curved mirrors are used, to produce magnified or diminished images or focus light or simply distort the reflected image. Mirrors are commonly used for personal grooming or admiring oneself, decoration, Mirrors are also used in scientific apparatus such as telescopes and lasers, cameras, and industrial machinery. Most mirrors are designed for light, however, mirrors designed for other wavelengths of electromagnetic radiation are also used. The first mirrors used by people were most likely pools of dark, still water, the requirements for making a good mirror are a surface with a very high degree of flatness, and a surface roughness smaller than the wavelength of the light. The earliest manufactured mirrors were pieces of polished stone such as obsidian, examples of obsidian mirrors found in Anatolia have been dated to around 6000 BC. Mirrors of polished copper were crafted in Mesopotamia from 4000 BC, polished stone mirrors from Central and South America date from around 2000 BC onwards. In China, bronze mirrors were manufactured from around 2000 BC, some of the earliest bronze, Mirrors made of other metal mixtures such as copper and tin speculum metal may have also been produced in China and India. Mirrors of speculum metal or any precious metal were hard to produce and were owned by the wealthy. Stone mirrors often had poor reflectivity compared to metals, yet metals scratch or tarnish easily, depending upon the color, both often yielded reflections with poor color rendering. The poor image quality of ancient mirrors explains 1 Corinthians 13s reference to seeing as in a mirror, glass was a desirable material for mirrors. Because the surface of glass is smooth, it produces reflections with very little blur. In addition, glass is very hard and scratch resistant, however, glass by itself has little reflectivity, so people began coating it with metals to increase the reflectivity. According to Pliny, the people of Sidon developed a technique for creating crude mirrors by coating glass with molten lead. Glass mirrors backed with gold leaf are mentioned by Pliny in his Natural History and these circular mirrors were typically small, from only a fraction of an inch to as much as eight inches in diameter. These small mirrors produced distorted images, yet were prized objects of high value and these ancient glass mirrors were very thin, thus very fragile, because the glass needed to be extremely thin to prevent cracking when coated with a hot, molten metal. Due to the quality, high cost, and small size of these ancient glass mirrors
Mirror
–
A mirror, reflecting a
vase
Mirror
–
A
first surface mirror coated with aluminum and enhanced with
dielectric coatings. The angle of the incident light (represented by both the light in the mirror and the shadow behind it) exactly matches the angle of reflection (the reflected light shining on the table).
Mirror
–
Seated woman holding a mirror.
Ancient Greek Attic
red-figure lekythos, c. 470–460 BC,
National Archaeological Museum, Athens
Mirror
–
A sculpture of a lady looking into a mirror, India
22.
Anti-reflective coating
–
An antireflective or anti-reflection coating is a type of optical coating applied to the surface of lenses and other optical elements to reduce reflection. In typical imaging systems, this improves the efficiency since less light is lost, in complex systems such as a telescope, the reduction in reflections also improves the contrast of the image by elimination of stray light. This is especially important in planetary astronomy, many coatings consist of transparent thin film structures with alternating layers of contrasting refractive index. Layer thicknesses are chosen to produce destructive interference in the beams reflected from the interfaces and this makes the structures performance change with wavelength and incident angle, so that color effects often appear at oblique angles. Anti-reflective coatings are used in a variety of applications where light passes through an optical surface. Examples include anti-glare coatings on corrective lenses and camera lens elements, opticians may recommend anti-reflection lenses because the decreased reflection enhances the cosmetic appearance of the lenses. Such lenses are often said to reduce glare, but the reduction is very slight, eliminating reflections allows slightly more light to pass through, producing a slight increase in contrast and visual acuity. Antireflective ophthalmic lenses should not be confused with polarized lenses, which decrease the visible glare of sun reflected off surfaces such as sand, water, and roads. The term antireflective relates to the reflection from the surface of the lens itself, many anti-reflection lenses include an additional coating that repels water and grease, making them easier to keep clean. Anti-reflection coatings are particularly suited to high-index lenses, as these reflect more light without the coating than a lower-index lens and it is also generally easier and cheaper to coat high index lenses. Antireflective coatings are used in microelectronic photolithography to help reduce image distortions associated with reflections off the surface of the substrate. Different types of coatings are applied either before or after the photoresist, and help reduce standing waves, thin-film interference. The simplest form of coating was discovered by Lord Rayleigh in 1886. The optical glass available at the time tended to develop a tarnish on its surface with age, Rayleigh tested some old, slightly tarnished pieces of glass, and found to his surprise that they transmitted more light than new, clean pieces. The tarnish replaces the air-glass interface with two interfaces, an interface and a tarnish-glass interface. Because the tarnish has a refractive index between those of glass and air, each of these interfaces exhibits less reflection than the air-glass interface did. In fact, the total of the two reflections is less than that of the naked air-glass interface, as can be calculated from the Fresnel equations, one approach is to use graded-index anti-reflective coatings, that is, ones with nearly continuously varying index of refraction. With these, it is possible to curtail reflection for a band of frequencies
Anti-reflective coating
–
Uncoated glasses lens (top) versus lens with antireflective coating. Note the tinted reflection from the coated lens.
Anti-reflective coating
–
An anti-reflection coated window, shown at a 45° and a 0° angle of incidence.
23.
Sunglass
–
Sunglasses or sun glasses are a form of protective eyewear designed primarily to prevent bright sunlight and high-energy visible light from damaging or discomforting the eyes. They can sometimes function as a visual aid, as variously termed spectacles or glasses exist. In the early 20th century, they were known as sun cheaters. The American Optometric Association recommends sunglasses whenever a person is in the sun. to protect the eyes from ultraviolet radiation and blue light, Sunglasses have long been associated with celebrities and film actors primarily from a desire to mask their identity. Since the 1940s, sunglasses have been popular as a fashion accessory, in prehistoric and historic time, Inuit peoples wore flattened walrus ivory glasses, looking through narrow slits to block harmful reflected rays of the sun. It is said that the Roman emperor Nero liked to watch gladiator fights with emeralds and these, however, appear to have worked rather like mirrors. Sunglasses made from flat panes of smoky quartz, which offered no corrective powers, ancient documents describe the use of such crystal sunglasses by judges in ancient Chinese courts to conceal their facial expressions while questioning witnesses. James Ayscough began experimenting with tinted lenses in spectacles in the mid-18th century and these were not sunglasses as that term is now used, Ayscough believed that blue- or green-tinted glass could correct for specific vision impairments. Protection from the Suns rays was not a concern for him, in the early 1920s, the use of sunglasses started to become more widespread, especially among movie stars. The stereotype persisted long after improvements in quality and the introduction of ultraviolet filters had eliminated this problem. Inexpensive mass-produced sunglasses made from celluloid were first produced by Sam Foster in 1929, Foster found a ready market on the beaches of Atlantic City, New Jersey, where he began selling sunglasses under the name Foster Grant from a Woolworth on the Boardwalk. By 1938, Life magazine wrote of how sunglasses were a new fad for wear on city streets, a favorite affectation of thousands of women all over the U. S. It stated that 20 million sunglasses were sold in the United States in 1937, Polarized sunglasses first became available in 1936, when Edwin H. Land began experimenting with making lenses with his patented Polaroid filter, at present, Xiamen, China, is the worlds largest producer of sunglasses, with its port exporting 120 million pairs each year. Sunglasses can improve comfort and visual clarity by protecting the eye from glare. Various types of disposable sunglasses are dispensed to patients after receiving mydriatic eye drops during eye examinations, the lenses of polarized sunglasses reduce glare reflected at some angles off shiny non-metallic surfaces, such as water. They allow wearers to see into water when only surface glare would otherwise be seen, Sunglasses offer protection against excessive exposure to light, including its visible and invisible components. Sunglasses that meet this requirement are often labeled as UV400 and this is slightly more protection than the widely used standard of the European Union, which requires that 95% of the radiation up to only 380 nm must be reflected or filtered out
Sunglass
–
Wearing sunglasses under direct sunlight: Large lenses offer good protection, but broad temple arms are also needed against "stray light" from the sides.
Sunglass
–
Inuit snow goggles function by reducing exposure to sunlight, not by reducing its intensity
Sunglass
–
Broad temple arms protect against "stray light" entering from the sides
Sunglass
–
Sunglasses with slim temple arms
24.
Photographic film
–
This article is mainly concerned with still photography film. For motion picture film, please see film stock, photographic film is a strip or sheet of transparent plastic film base coated on one side with a gelatin emulsion containing microscopically small light-sensitive silver halide crystals. The sizes and other characteristics of the crystals determine the sensitivity, contrast, the emulsion will gradually darken if left exposed to light, but the process is too slow and incomplete to be of any practical use. Instead, a short exposure to the image formed by a camera lens is used to produce only a very slight chemical change. This creates an invisible latent image in the emulsion, which can be developed into a visible photograph. In addition to light, all films are sensitive to ultraviolet, X-rays. Unmodified silver halide crystals are only to the blue part of the visible spectrum. This problem was overcome with the discovery that certain dyes, called sensitizing dyes, first orthochromatic and finally panchromatic films were developed. Panchromatic film renders all colors in shades of gray approximately matching their subjective brightness, by similar techniques special-purpose films can be made sensitive to the infrared region of the spectrum. In black-and-white photographic film there is one layer of silver halide crystals. When the exposed silver halide grains are developed, the silver halide crystals are converted to metallic silver, color film has at least three sensitive layers, incorporating different combinations of sensitizing dyes. Typically the blue-sensitive layer is on top, followed by a filter layer to stop any remaining blue light from affecting the layers below. Next come a green-and-blue sensitive layer, and a sensitive layer. During development, the silver halide crystals are converted to metallic silver. Because the by-products are created in direct proportion to the amount of exposure and development, following development, the silver is converted back to silver halide crystals in the bleach step. It is removed from the film during the process of fixing the image on the film with a solution of ammonium thiosulfate or sodium thiosulfate, fixing leaves behind only the formed color dyes, which combine to make up the colored visible image. Later color films, like Kodacolor II, have as many as 12 emulsion layers, the earliest practical photographic process, the daguerreotype, introduced in 1839, did not use film. The light-sensitive chemicals were formed on the surface of a copper sheet
Photographic film
–
135 Film Cartridge with DX barcode (top) and DX CAS code on the black and white grid below the barcode. The CAS code shows the ISO, number of exposures, exposure latitude (+3/−1 for print film).
Photographic film
–
Advertisement for Ansco Speedex Film, 1922.
Photographic film
–
DX film edge barcode
25.
Flooring
–
Flooring is the general term for a permanent covering of a floor, or for the work of installing such a floor covering. Floor covering is a term to describe any finish material applied over a floor structure to provide a walking surface. Both terms are used interchangeably but floor covering refers more to loose-laid materials, materials almost always classified as flooring include carpet, laminate, tile and vinyl. The floor under the flooring is called the subfloor, which provides the support for the flooring, special purpose subfloors like floating floors, raised floors or sprung floors may be laid upon another underlying subfloor which provides the structural strength. Subfloors that are below grade or ground level floors in buildings without basements typically have a cement subfloor, subfloors above grade typically have a plywood subfloor. The choice of material for floor covering is affected by such as cost, endurance, noise insulation, comfort. Some types of flooring must not be installed below grade, including laminate, carpet is a soft floor covering made of bound carpet fibers or stapled fibers. Carpeting refers to wall-to-wall coverage, whereas a rug is simply used to cover a space and this type of flooring is typically used indoors and can be used in both high and low traffic areas. It typically lasts for 15-18 years before it needs to be replaced, the quality of a carpet is usually measured in face weight, or how many fibers there are per square inch. The higher the weight the more plush a carpet will feel. Carpets come in a variety of materials including wool, nylon, olefin, there are different types of carpet like twists, which is commonly referred to as a berber. Twist carpeting is composed of multiple twisted fibers set into the carpet backing and it is typically used in low traffic areas. Another type of carpeting is looped carpets, which are composed of looped fibers set into the carpet backing and this type of carpeting is typically used in high traffic areas as it is easy to clean. Padding can be placed underneath the carpet to add comfort and provide some noise insulation, the level of comfort is determined by the type of material used, which can include memory foam and rubber regrind. Many different species of wood are fabricated into wood flooring in two forms, plank and parquet. Hardwoods are typically more durable than softwoods. Reclaimed lumber has an appearance and is used in green building. Engineered hardwood has a solid wood layer on top with a composite core
Flooring
–
Levelling of ceramic tiles floor with a
laser device
Flooring
–
Example of stone flooring: white marble slabs covering the floor of the courtyard of the
Mosque of Uqba also known as the Great Mosque of Kairouan, in Tunisia.
Flooring
–
Ceramic tiles flooring in
Istanbul street
26.
Bunding
–
Frequently, the liquids in these tanks and pipes are toxic, and bunding is used to prevent the liquid from causing damage. If a large tank has a failure, the liquid alone can cause extensive damage. If built properly, bunding is large enough and strong enough to contain the contents of an entire tank, when multiple tanks share a bund, the capacity is based on the largest tank. One of the most common designs for large tanks is a concrete or masonry wall around the tank with a concrete floor, the outside of the wall may be reinforced with an earth berm. Concrete works very well for many liquids, but it is unsuitable for applications like containing strong acids. Using earth berms for bunding is not recommended for most situations, smaller tanks often use containers made of steel or plastic. The material used depends on cost, the properties of the liquid. Plastic tanks cannot hold very dense liquids at high wall levels, large, exposed bunding will need a sump pump or some other system to remove precipitation, though it may also be used to transfer spilled liquid into another container. Rainwater must be treated if the liquid being stored is toxic because there may be small amounts of it surrounding the tank, the bund may have a roof to prevent precipitation from getting in, but steps must be taken to provide adequate ventilation when storing flammable liquids. If the wall is over a high, it may require a ladder or steps to allow people to escape quickly. Another design uses a channel that drains the liquid to a secondary container, when the risk of tank failure is not as likely or when it would not cause extensive damage, the bunding may be designed to merely contain small leaks from hoses and valves. This bunding may not be able to contain the volume of the tank. Plastic and steel are used, but another common method is making a hump or lip around the perimeter of a concrete floor, some bunding is temporary, such as short-term chemical storage in the field. A hump or slope type bunding is helpful when vehicles need access to the area, there is also a type of bunding that compresses when a vehicle passes over and expands once it has passed. Bunding is a requirement in many countries particularly around tanks, storage vessels. It is reasonably easy to construct a water-tight bund around the base of a tank or vessel, a concrete base and a sealed wall of masonry, brickwork, concrete or even prefabricated steel provides the holding capacity. In the UK commercial installations exceeding 200 litres and domestic installations exceeding 2500 litres require a tank to comply with Environment Agency control of pollution regulations. Almost all regulations require a holding capacity of 110% of the largest tank within the bund or 25% of the capacity of all the tanks within the bund whichever is the greatest
Bunding
–
Acid storage tanks inside a brick bund wall
27.
Waterproofing
–
Such items may be used in wet environments or under water to specified depths. Water resistant and waterproof often refer to penetration of water in its state and possibly under pressure. Permeation of water vapor through a material or structure is reported as a moisture vapor transmission rate, the hulls of boats and ships were once waterproofed by applying tar or pitch. Modern items may be waterproofed by applying water-repellent coatings or by sealing seams with gaskets or o-rings, waterproofing is used in reference to building structures, watercraft, canvas, clothing, electronic devices and paper packaging. In construction, a building or structure is waterproofed with the use of membranes and coatings to protect contents, in building construction, waterproofing is a fundamental aspect of creating a building envelope, which is a controlled environment. The roof covering materials, siding, foundations, and all of the various penetrations through these surfaces must be water-resistant and sometimes waterproof. Roofing materials are designed to be water-resistant and shed water from a sloping roof, but in some conditions, such as ice damming and on flat roofs. Walls are not subjected to standing water, and the water-resistant membranes used as housewraps are designed to be enough to let moisture escape. Walls also have barriers or air barriers. Damp proofing is another aspect of waterproofing and this causes hydrostatic pressure on both the membrane and structure, and requires full encapsulation of the basement structure in a tanking membrane, under slab and walls. Damp proofing, This is waterproofing used where the table is lower than the structure and there is good free-draining fill. The membrane deals with shedding of water and the ingress of water vapor only, generally, this incorporates a damp proof membrane to the walls with a polythene DPM under slab. In buildings using earth sheltering, a problem is too much humidity. Water seepage can lead to growth, causing significant damage. Properly waterproofing foundation walls is required to prevent deterioration and seepage, another specialized area of waterproofing is roof top decks and balconies. Waterproofing systems have become quite sophisticated and are a specialized area. Failed waterproof decks, polymer or tile, are one of the causes of water damage to building structures. Where major problems occur in the industry is when improper products are used for the wrong application
Waterproofing
–
Waterproofing conducted on the exterior of a freeway tunnel
28.
Damp proofing
–
Damp proofing in construction is a type of moisture control applied to building walls and floors to prevent moisture from passing into the interior spaces. Damp problems are among the most frequent problems encountered in homes, generally damp proofing keeps moisture out of a building where vapor barriers keep interior moisture from getting into walls. Moisture resistance is not necessarily absolute, it is defined by a specific test method, limits. Damp proofing is accomplished several ways including, A damp-proof course is a barrier through the structure by capillary action such as through a known as rising damp. Rising damp is the effect of rising from the ground into property. The damp proof course may be horizontal or vertical, a DPC layer is usually laid below all masonry walls, regardless if the wall is a load bearing wall or a partition wall. A damp-proof membrane is a material applied to prevent moisture transmission. A common example is polyethylene sheeting laid under a slab to prevent the concrete from gaining moisture through capillary action. A DPM may be used for the DPC, integral damp proofing in concrete involves adding materials to the concrete mix to make the concrete itself impermeable. Cavity wall construction, such as construction, is where the interior walls are separated from the exterior walls by a cavity. Pressure grouting cracks and joints in masonry materials, materials widely used for damp proofing include, Flexible materials like butyl rubber, hot bitumen, plastic sheets, bituminous felts, sheets of lead, copper, etc. Semi-rigid materials like mastic asphalt Rigid materials like bricks, stones, slates, cement mortar or cement concrete painted with bitumen. It can often be seen as a line in the mortar near ground level. To create a barrier, pieces of DPC or DPM may be sealed together. In addition, the DPC may be sealed to the DPM around the edges of the ground floor. In a masonry cavity wall, there is usually a DPC in both the outer and inner wall, in the outer wall it is normally 150 millimetres to 200 millimetres above ground level. This allows rain to form puddles and splash up off the ground, the wall below the DPC may become saturated in rainy weather. The DPC in the wall is usually below floor level, or, with a solid concrete floor
Damp proofing
–
A metal damp proof course between the stone foundation and brick wall
Damp proofing
–
DPC visible between concrete foundation and brickwork.
29.
Roof coating
–
A roof coating is a monolithic, fully adhered, fluid applied roofing membrane. It has elastic properties that allows it to stretch and return to their shape without damage. Typical roof coating dry film thickness vary from paint film thickness to more than 40 dry mils and this means a roof coating actually becomes the top layer of a composite roof membrane and underlying system. As such, the coating is the topmost layer of protection for the membrane, receiving the impact of sunlight (both infrared and ultraviolet, rain, hail. Roof Coatings should not be confused with deck coatings, deck coatings are traffic bearing - designed for waterproofing areas where pedestrian traffic is expected. Roof coatings will only waterproof the substrates but will not withstand any kind of on going use by people or vehicles, roof coatings are seamless and when installed correctly, can solve roof leaks on almost any type of roofing material. There are exceptions, professionals do not recommend using cool coatings over existing shingles, field-applied reflective roof coatings can extend the useful life of nearly every roof substrate keeping a roof surface cool and providing a level of protection from the sun and weather. However, coating asphalt shingles and built-up composition roofs requires more caution, anyone considering this type of application should be aware of the concerns so they can weigh them against the benefits claimed in coating product promotional materials. Roof coatings can add 25 years to the life of a roof. The infrared image on the right shows 175 °F on the section of the modified bitumen roof. The coated section is 79 °F. Field studies have shown that cool roof coatings can lower rooftop temperatures, most flat roofs are not perfectly sloped, causing water to puddle in some areas, in particular around the drains and scuppers. Many roof coatings are not rated or warranted for ponding water, serious consideration should be given to the performance and limitations of the coating being selected. Some manufacturers will warranty their coatings including ponding water, typically, manufacturers for acrylic roof coatings do not include warranties for ponding water, while some polyurethane roof coatings manufacturers will. Roof coatings are easy to install, smaller roofs in good, serviceable condition can be a weekend do-it-yourself project. Larger roofs with leaks and ponding water issues should be coated by a qualified professional, high pressure airless spray equipment, pressure washers with rotary nozzle, roof repair equipment and basic painting tools such as brushes, rollers, putty knives, and scaffolding
Roof coating
–
A 96 °F (36 °C) heat reduction was observed on this modified bitumen roof with a white, reflective roof coating.
Roof coating
–
Prepping the seams on a Metal Roof Prior to the Application of a Roof Coating
Roof coating
–
Top coating a commercial flat roof with a cool roof test
