Aluminium or aluminum is a chemical element with symbol Al and atomic number 13. It is a silvery-white, soft and ductile metal in the boron group. By mass, aluminium makes up about 8% of the Earth's crust; the chief ore of aluminium is bauxite. Aluminium metal is so chemically reactive that native specimens are rare and limited to extreme reducing environments. Instead, it is found combined in over 270 different minerals. Aluminium is remarkable for its low density and its ability to resist corrosion through the phenomenon of passivation. Aluminium and its alloys are vital to the aerospace industry and important in transportation and building industries, such as building facades and window frames; the oxides and sulfates are the most useful compounds of aluminium. Despite its prevalence in the environment, no known form of life uses aluminium salts metabolically, but aluminium is well tolerated by plants and animals; because of these salts' abundance, the potential for a biological role for them is of continuing interest, studies continue.
Of aluminium isotopes, only 27Al is stable. This is consistent with aluminium having an odd atomic number, it is the only aluminium isotope that has existed on Earth in its current form since the creation of the planet. Nearly all the element on Earth is present as this isotope, which makes aluminium a mononuclidic element and means that its standard atomic weight equates to that of the isotope; the standard atomic weight of aluminium is low in comparison with many other metals, which has consequences for the element's properties. All other isotopes of aluminium are radioactive; the most stable of these is 26Al and therefore could not have survived since the formation of the planet. However, 26Al is produced from argon in the atmosphere by spallation caused by cosmic ray protons; the ratio of 26Al to 10Be has been used for radiodating of geological processes over 105 to 106 year time scales, in particular transport, sediment storage, burial times, erosion. Most meteorite scientists believe that the energy released by the decay of 26Al was responsible for the melting and differentiation of some asteroids after their formation 4.55 billion years ago.
The remaining isotopes of aluminium, with mass numbers ranging from 21 to 43, all have half-lives well under an hour. Three metastable states are known, all with half-lives under a minute. An aluminium atom has 13 electrons, arranged in an electron configuration of 3s23p1, with three electrons beyond a stable noble gas configuration. Accordingly, the combined first three ionization energies of aluminium are far lower than the fourth ionization energy alone. Aluminium can easily surrender its three outermost electrons in many chemical reactions; the electronegativity of aluminium is 1.61. A free aluminium atom has a radius of 143 pm. With the three outermost electrons removed, the radius shrinks to 39 pm for a 4-coordinated atom or 53.5 pm for a 6-coordinated atom. At standard temperature and pressure, aluminium atoms form a face-centered cubic crystal system bound by metallic bonding provided by atoms' outermost electrons; this crystal system is shared by some other metals, such as copper. Aluminium metal, when in quantity, is shiny and resembles silver because it preferentially absorbs far ultraviolet radiation while reflecting all visible light so it does not impart any color to reflected light, unlike the reflectance spectra of copper and gold.
Another important characteristic of aluminium is its low density, 2.70 g/cm3. Aluminium is a soft, lightweight and malleable with appearance ranging from silvery to dull gray, depending on the surface roughness, it is nonmagnetic and does not ignite. A fresh film of aluminium serves as a good reflector of visible light and an excellent reflector of medium and far infrared radiation; the yield strength of pure aluminium is 7–11 MPa, while aluminium alloys have yield strengths ranging from 200 MPa to 600 MPa. Aluminium has stiffness of steel, it is machined, cast and extruded. Aluminium atoms are arranged in a face-centered cubic structure. Aluminium has a stacking-fault energy of 200 mJ/m2. Aluminium is a good thermal and electrical conductor, having 59% the conductivity of copper, both thermal and electrical, while having only 30% of copper's density. Aluminium is capable of superconductivity, with a superconducting critical temperature of 1.2 kelvin and a critical magnetic field of about 100 gauss.
Aluminium is the most common material for the fabrication of superconducting qubits. Aluminium's corrosion resistance can be excellent due to a thin surface layer of aluminium oxide that forms when the bare metal is exposed to air preventing further oxidation, in a process termed passivation; the strongest aluminium alloys are less corrosion resistant due to galvanic reactions with alloyed copper. This corrosion resistance is reduced by aqueous salts in the presence of dissimilar metals. In acidic solutions, aluminium reacts with water to form hydrogen, in alkaline ones to form aluminates—protective passivation under these conditions is negligible; because it is corroded by dissolved chlorides, such as common sodium chloride, household plumbing is never made from aluminium. However, because
Aroma of wine
The aromas of wine are more diverse than its flavors. The human tongue is limited to the primary tastes perceived by taste receptors on the tongue-sourness, saltiness and savoriness; the wide array of fruit, leathery, herbal and woodsy flavor present in wine are derived from aroma notes sensed by the olfactory bulb. In wine tasting, wine is sometimes smelled before being drunk in order to identify some components of the wine that may be present. Different terms are used to describe; the most basic term is aroma which refers to a "pleasant" smell as opposed to odor which refers to an unpleasant smell or possible wine fault. The term aroma may be further distinguished from bouquet which refers to the smells that arise from the chemical reactions of fermentation and aging of the wine. In professional wine tasting, there is a distinction made between "aromas" and a wine's "bouquet" while in casual wine tasting these two terms are used interchangeably. An aroma refers to the smells unique to the grape variety and are most demonstrated in a varietal wine—such as lychees with Gewürztraminer or black currant with Cabernet Sauvignon.
These are smells that are associated with a young wine. As a wine ages, chemical reactions among acids, sugars and phenolic compounds create new smells that are known as a wine's bouquet; these can include honey in truffles in a Pinot noir. The term bouquet can be expanded to include the smells derived from fermentation and exposure to oak. In Burgundy, the aromas of wines are sub-divided into three categories-primary and tertiary aromas. Primary aromas are those specific to the grape variety itself. Secondary aromas are those derived from fermentation. Tertiary aromas are those that develop through either oak aging; the technique of microoxygenation affects the aromatic bouquet. Within wine there are volatile and non-volatile compounds that contribute to the make up of a wine's aroma. During the fermentation and for the first few months of a wine's existence, chemical reactions among these compounds occur and a wine's aroma will change more during this period than at any other point; as a wine ages and matures and developments in aroma will continue to take place but at a slower and more gradual pace.
Volatile aroma compounds are present in the skin and juice of a grape berry and will vary in composition according to the individual grape variety. It is theorized that the Vitis vine developed these compounds as an evolutionary tool to aid in procreation by attracting insects to assist with pollination and birds and other animals to eat the berries and disperse the seeds; the diverse spectrum of aromas associated with individual grape varieties is a reflection of the vine's adaptation to ecological conditions and competition among other plants. The majority of volatile compounds responsible for aroma combine with sugars in the wine to form odorless glycosides. Through the process of hydrolysis, caused by enzymes or acids in the wine, they revert into an aromatic form; the act of tasting wine is the act of smelling these vaporized aroma compounds. Olfactory receptors cells, each sensitive to a different aroma, pick up these compounds and transfer the information to the brain by way of the olfactory bulb.
In the 1980s there was renewed focus in studying the correlation between aroma/flavor compounds in grapes and the resulting quality of wine. Scientists were able to use chromatograph-mass spectrometers to identify volatile aroma compounds in various grape varieties. Study of the compounds responsible for aroma and flavor, as well as their correlation with a wine's quality, is ongoing; as understanding of these compounds grows, there is concern that wines in the future could be "manipulated" through the use of chemical additives to add complexity and additional aromas to wine. In 2004, a winery in South Africa was found to have added illegal flavoring to their Sauvignon blanc to enhance the aroma. Viticultural studies have focused on how aroma compounds develop in the grapes during the annual growth cycle of the vine and how viticultural techniques such as canopy management may contribute to developing desirable aromatics in the wine; some of the identified aroma compounds include the following: Methoxypyrazine-grassy, herbaceous aroma compound associated with Cabernet Sauvignon and Sauvignon blanc.
Monoterpenes-responsible for the floral aromatics of varieties like Gewürztraminer and Riesling. Includes geraniol and nerol. Norisoprenoids-Carotenoid derived aromatic compounds that includes megastigmatrienone which produces some of the spice notes associated with Chardonnay and zingerone responsible for the different spice notes associated with Syrah. Other norisoprenoids include raspberry ketone which produces some of the raspberry aromas associated with red wine, damascenone which produces some of the rose oil aromas associated with Pinot noir and vanillin. Thiols/Mercaptans-sulfur contain compounds that can produce an aroma of garlic and onion, considered a wine fault, they have been found to contribute to some of the varietal aromas associated with Cabernet Sauvignon, Gewürztraminer, Muscat, Petit Manseng, Pinot blanc, Pinot gris, Scheurebe and Sylvaner. Some of the aromas perceived in wine are from esters created by the reaction of acids and alcohol in the wine. Esters can develop during fermentation, with the influence of yeast, or during aging by chemical reactions.
The precise yeast strain used during fermentation and temperature are two of the strongest indicators of what kind of esters will develop and helps explain why Chardonnay grown i
Boxed wine is wine packaged in a bag-in-box. Wine is contained in a plastic bladder with an air-tight valve emerging from a protective corrugated fiberboard box, it serves as an alternative to traditional wine bottling in glass with synthetic seal. It is sometimes called goon bag or "Chateau Cardboard" in Australia; the process for packaging'cask wine' was invented by Thomas Angove, a winemaker from Renmark, South Australia, patented by his company on April 20, 1965. Polyethylene bladders of 1 gallon were placed in corrugated boxes for retail sale; the original design required that the consumer cut the corner off the bladder, pour out the serving of wine and reseal it with a special peg and was based on a product on the market, a bag in a box used by mechanics to hold and transport battery acid. In 1967, Australian inventor Charles Malpas and Penfolds Wines patented a plastic, air-tight tap welded to a metallised bladder, making storage more convenient. All modern wine casks now use some sort of plastic tap, exposed by tearing away a perforated panel on the box.
For the next decades bag in a box packaging was preferred by producers of less expensive wines as it is cheaper to fabricate and distribute than glass bottles. In 2003, California Central Coast AVA–based Black Box Wines introduced mass premium wines in a box, which served to overturn the stereotype that boxed wines are an alternate packing on inexpensive jug wine. Within the decade premium wineries and bottlers began packaging their own high-quality boxed wine, including French rabbit, Bandit Wines, Octavin and hundreds of others; this coupled with an increased cultural interest in environmentally sustainable packaging has cultivated growing popularity with affluent wine consumers. During the mid-1970s, the bag in box packaging concept expanded to other beverages including spring waters, orange juices, wine coolers, however today wine and spring water are the main two beverages packed into these bags. Bag-in-box packaging is less expensive and more environmentally friendly than glass-bottled wine, as well as being easier to transport and store.
Typical bag-in-box containers hold one and a half to four 750 ml bottles of wine per box, though they come in a wide variety of volumes. The fact that wine is removed from the flexible bag without adding air to fill the vacated space reduces oxidation of the wine during dispensing. Compared to wine in a bottle which should be consumed within hours or days of opening, bag-in-box wine is not subject to cork taint and will not spoil for 3–4 weeks after breaking the seal. Wine contained in plastic bladders are not intended for cellaring and should be consumed within the manufacturer printed shelf life. Deterioration may be noticeable by 12 months after filling. In a 2007 editorial in The Sydney Morning Herald, Adele Horin criticized the lower level of alcohol excise levied on cask wine in Australia, saying it encourages binge drinking. Goon of Fortune Wine cask Franzia, brand of boxed wine Hardy Wine Company Flavored fortified wine Jug wine, inexpensive table wine
Annual growth cycle of grapevines
The annual growth cycle of grapevines is the process that takes place in the vineyard each year, beginning with bud break in the spring and culminating in leaf fall in autumn followed by winter dormancy. From a winemaking perspective, each step in the process plays a vital role in the development of grapes with ideal characteristics for making wine. Viticulturalists and vineyard managers monitor the effect of climate, vine disease and pests in facilitating or impeding the vines progression from bud break, fruit set, harvesting, leaf fall and dormancy-reacting if need be with the use of viticultural practices like canopy management, vine training and the use of agrochemicals; the stages of the annual growth cycle become observable within the first year of a vine's life. The amount of time spent at each stage of the growth cycle depends on a number of factors-most notably the type of climate and the characteristics of the grape variety; the grape starts its annual growth cycle in the spring with bud break.
In the Northern Hemisphere, this stage begins around March while in the Southern Hemisphere it begins around September when daily temperatures begin to surpass 10 °C. If the vine had been pruned during the winter, the start of this cycle is signaled by a "bleeding" of the vine; this bleeding occurs when the soil begins to warm and osmotic forces pushes water, containing a low concentration of organic acids, hormones and sugars, up from the root system of the vine and it is expelled from the cuts left over from pruning the vine. During this period a single vine can "bleed" up to 5 litres of water. Tiny buds on the vine start to swell and shoots begin to grow from the buds. Buds are the small part of the vine that rest between the petiole. Inside the buds contain three primordial shoots; these buds appear in the summer of previous growth cycle green and covered in scales. During winter dormancy they turn brown until the spring when the vine begins the process of bud break and the first sign of green in the vineyard emerges in the form of tiny shoots.
The energy to facilitate this growth comes from reserves of carbohydrate stored in roots and wood of the vine from the last growth cycle. The shoots sprout tiny leaves that can begin the process of photosynthesis, producing the energy to accelerate growth. In warm climates, after about 4 weeks the growth of the shoots starts to accelerate with the shoots growing in length an average of 3 cm a day. In temperate climates, where temperatures can reach above 10 °C in mid-winter, some early budding varieties can be at risk of premature bud break; this is a potential viticultural hazard in places like the Margaret River region of Western Australia where warm currents from the Indian Ocean can coax Chardonnay vines to prematurely bud in the mid-winter month of July. After bud break, the young shoots are vulnerable to frost damage with vineyard managers going to great lengths protect the fragile shoots should temperature drop below freezing; this can include setting up heaters or wind circulators in the vineyard to keep cold air from settling on the vines.
Depending on temperatures, 40–80 days after bud break the process of flowering begins with small flower clusters appearing on the tips of the young shoots looking like buttons. Flowering occurs when average daily temperatures stay between 15–20 °C which in the Northern Hemisphere wine regions is around May and for the Southern Hemisphere regions around November. A few weeks after the initial clusters appear, the flowers start to grow in size with individual flowers becoming observable, it is during this stage of flowering that the pollination and fertilization of the grapevine takes place with the resulting product being a grape berry, containing 1-4 seeds. Most cultivated Vitis vinifera grape vines are hermaphroditic, with both male stamens and female ovaries, while many wild grapes are either male, producing pollen but no fruit, or female, producing fruit only if a pollinator is nearby. Hermaphroditic vines are preferred for cultivation because each vine is more to self-pollinate and produce fruit.
At the beginning of the flowering process the only part, visible is the fused cap of petals known as the calyptra. Shortly after the calyptra is shed, liberating the pollen from the anthers of the stamen. Wind and insects play only a small role in aiding pollination, with the process being self-contained within the vine, but cross-pollination between vines of different varieties is possible: Cabernet Sauvignon is a cross of Cabernet Franc and Sauvignon blanc. During the process of fertilization, the pollen fertilizes the ovary which produces seeds as the flower begins the transformation into a grape berry, encapsulating the seed. Detrimental weather can affect the flowering process, causing many flowers not to be fertilized and produce a group, it is during this time. The stage of fruit set follows flowering immediately, when the fertilized flower begins to develop a seed and grape berry to protect the seed. In the Northern Hemisphere, this takes place in May and in the Southern Hemisphere in November.
This stage is critical for wine production since it determines the potential crop yield. Not every flower on the vine gets fertilized, with the unfertilized flowers falling off the vine; the percentage of fertilized flowers can get as high as 60 or be much lower. Climate and the health of the vine play an important role with low humidity, high t
Resin identification code
The ASTM International Resin Identification Coding System abbreviated RIC, is a set of symbols appearing on plastic products that identify the plastic resin out of which the product is made. It was developed in 1988 by the Society of the Plastics Industry in the United States, but since 2008 it has been administered by ASTM International, an international standards organization; the US Society of the Plastics Industry introduced the Resin Identification Code system in 1988, when the organisation was called Society of the Plastics Industry, Inc.. The SPI stated that one purpose of the original SPI code was to "Provide a consistent national system to facilitate recycling of post-consumer plastics." The system has been adopted by a growing number of communities implementing recycling programs, as a tool to assist in sorting plastics. In order to deal with the concerns of recyclers across the U. S. the RIC system was designed to make it easier for workers in materials recovery and recycling facilities to sort and separate items according to their resin type.
Plastics must be recycled separately, with other like materials, in order to preserve the value of the recycled material, enable its reuse in other products after being recycled. In its original form, the symbols used as part of the RIC consisted of arrows that cycle clockwise to form a triangle that encloses a number; the number broadly refers to the type of plastic used in the product, by chronological order of when that plastic became recyclable: “1” signifies that the product is made out of polyethylene terephthalate “2” signifies high-density polyethylene “3” signifies polyvinyl chloride “4” signifies low-density polyethylene “5” signifies polypropylene “6” signifies polystyrene “7” signifies other plastics, such as acrylic, nylon and polylactic acid. When a number is omitted, the arrows arranged in a triangle form the universal recycling symbol, a generic indicator of recyclability. Subsequent revisions to the RIC have replaced the arrows with a solid triangle, in order to address consumer confusion about the meaning of the RIC, the fact that the presence of a RIC symbol on an item does not indicate that it is recyclable.
In 2008, ASTM International took over the administration of the RIC system and issued ASTM D7611—Standard Practice for Coding Plastic Manufactured Articles for Resin Identification. In 2013 this standard was revised to change the graphic marking symbol of the RIC from the "chasing arrows" of the Recycling Symbol to a solid triangle instead. Since its introduction, the RIC has been used as a signifier of recyclability, but the presence of a code on a plastic product does not indicate that it is recyclable any more than its absence means the plastic object is unrecyclable. Sources: Below are the RIC symbols after ASTM's 2013 revision In the United States, use of the RIC in the coding of plastics has led to ongoing consumer confusion about which plastic products are recyclable; when many plastics recycling programs were first being implemented in communities across the United States, only plastics with RICs "1" and "2" were accepted to be recycled. The list of acceptable plastic items has grown since and in some areas municipal recycling programs can collect and recycle most plastic products regardless of their RIC.
This has led some communities to instruct residents to refer to the form of packaging when determining what to include in a curbside recycling bin, rather than instructing them to rely on the RIC. To further alleviate consumer confusion, the American Chemistry Council launched the "Recycling Terms & Tools" program to promote standardized language that can be used to educate consumers about how to recycle plastic products. Modifications to the RIC are being discussed and developed by ASTM's D20.95 subcommittee on recycled plastics. In the U. S. the Sustainable Packaging Coalition has created a "How2Recycle" label in an effort to replace the RIC with that aligns more with how the public uses the RIC. Rather than indicating what type of plastic resin a product is made out of, the four "How2Recycle" labels indicate whether a plastic product is Widely Recycled. Limited. Not Yet Recycled. Store Drop-Off; the "How2Recycle" labels encourage consumers to check with local facilities to see what plastics each municipal recycling facility can accept.
The different resin identification codes can be represented by Unicode icons ♳, ♴, ♵, ♶, ♷, ♸, ♹. ♺ is the portion of the symbol without the number or abbreviation. Recycling codes List of symbols Thermoplastic—softens with heat Thermosetting polymer—does not soften with heat Recycling Symbols for Plastics has symbols used in plastics recycling available in various formats for use in graphics
Wine is an alcoholic drink made from fermented grapes. Yeast consumes the sugar in the grapes and converts it to ethanol, carbon dioxide, heat. Different varieties of grapes and strains of yeasts produce different styles of wine; these variations result from the complex interactions between the biochemical development of the grape, the reactions involved in fermentation, the terroir, the production process. Many countries enact legal appellations intended to define qualities of wine; these restrict the geographical origin and permitted varieties of grapes, as well as other aspects of wine production. Wines not made from grapes include rice wine and fruit wines such as plum, pomegranate and elderberry. Wine has been produced for thousands of years; the earliest known traces of wine are from Georgia and Sicily although there is evidence of a similar alcoholic drink being consumed earlier in China. The earliest known winery is the 6,100-year-old Areni-1 winery in Armenia. Wine reached the Balkans by 4500 BC and was consumed and celebrated in ancient Greece and Rome.
Throughout history, wine has been consumed for its intoxicating effects. Wine has long played an important role in religion. Red wine was associated with blood by the ancient Egyptians and was used by both the Greek cult of Dionysus and the Romans in their Bacchanalia; the earliest archaeological and archaeobotanical evidence for grape wine and viniculture, dating to 6000–5800 BC was found on the territory of modern Georgia. Both archaeological and genetic evidence suggest that the earliest production of wine elsewhere was later having taken place in the Southern Caucasus, or the West Asian region between Eastern Turkey, northern Iran; the earliest evidence of a grape-based fermented drink was found in China, Georgia from 6000 BC, Iran from 5000 BC, Sicily from 4000 BC. The earliest evidence of a wine production facility is the Areni-1 winery in Armenia and is at least 6100 years old. A 2003 report by archaeologists indicates a possibility that grapes were mixed with rice to produce mixed fermented drinks in China in the early years of the seventh millennium BC.
Pottery jars from the Neolithic site of Jiahu, contained traces of tartaric acid and other organic compounds found in wine. However, other fruits indigenous to the region, such as hawthorn, cannot be ruled out. If these drinks, which seem to be the precursors of rice wine, included grapes rather than other fruits, they would have been any of the several dozen indigenous wild species in China, rather than Vitis vinifera, introduced there 6000 years later; the spread of wine culture westwards was most due to the Phoenicians who spread outward from a base of city-states along the Mediterranean coast of what are today Syria, Lebanon and Palestine. The wines of Byblos were exported to Egypt during the Old Kingdom and throughout the Mediterranean. Evidence includes two Phoenician shipwrecks from 750 BC discovered by Robert Ballard, whose cargo of wine was still intact; as the first great traders in wine, the Phoenicians seem to have protected it from oxidation with a layer of olive oil, followed by a seal of pinewood and resin, similar to retsina.
Although the nuragic Sardinians consumed wine before the arrival of the Phoenicians The earliest remains of Apadana Palace in Persepolis dating back to 515 BC include carvings depicting soldiers from Achaemenid Empire subject nations bringing gifts to the Achaemenid king, among them Armenians bringing their famous wine. Literary references to wine are abundant in Homer and others. In ancient Egypt, six of 36 wine amphoras were found in the tomb of King Tutankhamun bearing the name "Kha'y", a royal chief vintner. Five of these amphoras were designated as originating from the king's personal estate, with the sixth from the estate of the royal house of Aten. Traces of wine have been found in central Asian Xinjiang in modern-day China, dating from the second and first millennia BC; the first known mention of grape-based wines in India is from the late 4th-century BC writings of Chanakya, the chief minister of Emperor Chandragupta Maurya. In his writings, Chanakya condemns the use of alcohol while chronicling the emperor and his court's frequent indulgence of a style of wine known as madhu.
The ancient Romans planted vineyards near garrison towns so wine could be produced locally rather than shipped over long distances. Some of these areas are now world-renowned for wine production; the Romans discovered that burning sulfur candles inside empty wine vessels kept them fresh and free from a vinegar smell. In medieval Europe, the Roman Catholic Church supported wine because the clergy required it for the Mass. Monks in France made wine for years. An old English recipe that survived in various forms until the 19th century calls for refining white wine from bastard—bad or tainted bastardo wine; the English word "wine" comes from the Proto-Germanic *winam, an early borrowing from the Latin vinum, "wine" or " vine", itself derived from the Proto-Indo-European stem *win-o-. The earliest attested terms referring to wine are the Mycenaean Greek me-tu-wo ne-wo, meaning "in" or " of the new wine", wo-no-wa-ti-si, meaning "wine garden", written in Linear B inscriptions. Linear B includes, inter alia, an ideogram for wine
Closures are devices and techniques used to close or seal container such as a bottle, jar, can, etc. Closures can be a cap, lid, etc. Other types of containers such as boxes and drums may have closures but are not discussed in this article. Many containers and packages require a means of closing, it can lock. Depending on the contents and container, closures have several functions: Keep the container closed and the contents contained for the specified shelf life until time of opening Provide a barrier to dirt, moisture, etc. Control of permeation is critical to many types of products: foods, etc. Keep the product secure from undesired premature opening Provide a means of reclosing or reusing the container Assist in dispensing and use of product Allow reasonable ease to open the container by the intended user. Difficult to open containers may cause wrap rage; the force or torque required to open a closure is an important consideration for packaging engineers. Many types of packaging with their closures are regulated for strength, security, communication and environmental requirements.
Closures need a means of attaching to the container with sufficient security. Threads, hinges, adhesives, etc. are used. Many closures need to have the ability to adjust to slight manufacturing variation in the container and the closure structure; some closures are made of flexible material such as rubber, or plastic foam. An o-ring or a closure liner is used. Linerless closures use a deformable plastic rim or structure to maintain the seal. Secondary seals are common with sensitive products that may deteriorate or where extra security is needed. Foil or plastic innerseals are used on some bottles, Heat sealed lidding films are used on some tubs. External shrink bands and tapes are sometimes used outside the primary closure structure. Additionally, many closures feature ventilation to prevent bloating, collapse or explosion due to unequalized pressure during processing or storage. Venting technologies utilize common materials such as PP, etc.. These elements are preferred due to their ability to withstand temperatures of 260°C and water intrusion pressure levels of 770 mbar.
A screw closure is a mechanical device, screwed on and off of a threaded "finish" on a container. Either continuous threads or lugs are used. Metal caps can be either preformed or in some instances, rolled on after application. Plastic caps may use several types of molded polymer; some screw tops have multiple pieces. For example, a mason jar has a lid with a built in rubbery seal and a separate threaded ring or band. Beverage bottles are closed with crown beverage caps; these are shallow metal caps. Some closures snap on. For opening, the top is designed to break off, or have a built in dispenser; some containers have a loose lid for a closure. Laboratory glassware has ground glass joints that allow the pieces to be fitted together easily. An Interference fit or friction fit requires some force to close and open, providing additional security. Paint cans have a friction fit plug. Resistance to tampering is required for some types of products. Container closures can be one of several layers of packaging to deter tampering and to provide evidence of attempts at tampering.
*Sometimes tamper resistance is obtained by a tamper-evident band. A wide variety of convenience dispensing features can be built into closures. Spray bottles and cans with aerosol spray have special closure requirements. Pour spouts, sprayer cap, measuring attachments, sifting devices, etc. are common caps. A spray bottle is a bottle that can dispense, spray or mist fluids. A common use for spray bottles is dispensing cool cleaners and chemical specialties. Child-resistant packaging or C-R packaging has special closures designed to reduce the risk of children ingesting dangerous items; this is accomplished by the use of a special safety cap. It is required by regulation for prescription drugs, over-the-counter medications and household chemicals. Early pottery and ceramic containers had lids that fit reasonably snug onto the body of the container; the narrow necks of ancient amphora were closed with a plug of cork, wood, or ceramic and sealed with mortar. Wooden Barrels had bungholes closed by cork or wood bungs.
Some early tinplate cans were made with threaded necks for screw top closures. Beverage bottles started using the Hutter Stopper in 1893; this involved a porcelain plug fitted with a rubber washer, forced down into the lip of the bottle. This technique only works with carbonated beverages; the Hutter Stopper became standard in beer bottling in the late 1890s / early 1900s. Bail closures on bottles were invented by Henry William Putnam in 1859; these involved heavy wire bail attached to a bottle's neck. The world's first modern bottle cap, the crown cork, was invented by William Painter in 1890 in Baltimore; the screw cap using rust resistant aluminum was first used in prescription drug bottling in the 1920s. Molded urea based bottle caps were first introduced in the early 1900s. A history of accidents involving children opening household packaging and ingesting the contents led the US Congress to pass the Poison Prevention Packaging Act of 1970; the International Society of Beverage Technologists is the main trade association for closure manufacturers.
It develops voluntary industry standards for its members to