Japan is an island country in East Asia. Located in the Pacific Ocean, it lies off the eastern coast of the Asian continent and stretches from the Sea of Okhotsk in the north to the East China Sea and the Philippine Sea in the south; the kanji that make up Japan's name mean "sun origin", it is called the "Land of the Rising Sun". Japan is a stratovolcanic archipelago consisting of about 6,852 islands; the four largest are Honshu, Hokkaido and Shikoku, which make up about ninety-seven percent of Japan's land area and are referred to as home islands. The country is divided into 47 prefectures in eight regions, with Hokkaido being the northernmost prefecture and Okinawa being the southernmost one; the population of 127 million is the world's tenth largest. 90.7 % of people live in cities. About 13.8 million people live in the capital of Japan. The Greater Tokyo Area is the most populous metropolitan area in the world with over 38 million people. Archaeological research indicates; the first written mention of Japan is in Chinese history texts from the 1st century AD.
Influence from other regions China, followed by periods of isolation from Western Europe, has characterized Japan's history. From the 12th century until 1868, Japan was ruled by successive feudal military shōguns who ruled in the name of the Emperor. Japan entered into a long period of isolation in the early 17th century, ended in 1853 when a United States fleet pressured Japan to open to the West. After nearly two decades of internal conflict and insurrection, the Imperial Court regained its political power in 1868 through the help of several clans from Chōshū and Satsuma – and the Empire of Japan was established. In the late 19th and early 20th centuries, victories in the First Sino-Japanese War, the Russo-Japanese War and World War I allowed Japan to expand its empire during a period of increasing militarism; the Second Sino-Japanese War of 1937 expanded into part of World War II in 1941, which came to an end in 1945 following the Japanese surrender. Since adopting its revised constitution on May 3, 1947, during the occupation led by SCAP, the sovereign state of Japan has maintained a unitary parliamentary constitutional monarchy with an Emperor and an elected legislature called the National Diet.
Japan is a member of the ASEAN Plus mechanism, UN, the OECD, the G7, the G8, the G20, is considered a great power. Its economy is the world's third-largest by nominal GDP and the fourth-largest by purchasing power parity, it is the world's fourth-largest exporter and fourth-largest importer. Japan benefits from a skilled and educated workforce. Although it has renounced its right to declare war, Japan maintains a modern military with the world's eighth-largest military budget, used for self-defense and peacekeeping roles. Japan is a developed country with a high standard of living and Human Development Index, its population enjoys the highest life expectancy and third lowest infant mortality rate in the world, but is experiencing issues due to an aging population and low birthrate. Japan is renowned for its historical and extensive cinema, influential music industry, video gaming, rich cuisine and its major contributions to science and modern technology; the Japanese word for Japan is 日本, pronounced Nihon or Nippon and means "the origin of the sun".
The character nichi means "sun" or "day". The compound therefore means "origin of the sun" and is the source of the popular Western epithet "Land of the Rising Sun"; the earliest record of the name Nihon appears in the Chinese historical records of the Tang dynasty, the Old Book of Tang. At the end of the seventh century, a delegation from Japan requested that Nihon be used as the name of their country; this name may have its origin in a letter sent in 607 and recorded in the official history of the Sui dynasty. Prince Shōtoku, the Regent of Japan, sent a mission to China with a letter in which he called himself "the Emperor of the Land where the Sun rises"; the message said: "Here, I, the emperor of the country where the sun rises, send a letter to the emperor of the country where the sun sets. How are you". Prior to the adoption of Nihon, other terms such as Yamato and Wakoku were used; the term Wa is a homophone of Wo 倭, used by the Chinese as a designation for the Japanese as early as the third century Three Kingdoms period.
Another form of Wa, Wei in Chinese) was used for an early state in Japan called Nakoku during the Han dynasty. However, the Japanese disliked some connotation of Wa 倭, it was therefore replaced with the substitute character Wa, meaning "togetherness, harmony"; the English word Japan derives from the historical Chinese pronunciation of 日本. The Old Mandarin or early Wu Chinese pronunciation of Japan was recorded by Marco Polo as Cipangu. In modern Shanghainese, a Wu dialect, the pronunciation of characters 日本; the old Malay word for Japan, Japun or Japang, was borrowed from a southern coastal Chinese dialect Fukienese or Ningpo – and this Malay word was encountered by Portuguese traders in Southeast Asia in the 16th century. These Early Portuguese traders brought the word
A renewable resource is a natural resource which will replenish to replace the portion depleted by usage and consumption, either through natural reproduction or other recurring processes in a finite amount of time in a human time scale. Renewable resources are a part of Earth's natural environment and the largest components of its ecosphere. A positive life cycle assessment is a key indicator of a resource's sustainability. Definitions of renewable resources may include agricultural production, as in sustainable agriculture and to an extent water resources. In 1962, Paul Alfred Weiss defined Renewable Resources as: "The total range of living organisms providing man with life, etc...". Another type of renewable resources is renewable energy resources. Common sources of renewable energy include solar and wind power, which are all categorised as renewable resources. Water can be considered a renewable material when controlled usage and release are followed. If not, it would become a non-renewable resource at that location.
For example, as is removed from a aquifer at a rate much greater than its slow natural recharge, it is a considered non-renewable resource. Removal of water from the pore spaces in aquifers may cause permanent compaction that cannot be renewed. 97.5% of the water on the Earth is salt water, 3% is fresh water. The remaining unfrozen freshwater is found as groundwater, with only a small fraction present above ground or in the air. Water pollution is one of the main concerns regarding water resources, it is estimated. Major industrial users include hydroelectric dams, thermoelectric power plants and oil refineries and manufacturing plants. Desalination of seawater is considered a renewable source of water, although reducing its dependence on fossil fuel energy is needed for it to be renewable. Food is any substance consumed to provide nutritional support for the body. Most food has its origin in renewable resources. Food is obtained directly from animals. Hunting may not be the first source of meat in the modernised world, but it is still an important and essential source for many rural and remote groups.
It is the sole source of feeding for wild carnivores. The phrase sustainable agriculture was coined by Australian agricultural scientist Gordon McClymont, it has been defined as "an integrated system of plant and animal production practices having a site-specific application that will last over the long term". Expansion of agricultural land contributes to deforestation; the Food and Agriculture Organization of the United Nations estimates that in coming decades, cropland will continue to be lost to industrial and urban development, along with reclamation of wetlands, conversion of forest to cultivation, resulting in the loss of biodiversity and increased soil erosion. Although air and sunlight are available everywhere on Earth, crops depend on soil nutrients and the availability of water. Monoculture is a method of growing only one crop at a time in a given field, which can damage land and cause it to become either unusable or suffer from reduced yields. Monoculture can cause the build-up of pathogens and pests that target one specific species.
The Great Irish Famine is a well-known example of the dangers of monoculture. Crop rotation and long-term crop rotations confer the replenishment of nitrogen through the use of green manure in sequence with cereals and other crops, can improve soil structure and fertility by alternating deep-rooted and shallow-rooted plants. Other methods to combat lost soil nutrients are returning to natural cycles that annually flood cultivated lands such as the Flooding of the Nile, the long-term use of biochar, use of crop and livestock landraces that are adapted to less than ideal conditions such as pests, drought, or lack of nutrients. Agricultural practices are one of the single greatest contributor to the global increase in soil erosion rates, it is estimated that "more than a thousand million tonnes of southern Africa's soil are eroded every year. Experts predict that crop yields will be halved within thirty to fifty years if erosion continues at present rates." The Dust Bowl phenomenon in the 1930s was caused by severe drought combined with farming methods that did not include crop rotation, fallow fields, cover crops, soil terracing and wind-breaking trees to prevent wind erosion.
The tillage of agricultural lands is one of the primary contributing factors to erosion, due to mechanised agricultural equipment that allows for deep plowing, which increases the amount of soil, available for transport by water erosion. The phenomenon called peak soil describes how large-scale factory farming techniques are affecting humanity's ability to grow food in the future. Without efforts to improve soil management practices, the availability of arable soil may become problematic. Methods to combat erosion include no-till farming, using a keyline design, growing wind breaks to hold the soil, widespread use of compost. Fertilizers and pesticides can have an effect of soil erosion, which can contribute to soil salinity and prevent other species from growing. Phosphate is a primary component in the chemical fertiliser applied most in modern agricultural production. However, scientists estimate that rock phosphate reserves will be depleted in 50–100 years and that Peak Phosphate will occur in about 2030.
Industrial processing and logistics have an effect on ag
Tapioca is a starch extracted from cassava plant. This species is native to the north region and central-west region of Brazil, but its use spread throughout South America; the plant was carried by Portuguese and Spanish explorers to most of the West Indies and Africa and Asia. It is a tropical, perennial shrub, less cultivated in temperate climate zones. Cassava thrives better in poor soils than many other food plants. Although tapioca is a staple food for millions of people in tropical countries, it provides only carbohydrate food value, is low in protein and minerals. In other countries, it is used as a thickening agent in various manufactured foods. Tapioca is derived from the word tipi'óka, its name in the Tupí language spoken by natives when the Portuguese first arrived in the Northeast Region of Brazil around 1707; this Tupí word refers to the process. The cassava plant has either green branches with blue spindles on them; the root of the green-branched variant requires treatment to remove linamarin, a cyanogenic glycoside occurring in the plant, which otherwise may be converted into cyanide.
Konzo is a paralytic disease associated with several weeks of exclusive consumption of insufficiently processed bitter cassava. In the north and northeast of Brazil, traditional community-based production of tapioca is a by-product of manioc flour production from cassava roots. In this process, the manioc is ground to a pulp with a small hand- or diesel-powered mill; this masa is squeezed to dry it out. The wet masa is placed in a long woven tube called a tipiti; the top of the tube is secured while a large branch or lever is inserted into a loop at the bottom and used to stretch the entire implement vertically, squeezing a starch-rich liquid out through the weave and ends. This liquid is collected and the water allowed to evaporate, leaving behind a fine-grained tapioca powder similar in appearance to corn starch. Commercially, the starch is processed into several forms: hot soluble powder, pre-cooked fine/coarse flakes, rectangular sticks, spherical "pearls". Pearls are the most available shape.
Flakes and pearls must be soaked well before cooking, in order to rehydrate, absorbing water up to twice their volume. After rehydration, tapioca products become swollen. Processed tapioca is white, but sticks and pearls may be colored. Traditionally, the most common color applied to tapioca has been brown, but pastel colors have been available. Tapioca pearls are opaque when raw, but become translucent when cooked in boiling water. Brazil in South America, Thailand in Asia, Nigeria in Africa are the world's largest producers of cassava. Thailand accounts for about 60 percent of worldwide exports. Tapioca predominantly consists of carbohydrates, with each cup containing 23.9 grams for a total of 105 calories. One serving of tapioca pudding contains no dietary fiber, a small amount of oleic acid, no omega-3 or omega-6 fatty acids. A casabe is a thin flatbread made from bitter cassava root without leavening, it was produced by the indigenous Arawak and Carib peoples because these roots were a common plant of the rain forests where they lived.
In eastern Venezuela, many indigenous groups still make casabe. It is their chief bread-like staple. Indigenous communities, such as the Ye-Kuana, Kari-Ña, Guarao or Warao descended from the Caribe or Arawac nations, still make casabe. To make casabe, the starchy root of bitter cassava is ground to a pulp squeezed to expel a milky, bitter liquid called yare; this carries the poisonous substances with it out of the pulp. Traditionally, this squeezing is done in a sebucan, an 8 to 12-foot long, tube-shaped, pressure strainer, woven in a characteristic helical pattern from palm leaves; the sebucan is hung from a tree branch or ceiling pole, it has a closed bottom with a loop, attached to a fixed stick or lever, used to stretch the sebucan. When the lever is pushed down, stretching the sebucan, the helical weaving pattern causes the strainer to squeeze the pulp inside; this is similar to the action of a Chinese finger trap. The pulp is spread in round cakes about 2 feet in diameter on a budare to roast or toast.
Thin and crisp cakes of casabe are broken apart and eaten like crackers. Like bread, casabe can be eaten alone or with other dishes. Thicker casabe are eaten moistened. A sprinkle of a few drops of liquid is enough to transform a dry casabe into soft smooth bread. Tapioca balls known as boba in some cultures, are produced by passing the moist starch through a sieve under pressure. Pearl tapioca is a common ingredient in South and Southeast Asian desserts such as falooda, sago soup, in sweet drinks such as bubble tea, fruit slush and taho, where they provide a chewy contrast to the sweetness and smooth texture of the drink. Small pearls are preferred for use in puddings. In Brazil, the pearls are called sagu. Large pearls are preferred for use in drinks; these pearls most are brown, not white, due to the sugar added and are traditionally used in black or green tea drinks. They are used as various colors in hot drinks. In addition to their use in puddings and beverages, tapioca pearls may be used in cakes.
Processing of the cassava flour into tapioca pearls requires the intermediate step of a product called tapioca grit. Tapioca grit is dried ca
An automotive battery is a rechargeable battery that supplies electrical current to a motor vehicle. Its main purpose is to feed the starter. Once the engine is running, power for the car's electrical systems is supplied by the alternator. Starting uses less than three percent of the battery capacity. For this reason, automotive batteries are designed to deliver maximum current for a short period of time, they are sometimes referred to as "SLI batteries" for this reason, for Starting and Ignition. SLI batteries are not designed for deep discharging, a full discharge can reduce the battery's lifespan; as well as starting the engine, an SLI battery supplies the extra power necessary when the vehicle's electrical requirements exceed the supply from the charging system. It is a stabilizer, evening out damaging voltage spikes. While the engine is running, most of the power is provided by the alternator, which includes a voltage regulator to keep the output between 13.5 and 14.5 V. Modern SLI batteries are lead-acid type, using six series-connected cells to provide a nominal 12 volt system, or twelve cells for a 24 volt system in heavy trucks or earth-moving equipment, for example.
Battery electric vehicles are powered by a high-voltage electric vehicle battery, but they have an automotive battery as well, so that they can use standard automotive accessories which are designed to run on 12 V. Early cars did not have batteries. A bell was used instead of an electric horn, headlights were gas-powered, the engine was started with a crank. Car batteries became used around 1920 as cars became equipped with electric starters; the sealed battery, which did not require refilling, was invented in 1971. The first starting and charging systems were designed to be 6-volt and positive-ground systems, with the vehicle's chassis directly connected to the positive battery terminal. Today, all road vehicles have a negative ground system; the negative battery terminal is connected to the car's chassis. The Hudson Motor Car Company was the first to use a standardized battery in 1918 when they started using Battery Council International batteries. BCI is the organization. Cars used batteries until the mid-1950s.
The changeover from 6 to 12 V happened when bigger engines with higher compression ratios required more electrical power to start. Smaller cars, which required less power to start stayed with 6 V longer, for example the Volkswagen Beetle in the mid-1960s and the Citroën 2CV in 1970. In the 1990s a 42V electrical system standard was proposed, it was intended to allow more powerful electrically driven accessories, lighter automobile wiring harnesses. The availability of higher-efficiency motors, new wiring techniques, digital controls, a focus on hybrid vehicle systems that use high-voltage starter/generators have eliminated the push for switching the main automotive voltages. An automobile battery is an example of a wet cell battery, with six cells; each cell of a lead storage battery consists of alternate plates made of a lead alloy grid filled with sponge lead (cathode plates} or coated with lead dioxide. Each cell is filled with a sulfuric acid solution, the electrolyte. Cells each had a filler cap, through which the electrolyte level could be viewed and which allowed water to be added to the cell.
The filler cap had a small vent hole which allowed hydrogen gas generated during charging to escape from the cell. The cells are connected by short heavy straps from the positive plates of one cell to the negative plates of the adjacent cell. A pair of heavy terminals, plated with lead to resist corrosion, are mounted at the top, sometimes the side, of the battery. Early auto batteries used hard rubber cases and wooden plate separators. Modern units use plastic cases and woven sheets to prevent the plates of a cell from touching and short-circuiting. In the past, auto batteries required regular inspection and maintenance to replace water, decomposed during operation of the battery. "low maintenance" batteries use a different alloy for the plate elements, reducing the amount of water decomposed on charging. A modern battery may not require additional water over its useful life. A weakness of these batteries is that they are intolerant of deep discharge, for example when the car battery is drained by leaving the lights on.
This coats the lead plate electrodes with sulfate deposits and can reduce the battery's lifespan by a third or more. VRLA batteries known as absorbed glass mat batteries are more tolerant of deep discharge, but are more expensive. VRLA batteries do not permit addition of water to the cell; the cells each have an automatic pressure release valve, to protect the case from rupture on severe overcharge or internal failure. A VRLA battery cannot spill its electrolyte which makes it useful in vehicles such as motorcycles. Batteries are made of six galvanic cells in a series circuit; each cell provides 2.1 volts for a total of 12.6 volts at full charge. During discharge, a chemical reaction releases electrons, allowing them to flow through conductors to produce electricity; as the battery discharges, the acid of the electrolyte reacts with the materials of the plates, changing their surface to lead sulfate. When the battery is recharged, the chemical reaction is reversed: the lead sulfate reforms into lead dioxide.
With the plates restored to their original condition, the process may be repeated. Some vehicles use other starter batteries
Polybutadiene is a synthetic rubber. Polybutadiene rubber is a polymer formed from the polymerization of the monomer 1,3-butadiene. Polybutadiene has a high resistance to wear and is used in the manufacture of tires, which consumes about 70% of the production. Another 25% is used as an additive to improve the toughness of plastics such as polystyrene and acrylonitrile butadiene styrene. Polybutadiene rubber accounted for about a quarter of total global consumption of synthetic rubbers in 2012, it is used to manufacture golf balls, various elastic objects and to coat or encapsulate electronic assemblies, offering high electrical resistivity. 1,3-Butadiene is an organic compound, a simple conjugated diene hydrocarbon. Polybutadiene forms by linking many 1,3-butadiene monomers to make a much longer polymer chain molecule. In terms of the connectivity of the polymer chain, butadiene can polymerize in three different ways, called cis and vinyl; the cis and trans forms arise by connecting the butadiene molecules end-to-end, so-called 1,4-polymerisation.
The properties of the resulting isomeric forms of polybutadiene differ. For example, "high cis"-polybutadiene has a high elasticity and is popular, whereas the so-called "high trans" is a plastic crystal with few useful applications; the vinyl content of polybutadiene is no more than a few percent. In addition to these three kinds of connectivity, polybutadienes differ in terms of their branching and molecular weights; the trans double bonds formed during polymerization allow the polymer chain to stay rather straight, allowing sections of polymer chains to align to form microcrystalline regions in the material. The cis double bonds cause a bend in the polymer chain, preventing polymer chains from aligning to form crystalline regions, which results in larger regions of amorphous polymer, it has been found that a substantial percentage of cis double bond configurations in the polymer will result in a material with flexible elastomer qualities. In free radical polymerization, both cis and trans double bonds will form in percentages that depend on temperature.
The catalysts influence. The catalyst used in the production determines the type of polybutadiene product; this type is characterized by a small proportion of vinyl. It is manufactured using Ziegler–Natta catalysts based on transition metals. Depending on the metal used, the properties vary slightly. Using cobalt gives branched molecules, resulting in a low viscosity material, ease of use, but its mechanical strength is low. Neodymium gives a higher percentage of 98 % cis. Other less used catalysts include titanium. Using an alkyllithium as the catalyst produces a polybutadiene called "low cis" which contains 36% cis, 59% trans and 10% vinyl. Despite its high liquid-glass transition, low cis polybutadiene is used in tire manufacturing and is blended with other tire polymers it can be advantageously used as an additive in plastics due to its low contents of gels. In 1980, researchers from the Japanese company Zeon discovered that high-vinyl polybutadiene, despite having a high liquid-glass transition, could be advantageously used in combination with high cis in tires.
This material is produced with an alkyllithium catalyst. Polybutadiene can be produced with more than 90% trans using catalysts similar to those of high cis: neodymium, nickel; this material is a plastic crystal which melts at about 80 °C. It was used for the outer layer of golf balls. Today it is only used industrially, but companies like Ube are investigating other possible applications; the use of metallocene catalysts to polymerize butadiene is being explored by Japanese researchers. The benefits seem to be a higher degree of control both in the distribution of molecular mass and the proportion of cis/trans/vinyl; as of 2006, no manufacturer produces "metallocene polybutadiene" on a commercial basis. 1,3-butadiene is copolymerized with other types of monomers such as styrene and acrylonitrile to form rubbers or plastics with various qualities. The most common form is styrene-butadiene copolymer, a commodity material for car tires, it is used in block copolymers and tough thermoplastics such as ABS plastic.
This way a copolymer material can be made with good stiffness and toughness. Because the chains have a double bond in each and every repeat unit, the material is sensitive to ozone cracking; the annual production of polybutadiene is 2.1 million tons. This makes it the second most produced synthetic rubber behind styrene-butadiene rubber. Polybutadiene is used in various parts of automobile tires; the polybutadiene is used in the sidewall of truck tires, this helps to improve fatigue to failure life due to the continuous flexing during run. As a result, tires will not blow out in extreme service conditions, it is used in the tread portion of giant truck tires to improve the abrasion, i.e. less wearing, to run the tire comparatively cool, since the internal heat comes out quickly. Both parts are formed by extrusion, its main competitors in this application are natural rubber. Polybutadiene has the advantage compared to SBR in its lower liquid-glass transition temperature, which gives it a high resistance to wear and a low rolling resistance.
This gives the ti
Polyoxymethylene known as acetal and polyformaldehyde, is an engineering thermoplastic used in precision parts requiring high stiffness, low friction, excellent dimensional stability. As with many other synthetic polymers, it is produced by different chemical firms with different formulas and sold variously by such names as Delrin, Ramtal, Duracon and Hostaform. POM is characterized by its high strength and rigidity to −40 °C. POM is intrinsically opaque white, due to its high crystalline composition, but it is available in all colors. POM has a density of 1.410–1.420 g/cm3. Typical applications for injection-molded POM include high-performance engineering components such as small gear wheels, eyeglass frames, ball bearings, ski bindings, guns, knife handles, lock systems; the material is used in the automotive and consumer electronics industry. Polyoxymethylene was discovered by Hermann Staudinger, a German chemist who received the 1953 Nobel Prize in Chemistry, he had studied the polymerization and structure of POM in the 1920s while researching macromolecules, which he characterized as polymers.
Due to problems with thermal stability, POM was not commercialized at that time. Around 1952, research chemists at DuPont synthesized a version of POM, in 1956 the company filed for patent protection of the homopolymer. DuPont credits R. N. MacDonald as the inventor of high-molecular-weight POM. Patents by MacDonald and coworkers describe the preparation of high-molecular-weight hemiacetal-terminated POM, but these lack sufficient thermal stability to be commercially viable; the inventor of a heat-stable POM homopolymer was Stephen Dal Nogare, who discovered that reacting the hemiacetal ends with acetic anhydride converts the depolymerizable hemiacetal into a thermally stable, melt-processable plastic. In 1960, DuPont completed construction of a plant to produce its own version of acetal resin, named Delrin, at Parkersburg, West Virginia. In 1960, Celanese completed its own research. Shortly thereafter, in a limited partnership with the Frankfurt firm Hoechst AG, a factory was built in Kelsterbach, Hessen.
Both remain in production under the auspices of Celanese and are sold as parts of a product group now called Hostaform/Celcon POM. Different manufacturing processes are used to produce the homopolymer and copolymer versions of POM. To make polyoxymethylene homopolymer, anhydrous formaldehyde must be generated; the principal method is by reaction of the aqueous formaldehyde with an alcohol to create a hemiformal, dehydration of the hemiformal/water mixture and release of the formaldehyde by heating the hemiformal. The formaldehyde is polymerized by anionic catalysis, the resulting polymer stabilized by reaction with acetic anhydride. Due to the manufacturing process, large-diameter cross-sections may have pronounced centerline porosity. A typical example is DuPont’s Delrin; the polyoxymethylene copolymer replaces about 1–1.5% of the −CH2O− groups with −CH2CH2O−. To make polyoxymethylene copolymer, formaldehyde is converted to trioxane; this is done by acid catalysis followed by purification of the trioxane by distillation and/or extraction to remove water and other active hydrogen-containing impurities.
Typical copolymers are Hostaform from Celanese and Ultraform from BASF. The co-monomer is dioxolane, but ethylene oxide can be used. Dioxolane is formed by reaction of ethylene glycol with aqueous formaldehyde over an acid catalyst. Other diols can be used. Trioxane and dioxolane are polymerized using an acid catalyst boron trifluoride etherate, BF3OEt2; the polymerization can take place in neat trioxane. After polymerization, the acidic catalyst must be deactivated and the polymer stabilized by melt or solution hydrolysis to remove unstable end groups. Stable polymer is melt-compounded, adding thermal and oxidative stabilizers and optionally lubricants and miscellaneous fillers. POM is supplied in a granulated form and can be formed into the desired shape by applying heat and pressure; the two most common forming methods employed are injection extrusion. Rotational molding and blow molding are possible. Typical applications for injection-molded POM include high-performance engineering components.
The material is used in the automotive and consumer electronics industry. There are special grades that offer higher mechanical toughness, stiffness or low-friction/wear properties. POM is extruded as continuous lengths of round or rectangular section; these sections can be sold as bar or sheet stock for machining. When supplied as extruded bar or sheet, POM may be machined using traditional methods such as turning, drilling etc; these techniques are best employed where production economics do not merit the expense of melt processing. The material does require sharp tools with a high clearance angle; the use of soluble cutting lubricant is recommended. POM sheets can be cut cleanly and using an infrared laser, such as in a CO2 laser cutter; because the material lacks the rigidity of most metals, care should be taken to use light clamping forces and sufficient support for the work piece. As can be the case with many polymers, machined POM can be dimensionally unstable with parts that have large variati