Polyester is a category of polymers that contain the ester functional group in their main chain. As a specific material, it most commonly refers to a type called polyethylene terephthalate (PET). Polyesters include naturally occurring chemicals, such as in the cutin of plant cuticles, as well as synthetics such as polybutyrate. Natural polyesters and a few synthetic ones are biodegradable, but most synthetic polyesters are not. The material is used extensively in clothing.
Polyester fibers are sometimes spun together with natural fibers to produce a cloth with blended properties. Cotton-polyester blends (polycotton) can be strong, wrinkle and tear-resistant, and reduce shrinking. Synthetic fibers using polyester have high water, wind and environmental resistance compared to plant-derived fibers. They are less fire resistant and can melt when ignited.
Polyester blends have been renamed so as to suggest their similarity or even superiority to natural fibers (for example, China silk, which is a term in the textiles industry for a 100% polyester fiber woven to resemble the sheen and durability of insect-derived silk).
Liquid crystalline polyesters are among the first industrially used liquid crystal polymers. They are used for their mechanical properties and heat-resistance. These traits are also important in their application as an abradable seal in jet engines.
Natural polyesters could have played a significant role in the origins of life. Long heterogeneous polyester chains are known to easily form in a one-pot reaction without catalyst under simple prebiotic conditions.
Depending on the chemical structure, polyester can be a thermoplastic or thermoset. There are also polyester resins cured by hardeners; however, the most common polyesters are thermoplastics. Examples of thermoset polyesters include some of the Desmophen brand from Bayer. The OH group is reacted with an Isocyanate functional compound in a 2 component system producing coatings which may optionally be pigmented. Polyesters as thermoplastics may change shape after the application of heat. While combustible at high temperatures, polyesters tend to shrink away from flames and self-extinguish upon ignition. Polyester fibers have high tenacity and E-modulus as well as low water absorption and minimal shrinkage in comparison with other industrial fibers.
Unsaturated polyesters (UPR) are thermosetting resins. They are used in the liquid state as casting materials, in sheet molding compounds, as fiberglass laminating resins and in non-metallic auto-body fillers. They are also used as the thermoset polymer matrix in pre-pregs. Fiberglass-reinforced unsaturated polyesters find wide application in bodies of yachts and as body parts of cars.
According to the composition of their main chain, polyesters can be:
|Aliphatic||Homopolymer||Polyglycolide or polyglycolic acid (PGA)||Polycondensation of glycolic acid|
|Polylactic acid (PLA)||Ring-opening polymerization of lactide|
|Polycaprolactone (PCL)||Ring-opening polymerization of caprolactone|
|Copolymer||Polyethylene adipate (PEA)|
|Polybutylene succinate (PBS)||Polycondensation of succinic acid with 1,4-butanediol|
|Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV)||Copolymerization of 3-hydroxybutanoic acid and 3-hydroxypentanoic acid,|
butyrolactone, and valerolactone (oligomeric aluminoxane as a catalyst)
|Semi-aromatic||Copolymer||Polyethylene terephthalate (PET)||Polycondensation of terephthalic acid with ethylene glycol|
|Polybutylene terephthalate (PBT)||Polycondensation of terephthalic acid with 1,4-butanediol|
|Polytrimethylene terephthalate (PTT)||Polycondensation of terephthalic acid with 1,3-propanediol|
|Polyethylene naphthalate (PEN)||Polycondensation of at least one naphthalene dicarboxylic acid with ethylene glycol|
|Aromatic||Copolymer||Vectran||Polycondensation of 4-hydroxybenzoic acid and 6-hydroxynaphthalene-2-carboxylic acid|
Fabrics woven or knitted from polyester thread or yarn are used extensively in apparel and home furnishings, from shirts and pants to jackets and hats, bed sheets, blankets, upholstered furniture and computer mouse mats. Industrial polyester fibers, yarns and ropes are used in car tire reinforcements, fabrics for conveyor belts, safety belts, coated fabrics and plastic reinforcements with high-energy absorption. Polyester fiber is used as cushioning and insulating material in pillows, comforters and upholstery padding. Polyester fabrics are highly stain-resistant—in fact, the only class of dyes which can be used to alter the color of polyester fabric are what are known as disperse dyes.
Polyesters are also used to make bottles, films, tarpaulin, canoes, liquid crystal displays, holograms, filters, dielectric film for capacitors, film insulation for wire and insulating tapes. Polyesters are widely used as a finish on high-quality wood products such as guitars, pianos and vehicle/yacht interiors. Thixotropic properties of spray-applicable polyesters make them ideal for use on open-grain timbers, as they can quickly fill wood grain, with a high-build film thickness per coat. Cured polyesters can be sanded and polished to a high-gloss, durable finish.
Polyester is a synthetic polymer made of purified terephthalic acid (PTA) or its dimethyl ester dimethyl terephthalate (DMT) and monoethylene glycol (MEG). With 18% market share of all plastic materials produced, it ranges third after polyethylene (33.5%) and polypropylene (19.5%).
The main raw materials are described as follows:
In 2008, about 10,000 tonnes Sb2O3 were used to produce around 49 million tonnes polyethylene terephthalate.
Polyester is described as follows:
There are several reasons for the importance of polyester:
In the following table, the estimated world polyester production is shown. Main applications are textile polyester, bottle polyester resin, film polyester mainly for packaging and specialty polyesters for engineering plastics. According to this table, the world's total polyester production might exceed 50 million tons per annum before the year 2010.
|Product type||2002 (million tonnes/year)||2008 (million tonnes/year)|
The raw materials PTA, DMT, and MEG are mainly produced by large chemical companies which are sometimes integrated down to the crude oil refinery where p-Xylene is the base material to produce PTA and liquefied petroleum gas (LPG) is the base material to produce MEG.
After the first stage of polymer production in the melt phase, the product stream divides into two different application areas which are mainly textile applications and packaging applications. In the following table, the main applications of textile and packaging of polyester are listed.
|Staple fiber (PSF)||Bottles for CSD, water, beer, juice, detergents, etc.|
|Filaments POY, DTY, FDY||A-PET film|
|Technical yarn and tire cord||Thermoforming|
|Non-woven and spunbond||biaxial-oriented film (BO-PET)|
A comparable small market segment (much less than 1 million tonnes/year) of polyester is used to produce engineering plastics and masterbatch.
In order to produce the polyester melt with a high efficiency, high-output processing steps like staple fiber (50–300 tonnes/day per spinning line) or POY /FDY (up to 600 tonnes/day split into about 10 spinning machines) are meanwhile more and more vertically integrated direct processes. This means the polymer melt is directly converted into the textile fibers or filaments without the common step of pelletizing. We are talking about full vertical integration when polyester is produced at one site starting from crude oil or distillation products in the chain oil → benzene → PX → PTA → PET melt → fiber/filament or bottle-grade resin. Such integrated processes are meanwhile established in more or less interrupted processes at one production site. Eastman Chemicals were the first to introduce the idea of closing the chain from PX to PET resin with their so-called INTEGREX process. The capacity of such vertically integrated production sites is >1000 tonnes/day and can easily reach 2500 tonnes/day.
Besides the above-mentioned large processing units to produce staple fiber or yarns, there are ten thousands of small and very small processing plants, so that one can estimate that polyester is processed and recycled in more than 10 000 plants around the globe. This is without counting all the companies involved in the supply industry, beginning with engineering and processing machines and ending with special additives, stabilizers and colors. This is a gigantic industry complex and it is still growing by 4–8% per year, depending on the world region.
Synthesis of polyesters is generally achieved by a polycondensation reaction. See "condensation reactions in polymer chemistry". The general equation for the reaction of a diol with a diacid is :
In this classical method, an alcohol and a carboxylic acid react to form a carboxylic ester. To assemble a polymer, the water formed by the reaction must be continually removed by azeotrope distillation.
Aliphatic polyesters can be assembled from lactones under very mild conditions, catalyzed anionically, cationically or metallorganically. A number of catalytic methods for the copolymerization of epoxides with cyclic anhydrides have also recently been shown to provide a wide array of functionalized polyesters, both saturated and unsaturated.
In 1926, United States-based E.I. du Pont de Nemours and Co. began research on large molecules and synthetic fibers. This early research, headed by W.H. Carothers, centered on what became nylon, which was the first synthetic fiber. Carothers was working for duPont at the time. Carother’s research was incomplete and had not advanced to investigating the polyester formed from mixing ethylene glycol and terephthalic acid. The project was revived by British scientists Whinfield and Dickson, who patented polyethylene terephthalate (PET) or PETE in 1941. Polyethylene terephthalate forms the basis for synthetic fibers like Dacron, Terylene and polyester. In 1946, duPont bought all legal rights from Imperial Chemical Industries (ICI).
Unsaturated polyesters are thermosetting resins. They are generally copolymers prepared by polymerizing one or more diol with saturated and unsaturated dicarboxylic acids (maleic acid, fumaric acid...) or their anhydrides. The double bond of unsaturated polyesters reacts with a vinyl monomer, usually styrene, resulting in a 3-D cross-linked structure. This structure acts as a thermoset. The exothermic cross-linking reaction is initiated through a catalyst, usually an organic peroxide such as methyl ethyl ketone peroxide or benzoyl peroxide.
A team at Plymouth University in the UK spent 12 months analysing what happened when a number of synthetic materials were washed at different temperatures in domestic washing machines, using different combinations of detergents, to quantify the microfibres shed. They found that an average washing load of 6 kg could release an estimated 137,951 fibres from polyester-cotton blend fabric, 496,030 fibres from polyester and 728,789 from acrylic. Those fibers add to the general microplastics pollution.
Polyester is a synthetic petroleum-based fibre, and is therefore a non-renewable carbon-intensive resource. Nearly 70 million barrels of oil are used each year to make polyester around the world, which is now the most commonly used fiber in making clothes. But it takes more than 200 years to decompose.
BoPET (biaxially-oriented polyethylene terephthalate) is a polyester film made from stretched polyethylene terephthalate (PET) and is used for its high tensile strength, chemical and dimensional stability, transparency, reflectivity, gas and aroma barrier properties, and electrical insulation.
A variety of companies manufacture boPET and other polyester films under different brand names. In the UK and US, the most well-known trade names are Mylar, Melinex, and Hostaphan.Calendering (textiles)
Calendering of textiles is a finishing process used to smooth, coat, or thin a material. With textiles, fabric is passed between calender rollers at high temperatures and pressures. Calendering is used on fabrics such as moire to produce its watered effect and also on cambric and some types of sateens.
In preparation for calendering, the fabric is folded lengthwise with the front side, or face, inside, and stitched together along the edges. The fabric can be folded together at full width, however this is not done as often as it is more difficult. The fabric is then run through rollers that polish the surface and make the fabric smoother and more lustrous. High temperatures and pressure are used as well. Fabrics that go through the calendering process feel thin, glossy and papery.The wash durability of a calendared finish on thermoplastic fibers like polyester is higher than on cellulose fibers such as cotton. On blended fabrics such as Polyester/Cotton the durability depends largely on the proportion of synthetic fiber component present as well as the amount and type of finishing additives used and the machinery and process conditions employed.Charmeuse
Charmeuse (French: [ʃaʁmøːz]) is a lightweight fabric woven with a satin weave, in which the warp threads cross over four or more of the backing (weft) threads. These float threads give the front of the fabric a smooth, reflective finish, whereas the back has a dull finish. It can be made of silk or a synthetic lookalike such as polyester. Silk charmeuse is more expensive and delicate but is softer and a better insulator. Polyester charmeuse is cheaper and can often withstand machine washing, but it does not breathe as well as silk. Charmeuse differs from plain satin in that charmeuse has a different ratio of float (face) threads.
The luster and delicate hand make charmeuse suited to lingerie, flowing evening gowns, and draped blouses. Bridal gowns sometimes use charmeuse; however, the fabric does not hold a shape well, so it is not used for full, flared skirts; the charmeuse tends to cling and hang against the body. It is best suited to a more fluid, slinky bias cut, and drapes well.
Its uses in menswear include the lining of jackets and slacks, handkerchiefs, ties, and underwear such as charmeuse boxer shorts.
When woven from polyester it can be a challenging fabric to sew; it tends to be slippery and may be difficult to control through the presser foot of a sewing machine. Seams have a tendency to pucker and pull; a smaller stitch length and properly balanced tensions can minimize this, though the experience of the sewer will affect the finished result as well. Pins can make holes and marks in polyester charmeuse so it is very important to use proper, sharp dressmaker's pins with a smooth, not abrupt, taper to the point. For greater ease of sewing, a sizing product can be sprayed on before cutting and washed out after the garment is completed.
The look of satin is prized for dressy garments, especially when cut on the bias, since it flows well on the body and catches light in stunning patterns.Colletidae
The Colletidae are a family of bees, and are often referred to collectively as plasterer bees or polyester bees, due to the method of smoothing the walls of their nest cells with secretions applied with their mouthparts; these secretions dry into a cellophane-like lining. The five subfamilies, 54 genera, and over 2000 species are all evidently solitary, though many nest in aggregations. Two of the subfamilies, Euryglossinae and Hylaeinae, lack the external pollen-carrying apparatus (the scopa) that otherwise characterizes most bees, and instead carry the pollen in their crops. These groups, and most genera in this family, have liquid or semiliquid pollen masses on which the larvae develop.
They can be found all over the world, but the most species live in South America and Australia. Over 50% of all bee species living in Australia belong to this family. Only the genera Colletes and Hylaeus can be found in Europe, while in North America, in addition to these two, the genera Caupolicana, Eulonchopria, and Ptiloglossa are found.
Australian genera include Euhesma, a large genus, members of which has been split off into other genera such as Euryglossa and Callohesma.Traditionally, this family is believed to be likely the most "primitive" among extant bees, based primarily on the similarities of their mouthparts (the unique possession among bees of a bilobed glossa) to those of Crabronidae (the putative ancestors of bees), but recent molecular studies have disproved this hypothesis, placing the Melittidae (sensu lato) as the basal group of bees.Coolmax
Coolmax is the brand name for a series of polyester fabrics developed and marketed by Invista (formerly Dupont Textiles and Interiors).
Coolmax is marketed as "moisture-wicking" and "breathable". As a polyester, it is moderately hydrophobic, so it absorbs little fluid and dries relatively quickly (compared to absorbent fibers such as cotton). The cross-section is non-round, increasing surface area by an estimated 20% (over round fibers) in order to produce a wicking effect via capillary action.Invista makes extensive use of co-branding in their marketing of Coolmax and other clothing materials, partnering with their customers to increase awareness of their product among end consumers.Like other polyester fabrics, Coolmax is flammable and has a relatively low melting point (~255 °C), giving clothes made from it a tendency to melt and fuse to the wearer's skin when exposed to high heat. This has led to Coolmax and other polyesters (along with acrylic and rayon) being restricted or banned in certain high-fire-risk applications, such as firefighting and front-line combat.Decatising
Decatising or decatizing, also known as crabbing, blowing, and decating, is the process of making permanent a textile finish on a cloth, so that it does not shrink during garment making. The word comes from the French décatir, which means to remove the cati or finish of the wool. Though used mainly for wool, the term is also applied to processes performed on fabrics of other fibers, such as cotton, linen or polyester. Crabbing and blowing are minor variations on the general process for wool, which is to roll the cloth onto a roller and blow steam through it.
Decatized wool fabric is interleaved with a cotton, polyester/cotton or polyester fabric and rolled up onto a perforated decatizing drum under controlled tension. The fabric is steamed for up to ten minutes and then cooled down by drawing ambient air through the fabric roll. The piece is then reversed and steamed again in order to ensure that an even treatment is achieved.
There are several quite different types of wool decatizing machines including batch decatizing machines, continuous decatizing machines, wet decatising machines and dry decatizing machines.Film base
A film base is a transparent substrate which acts as a support medium for the photosensitive emulsion that lies atop it. Despite the numerous layers and coatings associated with the emulsion layer, the base generally accounts for the vast majority of the thickness of any given film stock. Historically there have been three major types of film base in use: nitrocellulose (cellulose nitrate), cellulose acetate (cellulose triacetate, cellulose diacetate, cellulose acetate propionate, and cellulose acetate butyrate), and polyester (polyethylene terephthalate (PET) (Kodak trade-name: ESTAR)).Long underwear
Long underwear, also called long johns or thermal underwear, is a style of two-piece underwear with long legs and long sleeves that is normally worn during cold weather. It is commonly worn by people under their clothes in cold countries.
In the United States, it is usually made from a cotton or cotton-polyester-blend fabric with a box-weave texture, although some varieties are also made from flannel, particularly the union suit, while many newer varieties are made from polyester, such as the Capilene trade name.
European manufacturers use wool blends or even 100% wool, usually Merino or other high-quality wool. Some models might include a thin layer of polyester to transport moisture away from the skin. Wool, in addition to being fire retardant, provides highly effective insulation and will keep its insulating properties even when wet, as opposed to cotton.
The type known as "thermal underwear" is made from two-ply fabric of either a wool layer and an artificial fibre, only wool or – again mostly in the U.S. – two layers of only artificial fibres, which uses trapped body heat to insulate against cold air.Microfiber
Microfiber (or microfibre) is synthetic fiber finer than one denier or decitex/thread, having a diameter of less than ten micrometres. This is smaller than the diameter of a strand of silk (which is approximately one denier), which is itself about 1/5 the diameter of a human hair. The most common types of microfibers are made from polyesters, polyamides (e.g., nylon, Kevlar, Nomex, trogamide), or a conjugation of polyester, polyamide, and polypropylene. Microfiber is used to make mats, knits, and weaves for apparel, upholstery, industrial filters, and cleaning products. The shape, size, and combinations of synthetic fibers are selected for specific characteristics, including softness, toughness, absorption, water repellency, electrostatics, and filtering capabilities.PET bottle recycling
Bottles made of polyethylene terephthalate (PET, sometimes PETE) can be used to make lower grade products, such as carpets. To make a food grade plastic, the bottles need to be hydrolysed down to monomers, which are purified and then re-polymerised to make new PET.
In many countries, PET plastics are coded with the resin identification code number "1" inside the universal recycling symbol, usually located on the bottom of the container.Photograph
A photograph is an image created by light falling on a photosensitive surface. The word photograph was coined in 1839 by Sir John Herschel and is based on the Greek φῶς (phos), meaning "light," and γραφή (graphê), meaning "drawing, writing," together meaning "drawing with light."Polar fleece
Polar fleece is a soft napped insulating fabric made from polyester.Polyester (film)
Polyester is a 1981 American black comedy film directed, produced, and written by John Waters, and starring Divine, Tab Hunter, Edith Massey, and Mink Stole. It was filmed in Waters' native Baltimore, Maryland, and features a gimmick called "Odorama", whereby viewers can smell what they see on screen using scratch and sniff cards.
The film is a satirical look at suburban life in the early 1980s involving divorce, abortion, adultery, alcoholism, foot fetishism, and the religious right.Polyester resin
Polyester resins are unsaturated synthetic resins formed by the reaction of dibasic organic acids and polyhydric alcohols. Maleic Anhydride is a commonly used raw material with diacid functionality. Polyester resins are used in sheet moulding compound, bulk moulding compound and the toner of laser printers. Wall panels fabricated from polyester resins reinforced with fiberglass—so-called fiberglass reinforced plastic (FRP)—are typically used in restaurants, kitchens, restrooms and other areas that require washable low-maintenance walls. They are also used extensively in cured-in-place pipe applications. Departments of Transportation in the USA also specify them for use as overlays on roads and bridges. In this application they are known as PCO Polyester Concrete Overlays. These are usually based on isophthalic acid and cut with styrene at high levels—usually up to 50%. Polyesters are also used in anchor bolt adhesives though epoxy based materials are also used. Many companies have and continue to introduce styrene free systems mainly due to odor issues.Polyethylene terephthalate
Polyethylene terephthalate (sometimes written poly(ethylene terephthalate)), commonly abbreviated PET, PETE, or the obsolete PETP or PET-P, is the most common thermoplastic polymer resin of the polyester family and is used in fibres for clothing, containers for liquids and foods, thermoforming for manufacturing, and in combination with glass fibre for engineering resins.
It may also be referred to by the brand names Terylene in the UK, Lavsan in Russia and the former Soviet Union, and Dacron in the US.
The majority of the world's PET production is for synthetic fibres (in excess of 60%), with bottle production accounting for about 30% of global demand. In the context of textile applications, PET is referred to by its common name, polyester, whereas the acronym PET is generally used in relation to packaging. Polyester makes up about 18% of world polymer production and is the fourth-most-produced polymer after polyethylene (PE), polypropylene (PP) and polyvinyl chloride (PVC).
PET consists of polymerized units of the monomer ethylene terephthalate, with repeating (C10H8O4) units. PET is commonly recycled, and has the number "1" as its resin identification code (RIC).
Depending on its processing and thermal history, polyethylene terephthalate may exist both as an amorphous (transparent) and as a semi-crystalline polymer. The semicrystalline material might appear transparent (particle size less than 500 nm) or opaque and white (particle size up to a few micrometers) depending on its crystal structure and particle size.
The monomer bis(2-hydroxyethyl) terephthalate can be synthesized by the esterification reaction between terephthalic acid and ethylene glycol with water as a byproduct, or by transesterification reaction between ethylene glycol and dimethyl terephthalate (DMT) with methanol as a byproduct. Polymerization is through a polycondensation reaction of the monomers (done immediately after esterification/transesterification) with water as the byproduct.Sponge (tool)
A sponge is a tool or cleaning aid made of soft, porous material. Typically used for cleaning impervious surfaces, sponges are especially good at absorbing water and water-based solutions.
Originally made from natural sea sponges, they are most commonly made from synthetic materials today.Tulle (netting)
Tulle ( TOOL) is a lightweight, very fine, stiff netting. It can be made of various fibres, including silk, nylon, polyester and rayon. Polyester is the most common fibre used for tulle. Rayon tulle is very rare. Tulle is most commonly used for veils, gowns (particularly wedding gowns), and ballet tutus. Tulle comes in a wide array of colors and it is readily available. It can be dyed at home if it is made from nylon, rayon or silk but not if it's made from polyester.
The name comes from Tulle, a city in the southern central region of France. Tulle was well known as a center of lace and silk production in the 18th century, and early tulle netting probably originated in this French city. Tulle netting certainly appeared earlier in Parisian ballet costume than in most other nations, suggesting that tulle netting may have been more readily available there than elsewhere.
One of the most common uses for tulle netting is in garments. Tulle is often used as an accent, to create a lacy, floating look. Tulle may also be used in underskirts or petticoats to create a stiff belled shape. Gowns are often puffed out with the use of several layers of stiff tulle. Tulle netting is also used to make veils, since it obscures the features of the face while allowing the wearer to see out.Decorative ornaments can also be made from tulle netting. It is frequently used to wrap up party favors and gifts, especially for weddings and baby showers. Scraps of tulle netting are sometimes used in quilting and crafts as well, to add texture to a project. Multicolored tulle netting is often used for this purpose, to create tulle flowers and other ornamental accents.Velour
Velour or velours is a plush, knitted fabric or textile similar to velvet or velveteen. It is usually made from cotton, but can also be made from synthetic materials such as polyester. Velour is used in a wide variety of applications, including clothing and upholstery. Other examples include car seats, leotards and robes. This means that it can be useful in many occasions.
Velour can also refer to a rough natural leather sometimes called velour leather. Chrome tanned leather is ground from the inside, which forms a delicate, soft layer on the surface. It is used for footwear, clothing, and upholstery. This type of leather is often confused with velvet suede and chamois.Vinyl coated polyester
Vinyl coated polyester is a material frequently used for flexible fabric structures. It is made up of a polyester scrim, a bonding or adhesive agent, and an exterior PVC coating. The scrim supports the coating (which is initially applied in liquid form) and provides the tensile strength, elongation, tear strength, and dimensional stability of the resulting fabric.
Depending on its formula, the PVC coating makes the material waterproof and resistant to dirt, mildew, oil, salt, chemicals and UV rays and gives the material added strength and durability. It can be sewn or heat sealed by way of RF(Radio Frequency) welding or hot-air welding.The base fabric's tensile strength is determined by the size (denier) and strength of the yarns and the number of yarns per linear distance. The larger the yarn and the more yarns per inch, the greater the finished product's tensile strength.
The adhesive agent acts as a chemical bond between the polyester fibers and the exterior coating and prevents fibers from wicking, or absorbing water into the scrim. This prevents damage caused by absorbed water during a freeze thaw cycle.
The PVC coating (vinyl Organisol or Plastisol) contains chemicals to achieve the desired color, water, mildew resistance, and flame retardancy. Fabric can also be manufactured with levels of light transmission that range from very transparent to completely opaque. After the coating has been applied to the scrim, the fabric is put through a heating chamber that dries the liquid coating.
|Environment and health|
Clothing materials and parts
|Animal hides / Leather|