Polyethylene terephthalate Fabrics

The primary substrates or support iaclude many types of paper and paperboard, polymer films such as polyethylene terephthalate, metal foils, woven and nonwoven fabrics, fibers, and metal cods. Although the coating process is better suited to continuous webs than to short iadividual sheets, it does work very well for intermittent coating, such as ia the printing process. In general, there is an ideal coater arrangement for any given product. 

Perhaps the most important polyester is polyethylene terephthalate), commonly known as PET (or PETE 1 on plastic beverage bottles). The annual production of PET in the United States is of the order of 108 kg (105 metric tons). Much of this is converted into fabric (trade name, Dacron) or magnetically coated film (Mylar). 

Polyesters, which are a class of engineering thermoplastics, are found in a wide variety of applications including carbonated drink bottles, fibers for synthetic fabrics, thin films for photographic films and food packaging, injection molded automotive parts, and housings for small appliances. In this chapter, we svill explore the synthesis of this class of polymers. We will also look at the typical properties and end uses for the most common of these resins, polyethylene terephthalate and polybutylene terephthalate, which are commonly known as PET and PBT, respectively. 

The most important polyester is polyethylene terephthalate (PET), which has mariy uses, from fabrics to milk bottles. The polymerization reaction between ethylene glycol (EG) and terephthahc acid (TPA),... 

Chemically, Dacron and Mylar are polymers made from a ring structure called dimethyl terephthalate and ethylene glycol (HO-CH2CH2-OH). The polymer unit is called polyethylene terephthalate, or PET. Dacron fiber is used in tires and fabrics, and is even used to repair blood vessels. Mylar is used in magnetic recording tape. In the 1960s, it was used in huge balloons that were sent into orbit around Earth. Plastic soda containers are made of PET. 

The first really successful artificial material used in the manufacture of synthetic blood vessels was Dacron , a polyester fiber made from polyethylene terephthalate (PET). The material is woven or knitted into thin tubes with dimensions similar to those of a natural blood vessel. The tubes are then treated with coagulated blood or with albumin, an important blood protein, to block the tiny holes in the fabric of which they are made. Over time, cells migrate into the blood or albumin trapped within the Dacron matrix and deposit collagen. As the blood or albumin degrades, it is replaced by the collagen, producing a vessel with some properties similar to those of natural blood vessels. 

The micro devices were fabricated from a polyethylene terephthalate (PET) substrate using 193 nm ArF excimer laser ablation [59], Microstructures produced in this way were thermally sealed by a lamination machine. 

Ablation using radiations of various wavelengths (IR, visible, UV, or x-ray) has been employed to fabricate plastic chips. For instance, photoablation using pulsed UV lasers (193 nm) has been used to fabricate plastic chips out of polyethylene terephthalate (PET, 100 pm thick) [189,190, 258,758] and polycarbonate (PC, 125 pm thick) [189,258]. Channels as narrow as 30 pm and as deep as 100 pm can be made [258,758]. The cross section of a photoablated PET channel plate laminated with another PET using a thin PE adhesive layer was shown in Figure 2.20 [191]. 

Vinylidene Chloride Copolymer Latex. Vinylidene chloride polymers are often made in emulsion, but usually are isolated, dried, and used as conventional resins. Stable latices have been prepared and can be used diiecdy for coatings (171—176). The principal applications for these materials are as barrier coatings on paper products and, more recently, on plastic films. The heat-seal characteristics of VDC copolymer coatings are equally valuable in many applications. They are also used as binders for paints and nonwoven fabrics (177). The use of special VDC copolymer latices for barrier laminating adhesives is growing, and the use of vinylidene chloride copolymers in flame-resistant carpet backing is well known (178—181). VDC latices can also be used to coat polyethylene terephthalate) (PET) bottles to retain carbon dioxide (182). 

Dacron fiber is used to make fabric and tire cord, and Mylar film is used to make magnetic recording tape. Mylar film is strong, flexible, and resistant to ultraviolet degradation. Aluminized Mylar was used to make the Echo satellites, huge balloons that were put into orbit around the Earth as giant reflectors in the early 1960s. Polyethylene terephthalate) is also blow-molded to make plastic soft-drink bottles that are sold by the billions each year. 

The butyrate or octanoate copolymer and butyrate or hexanoate or decanoate terpolymer have properties similar to those of higher-grade LLDPE (linear low-density polyethylene) and higher-grade PET (polyethylene terephthalate). They can be molded or converted into films, fibers, and nonwoven fabrics. The biopolymer is produced by low-cost fermentation or from wastestream substrates. 

All rubbers, glasses, and plastics are polymers. You are probably familiar with natural polymers like cellulose (the building block of plant fibers) and synthetic polymers like polyethylene (plastic milk cartons), polyisoprene (automobile tires), polyethylene terephthalate (soft drink bottles), polymethyl methacrylate (Plexiglas ), polyvinylidene chloride (transparent plastic wrap), polytetrafluoroethylene (Teflon ), and various polyesters (fabrics). Polyvinyl chloride, the polymer shown earlier, is used to make rigid pipes, house siding, and protective coverings for automobile seals and dashboards, among many other applications. 

An alternative method is to dissolve away the fabric substrate and leave the coating behind. Nylon can be dissolved in cold meta-cresol in about 1 min, or 90%v/v formic acid. Polyester (polyethylene terephthalate) will dissolve in hot meta-cresol, but PVC may also be affected. Alternatives are ort/zo-cresol and chloroform or ort/zo-chlorophenol. 

Figure 15.13 Analysis of synthetic polymers, using new and aged polyester fabric (after Swiss Federal Laboratories for Materials Testing and Research, St. Galien). Conditions sample, polyethylene terephthalate dissolved in hexafluoroisopropa-nol columns,fourcolumns25cm x 7 mm i.d. stationary phases, HibarLiChrogel PS 1, PS 20, PS 400, and PS 4000 in series, 10[im mobile phase, Imlrnin" chloroform-hexafluoroisopropanol (98 2) temperature, 35 °C UV detector, 254 nm.

The concept of polymeric soil release agents has been around for well over 25 years. The initial polymer chemistries (polyethylene terephthalate-polyoxyethylene terephthalate, PET-POET) were designed to deposit on fabrics and facilitate oily soil removal upon subsequent washing [98,133,134], The limitation of this chemistry was its effectiveness on synthetics (polyester) alone, with limited benefits being observed on cotton and synthetic blends. In recent years the focus has shifted to delivering soil release on cotton. Two classes of polymer chemistries have been disclosed in the recent patent literature for cotton soil release one based on hydrophobically modified polycarboxylates derived from acrylic acid and hydrophobic comonomers at defined molar ratios [188] and the other based on modified polyamines [189-193],... 

The reaction of polyethylene terephthalate) (PET) with diethanolamine, followed by propoxylation, gives liquid amidic polyols useful in rigid PU foam fabrication. This method is an efficient variant of PET waste chemical recovery (bottles, x-ray films, fibres and so on) [1]. 

Plastics make up only about 8 percent of the volume in the average landfill but represent a huge investment of energy and raw materials. Most plastics produced from petroleum materials by polymerization of monomers such as ethylene or vinyl chloride are thermoplastic materials and can be cleaned, melted, and re-formed. Thermosetting plastics can also be cut into pieces that are mixed with other plastics or used as fillers. High-density polyethylene (HDPE) and polyethylene terephthalate (PETE) are the most widely reused plastic materials, but polyvinyl chloride (PVC), polypropylene, and polystyrene account for 5 percent of the recycled plastics. In 2001 80 million pounds (36 milfion kilograms) of plastics were recycled in the United States. Recycled plastic materials are used in the production of bottles, fabrics, flowerpots, furniture, plastic lumber, injection molded crates, and automobile parts. 

For polymer materials, the relatively poor temperatme tolerance is a severe problem that hinders their applications. Common polymer substrates, such as polyethylene and polyethylene terephthalate can only withstand a maximal temperature of 80 and 150"C, respectively. They are obviously too low for high-temperature fabrication methods, such as chemical vapor deposition and thermal annealing. This dilemma is currently compromised by conducting a transfer process where the devices are first fabricated at high... 

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