Polyester fibers specific materials

In much the same way, natural polymeric fibers like wool, cotton, silk, etc., are often touted as superior to anything that is man-made or synthetic. But is this fair There is no doubt that natural fibers have a unique set of properties that have withstood the test of time (e.g., it is difficult, but not impossible, to match silk s feel or cotton s ability to breathe ). On the other hand, consider Lycra , a completely synthetic fiber produced by DuPont (Figure 1-12) that has a truly amazing set of properties and is the major component of Spandex (a material that keeps string bikinis on ). Or consider the wrinkle-free polyester fibers used in clothing and the stain proof nylon and polyacrylonitrile polymers used in carpets. The point here is that polymers, be they natural" or synthetic, are all macromolecules but with different chemical structures. The challenge is to design polymers that have specific properties that can benefit mankind. 

A local company, Griffin Manufacturing, produces a line of jog bras. These items are made from mixed fiber fabric that includes between 10 and 15% Lycra spandex blended with cotton and polyester. The complexity of the product contributes to the production of a large volume of landfilled remnants. The company landfilled an estimate of at least six tons of this specific material per month in addition to other fabric types. That volume had doubled in the last few years and was expected to grow. 

The greatest increase in synthetic fiber materials has been an increase in the polyesters, which now account for almost two-thirds of total synthetic fiber production. It must be remembered that terms such as polyester and polyamide refer to broad classes of compounds and not to specific materials. Each class contains untold thousands of possible variations in molecular structure, both from the chemical identity of the monomers used and from the order in which they react during polymerization. 

The white cell adsorption filter layer is typically of a nonwoven fiber design. The biomaterials of the fiber media are surface modified to obtain an optimal avidity and selectivity for the different blood cells. Materials used include polyesters, eg, poly(ethylene terephthalate) and poly(butylene terephthalate), cellulose acetate, methacrylate, polyamides, and polyacrylonitrile. Filter materials are not cell specific and do not provide for specific filtration of lymphocytes out of the blood product rather than all leukocytes. 

Sulfur dyes are used mainly for dyeing textile ceUulosic materials or blends of ceUulosic fibers (qv) with synthetic fibers such as acryUc fibers, polyamides (nylons), and polyesters. They are also used for sHk (qv) and paper (qv) in limited quantities for specific appHcations. Solubilized sulfur dyes are used on certain types of leathers (qv). 

Epoxy, polyester, phenolic and other resins are used as coatings and linings with or without reinforcement. Glass fiber, silica, carbon and many other materials can be used as filters or reinforcement to produce materials with specific properties of strength, flexibility, wear resistance and electrical conductivity. 

Historically, polyanhydrides were developed in the textile industry during the first half of the 20th century as alternate fiber materials. " However, the modern polyanhydrides that are currently under investigation as drug delivery platforms represent a novel class of polymer that, unlike the polyesters, has been specifically developed for biodegradable applications. In particular, these polyanhydrides were specifically prepared in attempts to produce surface-eroding dosage forms. 

Like many other industries, the challenges facing the retail industry are associated with three environmental aspects. The first is the continued access to and availability of material resources used for products and the function of the business. These resources include the materials used to build stores and warehouses, the fuel needed by global logistic networks, and necessary utilities such as gas and water. Of specific importance are the resources used for extraction or production of raw materials such as cotton, polyester, and animal fibers, as well as the resources needed for conversion of those materials into finished product, such as spinning, weaving, and coloration. 

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