Polyurethane garments

In the CSIRO process, a reactive polyurethane prepolymer is appHed to a garment from perchloroethylene. The garment is then pressed and subsequendy steamed in an oven. A second polymer may sometimes be used in conjunction with the prepolymer. When this is employed, the process is termed the Serolan BAP Process (178). A number of alternative treatments are being investigated to achieve finishes that are more environmentally friendly (179). 

Another widespread use of polyurethane elastic fibers is in disposable diapers and adult incontinence garments. Elastic strands are incorporated into waistbands and side panels made of non-woven fabrics where they improve fit and reduce leakage. 

Motor Cycling. One- or two-piece protective suits normally are made from fabric-supported flexible vinyl or from polyurethane materials. A typical garment would be sewn but with welds over the seams to ensure that it is waterproof. With polyurethane, welding alone often is quite satisfactory. In some parts of the garments, patches are over-welded as re-inforcement. 

The second widely used method for preparing polyurethane foam laminates is the liquid adhesive, or wet process. Here special adhesives, either in the form of water solutions, or as solutions in organic solvents, are applied to either the fabric or the foam. The equipment is conventional. The water or solvent is evaporated, and the bond may be set by drying or curing at elevated temperature (20). One of the adhesives used for this application is based on acrylic interpolymer latices. This adhesive is used in the manufacture of thermal garments and insulated bags. Carpet underlay can also be made by adhesive laminating (7). 

One particular form of thermoplastic polyurethane elastomer is the elastic fiber known as Spandex. Several commercial materials of this type have been introduced, which include Lycra (Du Pont), Dorlastan (Bayer) Spanzelle (Courtaulds), and Vyrene (U.S. Rubber). Spandex fibers have higher modulus, tensile strength, and resistance to oxidation, and are able to produce finer deniers than natural rubber. They have enabled lighter-weight garments to be produced. Staple fiber blends of Spandex fiber with non-elastic fibers have also been introduced. 

Adhesives in relation to coated fabrics can be thought of as either the tie-coat to bond the surface coating to the fabric, or the surface coating itself, directly bonded to the fabric. The types of polymers used in coating fabrics are rubbers, PVC, polyurethane, acrylics and silicones the coatings are usually cross-linked to increase durability but some topcoats can be thermoplastic, for example polyurethanes, to facilitate thermal bonding of seams in production of garments or other articles. 

These have become commercially important as a means of obtaining a flexible membrane of controlled water-vapour permeability which finds applications as a replacement for leather, laminates for waterproof garments and various medical uses. Polyurethanes are superior to other plastics and rubbers due to their following combination of properties ... 

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