Foams abrasion resistant

Cellular mbber has been used extensively as shoe soles, where its combination of cushioning abiUty and wear resistance, coupled with desirable economics, has led to very wide acceptance. In this case the cushioning properties are of minor importance compared with the abrasion resistance and cost. Other significant cushioning appHcations for cellular mbbers and latex foam mbbers are as carpet underlay and as cushion padding ia athletic equipment. 

Properties. Polyurethane elastomers generally exhibit good resiHence and low temperature properties, excellent abrasion resistance, moderate solvent resistance, and poor hydrolytic stabiHty and poor high temperature resistance. As castable mbber, polyurethanes enjoy a variety of uses, eg, footwear, toys, soHd tires, and foam mbber. 

Polyurethanes. This material is available in three forms - rigid foam, flexible foam and elastomer. They are characterised by high strength and good chemical and abrasion resistance. The rigid foam is widely used as an insulation material, the flexible foam is an excellent cushion material for furniture and the elastomeric material is used in solid tyres and shock absorbers. 

Two-pack polyurethanes Also called urethanes, these materials are similar to two-pack epoxies in that they can be formulated to provide different properties. They can be made into foams or soft, rubbery materials, as well as very hard, tough, abrasion-resistant coatings. 

Polyurethane foams are widely used. Rigid foams, for example, are used in cavity wall insulation in buildings, while flexible foams have, until recently, been used in soft furnishing for domestic use. They continue to be used in car seating. In addition to foams another major use of polyurethanes is in surface coatings. A variety of polyurethane-based polymers, some of considerable complexity, are used for this purpose, but all share the common desirable features of toughness, flexibility, and abrasion resistance. 

Another major use for semi-rigid polyurethane foams is as shoe soles. In this application, their light weight, abrasion resistance, and shock absorbing properties are important. In safety shoes, chemical and oil resistance are important. Polyether-based foams are used in applications where microbial attack is common, such as shoes intended primarily for use on soil or grass. 

Elastomers resulting from a series of organic reactions, e.g., a polyglycol ester of adipic acid reacted with an aromatic diisocyanate and cured with water, glycol or further reaction with an aromatic diisocyanate. These elastomers have high tensile strength, very high abrasion resistance, and lower hysteresis than natural rubber. A major use is in the manufacture of foamed polymers. 

Four major forms used fibers—swimsuits, foundation garments elastomers— industrial wheels, heel lifts coatings— floors where impact and abrasion resistance are required, bowling pins foams—pillows, cushions... 

EVA reins can be conveniently crosslinked by both peroxide or irradiation to enhance the mechanical properties and the heat resistance. It is the crosslinking, coupled with the inherent rubbery nature of the polymer, which makes EVA suitable for production of tough and abrasion resistant foams, especially suitable for footwear applications. Crosslinked EVA foams can be manufactured by two methods (8) ... 

It is important at this point to give due consideration to the various ways in which a plastics material may be applied. 1. The material may be strengthened with additives to afford specialized properties such as hardness, abrasion resistance, lubricity or tensile strength. 2. The material may be extended either by fillers or by foaming (that is, filling with air) to overcome perceived economic... 

PEs provide many unusual properties to the cellular plastics industry. These foams are tough, flexible and chemical and abrasion resistant. They are known to have superior electrical and thermal insulation properties. Their mechanical properties are intermediate between rigid and highly flexible foams. Densities are 2 lb/ft3 and higher, approaching that of the solid plastics. The highly expanded polyolefin foams are potentially the least expensive of the cellular plastics. However, they require expensive processing techniques and for this... 

Other important products include radiation cross-linked foamed polyethylene which is used for thermal insulation, floor mats, crash padding, floating jackets, and wood/plastic composites cured by gamma irradiation. These have been used successfully for flooring in places such as department stores, airports, hotels, and churches where their excellent abrasion resistance, the beauty of the natural grain, and low maintenance costs are important. This latter technique is also being used in the conservation of objects made of stone and wood of interest to our cultural heritage. 

Cellular polyolefins contribute many unusual properties to the cellular plastics industry. These foams are tough, flexible and chemical and abrasion resistant. They ate known to have superior electrical and... 

An example system is PVC and polyethylene wire and cabling irradiated to improve stresscracking resistance, abrasion resistance, high-temperature properties and flame retardance, via controlled electron-beam crosslinking (Loan, 1977). Additionally electron-beam crosslinking is utilized to impart memory into a polymer system, such as crosslinked PE materials for heat-shrinkable films and pipe applications (Baird, 1977). The control of electron-beam processing has advanced the quality of cell size and shape of PE foams via control of crosslink distribution (Paterson, 1984). 

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