Coating wire and cable

In this chapter we have introduced the basic principles underlying polymer extrusion. As we have seen, extruders have t vo primary purposes they convert polymer granules into a homogeneous molten stream that is pumped to a forming device. The forming devices can take many forms to make a wide variety of continuous products. Among the continuous products made by extrusion are films, pipes, and fibers, which are used in all manner of products that make modern life more convenient and comfortable. Each of the processes that we have described has multiple variants, both major and minor. In each of the sections 

---

The aryloxyphosphazene polymers, on the other hand, have been used primarily ia wire and cable coatings and jackets and as fire-resistant, low smoke, closed-ceU foams and sound-barrier sheets. 

High elasticity is also not utilised in the main application of chlorosulphonated polyethylenes, in wire and cable coating, which consume about 40% of output. The combination of heat and oil resistance has led to widespread use as sheathing for nuclear power cables, offshore oil rig cables and in diesel electric locomotives. Other uses include chemical plant hose, spark plug boots and as a base for flexible magnetic strips. 

The main use of ethylene-propylene rubber is to produce automotive parts such as gaskets, mechanical goods, wire, and cable coating. It may also be used to produce tires. 

For films, sheets, tubes, wire and cable coatings, fibres, mass production of household requisites, bottle racks, bins, containers, pallets, tubes, prostheses, antifriction parts. .. 

CPE has been used successfully in under-the-hood wire and cable-coating applications such as flex cord jackets, heater cords, jackets for industrial cables and radiation crosslink-able speciality cables. 

This technique is commonly used for wire and cable coating. 

Typical HDPE—blow-molded products bottles, cans, trays, drums, tanks, and pails injection-molded products housewares, toys, food containers, cases, pails, and crates films, pipes, bags, conduit, wire and cable coating, foam, insulation for coaxial and communication cables... 

Vehicle building (automotive plastics and composites, wiring and cable coatings, and paints, electronics, adhesives, and fuel cells) and automotive refinishing... 

Flexible Applications. The mainstay of the lead stabilizers in the United States is in flexible wire and cable coating applications. The nonconductive nature of lead stabilizers is unsurpassed by other classes of stabilizers. Rather high levels of stabilizers are necessary for these uses because... 

HDPE pipes are used for transporting water, sewer wastes, and gas they are also widely used in the chemical industry. Other significant applications include wire and cable coatings, foam, insulation for coaxial and communication cables, as well as those areas where high resistance to oil and chemicals is desirable. 

LLDPE is also widely used for wire and cable coating in electrical and telephone industry, which amounts to 2.5% of LLDPE production. 

Polypropylenes are available as molding powder, extruded sheet, cast film, textile staple, and continuous-filament yarn. They find use in packaging film molded parts for automobiles, appliances, and housewares wire and cable coating food container closures bottles, printing plates carpet and upholstery fibers storage battery cases crates for soft-drink bottles laboratory ware trays fish nets surgical casts and a variety of other applications. 

Wire and cable coating dies are used in the extrusion process for primary insulation of single conducting wires as well as the jacketing or sheathing of a group of wires already insulated electrically, for mechanical strength and environmental protection purposes. 

Two types of cross-head dies are used for wire and cable coating. The first type is an annular flow or tubing die, where a thin-walled tube is extruded and the molten tube drawn onto the conductor by vacuum after it leaves the die. The vacuum is applied through the clearance between the conductor and the guide, which is usually of the order of 0.2 mm. Tubing dies are commonly used for jacketing cables or coating very thin wires with polymer melts that are very viscous. 

Triorganotin compounds have also been used experimentally in controlled-release formulations to control the infective snail vector in the debilitating tropical disease schistosomiasis (bilharzia) and to control mosquitoes in stagnant ponds (103). As yet, the large-scale use of such methods has little support in the host third world countries where these problems are most severe. Tributyltin chloride has been used to confer rodent-repellent properties on wire and cable coatings (104). 

In some cases cost may be the dominant approval criterial. In applications where color is only an identifying attribute, the customer may be interested in just a close match to target, preferring that the colorist formulate for lowest cost. Examples of such applications could be wire and cable coatings, automotive dunnage applications, pallets, bread trays, and beverage crates. 

Use Automotive parts, gaskets, cable coating, mechanical rubber products, cover strips for tire side-walls, tire tubes, safety bumpers, coated fabrics, footwear, wire and cable coating, thermoplastic resin modifier. 

---