Tyre cords

Until the early 1960s the aromatic and cycloaliphatic polyamides were largely laboratory curiosities. By 1980 they were still only of minor importance to the plastics industry but of rapidly expanding interest as fibre-forming materials with a particular potential as tyre cord materials. 

Originally developed for tyre cords, Kevlar-type materials have also become widely used in composites. Uses include filament-wound rocket motors and pressure vessels, metal-lined Kevlar-overwrapped vessels in the space shuttle, boat and kayak hulls, Kevlar-epoxy helmets for the US military, and as one of the reinforcements in composite lorry cabs. 

Where resorcinol adhesives are not suitable, resins can be prepared from modified resorcinol [128], Characteristic of these types of resins arc those used for tyre cord adhesives, in which a pure resorcinol-formaldehyde resin is used, or alternatively, alkyl resorcinol or oil-soluble resins suitable for rubber compounding are obtained by prereaction of resorcinol with fatty acids in the presence of sulfuric acid at high temperature followed by reaction with formaldehyde. Worldwide more than 90% of resorcinol adhesives are used as cold-setting wood adhesives. The other most notable application is as tyre cord adhesives, which constitutes less than 5% of the total use. 

The twisted fibre of polyester, rayon, nylon or steel, which imparts strength to the tyre carcase and belt. See Tyre Cord. 

A method of measuring the adhesion between tyre cord and mbber. The test takes its name from the shape of the test specimen, two end strips of mbber with the interconnecting cord forming an H-shape. 

A synthetic polymer which is being developed as a textile for tyre cord, etc. 

A static test for determining the adhesion of tyre cord in rubber. The test piece is in the form of a loop shaped like the letter U. 

Applied to a tyre-cord fabric without any weft or cross-threads. The individual cords are spaced out by a reed, passed into an adhesive such as LRF, dried and coated with rubber compound by... 

The processing requirements for a PET-SSP plant for tyre cord are very different to those for a bottle-grade plant First, the raw material is typically a homopolyester with a melting point of 260 °C or higher, secondly the final viscosity of 1.0 to 1.2 is much higher, and thirdly the plant throughputs, typically between 30 and 90 t/d, are much smaller. These three differences result in a rather simplified process, as shown in Figure 4.19. 

Nylon 6 Is used for the manufacture of tyre cords, fabrics and ropes. 

BS 903 Part A4858 is identical to ISO 4647 and Part A 5659 identical to ISO 5603. It is significant that the equivalent ASTM standards are not produced under the auspices of the committee for rubber but in a subcommittee of the textiles committee specifically covering tyre cord and fabrics. The H-test is in D477660 and the method for steel cord in D222961. There is also a method for strap peel adhesion test of reinforcing cords or fabric in D439362. 

The extension is only 8 per cent, with the result that the yarn has no textile application because materials would crease so badly. It has been used for tyre cords and other industrial purposes where strength is of paramount importance. 

Only types (l)-(4) fall within the scope of this chapter. No further reference will be made to emulsion-polymerized prolybutadiene rubbers, because they are now of little industrial significance relative to the styrene-butadiene rubbers. Poly(vinyl chloride) is discussed elsewhere in this book. Brief reference will also be made in this chapter (Section 15.5) to the production and properties of carboxylated variants of styrene-butadiene rubber latexes. It may also be noted that latexes of rubbery terpolymers of styrene, vinyl pyridine and butadiene, produced by emulsion polymerization, have long been of considerable industrial importance for the specialized application of treating textile fibres (e.g., tyre cords) in order to improve adhesion between the fibres and a matrix of vulcanized rubber in which they are subsequently to be embedded. 

Du Pont and Monsanto, the two U.S. chemical companies responsible for the discovery of the known ultra-high modulus organic fibres, are actively testing their fibres in conjunction with potential users. The former company is now apparently committed to production of quite large quantities of tyre cord. Very little information is available about the chemical natures of the proprietary fibres but it seems reasonably certain that the information in Table 5 is correct. 

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