Textile cord

Textile applications Textile bags Textile bleaching Textile cord Textile dyeing Textile fibers Textile finishes Textile finishing... 

Tire Cord. Melamine resins are also used to improve the adhesion of mbber to reinforcing cord in tires. Textile cord is normally coated with a latex dip solution composed of a vinylpyridine—styrene—butadiene latex mbber containing resorcinol—formaldehyde resin.. The dip coat is cured prior to use. The dip coat improves the adhesion of the textile cord to mbber. Further improvement in adhesion is provided by adding resorcinol and hexa(methoxymethyl) melamine [3089-11 -0] (HMMM) to the mbber compound which is in contact with the textile cord. The HMMM resin and resorcinol cross-link during mbber vulcanization and cure to form an interpenetrating polymer within the mbber matrix which strengthens or reinforces the mbber and increases adhesion to the textile cord. Brass-coated steel cord is also widely used in tires for reinforcement. Steel belts and bead wire are common apphcations. Again, HMMM resins and resorcinol [108-46-3] are used in the mbber compound which is in contact with the steel cord to reinforce the mbber and increase the adhesion of the mbber to the steel cord. This use of melamine resins is described in the patent Hterature (49). 

The carcass ply/pHes coat compouad fuactioas are basically the same as the steel breaker compouad. Normally ia the steel belted PCT the ply is textile cord of polyester or rayoa fabrics which are soft and flexible. The tmck radial steel tire normally uses a steel cord ply. Earthmover tires are of two basic constmctions, ie, radial usiag steel and bias usiag textiles (see Tire cords). 

There are various textbooks available on the calendering process,which is referred for an extensive explanation. In this section the impact of the presented theory on the general layout of a dual-purpose calendering line for textile cord and steel cord coating is considered. 

Figure 35.43 shows a general layout of a dual-purpose calender line for coating steel cord and textile cord. The heart of the production line is the four-roll calender in an S-configuration. Two mbber sheets are formed in the upper and lower nip. The thin sheets are guided to the middle nip and the cords are coated in the middle nip between the two rubber sheets. Generally outer roll bending is applied on rolls 2 and 3 to compensate the roll deflection caused by the nip force in nip 2. Rolls 1 and 4 can be set crossed respectively to rolls 2 and 3. 

FIGURE 35.44 Typical thickness deviation across the calender direction for various products (textile cord sheet). 

As with reinforcing textile cords it may be necessary to rewind treated wire from production spools to smaller unit spools for specific machines, such as braiders. 

An international version of the H-pull test for textile cord was published as ISO 464753 in 1982 and the method for steel cord, ISO 560354, in 1986. It is perhaps a reflection of the responsible ISO committee being concerned with rubber testing generally, and not having any specific expertise in tyres, that the methods have not been revised since. In the steel cord method the... 

ISO 4647, 1982. Determination of static adhesion to textile cord - H-pull test. 

Figure 2.75 shows the constructions of a standard bias (diagonal) ply tire and a radial ply tire. The major components of a tire are bead, carcass, sidewall, and tread. In terms of material composition, a tire on an average contains nearly 50% of its weight in actual rubber for oil extended rubbers (typically containing 25 parts of aromatic or cycloparafiBnic oils to 75 parts of rubber), it is less. The remainder included carbon black, textile cord, and other compounding ingredients plus the beads. 

Textile cords or fabric and even steel cords constitute an important part of all rubber belting and hoses. The various types of cords used in the tire industry are also in use in the belting industry. 

A tire is a textile-steel-rubber composite the steel and textile cords reinforce the rubber and are the primary load-carrying structures within the tire. Because of the performance demands of fatigue resistance, tensile strength, durability, and resilience, seven principal materials have been found suitable for tire application cotton, rayon, nylon, polyester, steel, fiberglass, and aramid the latter three materials find primary usage in the tire crown or belt region. 

Wire and fiberglass, being high-modulus inorganic belt cords, are not processed like textile cords. Steel cord is brass plated at the foundry and, thus, can be used directly at the calendars. Glass yarn is treated with adhesive dip and then used directly in the weaving operation. 

The classical work of Borroff and Wake in 1949 on the adhesion between the textile cords and the rubber casing in automobile tyres demonstrated that the only significant factor was the penetration of the fibre ends into the rubber. These fibre ends originated from the natural textile fibre (usually cotton), and it was their absence in synthetic fibres (e.g. nylon monofilament) that caused the difficulty in using these for this product. Any specific interaction between the rubber and the fibre was insignificant and only affected... 

Before synthetic textile cord was developed, the rubber industry was using casein or animal blood to promote adhesion between cotton cords and rubber. However, when rayon started to be used in the manufacture of tires in 1931, a new adhesive system was needed to promote a good rubber-to-rayon bond. In 1938, W.H. Charch and D.B. Maney of DuPont developed a new adhesive system that involved dipping rayon cord into what is today referred to as an RFL dip. This RFL dip has changed and been modified for the newer synthetic cords discussed earlier however, basically it is still very similar to what was originally developed seven decades earlier. 

An RFL dip consists of an aqueous resorcinol formaldehyde resin liquid with a ruhher latex. The RF resin is used to achieve good adhesion to the organic fiber substrate whether it be rayon, nylon, or polyester. The rubber latex portion can be a natural rubber latex or a styrene butadiene vinylpyridine (terpolymer) latex or even a neoprene latex. This rubber latex is present to achieve good adhesion with the rubber matrix itself. So the RFL allows good adhesion between the rubber and the textile cord reinforcement whether it is used in the manufacture of passenger tires, truck tires, off-the-road tires, power transmission belts, V-belts, timing belts, or various hose products. 

The textile cord or fabric is first immersed in the RFL dip suspension and then passed through a vertical oven under tension at a predetermined elevated temperature and time. This process is called heat setting, where the adhesive dries and coats the cord or fabric while under tension. 

Resorcinol formaldehyde resin is a vital ingredient in preparing the RFL dips. Without the RF resin, it would be most difficult to achieve acceptable adhesion with the textile cord substrate. 

An aqueous solution of RF resin is used with different rubber latexes to make the RFL dip needed to treat the textile cord to allow it to achieve rubber-to-cord adhesion during the curing process. It is the RF resin portion of the RFL dip that is responsible for the good adhesion with the textile cord. 

RF resin has been used to achieve good rubber-to-textile cord adhesion since 1938. There are very few alternatives, and the substitutes have not really been proven viable in the long term. 

Styrene butadiene vinylpyridine latex (SBVPL) is the most popular rubber latex used to make RFL dips to achieve good rubber-to-fabric adhesion. Usually SBVPL is used for good adhesion between textile cord and rubber compounds based on general-purpose elastomers (NR, SBR, and BR). Occasionally other latexes besides SBVPL are used as well. For example, sometimes natural rubber latex is used for an RFL dip. Then again, neoprene latex can also be used, especially if the rubber compound is based on neoprene. The purpose of the rubber latex component of the RFL is to promote adhesion with the rubber matrix of the product. 

Certain textile cords, such as polyester, do not have sufficient surface activity to properly react with the RFL dip. Therefore, these special textile cords require a predip in a proprietary blocked polyisocyanate and/or an epoxy dip, after which they are heat treated and dried before the RFL dipping procedure. 

MDI is also used to help achieve a good bond between rubber and textile cord. 

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