Polyester cord fabric is characterized by heat resistance, good thermal stability, low elongation, high wet strength, but fatigue resistance and strength is not as good as nylon (nylon) cord fabric, and aging resistance is poor, the cost is higher, and the adhesion of the rubber is poor, so it is not as widely used as nylon cord fabric in the rubber industry. Mainly used for passenger tire carcass, can also be used for flying tires.

The cord of polyester impregnated cord fabric for tires is divided into ordinary type and dimensionally stable type ("Polyester impregnated cord fabric for tires" (GB/T 19390-2014)).

Impregnation treatment of polyester cord fabric

If polyester impregnated cord fabric adopts conventional impregnation treatment with m-methyl rubber emulsion (RFL), it is difficult to achieve the ideal effect of adhesion with rubber, and the following impregnation systems are used in the production process of polyester impregnated cord fabric:

Sealed isocyanate, epoxy resin impregnation system. This system is suitable for the double-bath method, i.e. the polyester cord fabric is impregnated and heat-treated in the first bath (impregnating solution consisting of epoxy resin, closed isocyanate, etc.) and then impregnated and heat-treated in the second bath (RFL impregnating solution);.

Vulcabond E impregnation system. Aqueous impregnating solution of chlorophenolic compounds (similar products are adhesives RP and DENABOND), which is mainly suitable for single-bath impregnation by aqueous impregnating solution of chlorophenolic compounds mixed directly into the RFL impregnating solution.

Fiber surface activation. That is, the use of closed isocyanate, epoxy resin, oleate, triol glycidyl ether, etc., in the spinning process of the unstretched monofilament coated with spinning oil directly after impregnation, but also can be impregnated in the monofilaments after stretching or in the monofilaments after stretching is about to be coiled before the monofilaments are impregnated, but also can be impregnated in the twisted cord or in the process of twisting the cord. After the activated cords have been woven into the cord fabric, they are impregnated with RFL impregnating solution.

Precautions in the use of polyester cord fabrics

Problems that may occur:

Polyester cord is subject to chemical degradation in the presence of amines. With the prolongation of the aging time, the early stage of degradation is faster, which is mainly degradation occurs first in the amorphous zone inside the polyester fiber; and the degradation of the crystalline zone with higher regularity is slower, and the loss of strength of polyester cord is smaller.

The effect of rubber accelerators on the degradation of polyester cord varies. Depends on the thermal stability of the accelerator, the activity of the amine group generated by the decomposition and its reaction with other additives in the rubber to form complexes of thermal stability and other factors.

Vulcanization accelerators in the rubber such as thiuram accelerators have the most significant effect on the amine decomposition of polyester cord, the lesser effect of subsulfonamide accelerators, and the least effect of thiazole accelerators.

Fatty acids, esters and other impurities in natural rubber are easy to cause degradation of polyester cord.

Different varieties of antioxidants also have different effects on the amination of polyester cord.

The larger the polyester fiber end carboxyl content, the more likely to produce chemical degradation, the greater the loss of strength.

Countermeasures:

Care needs to be taken to prevent aminolysis during the use of polyester cord fabrics. In the polyester cord fabric overlay formula, should try not to use or use less amine-containing substances;.

Impregnation heat treatment of polyester cord can not only enhance its adhesion with rubber, but also enhance its anti-degradation ability.

The addition of anti-ammonia agent can inhibit the amine group generated by the decomposition of the accelerator on the polyester cord amination, effectively improve the polyester cord in the heat state of the anti-ammonia ability, cord strength retention rate increased significantly.