The rubber skeleton material is the main part of the force in the rubber products containing the skeleton material compound, and also plays an important role in the stability of the shape of such rubber products in use. Such as tires, tapes, some hoses, seals and shock-absorbing rubber products are made of rubber elastomer parts and high modulus high-strength skeleton materials compounded from these rubber products have different requirements for their skeleton materials, so there are different materials and different structures of skeleton materials. Different materials are mainly natural fiber, synthetic fiber, metal materials. The different structures are mainly wire rope, cord fabric, canvas, non-woven fabric, etc. The surface treatment of the skeleton material and the adhesion with the rubber substrate are also very important issues.
1. The basic role of rubber skeleton material
Rubber material is a kind of polymer material with high elasticity, large deformation and low modulus. Such as sufficient elasticity can absorb shock and vibration, provide high wear resistance, friction coefficient and excellent adhesion. But in most cases pure rubber products cannot meet the actual use needs. Rubber products are subjected to large loads in most cases, such as tires, conveyor belts, etc. These rubber products need to be compounded with fiber, steel wire and other skeleton materials, thus making rubber materials more widely used. The rubber is firmly bonded to the skeleton material, which not only protects the skeleton material, but also enhances the role of the skeleton material to a fuller extent.
The purpose of using skeleton materials in rubber products is to give rubber products higher strength and dimensional stability. In tires, the tire body cord constrains the rubber to maintain a stable inflatable section width and outer diameter, while the bead part of the wire ring skeleton tightens the tire on the rim of the car and resists the effect of centrifugal force at high speed. The warp threads in the belt bear the tensile tension load and the weft threads provide impact resistance. The skeleton layer compiled or wound in the hose prevents the hose from bursting under high pressure or has enough stiffness when vacuum pumping, and the skeleton of sealing products with skeleton keeps its shape stable.
2. Types and classification of rubber skeleton materials
Rubber skeleton materials are mainly made of three major materials, natural cotton fibers, various chemical fibers and metal materials. In addition to the metal directly processed out of a certain shape of the skeleton and ordinary single steel wire, most of the rubber skeleton materials are produced from fiber or steel wire by twisting, stranding, weaving or impregnation of the rope, cord, or canvas. This series of different structures of the skeleton material is conducive to improving its fatigue resistance, binding to the rubber and easy processing, etc. The performance of the skeleton material depends on its material and its structure, now the main fiber and wire characteristics are briefly described below the classification and role of rubber products skeleton material.
(1) cotton fiber cotton fiber basic performance is low strength, and good adhesion of rubber.
(2) viscose fiber in which the high strength viscose fiber is commonly used in the rubber industry. Rayon dry strength is high, but the wet strength is low.
(3) polyvinyl alcohol fiber vinylon fiber high strength, abrasion resistance, good light resistance, but its resistance to heat and humidity is not good.
(4) polyamide fiber or nylon, also known as nylon, the fiber strength is higher, elongation at break is also higher, good elasticity, flexing, wear resistance than other fibers, but its thermal stability is poor, has been used in a large number of twill tires and other products.
(5) polyester fiber polyester fiber combined with the strength and elongation characteristics of nylon and the modulus characteristics of rayon, so it is suitable for many purposes, such as half wire radial tires in the carcass skeleton basic choice of polyester cord fabric.
(6) aramid fiber or aramid, aromatic polyamide fiber strength, low elongation, good heat resistance, "artificial steel wire", but its price is high, has been used in tires and high strength conveyor belts and other products.
(7) glass fiber glass fiber has a high modulus and heat resistance, but flexural resistance and adhesion with rubber are poor.
(8) steel cord steel cord, steel wire rope and ordinary single steel wire have very high strength and modulus, the surface of copper or galvanized steel wire has been a good solution to the adhesion problem with rubber, in tires, steel wire conveyor belt, steel hose and other products have been used in large quantities