With rubber as the main material (which may contain reinforcing materials such as fabrics and metal sheets), the sheet-like products with a certain thickness and a large area obtained by vulcanization are called rubber sheets. As for reinforced rubber sheets, as the name suggests, are rubber sheets containing reinforcing materials. Rubber sheets include fabric-reinforced rubber sheets and fiber-reinforced rubber sheets and others.
Reinforced rubber products are one of the composite material categories, although they are rarely called composites. Common examples are car tires, hoses and conveyor belts.
Composite reinforcement structure
Reinforced rubber products combine a rubber matrix and reinforcement so that high strength-to-flexibility ratios can be achieved. The reinforcement is usually a fiber that provides strength and stiffness. The low strength and stiffness of the rubber matrix provides air tightness and supports the reinforcement to maintain its relative position. These positions are important because they affect the resulting mechanical properties.
Reinforced rubber sheet is a rubber sheet of composite structure in which all fibers are loaded equally under compression, called isotropic structure, and the type of loading is called isotonic loading. To satisfy the isotonic concept, the structural geometry must have an isotonic meridian profile, and the fibers must be placed according to geodesic paths. A geodesic path through the shortest way connects two arbitrary points on a continuous surface.
Reinforce complex shaped rubber products
For a cylinder of constant diameter, the reinforcement angle is also constant, 54.7º. This is also called a magic angle or neutral angle. The neutral angle is the angle at which the wound structure is in equilibrium. For a cylinder, the angle is 54.7º, but for more complex shapes such as bellows, which have varying radii over the entire length of the product, the neutral angle is different for each radius. In other words, for complex shapes, there is no magic angle, but the fibers follow a geodesic path whose angle varies with radius. In order to obtain a reinforced structure with isotonic loading, the geometry of the complex shape must follow the isotonic meridian profile.
Fiber Reinforced Rubber Sheet
Fiber reinforced rubber Sheet with 1, 2 or more layer of fabric are being inserted in rubber sheets. This reinforcement could be of either nylon, cotton fabric. The reinforced rubber provide strength to the sheets. Nylon fabric reinforced rubber sheets are widely use as diaphragms for oil, LPG, solvents & gases resistant application in automobile & other industry.
Fiber reinforced rubber, which can significantly improve its strength, reduce its compression set and increase the tear resistance of a rubber sheet. The preparation method of fiber reinforced rubber comprises the following steps: a. rubber mastication; b. Reinforcing fillers, fibers, and auxiliary agents are added to the rubber, and kneading is performed; wherein, the fibers and reinforcing fillers are mixed uniformly to obtain a pre-dispersion and then added to the rubber. As a preferred solution, the rubber is styrene-butadiene rubber, nitrile butadiene rubber, neoprene. SBR, nitrile butadiene rubber and neoprene are several materials with excellent abrasion resistance, pressure resistance, oil resistance and water resistance, and air tightness. Produced by the present invention The rubber sheet can work for a long time in ultra-high temperature and high pressure and various media, the maximum working temperature can reach 300 ℃, and maintain good elasticity, low compression deformation and excellent physical and mechanical properties, which is lower than the performance at room temperature. no more than 20%.
Fabric reinforced rubber sheet
Fabric is a flat soft piece composed of small flexible long objects through crossing, knotting and connecting. Woven fabrics are made up of yarns that have intersecting relationships. Knitted fabrics are composed of yarns that are entangled. Non-woven fabrics are composed of yarns that are connected in a relationship. The third fabric is composed of yarns in a cross/twist relationship.
Numerous yarns form a stable relationship to form a fabric. Crossing, knotting and connecting are three stable structural relationships that yarns can form. Keep the fabric in a stable shape and with specific mechanical properties. By analyzing the relationship between yarn groups in fabrics and their running directions, running laws and formations, various fabrics can be clearly understood.
In order to meet the quality and performance of rubber products, as well as the production process requirements, the fibers are twisted, woven or impregnated into fabrics such as cords, canvases, and pads. As a reinforcing material for rubber products, fabrics are currently mainly made of synthetic fibers, and their properties are closely related to the quality of rubber products. As a reinforcing fabric, it must have the characteristics of high strength, high modulus, small deformation and good bonding performance with rubber.
Fabric reinforced rubber sheet is manufactured from a blend of natural and styrene-butadiene rubber (NR / SBR) with an encapsulated single ply cotton reinforcement. The fabric insert helps to prevent stretching and provides additional strength and tear resistance compared to standard commercial quality grades.
Fabric reinforcements can be applied to rubber products in different ways. For straight pipes, the most common processes are braiding, helical wrapping, braiding and wrapping. What the first three processes have in common is that, in an automated process, multiple strands of fibers are simultaneously applied to the product in a predetermined pattern. The fourth process involves manual or semi-automatic packaging of rubber sheets reinforced with fabric layers. To reinforce complex shaped rubber products such as bellows, most manufacturers use these fabric-reinforced rubber sheets. These sheets are made by calendering rubber onto prewoven fabrics. The product is made by winding these sheets (usually by hand) on a mandrel until enough rubber and reinforcement is applied. However, the disadvantage of using these sheets is that it is impossible to control the positioning of the individual fibers of the fabric when applied to complex shapes. Therefore, geodesic paths, and therefore isotonic loads, cannot be achieved.