Post curing method of rubber

After vulcanization, rubber products often need some post-treatment before they can become qualified products.

This includes:

a. trimming of rubber mold products to make the surface of the products smooth and clean and the overall dimensions meet the requirements;

b. After some special process processing, such as surface treatment of products, the service performance of products for special purposes is improved;

c.  Products containing fabric skeleton, such as adhesive tapes and tires, shall be cooled under inflation pressure after hot stretching and vulcanization to ensure product size, shape stability and good service performance.

Manual trimming

Manual trimming is an ancient trimming method, which includes manual punching of rubber edge with a punch; Use scissors, scrapers and other tools to remove the glue edge. The quality and speed of the rubber products trimmed by manual operation will vary from person to person. It is required that the geometric dimension of the finished products must meet the requirements of the product drawings, and there shall be no scratches, scratches and deformation. Before trimming, the trimming position and technical requirements must be clear, and the correct trimming method and tools must be mastered.

Mechanical finishing

Mechanical trimming refers to the process of trimming rubber mold products with various special machines and corresponding process methods. It is an advanced dressing method at present.

Mechanical punching and trimming: remove the rubber edge of the product with the help of pressure machinery, punching die and punching knife. This method is applicable to the products and the model products whose rubber edges can be placed on the bottom plate of the punching die or the punching knife, such as bottle stoppers and cups. For products with high rubber content and low hardness, impact edge cutting is generally adopted, which can reduce the uneven edge and side depression after cutting due to the large elasticity of the products; For products with low rubber content and high hardness, the knife edge die can be directly used for punching. In addition, punching is also divided into cold cutting and hot cutting. Cold cutting refers to punching under room temperature. It requires high punching pressure of equipment and good punching quality; Hot cutting means that at a high temperature - F, the high temperature shall be prevented from contacting the product for a long time during blanking, which will affect the product quality.

Mechanical cutting trimming is applicable to trimming of products with larger overall dimensions, and cutting tools are used. One side cutting machines are special machines, and different products use different cutters. For example, if there are rubber strips with different lengths at the air hole and exhaust line on the surface of the tire after vulcanization, the rubber strips must be removed with a tool with grooves under the condition of tire rotation.

Mechanical grinding trimming for die rubber products with inner holes and outer circles, grinding squares are usually used. The grinding tool is a grinding wheel with a certain particle size. The precision of grinding trimming is low, and the grinding surface is rough. There may be residual sand particles, which may affect the use effect.

Low temperature shot blasting trimming is applicable to fine products with high trimming quality, such as 0-ring and small cup. Use liquid nitrogen or dry ice to quickly cool the products to below the brittle temperature, and then spray metal or plastic bullets at high speed to break and fall off the flash, and finish trimming.