Compounding silicone rubber molding process

1. Application of compounding silicone rubber technology

Kneading silicone rubber is a synthetic rubber that is repeatedly refined by adding raw silicone rubber to a double-roll rubber mixer or a closed kneader and gradually adding silica, silicone oil, etc. and other additives. It can be widely used in aviation, cables, electronics, electrical appliances, chemicals, instruments, cement, automobiles, construction, food processing, medical equipment and other industries, and is used for deep processing of machinery such as molding and extrusion.

2. Process method of mixing silicone rubber

Silicone rubber: Mixing silicone rubber can be mixed without plasticizing. Generally, open mixer is used for mixing, and the roll temperature does not exceed 50 degrees.

Mixing is carried out in two stages:

The first paragraph: raw rubber-reinforcing agent-structure control agent-heat-resistant additive-thin-pass-lower sheet.

The second stage: a stage of refining – vulcanizing agent – thin pass – parking. Silicone rubber miscellaneous pieces.

Three, mixing silicone rubber molding process

1. Molding: first punch the rubber into a certain shape, fill it into the mold cavity, place the mold between the upper and lower plates of the heated flat vulcanizer, and heat and pressurize it according to the prescribed process to vulcanize the rubber. Lower the mold to obtain a section of vulcanized silicone rubber products

2. Transfer molding: put the prepared rubber material into the plug cylinder on the upper part of the mold, heat and plasticize, and use the pressure of the plunger to make the rubber material enter the heating mold cavity through the nozzle for molding.

3. Injection molding: Put the rubber material into the barrel for heating and plasticizing, inject the rubber material directly into the closed mold cavity through the nozzle through the plunger or screw, and realize rapid in-situ vulcanization under heating.

4. Extrusion molding: a continuous molding process for forcibly extruding the mixed rubber through a die into a product with a certain cross-sectional shape.

Therefore, when the silicone product factory realizes the molding of silicone products, it is necessary to select the appropriate molding method according to the product and operation method. If the quantity of silicone rubber products is large and light in weight, transfer molding can be selected instead of blind selection, which will not only cause production The inefficiency also took a toll on the factory.