The last molding process of silicone rubber compounding is filtering and extrusion molding, and then it is completed after cooling and then packing. So what is the main purpose of silicone rubber compounding and filtering?
The main purpose of silicone rubber compounding and filtering is to remove impurities in the rubber, and then the silicone rubber is mixed and pre-formed in a designated model to form a block-sized rubber that is easy to pack, transport and sell.
The main process of silicone rubber compounding and filtering is to place a high-mesh filter screen in the extrusion molding filter for filtering and extrusion, and then put the silicone rubber compounding blank rubber into the screw, and then filter through continuous extrusion. The net removes the impurities, and then pre-formed into the rubber material of the specified size in the specified model, which is convenient for packing.
Some manufacturers mainly use it for their own use, and do not need to carry out packing, only filtering. After extrusion, the width and height are still the same, but the length is not limited.
Silicone rubber compounding filter screens generally use 200 mesh screens. Too high meshes can easily cause blockage of the rubber, and too low meshes can easily cause fine impurities to pass through the filter.
If we encounter slow glue output during the filtration process, we must replace the filter in time. The frequency of replacing the filter mainly depends on the amount of impurities in the rubber.
At present, some silicone rubber compounding factories use rubber compounding and vulcanization and coloring without filtering, but this has high requirements for the workshop environment, and it must be dust-free and pollution-free.
In addition, the quality and cleanliness of the unfiltered silicone rubber compound is obviously inferior to that of the filtered rubber.
There will be some impurities in the unfiltered rubber material, so it is easy to cause the product to be scrapped during the production of silica gel products. If it is because the impurity particles are too large, it may even damage the mold.
There are two main purposes of silicone rubber compounding and filtering, one is to remove impurities in the rubber material, and the other is to facilitate packing after extrusion and pre-forming.
Silicone rubber compounding is a synthetic rubber with excellent comprehensive properties. It can be widely used in aviation, cables, electronics, electrical appliances, chemicals, instrumentation, cement, automobiles, construction, food processing, medical equipment and other fields. Deep processing of pressing and other machinery.
The process requires high quality. It is a combination of liquid silica gel and plastic. Silicone rubber compounding has good thermal stability, cold resistance, and excellent electrical insulation properties, and no toxic substances will be produced during combustion.
After silicone rubber is mixed with white carbon black, silicone oil, etc. to make a mixed rubber, the film made by calendering has obvious differences in physical and mechanical properties in the longitudinal and transverse directions. This phenomenon is the calendering effect.
The calendering effect is the result of the direction of the macromolecules and needle-like and sheet-like compounding agents in the rubber compound along the calendering direction during the calendering process. The size of the calendering effect is related to the composition of the rubber compound, calendering temperature, speed, speed ratio and so on.
Silicone rubber compounding has excellent thermal stability, high and low temperature resistance, long-term work at -60 ℃ ~ +250 ℃, ozone resistance, good weather resistance, good electrical properties, corona resistance, arc resistance, spark resistance, and good chemical stability, weather resistance, radiation resistance, physiological inertness and good air permeability.