Offered Types of Rubber Processing
Rubber Compression Molding
Rubber compression molding has a long history in the industry. It is an old process that has been widely used for many years and for good reason. Its applications include thermoplastic phonograph records, rubber times, various polymer matrix composite parts, and more. The process goes as follows: First, a precise amount of molding compound, the charge, is loaded into the bottom half of a heated mold. Second, the mold halves are brought together to compress the charge, forcing it to flow and morph to the shape of the given cavity. Lastly, the charge is then heated by means of the hot mold, which polymerizes and cures the material into a completely solidified product.
Compression molding employs molds that are more often simpler than injection molds. The process also tends to be limited to more simplistic part geometries as the starting materials have lower flow capabilities. Provision is always made for heating the mold, however. Rubber compression molds are generally considered hand molds, used mostly for trial runs.
Rubber Transfer Molding
In the transfer molding process, the charge enters a chamber ahead of the mold cavity. This is where the heating occurs. Then pressure is applied to make the charge to go into the mold where the curing process occurs.
This process is utilized on thermosets and elastomers, the same polymer types in the compression molding process. There is also common ground between transfer and injection molding due to the process of heating the charge in a separate chamber from the mold. However, transfer molding can only capable of molding part shapes more complex than compression molding but not injection molding. It also tends to mold with inserts. In this process, a metal or ceramic insert in put into the cavity before injection. Then the heated plastic bonds to the previously applied insert during the molding.
Rubber Injection Molding
In injection molding, the rubber is pre-heated before entering the mold, allowing for an easier flow. This also can sustain higher mold temperatures, facilitating the curing cycle. The presses employed in injection molding provide tight clamping, resulting in little flash if at all. It is not unusual for products manufactured with injection molding to not need extra finishing. This process tends to be utilized for high-production runs and for items that require much tighter tolerances.
Rubber Mandrel Process
In Wuxi Aoweite’s rubber mandrel process, custom wrapped products are designed to work for you specific needs. Producing molds for mandrel wrapped products is costly, which is why they are usually low-volume products.
This process goes as follows: Raw, uncured rubber is wrapped on a pipe mandrel or directly onto a completely part. It is then cured so it can be made to any desired shape. This is a process that can save thousands of dollars on tooling and time for making a product.