Rubber molding has applications in manufacturing electronic parts, automotive components, and aerospace systems. Although the process involves using a mold, manufacturers utilize different techniques during the molding process. Common molding methods include injection, transfer, and compression:
Injection Molding
The injection rubber molding process often starts with preparing the material barrel and loading the rubber compound. Natural rubber, silicone, or nitrile rubber may be used. Technicians set the appropriate injection pressure and speed before filling the mold cavity with liquid rubber. Once the cavity is filled, the rubber must solidify and cure before the object can be removed and excess rubber trimmed.
Injection molding is often used to produce interior automotive parts or precision medical devices. The process also assists with designing and manufacturing electrical connector bodies, miniature rubber parts, and medical diagnostic equipment. Certain geometric designs and electrical insulation components also require injection molding during manufacturing. This process can also test the materials’ consistency, verify the accuracy of the dimensions, and handle robotic parts.
Transfer Molding
In transfer molding, the rubber compound is loaded into a “pot” that is part of the mold. When the mold is closed, a plunger compresses the material, moving it, or transferring it, into the mold’s cavity. Molding specialists must determine the proper temperature for heating the rubber so that it moves easily from the pot into the mold. They must also regulate the injection speed as the rubber material is distributed to avoid overfilling the mold. The mold remains closed during curing, and any excess material is removed after the object has solidified.
Transfer molding is often used to create medical implants, electrical connectors, and valve seats. It may also be used to manufacture parts for hydraulic systems, vibration dumpling mounts, or chemical-resistant fittings. Manufacturers may prefer the transfer molding process because it supports the integration of metal components or electronic parts. It can also produce objects with sharper edges, allowing greater flexibility in part design.
Compression Molding
In compression molding, the rubber material is weighed, added to the mold cavity, and heated. Pressure is applied to fill the cavity, and excess material flows into overflow grooves on the mold. Technicians must maintain a consistent pressure and temperature to spread the material uniformly. After curing is complete, the mold is opened, and the excess rubber is cut away.
Compression molding is often used to produce automotive door seals, medical tube gaskets, rubber mounting pads, and electrical wire grommets. The aerospace industry uses compression molding to create panel and engine component seals. This molding process is usually good for shaping materials that resist bending, like uncured rubber and thermoplastics. It is also usually selected for projects that require large parts or long-curing times.
Use Rubber Molding Today
Rubber molding can help you design cutting-edge technical components with applications in different industries, including manufacturing and robotics to medical equipment design. Whether using injection, transfer, or compression techniques, rubber molding produces consistent and durable products with low waste. Contact a rubber manufacturing company today for custom molding services that meet your needs.