The Rubber Compression Molding Process
The rubber compression molding process uses a preformed piece of uncured rubber that is placed in an open mold cavity. The mold is preheated to an elevated temperature. As the mold closes in the press, the material is compressed and flows to fill the rubber mold cavity.
The combination of elevated temperatures and high pressures activates the vulcanization process and curing of the rubber compound. Once an optimal cure is reached, the part hardens and cools then the mold is opened and the final part removed. The next rubber preform is inserted into the mold and the cycle repeats.
The basic compression mold is usually a two-piece construction consisting of a top and bottom plate. Half of the part cavity is usually cut into each plate of the mold. A trim area is created by grooves cut around each cavity which allows the excess rubber to flow out of the cavity. Compression molds are typically secured between heated press platens. The molded parts require trimming to remove the groove overflow. An additional bake cycle may be required for partially cured parts.
Advantages
1. Simple equipment – Only requires a hydraulic press and molds, with low maintenance costs.
2. Lower mold costs– Simplified structure and shorter machining cycles (30%~50% cheaper than injection molds).
3. Material versatility – Suitable for high-viscosity or fiber-reinforced rubber (e.g., FKM), with minimal flow requirements.
4. Ideal for large components– Accommodates longer curing times.
5. Small-batch flexibility – Cost-effective for prototyping or custom orders without bulk material pre-stocking.
Limitations
1. Slower production – Manual loading + extended curing cycles (typically 5–20 min/part), with limited automation.
2. Lower dimensional accuracy** – Tolerance range ±0.3–0.5mm, inferior to injection molding (±0.1mm).
3. Labor-intensive– Higher manual operation requirements.
Why should you choose Vulkon for Rubber Compression Molding?
– Trusted experience to solve your problems from design to price to delivery – try us!
– Short-runs with fast turnaround
– Competitive pricing on a variety of rubber parts
Rubber tires customized for hospital bed use.
– We work with your tooling either from other molders or can purchase new tooling for you. You always own the tooling so we keep you as a customer through outstanding performance and customer service.
– 3-shift/24-hour production for the quickest turnaround
– We aggressively monitor raw material costs to maintain the lowest possible pricing
– Green initiatives with repurposed rubber to reduce costs and save from landfills
Custom Rubber Molding Co.