Full definition
The most common and economical rubber molding process, in which a pre-weighed piece of uncured rubber compound (preform) is placed into the open cavity of a heated mold, the mold is closed under hydraulic pressure (50-200 bar), and heat (150-180°C) cross-links (vulcanizes) the rubber into the final part shape. The excess rubber (flash) is squeezed into overflow grooves and is later trimmed. Cure time: 2-30 minutes depending on part thickness, compound, and temperature. Advantages: lowest tooling cost (simple two-piece molds), suitable for large parts, no injection runner waste, and easy material changeover. Limitations: longer cycle times than injection molding, more flash to trim, labor-intensive preform placement, and less suitable for complex geometries or tight tolerances. Press types: up-stroke (standard) and down-stroke. Standard press sizes: 50-1,000 tonnes clamping force. Ideal for: gaskets, O-rings (in large quantities), diaphragms, rubber pads, bridge bearings, anti-vibration mounts, and medium-volume production runs. Per standard rubber molding practice. Press temperature uniformity: ±3°C across the platen for consistent cure.