Vacuum Molding Presses for Precision Rubber Parts
WCRM’s VP Series vacuum molding presses are designed for rubber molding applications where air must be removed from the mold cavity before cure. These presses evacuate the mold enclosure to 27–29.5 inHg typical before the cure cycle proceeds, reducing porosity, voids, and surface defects in finished parts. Available as single self-contained units or in multiple bank configurations for higher-volume production.
When Standard Compression Molding Is Not Enough
In standard compression molding, air trapped in the mold cavity or within the compound can remain in the finished part as voids, porosity, or surface defects. For general-purpose rubber parts, this may be acceptable. For precision seals, aerospace components, bonded rubber-to-metal assemblies, and medical rubber parts, it typically is not.
Applications where vacuum is commonly required:
Precision Seals & O-Rings
Internal porosity that is not visible at the surface can cause sealing failure in service. Vacuum molding reduces the risk of voids that compromise sealing performance.
Aerospace & Defense Components
Material certification requirements and structural reliability demands make void-free molding essential for many aerospace rubber parts.
Bonded Rubber-to-Metal Assemblies
Air at the bond line reduces adhesion. Vacuum evacuation before cure helps ensure consistent bonding across the full contact area.
Silicone Components
Silicone compounds are particularly susceptible to surface blistering and internal voids when air is not removed before cure.
Medical & Regulated Rubber Parts
FDA-regulated and medical-grade rubber components require verifiable compound integrity throughout the part.
Complex Cavity Geometries
Thin wall sections and intricate cavities trap air that cannot escape by flow alone—vacuum evacuation is often the only reliable solution.
What Makes a WCRM Vacuum Press Work
Effective vacuum molding requires more than connecting a pump to a press. The enclosure, seals, controls, and cycle sequencing all have to work together to achieve reliable evacuation within the available cycle time.
Vacuum Enclosure: Press frame configured as a sealed vacuum chamber, achieving 27–29.5 inHg typical before the cure cycle is initiated.
Vacuum Level Monitoring & Interlock: Controls verify that the target vacuum level is achieved before pressure is applied—the cure cycle will not proceed if vacuum is not confirmed.
Pressure Ramping: Controlled pressure application after vacuum pull-down, reducing the risk of compound disturbance as mold pressure increases.
Bump Pulsation: Optional bump cycling to assist air release from deep or complex cavities before final mold closure.
Heated Platens: Electric, hot oil, or hot water heating with multi-zone temperature control for consistent thermal distribution across the mold area.
Platen Flatness & Parallelism: Precision platen surfaces that maintain vacuum seal integrity and consistent pressure distribution under operating conditions.
Single or Bank Configuration: Available as individual self-contained press units or in multiple bank arrangements for higher-volume production environments.
Process Control Upgrades – Accudyne Hydraulic Presses
Specified to Your Application
Tonnage: Force capacity matched to your mold size, compound, and cavity pressure requirements.
Platen Size: Working area configured for your tooling dimensions.
Vacuum Level: System engineered to meet your specific evacuation requirement.
Heating Method: Electric, hot oil, or hot water platens to suit your temperature and cycle time needs.
Daylight: Ram stroke and open height configured for your mold and loading workflow.
Bank Configuration: Single unit or multiple presses in a shared bank arrangement for production environments requiring higher throughput.
Engineering FAQ
What vacuum level do your presses achieve?
Most rubber molding applications operate in the range of 27 to 29.5 inHg. The specific system is sized to achieve the required vacuum level within your available cycle time.
Can an existing compression press be retrofitted for vacuum?
In some cases, yes. Feasibility depends on the press frame and platen configuration, available daylight, and the machine’s overall condition. Contact WCRM to discuss your existing equipment.
What is a bank configuration?
A bank configuration places multiple vacuum press units together sharing infrastructure, allowing higher throughput without requiring a separate stand-alone unit for each mold. WCRM’s VP Series is available in multiple bank arrangements.
What information do I need to provide for a quote?
Helpful starting information includes part description and quality requirements, mold dimensions, compound and cure temperature, production volume and cycle time targets, and whether you are considering a new press or a retrofit to existing equipment.
Talk to WCRM About Your Vacuum Molding Application
Whether you are specifying a new vacuum press, evaluating a retrofit, or troubleshooting an existing vacuum system, our team can help you identify the right configuration.