SME Plastic is a professional custom cast aluminum vacuum forming molds and thick guage thermoforming molds manufacturer from China, our cast aluminum molds are perfect for forming large sized or thick gauge plastic products. Designed to handle complex shapes and high forming pressures, they are widely used in heavy-duty vacuum forming applications across various industries.
Cast Aluminum Vacuum Forming Mold Products
Cast Aluminum Vacuum Forming Mold Production Process
Below is the step-by-step procedure for manufacturing cast aluminum vacuum forming molds. The molds are made from cast aluminum alloy and are used for thick gauge vacuum forming applications.
Preliminary Preparation
Product Design and Analysis
- Based on the 3D model provided by the customer, we confirm the structure, dimensions, draft angles (usually ≥3°), parting lines, and vacuum venting needs of the thermoformed product.
- Analyze the thickness of the plastic sheet (typically 2–10mm for thick sheet forming) and optimize the mold to account for material shrinkage, considering the difference in thermal expansion between plastic and aluminum.
Mold Design
- Convert the product’s 3D model into a mold cavity. Design the parting surface, internal cooling system (water channels), and vacuum vent holes (diameter: 0.5–1mm, spacing: 20–30mm).
- Choose the appropriate casting method (sand casting or plaster mold casting) based on mold size, and reserve machining allowance (usually 2–5mm per side).
Mold Casting Process
Selecting the Casting Method
- Material: Use A356-T6 cast aluminum alloy for its excellent fluidity, high thermal conductivity, and low thermal deformation.
- Pattern Making: Create a foam or wooden pattern of the mold using CNC machining or 3D printing, suitable for use as a lost pattern in sand casting.
Selecting the Casting Method
- Prepare the sand mold, including gates and venting channels.
- Melt the aluminum alloy at 700–750°C and pour it into the mold.
- After cooling, remove the casting, cut off the gating system, and clean the surface using sandblasting to remove residual sand.
Machining and Finishing
Rough Machining
- Use CNC machines to remove excess material and establish reference surfaces for the mold cavity.
Precision Machining
- Use CNC milling machines or machining centers to finely mill the mold cavity, maintaining tight tolerances (±0.1mm).
- Drill vacuum vent holes and cooling channel connections.
Surface Treatment
- Manually or mechanically polish the cavity surface to achieve a surface roughness of Ra 0.8–1.6μm, which reduces plastic sticking.
- Optional treatments include:
Teflon coating for improved release properties.
Hard anodizing to enhance wear resistance.
Mold Assembly and Testing
Mold Frame Installation
- Mount the machined aluminum cavity onto a steel mold frame or aluminum base, ensuring the parting surface is level.
- Connect the cooling water lines and vacuum system interface.
Trial and Adjustment
- Install the mold on a vacuum forming machine and test it using thick sheet plastic such as ABS or HDPE.
- Adjust forming parameters:
Heating temperature: 150–300°C depending on material.
Vacuum pressure: ≥0.08MPa.
Cooling time: As needed. - Check for smooth demolding and even wall thickness. Modify vent holes or heating zones if necessary.
Final Delivery and Maintenance
Final Inspection
- Conduct a sample run of 10–20 pieces to verify dimensional accuracy, appearance, and mold stability.
Maintenance Recommendations
- Regularly clean the vent holes to remove any plastic residue.
- Check cooling channels for blockages.
- Apply rust-preventive oil on the mold surface during long-term storage
Key Considerations
Cooling System Design
Keep water channels 8–15mm away from the cavity surface to ensure even heat dissipation.
Vacuum Venting Optimization
For thick sheet forming, better vacuum efficiency is essential. Add auxiliary venting grooves (depth: 0.05–0.1mm) if needed.
Casting Defect Prevention
Apply T6 heat treatment (solution treatment + aging) to relieve internal stress and reduce the risk of deformation.
Custom Quote
Need vacuum forming molds for large size or thick gauge plastic parts? Send us your requirements now to receive a personalized quotation and technical advice from our team.
CONTACT US
- Guangzhou SME Plastic Corp
- E-mail: [email protected]
- Mob: +86-13928889690
- Whatsapp: +86-13928889690
- Address: No.10, 3rd st, Minying Industrial Zone, Shawan Town,Panyu District, Guangzhou City, Guangdong, PRC
