SME Plastic is a professional custom FRP vacuum forming molds manufacturer from China, our FRP molds are a cost-effective solution for producing large plastic parts that do not require high dimensional accuracy. They are commonly used in bathtub forming and similar applications where lightweight and flexibility are important.
FRP Vacuum Forming Mold Products
FRP Vacuum Forming Mold Production Process
Preliminary Preparation
3D Design and Verification
Based on the 3D model of the bathtub, determine the mold’s parting line and optimize the draft angle (usually ≥3° to prevent sticking).
Design vacuum suction holes with a diameter of 0.8–1.5 mm and spacing of 20–30 mm, focusing on corners and deep grooves for better suction performance.
Master Mold Fabrication
High-Precision Master Mold: CNC-machined aluminum mold or resin prototype coated with high-gloss gel coat.
Surface Treatment: Polish the surface to Ra ≤ 0.2 μm (mirror finish) and apply a high-temperature mold release agent (e.g., silicone-based).
Mold Body Fabrication (Example: Aluminum Alloy Mold)
Material Selection
Use 6061 or 7075 aluminum alloy for its high strength and excellent thermal conductivity.
Thickness varies depending on bathtub size (typically 20–50 mm).
CNC Machining
Rough Machining: Leave a machining allowance of 0.5–1 mm to remove excess material.
Finishing: Use ball-end milling tools to form curved surfaces, ensuring a surface roughness of Ra ≤ 0.8 μm.
Drilling: Follow design drawings to drill vacuum holes and cooling channels (if temperature control is required).
Vacuum System Integration
Machine vacuum grooves (depth 3–5 mm) on the back of the mold and connect to a vacuum pump interface.
Install quick-connect vacuum fittings (recommended pneumatic connectors of Φ8–10 mm).
Surface Hardening (Optional)
Apply anodizing (thickness 10–20 μm) or spray Teflon coating to improve wear resistance and demolding performance.
Resin Composite Mold Fabrication (Cost-Effective Option)
Master Mold Replication
Apply silicone or fiberglass over the prototype to create a negative mold.
Spray a mixture of epoxy resin and aluminum powder (2:1 ratio) inside the negative mold to a thickness of 8–10 mm.
Reinforcement Structure Embedding
Add laminated steel plates or aluminum honeycomb cores to enhance structural rigidity.
Embed copper tubes to form internal cooling channels, connected to an external water circulation system.
Vacuum Hole Processing
After curing, drill suction holes and install nylon vacuum nozzles designed to prevent blockage.
Mold Testing and Verification
Vacuum Testing
Connect the mold to a vacuum pump (vacuum level ≥ -0.08 MPa).
Cover the mold surface with a plastic film to check for even suction across the surface.
Temperature Control Testing (Optional)
Heat the mold to 80–100°C using electric heaters or oil temperature machines.
Test temperature distribution; ensure the variance is within ±5°C.
Trial Forming
Use acrylic or PETG sheets for vacuum forming tests.
Inspect for forming depth, surface defects (e.g., orange peel), etc.
Adjust vacuum hole layout or heating parameters to improve forming quality.
Custom Quote
Interested in affordable molds for large bathtubs or Jacuzzi? Submit your inquiry through below contact form to receive a tailored quote from our experts.
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
