The production of high-quality SMC molded parts is a sophisticated balance of material science and mechanical precision. By applying heat and pressure to Sheet Molding Compound (SMC) within a specialized mold, manufacturers can create complex, high-strength components used across various industries.
As a leading provider, RDS Composite ensures every step—from material cutting to thermal solidification—meets international standards. In this guide, we break down the three essential stages of the SMC molding process.
1. The Preparation Stage: Setting the Foundation
Success in molding begins long before the press is activated. Proper preparation prevents material shortages and surface defects.
- Material Pretreatment: SMC is typically stored at 4-10℃. It must be warmed at room temperature (20-25℃) for 4-8 hours to restore flowability.
- Precision Cutting: We cut the SMC sheet based on the mold cavity shape. Our principle is to "cover the cavity without waste," ensuring deep cavities have enough material reserved.
- Mold Maintenance: The mold is cleaned with compressed air and alcohol to remove residual resin. It is then preheated to 135-160℃, maintaining a uniform temperature (variance ≤5℃).
2. The Molding Stage: Pressure, Temperature, and Time
This is the critical phase where the SMC composite takes its final shape. We strictly control three core parameters:
Material Placement & Closing
The cut sheet is laid flat, following the "even distribution" principle. To compensate for potential molding loss, the charge weight is typically 5%-10% heavier than the final part. The mold closes at a controlled speed of 5-10mm/s to ensure seamless contact.
Pressurizing and Filling
The machine increases pressure to 10-50MPa. This high pressure forces the SMC to fill the entire cavity and discharge internal air, preventing bubbles or missing corners.
Thermal Solidification (Curing)
Curing time depends on the part's thickness:
- Thin-wall parts (1-3mm): 1-3 minutes.
- Thick-wall parts (5-10mm): 3-8 minutes. Complete curing is vital to avoid deformation and ensure mechanical strength.
3. Post-Treatment and Quality Control
Once the curing is complete, the part is removed using specialized fixtures to prevent burns.
- Trimming: Removing residual flash and overflow material.
-
Inspection: Ensuring the SMC components meet the specific dimensions and specifications of the customer’s drawings.
Why Choose RDS Composite for Your SMC Needs?
At RDS Composite, we specialize in customizing both SMC and DMC products in various sizes and shapes. Our commitment to quality control—from raw material procurement to final delivery—guarantees reliable, high-performance composite solutions for our global clients.
Ready to start your next project? Contact RDS Composite Today for professional advice on SMC molding and custom component manufacturing.