Compression molding is a closed-mold composite manufacturing process where fiber-reinforced resin is compressed under heat and pressure to form high-strength components. It integrates engineered textile reinforcements like woven and nonwoven fabrics, enabling precise control of structural performance—making it a key process in technical textile-based composites.
Step by Step Guide
- Material Preparation :SMC/BMC or prepreg textile-reinforced charge prepared
- Mold Loading : Material placed into heated steel/aluminum mold
- Compression : Hydraulic press applies high pressure to shape material
- Curing : Heat activates resin flow and solidification
- De-molding : Finished part ejected with near-net shape
Materials Used
Fibers
- Glass Fiber (cost-efficient, widely used)
- Carbon Fiber (high strength & stiffness)
- Aramid Fiber (impact resistance)
Fabric Forms
- Woven Fabrics
- Nonwoven Mats (glass mats)
- Multiaxial Fabrics
- Preforms (stitched / 3D textiles)
Resins
- Thermosets: Polyester, Epoxy, Vinyl Ester
- Thermoplastics: Polypropylene (PP), Polyamide (PA), PEEK
Advantages
- High strength & structural integrity
- Excellent surface finish (both sides)
- Consistent quality for mass production
- Low material waste (near-net shaping)
Limitations
- High tooling and mold cost
- Limited flexibility for design changes
- Requires precise material placement
Applications & End Products
Automotive
Body panels, bumpers, engine covers
Aerospace
Interior panels, structural components
Electrical & Electronics
Insulators, switchgear housings
Consumer & Sports
Appliance housings, furniture, bicycle frames, prosthetics
Selection Criteria
Choose compression molding when:
- High production volume is required
- Complex shapes with smooth surfaces are needed
- Structural strength and consistency are critical
- Textile-reinforced composites are essential
- Low waste and repeatability are priorities