Compression is a process used to shape thermoplastic and composite materials.
It consists of making a product by means of compressing the material using a hydraulic press in a mold.
THERMOPLASTIC COMPRESSION
The material used is a semi-finished product composed of a fiber reinforcement (glass, carbon, etc.) impregnated or powdered with a thermoplastic binder. It comes in the form of a thick sheet.
A hydraulic press compresses this compound after it has been placed in a metal die and heated to the temperature for the transformation of the thermoplastic binder.
Where used :
- The manufacturing of complex, large parts with two smooth sides.
- Considerable molding precision is possible with this process and the raw material offers sought-after properties.
- Investments are high and molding speed is low when compared with mass car production, for example.
SMC (SHEET MOULDING COMPOUNDS)
SMC is a semi-finished thermoset product consisting of a chopped fiber reinforcement sheet impregnated with a polyester resin. It comes in the form of a thick sheet.
A hydraulic press compresses this compound in a mold at a temperature between 140 and 160°C and a pressure of 50 to 100 bar.
Where used :
- The manufacturing of complex, large parts with two smooth sides.
- Considerable molding precision is possible with this process and the raw material offers sought-after properties.
- Investments are high and molding speed is low when compared with mass car production, for example.
BMC (BULK MOULDING COMPOUNDS)
BMC is a polyester resin-based semi-finished product with various loads and additives, reinforced with chopped glass fibre. It comes in bulk.
A press injects it or compresses this compound in a closed mold at a temperature between 150 and 160°C at high pressure from 150 to 180 bar.
Where used :
- The manufacturing of complex, large parts with two smooth sides.
- Great molding precision is possible with this process, even though the raw material is less expensive. The labor has little influence over the quality of the product.
- For this reason, investments are lower and molding speed is higher.
- But the mechanical properties of this technology are modest.
- Dimensions are limited and the material must be precisely measured.
