3. Implementation

3.1 Injection

PP injection conditions depend essentially on the dimensions of the object to be manufactured. Injection pressure ranges from 80 to 200 MPa; injection temperature can vary from 210 to 280 ˚C; the mold is generally at room temperature. Shrinkage of molded parts is between 1 and 3%.

Today's injection molding machines, with their very short cycle times and the development of suitable grades, enable the injection of thin-walled objects such as butter or margarine packaging, or yoghurt pots. Injection molding thus competes with thermoforming.