Injection molding apparatus, injection molding system, pellet feeding unit, method for injection molding, and injection molding product

摘要

In a conventionally used injection molding apparatus, undried resin pellet is put in a drier of a predetermined temperature and water and gas in the undried resin pellet is completely removed, and the dried pellet deprived of water and gas is thrown into the injection molding apparatus. It is therefore necessary to carefully control quality of water and gas of pellet before pellet is thrown into the injection molding apparatus. In injection molding of undried resin pellet, evaluate injected resin, control operation conditions such as the feeding amount of pellet and the decompression degree, and determine the best operation conditions and the best accumulation amount wherein excellent articles are obtained. The accumulation amount of pellet fed in an injection molding chamber is detected, and feeding to the injection molding chamber is controlled upon the detection information. In the process of melting of the injection molding chamber, water and gas vaporized from pellet is discharged to the atmosphere under decompression.