INJECTION MOULDING AT LOW, IN FACT, CONSTANT PRESSURE Russian patent published in 2015 - IPC B29C45/77 B29C45/78 

FIELD: process engineering.

SUBSTANCE: set of invention relates to injection moulding. Claimed process comprises the steps that follow. (a) Injection mould, not pressurized, is filled with the portion of fused thermoplastic material. The portion of said material features the melt pressure whereat after portion injection into the mould cavity exceeds that of fused thermoplastic material before injection. (b) The melt pressure is kept constant and equal less than 6000 psi during the mould cavity with the portion of fused thermoplastic material. Note here that the mould cavity inner part extending from at least for 2 mm from the mould cavity surface, the first to contact with the fused thermoplastic material portion, is kept at the temperature lower that 100°C. Said thermoplastic material features the moulding index varying from 0.1 g/10 min to approx 500 g/10 min.

EFFECT: decreased depth of boundary layer in the mould, accelerated cycle of one part forming, higher machine efficiency.

20 cl, 5 dwg