US 11,718,003 B2
Method for simultaneous closed loop control of gas assist and gas counter pressure in an injection molding process relative to plastic melt pressure and plastic melt flow position
William Francis Lawless, III, Medford, MA (US); H. Kenneth Hanson, III, Cincinnati, OH (US); Gene Michael Altonen, West Chester, OH (US); and Chow-Chi Huang, West Chester, OH (US)
Assigned to IMFLUX INC., Hamilton, OH (US)
Filed by IMFLUX INC., Hamilton, OH (US)
Filed on Apr. 17, 2019, as Appl. No. 16/386,523.
Claims priority of provisional application 62/704,009, filed on Jun. 5, 2018.
Prior Publication US 2019/0366607 A1, Dec. 5, 2019
Int. Cl. B29C 45/17 (2006.01)
CPC B29C 45/1732 (2013.01) [B29C 45/1704 (2013.01); B29C 45/174 (2013.01); B29C 2045/1728 (2013.01); B29C 2945/76006 (2013.01); B29C 2945/7611 (2013.01); B29C 2945/76083 (2013.01); B29C 2945/76137 (2013.01); B29C 2945/76498 (2013.01); B29C 2945/76779 (2013.01); B29C 2945/76812 (2013.01); B29C 2945/76859 (2013.01); B29C 2945/76933 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A method for controlling an injection molding filling cycle, comprising:
injecting a molten thermoplastic material into a mold cavity;
injecting a first gas at an initial pressure into a portion of the mold cavity downstream of a flow front of the injected molten thermoplastic material;
determining a melt pressure of the injected molten thermoplastic material;
determining a flow front position of the injected molten thermoplastic material;
injecting, after the flow front has reached a first part specific position in the mold cavity, a second gas at an initial pressure into a portion of the mold cavity upstream of the flow front of the injected molten thermoplastic material;
increasing the pressure of the second gas until the melt flow reaches a second part specific position of the mold cavity;
changing, in real-time during a single injection molding filling cycle, the pressure of the first gas at least in part based on at least one of (i) the determined melt pressure of the injected molten thermoplastic material, or (ii) the determined flow front position of the injected molten thermoplastic material; and
changing, in real-time during the single injection molding filling cycle, in addition to increasing the pressure of the second gas until the melt flow reaches a second part specific position of the mold cavity, the pressure of the second gas at least in part based on at least one of (i) the determined melt pressure of the injected molten thermoplastic material, or (ii) the determined flow front position of the injected molten thermoplastic material.