Injection molding method for producing shaped, hollow resin articles, and mold for use therein
US5902541A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 12, 1997 |
| Grant date | May 11, 1999 |
| Priority date | — |
| Expiry date | Mar 12, 2017 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C2045/1717
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
Disclosed is an injection molding method for producing a shaped, hollow resin article by introducing a pressurized fluid into a molten resin mass injected into a mold cavity, wherein, during the introduction of the pressurized fluid, the temperature of at least one preselected portion of a back surface of the molten resin mass is maintained at a level which is at least 5.degree. C. higher than the temperature of a front surface of the molten resin mass, causing the fluid to flow into the molten resin mass along a line substantially corresponding to a line along which the preselected portion of the back surface extends, so that a shaped, hollow resin article produced has a hollow in a position corresponding to the preselected portion of the back surface. By the method of the present invention, the flow of the pressurized fluid introduced can be surely led to an intended portion in the molten resin mass, so that the location of a hollow in the molten resin mass can be surely controlled. According to one preferred embodiment of the present invention, the shaped, hollow resin article produced has a thickness of at least 1.0 mm as measured at a portion having a hollow therein. According…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.