Method and apparatus for purging leaked resin in a preplasticization injection molding machine
US6284167A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 8, 1998 |
| Grant date | Sep 4, 2001 |
| Priority date | — |
| Expiry date | Dec 8, 2018 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C45/1753
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
When a process measurement metering operation is performed during a molding cycle, a plunger is forcibly caused to retract to a position behind measurement metering completed position, while at the same time a periodic forced purge operation is implemented in which the plunger is immediately restored to the vicinity of the position at which the forced retraction operation commenced. By this operation, leaked resin is removed to the rear, i.e., beyond the plunger metering stroke range, and any increase in resistance to movement of the plunger due to disposition of leaked resin is avoided. The forced purge operation is preferably performed either immediately prior to the normal metering operation, or after a specified time has elapsed following completion of a metering operation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.