Method of making a molded plastic product
US4824627A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 12, 1988 |
| Grant date | Apr 25, 1989 |
| Priority date | — |
| Expiry date | Apr 12, 2008 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S264/92
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
The method of the present invention involves taking a comminuted mixture of waste plastic materials, feeding the mixture into a screw extruder capable of applying heat and pressure to the mixture; using the screw extruder to heat the mixture to a temperature of between 350.degree. and 600.degree. Fahrenheit; and forcing the molten mixture outwardly through a die opening under a pressure of from 100 lbs. per sq. inch to 600 lbs. per sq. inch into a mold in tightly sealed relationship over the die opening. The mold, after being filled, is removed from the screw extruder, and the mixture is permitted to cool and harden in the mold. The hardened mixture is then removed from the mold.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.