Patent · US Expired

Screw extruder for plastics

US4569595A · kind A · utility

8Cited by
13References
10Claims
0Family size

Assignee

Inventor

Key dates

Filing dateJun 7, 1985
Grant dateFeb 11, 1986
Priority date
Expiry dateJun 7, 2005

Classification

  • Technology area (CPC B)Performing Operations; Transporting
  • CPC primaryB29C48/03
  • WIPO fieldOther special machines
  • WIPO sectorMechanical engineering

Abstract

The cylinder of the extruder comprises two parts separated by a heat-insulating gasket. In the wall of the upstream part there are ducts through which a cooling fluid flows. The inside surface of the upstream part is provided with parallel longitudinal grooves or spiralling grooves. The screw is divided into two zones, viz., a feed zone and a plasticizing zone which starts just after the heat-insulating gasket. The plasticizing zone includes an entry channel which gradually decreases in depth downstream and an exit channel which gradually increases in depth downstream. The mass of plastic material leaving the extruder is homogeneous and at a predetermined temperature with high output, as independently as possible of the material used.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.