Method of building up pressure by multi-shaft screw extruders
US4040607A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 22, 1975 |
| Grant date | Aug 9, 1977 |
| Priority date | — |
| Expiry date | Sep 22, 1995 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C48/03
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
This invention relates to multi-shaft screw extruders in which the screw shafts are arranged to intermesh in pairs and rotate pairwise in the same sense, each shaft of a pair having at least one double threaded or triple threaded pressure build-up section corresponding to that of the other shaft. This invention also relates to a method of using such an extruder to build up pressure within a material with a minimum pressure build-up section and a minimum power input. The extruder and its method of operation are characterized by the fact that at least a portion of the pressure build-up section satisfies ##EQU1## WHEREIN T IS THE SCREW PITCH, D IS THE INTERNAL DIAMETER OF THE HOUSING, Q IS THE VOLUMETRIC THROUGHPUT OF MATERIAL OF A SCREW PAIR AND N IS THE SPEED OF ROTATION OF THE SCREW SHAFTS AND: ##EQU2## WHEREIN IN TRIPLE THREAD PRESSURE BUILD-UP SECTIONS A = 0.1082; PA1 a = 15.316; PA1 b = 69.111; And PA1 c = 261.85 And in double thread pressure build-up sections PA1 A = 0.206; PA1 a = 8.8212; PA1 b = 18.414; And PA1 c = 31.668.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.