Patent · US Expired

Device for manufacturing blocks of porous thermoplastic in a continuous process

US4008030A · kind A · utility

7Cited by
3References
2Claims
0Family size

Assignee

Inventor

Key dates

Filing dateSep 22, 1975
Grant dateFeb 15, 1977
Priority date
Expiry dateSep 22, 1995

Classification

  • Technology area (CPC B)Performing Operations; Transporting
  • CPC primaryB29C44/206
  • WIPO fieldOther special machines
  • WIPO sectorMechanical engineering

Abstract

Two, endless, perforated steel belts are mounted one above the other to travel about spaced rolls, and between a pair of spaced, parallel, stationary side walls, so that confronting portions of the belts form two sides of an elongate, rectangular channel. Granules of thermoplastic material are continuously fed into one end of the channel in a quantity sufficient to completely fill the channel. The moving belts convey the granules first past a heating zone, where steam is introduced through the perforated belts to cause the granules to expand, and then past a cooling zone, where the granules are sintered to form a solid, rectangular block which is discharged continuously from the opposite end of the channel and onto a surface where it is severed into individual blocks. The diameters of the holes in the belts range from 0.5 to 0.8 mm., and the number of holes ranges from 20,000 to 30,000 per square meter of belt.

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