Device for manufacturing blocks of porous thermoplastic in a continuous process

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.

Dependencies are inferred from the claim text.