Method and apparatus for extruding plastic conduit

Abstract

Abstract 960,715. Extruding thermoplastic tubing. PLASTEX CO. June 5, 1961, No. 20204/61. Heading B5A. Thermoplastic tubing 23 is extruded through a die 22 and drawn by tensioning rollers 30 through a liquid coolant bath 25 contained in a container 26 and communicating pipe sections 27, 28, a further liquid coolant at a temperature below that of the bath 25 being supplied continuously to the interior of the tubing 23 at a point below the surface level 38 of the bath 25 and withdrawn continuously whilst maintaining its surface level 64 above the bath level 38. In one embodiment (Figs. 1 and 2) the die 22 has a bore 46 housing a liquid coolant supply pipe 50 and a vertically adjustable suction pipe 48 for discharging warmed coolant from the interior and controlling the level 64. The level 38 is determined by the position of the top 40 of a vertically adjustable, flexible hose 24 communicating with the bath 25. In an alternative embodiment (Fig. 4, not shown) the pipe 48 is dispensed with and the coolant liquid is drained through the open end of the tubing 23, the height of the rollers 30 being adjustable to control the liquid level 64 at each end of the tubing 23. In a further embodiment (Fig. 5) liquid coolant is supplied to the tube interior through a pipe 100 contained within a suction pipe 102, the pipe 100 being provided with orifices 124 to facilitate cooling near the surface 118.

Inventors

• 👤 Joseph H Given

Bibliographic Details