Apparatus for cooling and sizing hot thermoplastic extrudates

Claim 1

Apparatus for cooling and sizing a hot thermo-plastic extrudate which comprises a continuous hollow porous sleeve having inner and outer surfaces, the inner surface having the desired eventual shape of the extrudate, said sleeve having a series of adjacent transverse sections with respect to the longitudinal axis of the sleeve, each section having at least a partial lateral seal between it and its neighboring adjacent sections, the outer surfaces of alternating sections of the sleeve being connected to a first liquid coolant system under sufficient pressure to force cooling liquid through the pores in the sleeve inwardly through the sections such that the liquid contacts the extrudate and the outer surfaces of the alternating remaining sections of said sleeve being connected to a second liquid coolant system under sufficient reduced pressure to draw a portion of the cooling liquid outwardly through the section via the pores in the sleeve, said liquid coolant systems including means for maintaining the aforesaid pressures on the cooling liquid and for sealing said liquid coolant system against atmospheric pressure outside the apparatus.