Abstract 1. Method for shaping hollow extruded articles of synthetic thermoplastic which comprises (1) passing a still warm hollow, extruded article through a zone sealed off at the inlet and outlet and containing a low pressure gaseous medium created by applying suction to said zone, the interior of said hollow article being under atmospheric pressure; (2) dimensioning said hollow article by the action of said suction and cooling said hollow article simultaneously in said zone while applying said suction to said zone; (3) dimensioning said hollow article in said zone by passing said hollow article in the presence of said low pressure gaseous medium through spaced apart shaping plates arranged one behind the other in said zone, said plates having apertures corresponding to the profile of said hollow article, said suction conforming said hollow article to the apertures of said shaping plates; and (4) simultaneously cooling said hollow article in said zone by spraying said hollow article between said shaping plates with a cooling liquid from sources located near said shaping plates and extending along said hollow article and said shaping plates thereby forming a hardened boundary layer on the surface of said hollow article immediately after extrusion which stabilizes and supports said hollow article as it passes through said zone.
Method for shaping hollow extruded articles of synthetic thermoplastic which comprises (1) passing a still warm hollow, extruded article through a zone sealed off at the inlet and outlet and containing a low pressure gaseous medium created by applying suction to said zone, the interior of said hollow article being under atmospheric pressure; (2) dimensioning said hollow article by the action of said suction and cooling said hollow article simultaneously in said zone while applying said suction to said zone; (3) dimensioning said hollow article in said zone by passing said hollow article in the presence of said low pressure gaseous medium through spaced apart shaping plates arranged one behind the other in said zone, said plates having apertures corresponding to the profile of said hollow article, said suction conforming said hollow article to the apertures of said shaping plates; and (4) simultaneously cooling said hollow article in said zone by spraying said hollow article between said shaping plates with a cooling liquid from sources located near said shaping plates and extending along said hollow article and said shaping plates thereby forming a hardened boundary layer on the surface of said hollow article immediately after extrusion which stabilizes and supports said hollow article as it passes through said zone.
Claim 2
Dependent Claim
209 words
Method for shaping hollow extruded articles of synthetic thermoplastic which comprises (1) passing a still warm hollow, extruded article through a zone sealed off at the inlet and outlet and containing a low pressure gaseous medium created by applying suction to said zone, the interior of said hollow article being under atmospheric pressure; (2) dimensioning said hollow article by the action of said suction and cooling said hollow article simultaneously in said zone while applying said suction to said zone; (3) dimensioning said hollow article in said zone by passing said hollow article in the presence of said low pressure gaseous medium through spaced apart shaping plates arranged one behind the other in said zone, said plates having apertures corresponding to the profile of said hollow article, said suction conforming said hollow article to the apertures of said shaping plates; and (4) simultaneously cooling said hollow article in said zone by spraying said hollow article between said shaping plates with a cooling liquid from sources located near said shaping plates and extending along said hollow article and said shaping plates thereby forming a hardened boundary layer on the surface of said hollow article immediately after extrusion which stabilizes and supports said hollow article as it passes through said zone.