Cooling tube with porous insert

Abstract

An injection-molding machine cooling tube, which cools molded plastic parts, includes a porous cooling tube having an outer surface and an inner surface. Preferably, the porous cooling tube has a porosity in the range of 3-20 microns. A cooling fluid passageway is preferably disposed adjacent the porous cooling tube outer surface and is configured to carry a cooling fluid to extract heat from the porous cooling tube. Fluid flow structure, preferably a vacuum, is configured to cause a molded plastic part inside the porous cooling tube to expand into contact with at least a portion of the inner surface of the porous cooling tube.

1 - 21 . (canceled)  
     
     
         22 . A molded plastic article, comprising: 
 a closed end:    an open end;    an inside surface; and    an outside surface;    a portion of the outside surface having a profile corresponding substantially to a porous cooling cavity inside surface which has interstitial spaces that are configured to provide, in use, a low pressure sufficient to cause the molded plastic article to expand and contact the cooling cavity inside surface, the portion of the molded plastic article outside surface having surface finish which corresponds substantially to the interstitial spaces of the porous cooling cavity.    
     
     
         23 . A molded plastic article with a shape of at least a portion of its outside surface defined by a profiled inside surface of a porous member, the molded plastic article formed by the process of: 
 (i) receiving a malleable molded plastic article into the porous member;    (ii) evacuating the air surrounding the molded plastic article through a plurality of interstitial spaces that are configured along the inside surface of said porous member causing the portion of the outside surface of the molded plastic article to move into contact with the profiled inside surface of the porous member, thereby to attain a shape substantially corresponding to the profiled inside surface; and    (iii) extracting heat from the molded plastic article through a heat dissipation path to solidify the molded plastic article sufficiently such that the outer shape of the molded plastic article is preserved; whereby the portion of the outside surface of the molded plastic article takes on a surface finish that corresponds substantially to the interstitial spaces of the porous cooling cavity.    
     
     
         24 . The molded plastic article according to  claim 22 , wherein the porous member is formed of a porous substrate with the profiled inside surface having interstitial spaces preferably within a range of about 3 to 20 microns. 
 (i) receiving a malleable molded plastic article into the porous member;    (ii) evacuating the air surrounding the molded plastic article through a plurality of interstitial spaces that are configured along the inside surface of said porous member causing the portion of the outside surface of the molded plastic article to move into contact with the profiled inside surface of the porous member, thereby to attain a shape substantially corresponding to the profiled inside surface; and    (iii) extracting heat from the molded plastic article through a heat dissipation path to solidify the molded plastic article sufficiently such that the outer shape of the molded plastic article is preserved; whereby the portion of the outside surface of the molded plastic article takes on a surface finish that corresponds substantially to the interstitial spaces of the porous cooling cavity.    
     
     
         25 . The molded plastic article according to  claim 22 , wherein molded plastic article is a preform.