Zipper End Sealing

Abstract

A method of sealing together end portions of zipper profile lengths 12, 14 uses a heated pin 18 which is inserted into the end portions of the joined profile lengths to form a cavity 32 which is closed by subsequent application of pressure by a pressure element 28. The method avoids the use of heated crushing devices and ultrasonics.

1 . A method of joining an end of a pair of zipper profiles, the method comprising: 
 bringing the zipper profiles into engagement with each other at least over an end portion at which the profiles are to be joined;    introducing a heated probe into the engaged end portions of the zipper profiles in order to form a recess in the zipper profile material in the region of the probe;    withdrawing the probe; and    applying external pressure to the end portion of the zipper.    
     
     
         2 . A method according to  claim 1 , in which the pressure is applied in the absence of external heat.  
     
     
         3 . A method according to  claim 2 , in which the pressure is applied as the sole external means of joining the profile end portions.  
     
     
         4 . A method according to  claim 1 , in which the probe is introduced into the profile end portions in a direction substantially longitudinally of the profile lengths.  
     
     
         5 . A method according to  claim 1 , in which the recess is formed at least partially by vaporisation of the zipper profile material.  
     
     
         6 . A method according to  claim 1 , carried out simultaneously on both ends of the zipper profiles.  
     
     
         7 . An apparatus for joining the ends of a pair of zipper profiles, the apparatus comprising a means for receiving a pair of zipper profile lengths in engagement with each other over at least over an end portion at which the profiles are to be joined, a probe which is movable between a first position in which, in use, it is clear of the engaged profile lengths and a second position in which it has penetrated into the material of the end portions, means for heating the probe, and means for applying external pressure to the zipper profile end portions when the probe is in its second position.  
     
     
         8 . An apparatus according to  claim 7 , in which the probe is movable between its first and second positions in a direction substantially longitudinally of the profiles.  
     
     
         9 . An apparatus according to  claim 7 , in which the heating means comprises and electrical heating element within a rear portion of the probe.  
     
     
         10 . An apparatus according to  claim 7 , including a further said probe, heating means and external pressure means at the opposite end of the receiving means.  
     
     
         11 - 12 . (canceled)