Vertical, form, fill and seal machine with heating element resistant to thermal cycling

Abstract

A vertical form, fill and seal machine of the type that includes at least one fill chamber for forming liquid-filled pouches of impermeable material. A heating element is fixed to a slidable sealing head. The heating element comprises a ribbon of metallic material, and an insulative base having a slot for receiving the metallic ribbon. The sealing head faces a backstop. The metallic ribbon is held at and above the upper edge of a pedestal formed in the insulative base. The insulative base is formed of mating base elements secured to one another by at least one fastener.

1 . In a vertical form, fill and seal machine for forming liquid-filled sealed pouches of heat sealable web material, of the type that includes at least one fill chamber that comprises a slidable sealing head having a heating element comprising a metallic ribbon fixed to an insulative base and a backstop aligned in opposed relation to said sealing head with said sealing head including opposed surfaces facing toward and away from said backstop with said insulative base being fixed to said surface of said sealing head that faces said backstop, said metallic ribbon being fixed to said insulative base so that an edge thereof extends above said insulative base, the improvement in said machine comprising said insulative base comprising a pair of mating base elements arranged to define a slot therebetween for receiving said ribbon. 
     
     
         2 . A vertical form, fill and seal machine as defined in  claim 1  wherein said sealing head further includes at least one fastener for maintaining said base elements in intimate contact. 
     
     
         3 . A vertical form, fill and seal machine as defined in  claim 2  wherein said base further comprises;
 a) a pedestal, said pedestal spanning said base; and   b) said slot for receiving said heating element being located within and extending above an upper surface of said pedestal.   
     
     
         4 . A vertical form, fill and seal machine as defined in  claim 3  further including:
 a) each of said base elements comprising a pedestal section;   b) said pedestal section of each base element being located adjacent a mating edge of each of said base elements.   
     
     
         5 . A vertical form, fill and seal machine as defined in  claim 4  wherein said at least one fastener traverses mating pedestal sections of said base elements. 
     
     
         6 . A vertical form, fill and seal machine as defined in  claim 1  wherein said metallic ribbon comprises titanium. 
     
     
         7 . A vertical form, fill and seal machine as defined in  claim 1  wherein said base is of molded ceramic material.