Film of plastics material stretched to present a privileged shrinkage orientation, a heat-shrink sleeve made out of the film, and an article covered in such a sleeve

Abstract

The invention relates to a film of plastics material stretched to present a privileged shrinkage orientation and used in particular for fabricating heat-shrink sleeves, the film including at least one line of mechanical weakness and at least one local region of extra thickness extending along the line of weakness so as to border it, the line of weakness and the adjacent local region of extra thickness together defining a tear line. According to the invention, the local region of extra thickness is constituted by applying liquid or semi-liquid material to the film, the applied material being applied to the film in a quantity that depends on the expected shrinkage ratio in the portion of the film that includes the tear line while a sleeve made using such a film is being heat-shrunk onto an article.

1 . A film of plastics material stretched to present a privileged shrinkage orientation and used in particular for fabricating heat-shrink sleeves, the film including at least one line of mechanical weakness and at least one local region of extra thickness extending along the line of weakness so as to border it, the line of weakness and the adjacent local region of extra thickness together defining a tear line, wherein the local region of extra thickness is constituted by applying liquid or semi-liquid material to the film, the applied material being applied to the film in a quantity that depends on the expected shrinkage ratio in the portion of the film that includes the tear line while a sleeve made using such a film is being heat-shrunk onto an article. 
     
     
         2 . The film according to  claim 1 , wherein the quantity of material applied is inversely proportional to said expected shrinkage ratio. 
     
     
         3 . The film according to  claim 1 , wherein the applied material is polymer varnish. 
     
     
         4 . The film according to  claim 3 , wherein the varnish is treated to increase the visibility of the tear line. 
     
     
         5 . The film according to  claim 4 , wherein the treatment is selected from dying the varnish, including pigments, including flakes. 
     
     
         6 . The film according to  claim 1 , including two local regions of extra thickness bordering the line of weakness on either side thereof. 
     
     
         7 . The film according to  claim 1 , wherein the tear line extends around a closed outline. 
     
     
         8 . The film according to  claim 1 , having two parallel tear lines defining a tear strip between them. 
     
     
         9 . The film according to  claim 8 , including a cutout extending transversely to the two tear lines so as to define a grip tab in the tear strip. 
     
     
         10 . A heat-shrink sleeve fabricated from a film according to  claim 1 . 
     
     
         11 . An article covered by a sleeve according to  claim 10  by heat-shrinking.