Polyester Straps Useful in Binding Applications, Methods of Manufacture, Systems and Uses Thereof

Abstract

The present invention relates to polyester straps, methods of their manufacture, systems and uses thereof, particularly as may be used in binding applications of discrete articles into bundles. The polyester straps comprise voids extending into the interior of the strap from one or more of the surfaces there

1 . A plastic strap formed of an at least partially crystalline thermoplastic material which is ultrasonically welded, the plastic strap having a length, a width and a thickness, two substantially parallel major faces having a width and a length separated by the thickness, at least one of the major faces having a plurality of voids extending into the thickness from the major face, each of the voids having straight boundary lines at their periphery wherein they intersect a major face of the plastic strap, each of the voids present in the interior of the plastic strap and having a depth, a void surface area and a void volume measurable from the major face of the plastic strap, wherein per unit length of the plastic strap the cumulative void surface area is from 20% to 90%, and the cumulative void volume is from 5% to 65 in the region of the plastic strap which is subsequently ultrasonically welded and at least partially melted forming a bond therebetween. 
     
     
         2 . The plastic strap of  claim 1 , wherein the plastic strap comprises a substantial portion of a polyalkylene terephthalate. 
     
     
         3 . The plastic strap of  claim 2 , wherein the polyalkylene terephthalate is polyethylene terephthalate. 
     
     
         4 . The plastic strap of  claim 1  which has a width not in excess of 5 mm. 
     
     
         5 . The plastic strap  claim 1  wherein the voids are present in an array. 
     
     
         6 . The plastic strap of  claim 1  wherein the voids have boundary lines of parallelogram shape having four apices and which voids have a pyramidal cross-section. 
     
     
         7 . The plastic strap of  claim 1  wherein peripheral boundary of most of the voids present on a major face of a plastic strap are entirely within the width of the plastic strap, but which include incomplete voids having peripheral boundaries which intersect the and edge of the plastic strap. 
     
     
         8 . The plastic strap of  claim 1 , wherein the cumulative void volume is from 25% to 30% in the region of the plastic strap which is subsequently ultrasonically welded and at least partially melted forming a bond therebetween. 
     
     
         9 . The plastic strap of  claim 8 , which has a width not in excess of 5 mm. 
     
     
         10 . A process for tensile bundling of loads which comprises the steps of,
 utilizing a plastic strap according to  claim 1 ,   forming a loop about the load with the plastic strap, and,   ultrasonically welding parts of the looped plastic strap.   
     
     
         11 . The process of  claim 10  where the plastic strap has a width no in excess of 5 mm. 
     
     
         12 . A bundled load comprising an ultrasonically welded formed loop of a plastic strap according to  claim 1 .