This invention relates to a strap feeding and tensioning mechanism which feeds strap around an article or a package and thereafter tensions the fed strap. After a loop is formed and tensioned, the strap ends are secured by a joint or seal.
It is known to tie packages of various shapes and configurations by means of thermoplastic strap. While such strap can be secured in place using an external seal which is crimped about overlapping strap regions, or by the so-called hot knife method, in many instances it is more desirable to secure the strap by fusing together the overlapping strap ends by the generation of heat in situ by the rapid relative movement of overlapping strap portions which are biased toward one another by externally applied pressure. Joints formed in the foregoing manner are commonly referred to as friction-fused joints.
In many packaging applications it is desirable to feed strap at a relatively high rate about a package and to pull considerable tension on the strap that has been looped about a package; however, convenient means for the rapid feeding of strap about a package and subsequent pulling of relatively high tension in the strap looped about a package heretofore have not been available.