Patent ID: 6221483
Filing Date: 2001-04-24
Classification: A61F,B29C,Y10T

Abstract:
A construction film comprising a coextrusion of adjacent elastic lanes and inelastic lanes for use in making a reversibly extensible stretchable film including a stretch zone which is tensioned by sheer loads during use of the stretchable film, said construction film having a machine direction and a cross direction with said lanes being laterally spaced in said cross direction and longitudinally parallel in said machine direction, said stretchable film being formed from said construction film so that said stretchable film has a length extending in the cross direction and a width extending in the machine direction of said construction film, said inelastic lanes being formed of a thermoplastic polymer and said elastic lanes being formed of a thermoplastic elastomer, said stretchable film and said construction film lanes being dimensioned so that said stretchable film has at least two spaced elastic lanes extending across the width of said stretchable film within said stretch zone to distribute shear loads applied to said stretchable film and inhibit propagation of tearing failures, said thermoplastic elastomer comprising a block polymer of molecules having rubbery segments and non-rubbery segments, said block polymer including terminal end segments formed of said rubbery segments.