Heat-shrinkable elastomer production

A method of producing a heat-shrinkable elastomer comprising the steps of: (a) without the application of external heat, extending an elastomer comprising a copolymer of alternating polyamide and polyether repeat block polymer segments to an extension beyond that at which permanent deformation occurs thereby to orient said elastomer uniaxially, and (b) subsequently releasing the tension on said elastomer to allow natural relaxation thereof to a linear density substantially above the minimum linear density achieved in the extension of step (a) and substantially below that of said elastomer before the extension of step (a). Upon subsequent application of heat, the elastomer shrinks and recovers its elastic properties. Articles or garments such as disposable diapers advantageously use the heat-shrinkable elastomer of the present invention as a means to shirr portions thereof, such as waistbands.