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AssigneeShaw Industries Ltd.
InventorsRobert E. Steele, Michael A. Romano, Dilip K. Tailor
Estimating the term…
A longitudinally heat shrinkable closure sheet has a hold-down adhesive portion adjacent each longitudinal end for application on the exposed end portions a heat shrinkable wrap-around sleeve applied around a pipe or other article to be covered. Heat is applied to the closure sheet in order to weld the adhesive free portion of the underside of the closure sheet to the end portions of wrap-around sleeve. The initial shrinkage of the closure sheet between the hold-down adhesive portions draws it tightly into contact with the upper side of the end portions. Shearing forces are applied between the closure sheet and the end portions firstly as the closure sheet contracts relative to the end portions, and secondly, as the sleeve shrinks, develops hoop stress and stretches the closure sheet, and a high strength fusion bond is achieved between the closure sheet and sleeve.
A heat shrinkable closure for a dimensionally heat unstable wrap-around covering, said closure comprising s fusion bondable sheet of flexible material having longitudinally spaced end portions, the material having been stretched from an original heat stable form to a dimensionally heat unstable form capable of moving in the direction of its original form by the application of heat alone, said sheet having on one side to be applied to said covering a hold-down adhesive portion extending across a zone transverse to said direction of stretch and adjacent each said end portion, and an adhesive free zone between said hold down adhesive portions whereby said closure can be applied over adjoining end portions adhesively bonded to the end portions of wrap-around covering and whereby said one side of the closure can be fusion bonded to the upper sides of said end portions of said covering.
A closure as claimed in claim wherein said closure sheet is a weld efficient polymer.
A closure as claimed in claim wherein said closure sheet material is crosslinked to a degree of about 25% to about 85%.
A closure as claimed in claim wherein the recovered thickness of said closure sheet is about 0.01 to about 0.2 inches thick.
A sleeve structure comprising a wrap-around covering and a closure therefor, said covering comprising a sheet of dimensionally heat unstable flexible material having longitudinally spaced end portions capable of being juxtaposed when the covering sheet is applied to an article to be covered, said closure comprising a sheet of flexible material fusion bondable with said covering sheet and having longitudinally spaced end portions, the material of each of the closure sheet and the covering sheet having been stretched in the longitudinal direction from an original dimensionally heat stable form to a dimensionally heat unstable form capable of moving in the direction of its original form by the application of heat alone, said closure sheet having on a side to be applied to said covering a hold-down adhesive portion extending across a transverse zone adjacent each said end portions, and an adhesive free zone between said hold-down adhesive portions whereby said closure can be applied over adjoining end portions of said wrap-around covering with said hold-down adhesive portions adhesively bonded to the end portions of said wrap-around covering and whereby said side of the closure can be fusion bonded to the upper sides of said end portions of said covering.
The structure as claimed in clain 30 having a thermochromic indicator on said one side of said sheet and visible through said translucent or transparent sheet from an opposite side.
A method of applying a close fitting protective covering to an article to be covered, comprising providing a covering sheet and a closure sheet each having longitudinal end portions and each having been stretched in the longitudinal direction from an original heat stable form to a dimensionally heat unstable form capable of moving in the direction of its original form by the application of heat alone, said closure sheet having on one side a hold-down adhesive portion extending across a transverse zone adjacent each end portion and an adhesive free zone between the hold-down adhesive portions, wrapping the covering sheet around the article by laying the sheet against the article and juxtaposing its end portions, applying the closure sheet to said covering sheet with its adhesive free zone spanning said end portions and bonding the hold-down adhesive covered portions on said end portions, respectively, heating the closure sheet to effect a fusion bond between the adhesive free zone of the closure sheet and said end portions of the covering sheet, and heating the covering sheet to shrink it into close fitting relation to the article.
Dependencies are inferred from the claim text.