Embodiments of the present invention are directed to a method of application of heat-shrinkable articles to an apparatus, such as, for example, a conduit, an air duct, a piping apparatus, and the like. In an embodiment of the present invention, a method of application of a heat-shrinkable article comprising thermoset cross-linked polymeric compositions that comprise less than about 50 percent by weight of a polypropylene polymer is provided.
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Other embodiments of the present invention include a heat-shrinkable article 200 having a first end 202, wherein the first end 202 has multiple extended portions 206 and multiple non-extended portions 208, arranged in a design based upon the specific application. One embodiment of the present invention includes a heat-shrinkable article 200 having a first end 202 and a second end 204, wherein the first end 202 has multiple extended portions 206 and multiple non-extended portions 208 positioned adjacent to each other.
The article 200 may have an adhesive compound applied to a side of the article 200, such that the adhesive compound contacts the apparatus when the article 200 is applied in operation. The adhesive compound may be a heat-sealing adhesive, a pressure sensitive adhesive, a combination of the two, and the like. An example of an adhesive compound is described in U.S. Pat. No. 6,841,212, entitled “Heat-Recoverable Composition and Article,” which, herein, is incorporated by reference in its entirety. Other embodiments of the present invention include applying a coating of epoxy to the sleeve as an adhesive for affixing the sleeve during application.
The pipes 302 may be made primarily of material 304, such as metal, that has a lower bonding temperature to apply a heat-shrinkable article than an area of the pipe 302 that may be coated with a protective coating 306, such as, for example, a thermoplastic corrosion protective coating, which has a higher bonding temperature when applying a heat-shrinkable article. When joined end to end, the metal 304 may be exposed to facilitate sealing of the pipes 302 together.
The heat-sleeve 308 may comprise a thermoset cross-linked polymeric composition having at least one polypropylene polymer and at least one polyethylene polymer, the thermoset cross-linked polymeric composition having a polypropylene content of less than about 50 percent by weight, and having a polyethylene content of less than about 50 percent by weight, based on the total weight of the cross-linked polymeric composition. An adhesive compound is applied to a side of the heat-sleeve that is placed adjacent to the pipes 302. The heat-sleeve 308 has a first end 310 and a second end 312, wherein the first end 310 has at least one extended portion 314 and one or more non-extended portions 316. In an embodiment of the present invention, the extended portion 314 is sized from about 5 centimeters to about 10 centimeters in height from the non-extended portions 316.
When the heat-sleeve 308 is applied to the pipes 302, the heat-sleeve 308 wraps around the pipe ends and the first end 310 and the second end 312 are positioned such that the extended portion 314 substantially covers the exposed pipe metal 304 and is layered with an area 320 of the second end 312, producing a double layer of heat-sleeve material 308. The non-extended portions 316 are positioned to substantially cover the protective coating 306 of the pipe but not the exposed pipe metal 304. Further, the non-extended portions 316 are positioned such that an edge portion 322 of the non-extended portions 316 abuts a first edge portion 320 of the second end 312, producing a single layer of heat-sleeve material 308.
Heat then is applied to the system 300 to cause shrinkage of the heat-sleeve 308 to the pipe ends and to activate the adhesive compound, thereby sealing the pipe ends. The heat penetration rate necessary to penetrate the single layer of heat-sleeve material 308 covering the low-bond temperature are 306 and sufficiently adhere the non-extended portions 316 and the second end 312 is substantially similar to the heat penetration rate necessary to penetrate the double layers of the heat-sleeve material 308 covering the low-bond temperature area 304 to adhere the extended portion 314 of the first end 310 and the area 320 of the second end 312. The result is an optimum uniform adhesion of the heat-sleeve 308 to the pipes 302.
At step 408, the heat-sleeve is applied to an air duct where both a low-bond temperature area and a high-bond temperature area exist, such as, for example, an area of exposed steel (low-bond temperature) and an area with a thermoplastic coating (high-bond temperature). At step 410, the first end and the second end of the heat-sleeve are positioned such that the extended portion(s) of the first end are layered upon one or more areas of the second end, depending on the cutting design of the first end. For example, an embodiment of the present invention provides a method comprising cutting a first end of a heat-sleeve to create multiple alternating extended and non-extended portions due to multiple areas with low-bond and high-bond temperatures positioned adjacent to each other.
At step 412, the non-extended portion(s) are positioned such that an edge of the non-extended portion(s) abuts a first edge of the second end but does not layer the second end. To cause shrinkage of the heat-sleeve to conform to the air duct and produce a seal, in step 414, heat is applied substantially uniformly to the air duct and the heat-sleeve, activating the adhesive compound and adhering the heat-sleeve to the air duct. Because the first end and the second end of the heat-sleeve are layered only over the low-bond temperature area(s) of the air duct and not the high-bond temperature area(s), the heat penetration rate necessary to adhere the single-layer portion of the heat-sleeve to the high-bond temperature area is similar to the heat penetration rate necessary to adhere the double-layer portion of the heat-sleeve to the low-bond temperature areas, providing optimal adhesion of the entire heat-sleeve to the air duct while allowing for shrinkage of the heat-sleeve without exposure of the air duct. The method then ends at step 416.
While the foregoing is directed to embodiments of the present invention, other and further embodiments of the present invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.
This application is a continuation-in-part of U.S. patent application Ser. No. 11/469,787, filed on Sep. 1, 2006, of which is incorporated herein by reference in its entirety.
Number | Date | Country | |
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Parent | 11469787 | Sep 2006 | US |
Child | 11613568 | US |