US4464425A — Foamed polymeric shrink-fit objects and their pro…

Claim 1

Independent Claim 46 words

A shrink-fitting article such as a shrink hose, shrink sleeve, or shrink cap, made from a hollow article comprised of an extruded and cross-linked foam material, the hollow article as a whole having been expanded to a larger size following completion of cross-linking and foam expansion.

Claim 2

Dependent Claim 46 words

A shrink-fitting article such as a shrink hose, shrink sleeve, or shrink cap, made from a hollow article comprised of an extruded and cross-linked foam material, the hollow article as a whole having been expanded to a larger size following completion of cross-linking and foam expansion.

Claim 3

Dependent Claim 26 words

A hollow article as in claim 1, wherein the article has a foam surface layer and beneath the foam surface layer there is an unfoamed layer.

Claim 4

Independent Claim 104 words

A method of making a shrink-fit article such as a hose, a sleeve, a cap, or the like, comprising the steps of extruding or injection-molding a silane-grafted polymeric material capable of cross-linking in the presence of moisture, under development of foaming, at least at the surface, in order to shape-form a hollow polymeric article in the configuration it is to have following a shrink fit; causing the article as extruded to cross-link in the presence of moisture; expanding the cross-linked and foamed article at an elevated temperature to obtain larger dimensions; and cooling the article in the expanded state to form said shrink-fit article.

Claim 5

Independent Claim 104 words

A method of making a shrink-fit article such as a hose, a sleeve, a cap, or the like, comprising the steps of extruding or injection-molding a silane-grafted polymeric material capable of cross-linking in the presence of moisture, under development of foaming, at least at the surface, in order to shape-form a hollow polymeric article in the configuration it is to have following a shrink fit; causing the article as extruded to cross-link in the presence of moisture; expanding the cross-linked and foamed article at an elevated temperature to obtain larger dimensions; and cooling the article in the expanded state to form said shrink-fit article.

Claim 6

Dependent Claim 25 words

A method as in claim 1, wherein the cross-linking is carried out by means of a high-energy radition rather than graft cross-linking by hydrolitic techniques.

Claim 7

Dependent Claim 25 words

A method as in claim 1, including the step of reheating the article following the foaming and the cross-linking, but prior to the expansion step.

Claim 8

Dependent Claim 17 words

A method as in claim 5, the reheating step being carried out by means of microwave radiation.

Claim 9

Dependent Claim 24 words

A method as in claim 1 or 2, including blending of the material with a foaming agent which will chemically decompose during the extruding.

Claim 10

Dependent Claim 29 words

A method as in claim 1 or 7, including blending of the material with a foaming agent which will physically expand during the extruding to thereby obtain the foaming.

Claim 11

Dependent Claim 29 words

A method as in claim 1 or 7, including blending of the material with an additive which releases water during the extruding so that cross-linking begins internally during shape-forming.

Claim 12

Independent Claim 121 words

The method of making a shrinks-fit object, comprising the steps of providing a polymer blend with silane as a graft component; causing the graft component to be grafted upon the polymer, the graft component being of the type for cross-linking the polymer molecules in the presence of moisture; shaping the grafted-on polymer into a particular hollow object and causing at least a portion of the blend to foam by means of blowing in order to obtain at least partially a foamed surface; exposing said grafted-on polymer to moisture for obtaining the cross-linking; expanding the completely shaped and completely cross-linked object as a whole at an elevated temperature; and maintaining the expanded state as the object cools to obtain said shrink-fit object.

Claim 13

Independent Claim 121 words

The method of making a shrinks-fit object, comprising the steps of providing a polymer blend with silane as a graft component; causing the graft component to be grafted upon the polymer, the graft component being of the type for cross-linking the polymer molecules in the presence of moisture; shaping the grafted-on polymer into a particular hollow object and causing at least a portion of the blend to foam by means of blowing in order to obtain at least partially a foamed surface; exposing said grafted-on polymer to moisture for obtaining the cross-linking; expanding the completely shaped and completely cross-linked object as a whole at an elevated temperature; and maintaining the expanded state as the object cools to obtain said shrink-fit object.

Claim 14

Independent Claim 107 words

The method of making a shrink-fit article such as a hose, a sleeve, a cap, or the like, comprising the steps of providing a blend of a silane and a base polymer and a blowing agent; extruding the blend to melt the blend and to graft the silane onto the base polymer, and to obtain foaming while forming the article; causing the article to cross-link by exposure to moisture; re-shaping the article prior to completion of cross-linking to form a hollow article; expanding the hollow article as a whole and at an elevated temperature; and cooling the article in the expanded state to form a shrink-fit article.

Claim 15

Independent Claim 107 words

The method of making a shrink-fit article such as a hose, a sleeve, a cap, or the like, comprising the steps of providing a blend of a silane and a base polymer and a blowing agent; extruding the blend to melt the blend and to graft the silane onto the base polymer, and to obtain foaming while forming the article; causing the article to cross-link by exposure to moisture; re-shaping the article prior to completion of cross-linking to form a hollow article; expanding the hollow article as a whole and at an elevated temperature; and cooling the article in the expanded state to form a shrink-fit article.

Claim 16

Dependent Claim 31 words

A method as in claim 8 or 9, wherein the foaming step includes the introduction of a pressurized, moist gas into the blend so that foaming and onset of cross-linking concur.

Claim 17

Dependent Claim 29 words

A method as in claim 10 or 11, wherein the foaming step includes adding a water-releasing blowing agent to the blend so that foaming and onset of cross-linking concur.

Claim 18

Dependent Claim 24 words

A method as in claim 10 or 11, including the step of adding a filler to the blend which releases water in the extruder.

Claim 19

Dependent Claim 26 words

A method as in claim 11 as applied to extruding a shrink hose, including the step of expanding the hose when still warm from the extrusion.

Claim 20

Dependent Claim 31 words

A method as in claim 1 or 11, wherein the polymer material is polyethylene, a copolymer of ethylene, an ethylene-propylene rubber, by itself or blended with a polyolefin, such as polypropylene.

Claim 21

Dependent Claim 19 words

A method as in claim 1 or 11, comprising: the step of adding nonhygroscopic carbon black to the blend.

Claim 22

Dependent Claim 33 words

A method as in claim 1 or 11, including providing a non-foamed substrate, said extrusion being carried out on said substrate so that said foam develops on the non-foamed substrate of the article.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1987-08-07	1988-02-06	1988-08-07	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1991-08-07	1992-02-06	1992-08-07	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1995-08-07	1996-02-06	1996-08-07	$7700.00	Window Closed / Lapsed

Foamed polymeric shrink-fit objects and their process of manufacture

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