Flexible insulating sleeve
View Patent ↗The present invention relates to flexible cylindrical sleeves for use in protecting wires or conduits from excess heat and/or abrasion. In particular, the present invention provides a flexible sleeve made of multiple bands that are continuously spirally wrapped around each other to form a tube of any desired length. The sleeve generally includes at least two bands, an outer band and an inner band. The outer band and the inner band are laminates in that each is formed of multiple layers. The outer band includes an outer layer of metal foil and the inner band has an innermost layer of woven heat resistant fabric. In another embodiment, one or more additional bands may be wrapped between the inner band and the outer band depending upon the specific application in which the sleeve will be used.
1. A method of making an insulating sleeve, comprising the steps of:
supplying a first band having a metal foil superimposed on a thermally insulating fabric;
supplying a second band having a metal foil superimposed on a scrim layer;
winding the first band along a spiral path and overlaying the second band over a seam between adjacent turns of the first band; and
adhering the first band to the second band.
2. A method of claim 1 , wherein the supplying steps include supplying the first and second bands on respective spools to a spiral wrapping machine.
3. A method of claim 1 , wherein the winding step includes winding at least the second band such that an edge of the band in one turn abuts an opposite edge of the band in an adjacent turn.
4. A method of claim 1 , wherein the winding step includes offsetting the second band from the first band by one half the width of the outer band.
5. A method of claim 1 , wherein the winding step includes winding the first band and the second band at different helix angles.
6. A method of claim 1 , wherein the winding step includes wrapping the first band around a mandrel of a spiral wrapping machine.
7. A method of claim 1 , further comprising the step of heating at least one of the bands to bond the bands together.
8. A method of claim 7 , wherein the heating step includes blowing heated air on at least one of the bands.
9. A method of claim 7 , further comprising the step of pressing the bands together after heating.
10. A method of claim 7 , further comprising the step of pressing the bands together before heating.
11. A method of claim 7 , wherein the heating step includes preheating at least one of the bands before the winding step.
12. A method of claim 1 , further comprising the step of applying an adhesive to at least one of adjacent outer and inner surfaces of the first and second bands, respectively, to bond the first and second bands together.
13. A method of claim 12 , further comprising the step of activating the adhesive.
14. A method of claim 13 , wherein the activating step includes heating at least one of the bands.
15. A method of claim 1 , further comprising the step of applying a cohesive on both an inner surface of the second band and an outer surface of the inner band to bond the inner and outer bands together.
16. A method of claim 15 , further comprising the step of pressing the first and second bands together.
17. A method of claim 1 , further comprising the step of flattening the sleeve.