Flammability of heating cable

Patent metadata

Field	Value
Publication number	US-11778700-B2
Application number	US-201916708173-A
Country	US
Kind code	B2
Filing date	Dec 9, 2019
Priority date	Dec 7, 2018
Publication date	Oct 3, 2023
Grant date	Oct 3, 2023

Abstract

Embodiments of the invention provide a self-regulating heating cable. The cable includes a primary jacket including a first low-smoke, zero halogen material. The cable also includes a braid surrounding the primary jacket. The cable also includes a final jacket surrounding the braid and comprising a second low-smoke, zero halogen material. The final jacket is formed to the braid during an extrusion process in order to create a mated connection between the final jacket and the braid.

First claim

The invention claimed is:

1. A self-regulating heating cable comprising:
a semi-conductive heating core;
two conductive wires embedded within and separated by the semi-conductive heating core;
a primary jacket surrounding the semi-conductive core and comprising a first low-smoke, zero halogen material;
a braid surrounding the primary jacket; and
a final jacket surrounding the braid and including a second low-smoke, zero halogen material, the final jacket formed to the braid during an extrusion process in order to create a mated connection between the final jacket and the braid.

2. The self-regulating heating cable of claim 1 , wherein the final jacket is formed to the braid using an extruder with pressure tooling, and wherein the mated connection increases the flammability protection of the cable.

3. The self-regulating heating cable of claim 1 , wherein the final jacket is formed to the braid using vacuum extrusion.

4. The self-regulating heating cable of claim 1 , wherein the final jacket is formed to the braid using an extruder with post extrusion compression.

5. The self-regulating heating cable of claim 1 , wherein the final jacket is formed to a cross-sectional profile of the braid.

6. The self-regulating heating cable of claim 5 , wherein the cross-sectional profile changes along a length of the self-regulating heating cable, and the final jacket is formed to the braid to create the mated connection along the length of the self-regulating heating cable.

7. The self-regulating heating cable of claim 1 , wherein the braid comprises copper, and wherein at least one of the first and second low-smoke, zero halogen materials includes a polyolefin flame-retarded with inorganic hydrated mineral fillers.

8. The self-regulating heating cable of claim 1 , and further comprising a barrier layer surrounding the primary jacket, the braid surrounding the barrier layer.

9. The self-regulating heating cable of claim 8 , wherein the barrier layer comprises aluminum foil.

10. The self-regulating heating cable of claim 1 , wherein the self-regulating heating cable is VW-1 rated.

11. A self-regulating heating cable comprising:
a primary jacket comprising a first low-smoke, zero halogen material;
a braid surrounding the primary jacket; and
a final jacket surrounding the braid and comprising a second low-smoke, zero halogen material, the final jacket formed to the braid during an extrusion process in order to create a mated connection between the final jacket and the braid.

12. The self-regulating heating cable of claim 11 , wherein the braid comprises a first portion and a second portion, the first portion being positioned below the second portion, and wherein the final jacket is configured to conduct an approximately equal amount of heat to the first portion and the second portion.

13. The self-regulating heating cable of claim 12 , wherein the amount of heat conducted to the first portion is within about twenty percent of the amount heat conducted to the second portion.

14. The self-regulating heating cable of claim 12 , wherein at least one of the first and second LSZH materials comprises a polyolefin flame-retarded with inorganic hydrated mineral fillers.

15. The self-regulating heating cable of claim 11 , wherein the braid comprises a metal and provides a ground path.

16. The self-regulating heating cable of claim 11 , wherein the final jacket is formed to the braid using an extruder with pressure tooling, and wherein the mated connection increases the flammability protection of the cable.

17. A manufacturing process for producing a heating cable, the manufacturing process comprising:
receiving a partially finished heating cable comprising parallel conductor wires, a core, a primary jacket, and a braid;
forming a final jacket to the braid to create a mated connection between the final jacket and the braid; and
outputting a finished heating cable including the parallel conductor wires, the core, the primary jacket, the braid, and the final jacket.

18. The manufacturing process of claim 17 , wherein forming the final jacket to the braid to create the mated connection between the final jacket and the braid comprises forming the final jacket to the braid using an extruder with pressure tooling, and wherein the finished heating cable has increased flammability protection as a result of mated connection.

19. The manufacturing process of claim 17 , wherein forming the final jacket to the braid to create the mated connection between the final jacket and the braid comprises forming the final jacket to the braid using an extruder with post extrusion compression to press the final jacket into the braid.

20. The manufacturing process of claim 17 , wherein forming the final jacket to the braid to create the mated connection between the final jacket and the braid comprises forming the final jacket to the braid using vacuum extrusion.

Assignees

• Nvent Services Gmbh

Inventors

• Jenkins Sirarpi B

Classifications

• H05B3/565 Primary

  flat cables · CPC title

• H05B2203/017

  Manufacturing methods or apparatus for heaters · CPC title

• H05B2203/02

  Heaters using heating elements having a positive temperature coefficient · CPC title

• H05B3/56 Primary

  Heating cables · CPC title