CA1107665A

CA1107665A - Crush resistant hose

Info

Publication number: CA1107665A
Application number: CA308,602A
Authority: CA
Inventors: Richard Bentley
Original assignee: Individual
Current assignee: Individual
Priority date: 1977-08-05
Filing date: 1978-08-02
Publication date: 1981-08-25
Also published as: GB2002085A; GB2002085B; BR7805035A; DE2833610A1; JPS5440330A; NZ187993A; ZA784412B; PH15032A; FR2399600A1; BE869523A; NL7808225A

Abstract

Abstract Novel industrial tubing comprising at least one helix of a polyolefin integral with the tubing wall to produce a crush-resistant tubing. In particular a crush-resistant vulcanised rubber tubing is provided which has formed integral with the wall thereof at least one helix of "tuffclad".

Description

s The present invention relates to crush-resistant tubing and in particular crush-resistant rubber hoses.
Throughout the specification the term "crush-resistant tubing or hose" will be defined as tubing or hose which can be crushed flat by some heavy weight and will substantially return to its original shape without any significant weakening of the properties of the tubing or hose.
In heavy industry it is often nècessary to use large diameter hoses, to carry slurry, water or other such materials. These hoses were convention-ally made from rubber with wire reinforcing. Unfortunately when a section of these hoses are flattened, it is necessary to use physical force, such as hammering to return the hose substantially to its original shape. Unfortu-nately the wire reinforcing undergoes cold working during the crushing and the subsequent hammering. The wire usually breaks at the area of cold working and the tubing becomes delaminated from the wire thus, ultimately the hose fails after only a few crushings and reshapings.
The present invention overcomes this problem by providing a crush-resistant tubing.
According to the present invention there is provided a crush-resistant tubing comprising a wall formed from vulcanized rubber and a wall

2~ reinforcement completely embedded in and integrally bonded to said rubber formed from a non-overlapping helix having axially spaced turns of ultra high molecular weight polyethylene of 0.94 g/cm specific gravity.
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As "Tuffclad" has self-lubricating and high-slip properties its suitability for strengthening tubing was unsuspected. However, during experimentation it was surpris-ingly found that a strip of "Tuffclad" was bonded into the wall of a rubber hose during the normal vulcanising step and forming a strong bond between the rubber and the "Tuffclad", such that the rubber hose exhibits "crush-resistant"
properties. The resulting bond is such that during reported deformation tests there appeared to be no separation between the "Tuffclad" and the rubber.
In a typical vulcanising process the high density polyethylene is wrapped in its appropriate configuration in the tubing wall and the thus layered uncured tubing placed in an autoclave to cure for 6 - 8 hours at a temperature of about 500 F.
The polymeric material can be wrapped in the rubber wall in an configuration necessary to strengthen the hose, for example double helixes, single helixes, a complete layer.
In using double helixes each separate helix can be positioned such that the two helixes run in with no overlap-ping or run overlapping each other. The thickness width and spacing of the polymeric material will depend on the size and strength requirements of the tubing.
To provide an abrasive resistant lining as well as a crush resistant hose the inner layer of the hose can be formed of overlapping layers of "Tuffclad" which are wound on a mandril with the composite rubber hosing and core built on top of the thus coated mandril and the tubing then vulcanised.
The thus formed tubing provides an improvement over existing piping such as steel in that previously problems arose ' , in providing a layer of "Tuffclad" which would bond because of the differential between the expansion properties of "Tuffclad" and previously used pipe walls.
The end of each tubing can have a flange of "Tuffclad" projecting outwardly therefrom such that in joining tubing together the "Tuffclad" flanges are positioned -together and a flange of suitable material is clamped on each side of the mating "Tuffclad" flanges by any convenient means, such as bolting, to form a leakproof joint between the tubing.

- 6 _

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A crush-resistant tubing comprising a wall formed from vulcanized rubber and a wall reinforcement completely embedded in and integrally bonded to said rubber formed from a non-overlapping helix having axially spaced turns of ultra high molecular weight polyethylene of 0.94 g/cm3 specific gravity.

2. A crush-resistant tubing comprising a wall formed from vulcanized rubber and a wall reinforcement completely embedded in and integrally bonded to said rubber formed from a non-overlapping helix having axially spaced turns of polyethylene having a molecular weight of from 4 to 4.5 million as measured by the light diffusion method and having a specific gravity of 0.94 g/cm3.