AU633910B2 - Cover repairing - Google Patents

Description

Short Title: Int. CI: Application Comniete S lAi AUST IALrA,. L Form PATENTS ACT 1952 COMPLETE SPECIFICATION

(ORIGINAL)

FOR OFFICE USE Number: Lodged: pecification-Lodged: Accepted: Lapsed: Published: Priority: Related Art: TO BE COMPLETED BY APPLICANT Name of Applicant: Nethchem Pty. Limited Address of Applicant: Factory 9, 136 Taren Point Road, Taren Point, N.S.W. 2229 Actual Inventor: Address for Service: Timothy James Nethery H.J. Rantzen Co., Patent and Trade Mark Attorneys.

John Street, Woollahra N.S.W. 2025.

Tel: (02) 328-7b30.

Complete Specification for the invention entitled: COVER REPAIRING The following statement is a full description of this invention, including the best method of performing it known to me:- SNote: The description is to be typed in double spacing, pica type face, in an area not exceeding 250 mm in depth and 160 mm in width, on tough white paper of good quality and it is to be inserted inside this form.

14166/77-L Printed by C. J. TIIojMISON. Acting Coininonwlll Gjoverlnment Printer, Canberra THIS INVENTION relates to the repair of tears and perforations in thin, flexible covers and is especially, although not exclusively, concerned with repairing reinforced plastics covers which are currently used for protecting bulk objects which would otherwise be exposed to ambient weather conditions.

Flexible covers of reinforced plastics material such as polyvinyl chloride are used to protect exposed loads on the tailboards of trucks, and by farmers to store modules of compressed cotton in fields while awaiting transportation to a cotton store. The module comprises a compressed mass of picked cotton and seeds. It is of large size, weighing upwardly of twelve tons, and has 13 to be protected from rain while awaiting collection. It is normally left in the field and protected from the weather by a plastics cover.

It is not uncommon for the reinforced plastics cover to be cut or perforated by agricultural equipment or vandals. This allows rain to enter the cotton and reduce its commercial value. If the cover is found to have been damaged, it is replaced by a new one and repaired in a workshop.

The normal method of repairing a cover is to stitch a patch over the cut or perforation. This does not prevent moisture from entering the cover through the stitch holes however. Also the line of the stitch holes can represent a weakness in the cover. It is not possible to repair a cover at the site of use. Also, the repair of the cover is relatively expensive as it is timeconsuming to replace one cover with another and to then transport the damaged cover to and from a workshop, and the cost of a new replacement cover is substantial.

An object of this invention is to provide an improved way of repairing a flexible thin cover.

In accordance with a first aspect of the invention there is provided a method of repairing a damaged zone of a thin flexible cover, comprising placing over the zone a self-adhering patch having an exposed face, and coating the exposed fate of the patch and the surrounding marginal portion of the cover with a viscous liquid coating of a mailerial which dries to provide

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a tough flexible and waterproof sheath keyed to tie patch and adhering to the marginal portion of the cover surrounding it.

In accordance with a second aspect of the invention, there is provided a cover repair kitA which includes: a porous flexible patch, a First face of said patch offering a rough surface, a second face of said patch having thereon a self-adhesive layer, peel-off strips covering said layer to protect it when the patch is not required for use, and a viscous liquid coating material which cures rapidly when exposed to air to leave a tough waterproof and flexible coating adhering to the patch and the surrounding marginal portion of the cover.

In accordance with a third aspect of the invention a cover has a damaged zone repaired by an adherent patch of a strong porous nature protected byan external cured coating of a waterproof tough and flexible material adhering to the patch and the adjoining marginal portion of the cover surrounding it.

Preferably the patch is made of a porous material. Suitably it has its face which is to adhere to the cover coated with a self-adhesive layer which holds the patch securely to the damaged zone of the cover. To use the patch, the damaged area of the cover is pulled out flat, and the protective slips covering the self-adhesive face of the patch are removed. The patch is then placed, adhesive face downwards, onto the damaged zone of the cover. The viscous coating, which may be an acrylic copolymer, is then brushed or sprayed over the patch and the adjoining marginal portion ol the cover. When it cures it adheres to the margin of the cover surrounding the patch to some extent, and tenaciously to the patch because of its rough exposed surface which allow the coating to key itself to the patch very effectively. The adhesive used to attach the patch is chosen to be sufficiently tenacious to make delamination of the patch from the cover very difficult.

In the preferred way of carrying out the invention, the patch is a woven fabric having strong tensile warps made from solid, flexible, strong, parallel cores of a material such as nylon, held together by wefts of a strong but highly flexible polyester thread. The cured coating serves not only to make the patch waterproof, but also to improve the adherence of the patch to I. -3the cover by filling up the interstices in the patch.

The invention will now be described in more detail, by way of example, with reference to the accompanying drawings, in which:- FIGURE 1 is a diagrammatic perspective view of a cotton module protected by a cover while standing in a field; and, FIGURE 2 is a fragmentary perspective view, partially cut-away, of a damaged zone of the cover repaired by a coated self-adhesive woven patch.

Figure 1 shows a module 1 of compressed cotton and seeds. It weighs about 12 tons and is about 3 metres high, 2.5 metres wide and about 10 metres long. It is normally left standing in the open until arrangements can be made to collect it and convey it to a permanent covered cotton store. It is protected while in the open by being covered with a waterproof cover 2 of tough plastics material such as a fabric-reinforced, polyvinylchloride (PVC).

16 The cover is about 300 microns thick and the fabric reinforcement is embedded in it so that both surfaces of the cover are smooth.

A problem with storing a cotton module under a cover, is that its watertight integrity is easily impaired by the cover being perforated. This can occur through vandalisation or through the cover being struck by a sharp edge of a piece of farm tackle.

Figure 2 shows how a perforation 6, shown in broken outline, in a damaged zone of the cover can be repaired. A self-adhesive patch 10 is placed with its adhesive face downwards, over the damaged zone of the cover after it has been pulled out flat. The patch 6 is of woven construction having solid, relatively tough spaced, parallel, nylon warps 11 resistant to tension and creasing. The weave of the patch has strong but easily flexible wefts 9 formed from polyester thread. Such a patching material is available in Australia from the Applicant, Nethchem Pty. Limited., under the trademark NYLOMAT. One face of the patch is coated with a thin layer 12 of a hot melt glue or adhesive capable of securing the patch securely to the damaged zone of the cover. The layer 12 is normally protected by paper peel-off slips which are readily removed when the patch is required for use.

The patch 10, being of woven construction, has a rougi, exposed face and the interstices between the warps and the wefts render it porous.

The patch 10 and the adjacent marginal edge-portion of the damaged zone of the cover are coated with a thick viscous layer 8 of. quick-curing acrylic copolymer such as that obtainable from Nethchem Pty. Ltd. of Sydney under !0 the trade mark FLEXICLAD. The coating may be applied by brush or by a spray gun and cures to leave a flexible tough and waterproof coating which is keyed tenaciously to the patch 10 by locking into its interstices. It also adheres, but less strongly, to the smooth surface of the cover surrounding the patch. The coating is about the same thickness as the cover, namely, about 300 microns. The adherence of the coating to the cover may be improved by roughening its surface or by employing in the coating a reagent which chemically bonds itself to the cover.

In some cases it may be required to stitch the patch to the cover before the coating is applied to improve their attachment to one another, to make it harder for vandals to manually delaminate the patch fiom the cover.

The subsequently-applied coating fills the stitch-holes so that the waterproof integrity of the cover is not impaired.

In a first variation of the invention, the layer 12 of adhesive between the patch 10 and the cover is applied to the cover before the patch is applied.

The patch does not then require a self-adhesive layer. In a second variation, the layer 12 is formed from a two-part composition, one of the parts being applied to one face of the patch 10 and being protected by peel-off paper slips, and the other part being brushed or sprayed onto the damaged zone of the cover before the patch is applied, and having a reagent which chemically bends it to the cover.

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Claims (9)

1. A method of repairing a damaged zone of a thin flexible cover, comprising placing over the zone a self-adhering patch having an exposed face, and coating the exposed face of the patch and the surrounding marginal portion of the cover with a viscous liquid coating of a material which cures to provide a tough, flexible and waterproof sheath keyed to the patch and adhering to the marginal portion of the cover surrounding it. hhW'^ /AS'/r-L 11o'u/ rs riT accordance w;Jir e wooiA 44c CI&cf

2. A cover repair kit which includes a porbus flexible patch, a first face of said patch offering a rough surface, a second face of said patch having thereon a self-adhesive layer, peel-off strips covering said layer to protect it when the patch is not required for use, and a viscous liquid coating material which cures rapidly when exposed to air to leave a tough waterproof and flexible coating adhering to the patch and the surrounding marginal portion of the cover.

3. A thin flexible cover having a damaged zone repaired by an adherent patch of a strong porous nature protected by an external cured coating of a waterproof, tough and flexible material adhering to the patch and to the adjoining marginal portion of the cover surrounding it, the coating penetrating through the pores of the patch.

4. A kit as claimed in claim 2, in which the patch comprises a woven synthetic material.

A kit as claimed in claim 4, in which the patch has monofilament nylon cores providing warps, and fibrous synthetic plastics threads providing wefts.

6. A kit as claimed in claim 2 or either of claims 4 and 5, in which the liquid coating is a quick-drying acrylic copolymer.

7. A cover as claimed in claim 3, in which the patch is a woven fabric having monofilament plastics cores providing the warps of the weave, and the wefts are provided by fibrous threads of a synthetic plastics material. S' 1 -6- "I "j- 6 I-

8. A cover as claimed in claim 3 or claim 7, in which the coating is an acrylic plastics copolymer, the cover is made of synthetic plastics material and has the patch stitched to it, and the stitch-holes are sealed by the coating.

9. A method of repairing a cover, substantially as described with reference to the accompanying drawings. A cover repair kit as claimed in claim 2, and including components substantially as hereinbefore described with reference to the drawings. DATED THIS 16 DAY OF MAY 1990. NETHCHEM PTY. LIMITED. i Applicant's Patent LTttorney. 16