AU713594B2 - Method of adhering an article to polyurethane and corrosion or abrasion protective sheet - Google Patents

Description

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT S S

C.

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*5

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.5 Applicant(s): POLYSCREEN PTY LTD A.C.N. 008 521 702 Invention Title: METHOD OF ADHERING AN ARTICLE TO POLYURETHANE AND CORROSION OR ABRASION PROTECTIVE SHEET 555e 5S S

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The following statement is a full description of this invention, including the best method of performing it known to me/us: 2- METHOD OF ADHERING AN ARTICLE TO POLYURETHANE AND CORROSION OR ABRASION PROTECTIVE SHEET This invention relates to a method of securing an article to a polyurethane member.

Screening plants generally include screening machines upon which earth and rock are loaded to separate large fragments from smaller fragments for mineral recovery and other uses.

Rock and dirt are conveyed along chutes, runways or the like. The walls, floor and other surfaces of such chutes or runways etc which will come into contact with the earth and rock are formed from steel. In order to protect the oooo "steel from corrosion or abrasion, the steel is covered by 15 polyurethane sheets which are typically secured to the oe*° steel substrate by bolts. As the polyurethane wears out, the bolts are removed and new polyurethane sheets are installed.

20 The removal of worn sheets and the installation of new sheets is time consuming and therefore adds to the downtime of the plant.

This invention concerns the manner in which an article is 25 bonded to a polyurethane member. Usual adhesives do-not adhere to polyurethane and therefore articles cannot be bonded to polyurethane by means of adhesives.

We have found that by using a bonding agent together with an adhesive articles can be bonded to polyurethane.

The invention therefore provides a method of bonding an article to a polyurethane member including the steps of: applying a bonding agent to the polyurethane member; and adhering the article to the bonding agent by H:\karen\keep\div-28504-95-POLYSCREEN doe 20/10/98 I III 3means of adhesive whilst the bonding agent is tacky.

Preferably the polyurethane member is a polyurethane protective sheet and the article comprises a first component of a loop and hook type fastener.

Preferably the bonding agent is made by Morton International, Inc. of Dayton, Ohio, U.S.A. and sold under the name Thixon 412 or 415.

Most preferably the component of the loop and hook type fastener attached to the protective member is applied to the bonding agent while the bonding agent is still tacky.

15 A preferred embodiment of the invention will be described, by way of example, with reference to the accompanying drawings in which: Figure 1 is a cross-sectional view through a protective member and substrate according to the preferred 20 embodiment of the invention; Figure 2 is a separated view of the protective member and the substrate; and Figure 3 is a plan view of the inner side of the protective member of Figures 1 and 2.

With reference to Figure 1 and 2, a steel substrate 10 is shown protected by a polyurethane sheet 12. The substrate may be any appropriate component in a screening plant, wash plant or any other plant in which the substrate may be subject to corrosive or abrasive agents which therefore may require protection.

The polyurethane protective sheet 12 is secured to the substrate 10 by a loop and hook type fastener 14 such as a Velcro (trade mark) type fastener.

H: \karen\keep\div-28504-95-POLYSCREEN.doc 20/10/96 4 Figure 2 shows the polyurethane protective member 12 and the substrate 10 separated from one another. The first component of the loop and hook type fastener and most preferably the loop component is applied to the protective member 12 as represented by reference numeral 14a. As is shown in Figure 2, the component 14a is applied about the periphery of the protective sheet 12 and also down a central region of the protective sheet 12. Of course the surface upon which the component 14a is applied is the innermost surface of the protective sheet 12 which is intended to lie adjacent to the substrate As is also shown in Figure 2, the substrate 10 has the other component 14b of the loop and hook type fastener 15 (such as the hook part of the fastener) applied to its outer surface which would normally be subject to the abrasive or corrosive agents. The hook component 14b is applied in a similar pattern to the component 14a so that when the protective sheet 12 is applied to the substrate 10, the loop component 14a engages with the hook component 14b to releasably secure the protective sheet 12 to the substrate When the protective sheet 12 wears out due to action of the abrasive or corrosive agents, the sheet 12 is simplyremoved from the substrate 10 by pulling in the direction of arrow A in Figure 1 to release the loop component 14a from the hook component 14b. A new sheet 12 is identical to the sheet 12 shown in Figure 1 can then be installed in place. Thus, the worn sheets 12 can be quickly removed and replaced with minimal plant downtime and with minimal effort.

It is most preferred that the hook type component be on the substrate 10 and the loop component be on the protective sheet 12 so that earth, gravel or the like which may fall H:\karen\keep\div-28504-95-POLYSCREEN.doc 20/10/98 onto the substrate 10 (such as when the protective sheet 12 is being replaced or before it is installed) can be more easily swept away or removed.

The protective sheet 12 is formed from polyurethane and as is well known, it is difficult, if not impossible to attach articles to polyurethane by adhesive. We have found by using a bonding agent the relevant component of the loop and hook type fastener can be bonded to the polyurethane sheet 12.

As is best shown in Figure 3, a bonding agent shown by reference numeral 30 is applied to the polyurethane sheet 12 by brushing or the like in the regions at which the loop component 14a of the fastener 14 is to be attached. An o* adhesive is provided on the base of the loop component 14a and whilst the bonding agent 30 is tacky, the component 14a is applied to the bonding agent so that the adhesive is caused to bond to the polyurethane sheet 12 by virtue of S 20 the adhesive on the component 14a and the bonding agent applied to the polyurethane sheet 12. The bonding agent is preferably Thixon 412 or 415 made by Morton International, Inc. as previously mentioned.

25 After the protective sheet 12 is secured in place as-shown 0. in Figure 1, the edges of the sheet 12 are sealed to the substrate 10 by silicon or the like to stop water or material from getting beneath the protective sheet 12.

Since modifications within the spirit and scope of the invention may readily be effected by persons skilled within the art, it is to be understood that this invention is not limited to the particular embodiment described by way of example hereinabove.

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Claims (3)

1. A method of bonding an article to a polyurethane member including the steps of: applying a bonding agent to the polyurethane member; and adhering the article to the bonding agent by means of adhesive whilst the bonding agent is tacky.

2. The method of claim 6 wherein the polyurethane member is a polyurethane protective sheet and the article comprises a first component of a loop and hook type fastener. 15

3. The method of claim 6, wherein the bonding agent is made by Morton International, Inc. of Dayton, Ohio, U.S.A. and sold under the name Thixon 412 or 415. The method of claim 6, wherein the component of .20 the loop and hook type fastener attached to the protective member is applied to the bonding agent while the bonding agent is still tacky. 9 25 Dated this 20th day of October 1998 POLYSCREEN PTY. LTD. By Its Patent Attorneys: GRIFFITH HACK Fellows Institute of Patent Attorneys of Australia. H:\karen\keep\div-285O4-95-POLYSCREEN.doc 20/10/98