AU626092B2

AU626092B2 - Composite panel

Info

Publication number: AU626092B2
Application number: AU41110/89A
Authority: AU
Inventors: John Simon
Original assignee: RALPH SYMONDS AUSTRALIA LIMITE
Current assignee: Symonite Australia Pty Ltd
Priority date: 1988-09-07
Filing date: 1989-09-06
Publication date: 1992-07-23
Anticipated expiration: 2009-09-06
Also published as: AU4111089A

Description

626092 COMMONWEALTH OF AUSTRALIA PATENTS ACT 1952 COMPLETE

SPECIFICATION

(ORIGINAL)

Class Int. Class Application Number: Lodged: Complete Specification-Lodged: Accepted oPublished: Priority: 00*d0 r o~iRolaited Art: o 0*00o Name of Applicant: 0440 Address of Applicant: Actual Inventor: Address for Service: Complete Specification TO BE COMPLETED BY APPLICANT RALPH SYMONDS AUSTRALIA LIMITED 1 Bennelong Road, Homebush Bay, New South Wales, Australia John SIMON HALLIDAYS. Patent Attorneys, 44 Ashley Street, Hornsby, New South Wales, 2077, Aust.

for the invention entitled: COMPOSITE PANEL The following statement is a full description of this invention, including the best method of performing it known to me:- :Z-C0"767 C- t This invention relates to a rigid composite panel of the type that can be used for building purposes and article construction. The material is in laminate form typically tI comprised of a non-metallic core between metal cladding sheets. The panel would be particula.rly suitable for the building trades for use in the construction of fascias and facades for buildings and would also have ready application in the construction of partitioning, decking, furniture, signboards, containers and vehicle components, to name only 0 a few of its possible uses.

;0 0 S In the past material for such purposes has been available in a number of forms, including laminated forms, however there has been a need for panel as specifically proposed by this invention wherein the core material is a panel of thermo-setting resin. The advantage of such a core is its rigidity which imparts to the panel a robustness making it r °particularly suitable for a number of uses.

Hereinafter there is described the method and product of the invention and in the description reference is made to sheets of metal. The term sheet is to be understood as having the meaning given to that term and the terms foil and plate in the Aluminium Standards and Data publication of The Aluminium Development Council of Australia and similar publications related to other metals.

2e~ L~i~lPIIC~C~C~C~C~C~C~C~C~C~C~C~C~C~C~C~ 111 q Specifically, SHEET is a rolled rectangular section of thickness over 1.5mm up to 6.0mm, with sheared, slit, or sawn edges. PLATE is a rolled rectangular section of thickness greater than 6.0mm with either sheared or sawn edges. FOIL is a rolled rectangular section of thickness 0.15mm or less with sheared or slit edges.

Broadly, the invention can be said to comprise a process for :o the manufacture of a metal-clad rigid non-porous panel comprising the steps of providing an assembly of overlying 10 substantially identical Kraft paper sheets of the same weight where the weight is selected from the range 170-200 grams per square meter and where the paper sheets are all impregnated to substantially the same degree with hexamine catalysed Phenol Formaldehyde which when polymerised in a fusing step under heat and pressure will provide a non--ionic «o°i 'rigid core for the panel, providing metal cladding sheets as hereinbefore defined on both sides of the assembly of Kraft paper sheets with a thermosetting glue film sheet between the metal sheets and the Kraft paper sheets immediately 20 adjacent thereto, fusing the Kraft paper sheets together to form a rigid core panel and fusing the metal sheets to the core in a single operation in which the assembly of Kraft paper sheets and the metal cladding sheets are subjected to a temperature in the range of 120 to 150 degrees C at a pressure of 1 to 1.4 M.Pa in a platen press.

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and bond the cladding sheet -to the core.

The invention further provides a laminate when made according to the above method.

In a presently preferred form the panel material would comprise a core sheet made up of a plurality of Kraft paper layers bonded together with phenolic resin and the cladding on one or both sides of the core sheet would be aluminium.

It is to be understood however that the core can be another form of thermosetting resin and that the cladding can be selected from a range of metal sheeting, as may be required for special purposes. By way of example, where haid wearing qualities are required (including resistance to corrosive atmospheres) with a high polish or brushed surface finish, the cladding sheets could be stainless steel. Where decorative finishes are required, the cladding sheet could be embossed, etched or otherwise surface finished or treated copper sheeting. Where low cost and heavy duty non-decorative panels are required, the cladding sheets could be mild steel lacquered, painted or plain.

I 20 As will be understood the cladding sheets could be of different types on opposite sides of the panel, for example decorative copper sheet on one side and enamelled steel on the other. It would also be within the scope of the invention to have cladding on only one side of the core sheet. i -3r The method of manufacture could be varied to suit production techniques and end product requirements. In a presently preferred method of manufacture the resin impregnated sheets of the core and the cladding sheet(s) have substantially the same dimensions which couldquite large. For example, the core sheet and cladding sheets could be ten metres by four metres.

It will be understood economics in manufacture can be achieved by the utilisation of existing equipment suitable for the forming of large sheets from other materials. In known manufacturing processes large presses for the formation of sheets of the above suggested size of ten metres by four metres are already used thereby making the manufacture of sheets of the type and size proposed by the present invention immediately viable.

fie# 44 4 Whilst the size of the core sheets and the cladding sheet(s) i are desirably substantially the same to facilitate the manufacture of the laminate sheet, if it is the case that due to manufacturing limitations or transport limitations the cladding sheet sizes are less than the size of the core alternative steps may be taken. For example, a number of suitable sized cladding sheets could be placed side by side to collectively provide a cladding for the core and these would be bonded to the core in the press in a single heat/pressure cycle.

Such an arrangement would be an acceptable practice where 4 i

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j~f I!:1 4 4. 4.s the finished laminate panel was to be cut after manufacture into smaller sheets or where the joins between the cladding sheets would not be detrimental to the final product. If joins would be detrimental to the final product a cover strip of architecturally and aesthetically acceptable form could be placed over the join.

As will be appreciated from the above the process provides an opportunity to clad a large core in different zones with different forms of cladding. Such an arrangement would allow a continuous core to be clad in some zones with appropriate, possibly decorative, cladding whilst in other zones it would be clad with utility hard wearing metal sheeting. Thus a panel for the interior lining of a building, for example, could be provided in a fully finished form ready for installation with various zones suitably finished.

It would also be possible to manufacture laminated sheets as proposed by the invention in a continuous manner where prepared sheets of core material (resin impregnated fibrous porous sheet material) are continuously fed into a machine with cladding material from coil supplies overlying one or both sides of the core. The loose laminate so formed would then pass through a processing zone in the machine where heat and pressure would be applied to the degree required to cause bonding of the core sheets together to form a rigid core member and at the same time to bond the cladding to the core member.

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o 1 4:041 010 Where end joints occur between the ends of the sheets forming the core assembly, as will result from the use of fixed size core sheets or end joints between core sheet material from reel stock, the end joints would be staggered in the interest of providing uniform strength in the core material.

The result of the foregoing would be a continuous process in which a continuous strip of finished material would be produced. This method of manufacture lends itself, where the process requires a period of non-movement whilst bonding takes place, to a commercial sheet sizing step where the material already laminated could be cut into sheets of smaller utility size whilst the bonding of a subsequent portion was taking place.

As will be understood, in a process where the bonding heat and pressure were applied in a continuous manner in a bonding zone as the loose laminate passed through the zone a strip of a predetermined maximum length of laminate could be formed. When that length was achieved the process would be temporarily terminated whilst the strip was relocated on a sizing bench or, during the temporary interruption of the process, mechanised means associated with the laminating machinery could quickly convert the strip into commercial sized sheets.

The material preparation prior to the commencement of the 6 i i manufacturing process is, in a typical operation, to first prepare the core by assembling a plurality of fibrous porous sheets which are resin impregnated, the fibrous sheets are ;I preferably of the material known in the industry as "Kraft" paper. Suitable Kraft paper would be of a weight of 170 to 250 grams per square meter, and is preferably of a weight in the order of 183 grams per square meter. The impregnation is with a partially catalysed phenolic resin or other like synthetic resin in an amount of 105 to 130 grams per square meter and preferably in an amount of 117 grams per square meter. The resin is preferably hexamine catalysed Phenol Formaldehyde resin. During the heat and pressure step of the invention the resin is reacted and cured resulting in a solid, rigid and substantially climatically stable core panel material.

The cladding sheets of metal, of a suitable type as hereinbefore discussed, are cleaned and textured on the surface to be bonded by a linishing process utilising wire brushing techniques. If desired the finish of the outer surfaces of the cladding sheets may be protected by stripable plastic coating sheets.

The bonding medium required for the laminating step, in a presently preferred form, is a phenolic resin impregnated paper gluefilm. Typically the gluefilm would comprise a Kraft paper of 20 gram per square meter weight impregnated with 50 grams per square meter hexamine catalysed Phenol Formaldehyde resin. It is to be understood that the paper 7 ,j weight and the degree of impregnation can vary from the foregoing depending on requirements.

Si| SThe lamination conditions can vary whilst still providing suitable end product. It has been found however that bonding and curing in a single operation in which the plurality of resin impregnated core sheets are consolidated into a core panel simultaneously with the bonding of the cladding sheet to the core panel is most effective. Specifically, the best results are achieved when the method is carried out in a steam-heated platen press with the platen temperature in the range of 120 to 150 degrees C, and preferably at 135 degrees C. At the same time the pressure exerted by the press is in the order of 1 to 1.4 M.Pa. and preferably 1.2 M.Pa.

In a typical platen press the pressure would be exerted by hydraulic cylinders.

In a typical end product the laminate would be in the order of 3 to 25 mm in thickness. The core and cladding sheet i thicknesses are a matter of design having regard to the /i ope:"ating conditions to which the laminate is to be subjected.

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Claims

1. A process for the manufacture of a metal-clad rigid

4. T non-porous panel comprising the steps of providing an imprec assembly of overlying substantially identical Kraft paper 105 tc sheets of the same weight where the weight is selected from the range 170-200 grams per square meter and where the paper sheets are all impregnated to substantially the same degree where with hexamine catalysed Phenol Formaldehyde which when amounI polymerised in a fusing step under heat and pressure will provide a non-ionic rigid core for the panel, providing6. T metal cladding sheets as hereinbefore defined on both sides too**#the of the assembly of Kraft paper sheets with a thermosetting ,ipe 4*4444c 04 t0 &V 4 4 :glue film sheet between the metal sheets and the Kraft paper0t resin 4 sheets immediately adjacent thereto, fusing the Kraft paper grams sheets together to form a rigid core panel and fusing the metal sheets to the core in a single operation in which the7. T *0 assembly of Kraft paper sheets and the metal cladding sheetsoft 4 are subjected to a temperature in the range of 120 to 150mer 0meter degrees C at a pressure of 1 to 1.4 M.Pa in a platen press. 2. The process claimed in claim 1 wherein the fusion of the panel sheets is carried out at 135 degrees C and at a ttpressure of 1.2 M.Pa. proce: 3. The process of claimn 1 or claim 2 wherein the Kraft paper sheets are each of a weight equal to 183 grams perDae square meter. RALPH By it HALLI -9- j A, Fl 4. The process of any one of claims 1 to 3 where the impregnation of the Kraft paper sheets is in the amount of 105 to 130 grams per square meter. The process as claimed in any one of claims 1 to 4 where the impregnation of the Kraft paper sheets is in the amount of 117 grams per square meter. e a t 6. The process as claimed in any one of claims 1 to 5 where o o p the glue film sheet is a glue sheet of Kraft paper impregnated with a hexamine catalysed Phenol Formaldehyde o 4 resin where the glue sheet has a weight in the order of 0"49 grams per square meter.

7. The process as claimed in claim 6 where the impregnation of the glue sheet is in the order of 50 grams per square ,.ti meter. -*4

8. A metal clad rigid non-porous panel when made by the o S1 process of any one of claims 1 to 7. Dated this Ist day of April, 1992 RALPH SYMONDS AUSTRALIA LIMITED By its Patent Attorneys, HALLIDAYS. I