NZ201447A

NZ201447A - Heat shrunk plastics sheet on each side of a grid of intersecting metal rods

Info

Publication number: NZ201447A
Application number: NZ201447A
Authority: NZ
Inventors: Carl Heinz
Original assignee: Carl Heinz
Priority date: 1981-09-28
Filing date: 1982-07-30
Publication date: 1986-04-11
Also published as: CA1201371A; EP0075641A3; EP0075641B1; DE3278972D1; EP0075641A2

Description

1447 Priority Date(s): Q3:JQ . .c?S Complete Specification Filed: Class: €£5cl£) . <3^.9. ftcp.7/O&v /sa> .as Publication Date: Ji!. ?. 1986...

P.O. Journal, No: ..

Patents Form No.5 NEW ZEALAND PATENTS ACT 1953 COMPLETE SPECIFICATION "COMPOUND MATERIAL" 1,-WE- HEINZ CARL, of Waldstrasse 16, D-8644 Pressig, West Germany, a German Citizen hereby declare the invention, for which-3E/we pray that a patent may be granted to me-/us, ..and the method by which it is to be performed, to be particularly described in and by the following statement (followed by page f A.) JUL 1982 RBCBVeq - 1A - A Compound Material ^01^147 Description This invention relates to a compound material as specified in the generic clause of claim 1.

Compound materials formed of various base materials are known for widely varying uses.

The majority of such compound materials is of relatively complicated structure and expensive as regards consumption of base materials and manufacture.

New Zealand Patent Specification No:201346 relates to a cover structure comprising a substantially rigid grid-like frame structure and a pair of shrinkable plastic sheets each covering one side of the frame structure and adhered thereto permitting the cover structure to be bent to any desired shape.

It is an object of the present invention to provide a compound material which is of simple construction, lends itself to cost-effective manufacture and is adapted to be employed for widely varying uses.

This object is attained according to the invention by the characterizing features of the main claim.

The framework formed by said grid structure imparts the compound material the required strength, while the flexible plastic sheet closes the grid openings.

Particular advantages are obtained according to claim 2 by covering both sides of the grid structure with the plastic sheet, so that the grid structure is enclosed between two plastic sheet layers. There is thus achieved an increased strength and improved protection of the grid structure against corrosion.

The configuration of the grid structure according to claim 1, consisting of intersecting metal rods, imparts the required rigidity and strength to the finished compound material. 201447 A particularly advantageous embodiment is defined in claim 3. The mesh structure interposed between the plastic sheet and the grid structure serves as a support for the plastic sheet. This permits the grid structure to be dimensioned solely in proportion to the loads to be absorbed thereby.

Claim 4 describes a particularly preferred method for making the compound material according to the invention.

Claims 9 to 12 describe an advantageous apparatus for manufacturing the compound material according to the invention. ^ v<i * ;(V ;• . O' ;31 JANim ;mm ;3 ;2 0 144 ;The invention shall now be described in detail with reference to the accompanying drawings, wherein: ;fig. 1 shows an exploded perspective view of a compound material of the invention comprising a single sheet', ;fig. 2 shows an exploded perspective view of a compound material of the invention with plastic sheeting applied to both sides, ;fig. 3 shows an exploded perspective view of a compound material of the invention comprising a single sheet an an interposed mesh structure, ;fig. 4 shows an exploded perspective view of the compound material of fig. 3 comprising two sheeting layers, ;fig. 5 shows a diagrammatical view of an assembly line for manufacturing the compound material according to the invention, and fig. 6 shows a top plan view of the assembly line of fig. 5. ;Shown in fig. 1 is an exploded perspective view of a compound material according to the invention. It consists of a grid structure 1 of intersecting metal rods and a flexible plastic sheet 2 covering the grid openings. Grid structure 1 is formed of perpendicularly intersecting metal rods. The diameter and spacing of the rods are determined by the intended use, i.e. by the loads to be supported, the required stability and the thickness of sheet 2. In making the compound material of fig. 1, sheet 2 is spread on a pre-cut section of grid structure i of the required size, and affixed thereto as by heat-shrinking, welding, adhesion, for instance by means of adhesive strips, ;4- ;2 0 1447 ;or by mechanical means such as binding wire or staples. ;Pig. 2 shows a compound material formed of a grid structure 1 enclosed between an upper and a lower plastic sheet 2a and 2b, respectively. Sheets 2a and 2b are commercially available shrinkable foils adapted to be tensioned over grid structure 1 and connected thereto as well as to one another by application of heat. The connection areas are located mainly along the edges and in all or selected ones of the grid openings. ;Fig. 3 shows a compound material composed of a metal grid structure 1 and a plastic sheet 2. Interposed between grid structure 1 and sheet 2 is a mesh structure 3 in the form of a commercially available wire mesh having'substantially smaller mesh openings than grid structure 1. As the expected static forces as well as the forces generated by the heat-shrinking step are fully absorbed by grid structure 1, mesh structure 3 nay be relatively thin and flexible. Mesh structure 3 forms a reinforcement of plastic sheet 2, substantially preventing the latter from being penetrated. The grid structure may thus be dimensioned solely with regard to the static forces to be absorbed, i.e. the spacing and diameter of the metal rods employed as well as their connection to one another are determined by the expected loads. The three base materials 1, 2 and 3 are connected to one another in the manner described with reference to fig. 1. ;A bompound material shown in fig. 4- is a combination of the embodiments of figs. 2 and 3. The plastic sheets 2a, 2b are again commercially available shrinkable foils connected to one another and to grid structure 1 and mesh structure 3 in the manner described. They tightly enclose grid structure 1 and mesh structure 3> so that the individual layers of the compound are retained in their positions relative to one another without any further aid. ;5 ;201447 ;Shown at the left of fig. 5 is the forward portion of a first conveyor 4 formed as a roller table. Supported on conveyor 4 is the grid structure 1 and, if required, the mesh structure 3 to be conveyed in the position shown to the forward end of the first conveyor. Grid structure 1 and mesh structure 3 may be withdrawn from supply rolls (not shown) in the form of flat endless webs, or may be supplied in the form of pre-cut sections of identical size. The forward end 5 of conveyor 4 is located closely upstream of a location whereat a sheet 2 consisting of shrinkable foil extends between a pair of supply rolls 6 and 7. Sheet 2 is retained in position adjacent forward end 5 of conveyor 4 by pairs of guide rollers 8 and 9-Sheet supply rolls 6 and 7 are rotatably mounted in a frame 10 with their axes 11 and 12, respectively, extending transversely of the feed direction indicated by arrow 13. In this manner sheet 2 has to be deflected to a limited degree only, which may be accomplished in a simple manner by individual deflection rollers mounted parallel to the pairs of guide rollers 8 and 9. In order to keep the tension exerted on the sheet by the advancing grid structure within acceptable limits, the sheet supply rollers may be driven so as to unwind the sheet in synchronism with the advance of the grid structure. ;From the position shown in figs. 5 and 6, grid structure 1 and, if present, mesh structure 3 is/are further advanced in the direction of arrow 13, carrying sheet 2 along with its/their forward edge(s). The drive means (not shown) of sheet supply rolls 6 and 7 ensure uniform unwinding of the sheet from the supply rolls without undue tension with respect to the forwards advancing grid structure 1. Grid structure 1 advances onto a second conveyor 14, also in the form of a roller table, located at a certain distance from forward end 5 of first conveyor 4, so that the sheet b extending from supply rolls 6 and 7 may freely pass 'therebetween. A shrinking and welding apparatus 15 com- ;6 ;201447 ;heated gas generators 16, 17 located above and below, respectively, of second conveyor 14- so as to direct heated gas streams opposite each other onto the sheets covering both sides of the grid structure. The kinetic energy of the heated gas streams causes the sheets to buckle into \ contact with one another, resulting in the sheets being welded to one another within the grid and/or mesh openings. Second conveyor 14- continues downstream of the heated gas generators 16, 17 to form a cooling section the length of which is determined by that of the grid structure sections on the one hand, and by the requirement for the heated and thereby softened sheets to cool down to a suitable temperature for shrinking. Second conveyor 14-, or cooling section 18, respectively, leads to a cutting station 19 operable either to cut only the welded sheets between the pre-cut grid and mesh structure sections, or to cut the continuous web, preferably also by the application of heat, into suitable lengths for later use. ;Downstream of cutting station 19 there is a third conveyor 20 for carrying away the finished compound material lengths. ;In the embodiment shown and described, a single integral sheet web initially extends between the first and second conveyors inthe vertical direction. At the start of the apparatus, the leading edge of the grid structure carries the sheet along, so that the latter is tensioned over both sides of the grid and mesh structures. It is also possible, to employ two separate sheet supply rolls and to interconnect the free ends of the sheet webs carried thereon as by welding or shrinking. ;Prior to being covered with the sheets, grid structure 1 and mesl} structure 3 may be straightened and/or flattened as required by a suitable device (not shown). Immediately „ ojj downstream of the shrinking and welding apparatus there ;^4 nmei ;0h ;7 ;201447 ;may be additionally provided one or more pairs of pressure rollers of felt or a similar material for compressing the sheets into contact with, one another and. with the grid and mesh structures. ;The invention is not limited to the embodiments described. The characteristic features described with respect to individual figures may be combined in any suitable manner. The base materials employed may also be different from those described. Thus the mesh structure may consist of any suitable material in any suitable configuration. It may thus consist of a commercial-grade mosquito screen of mnetal wires or plastic, or of a conventional wire netting of coarser or finer mesh in any configuration. Depending on the intended use, the grid structure may be formed of thicker or thinner, rigid or bendable rods intersecting at right angles or obliquely at a greater or smaller spacing, braided or interwoven in any manner. The sheets may be made of any plastic material of any suitable thickness, opaque or transparent. ;' * 201447

Claims

WHAT WE CLAIM IS:

1. A compound laminated material comprising a grid structure consisting of intersecting metal rods forming a carrying framework and a flexible, plastics, heat-shrinkable material sheet shrunk onto both sides of said grid structure.

2. A compound material according to claim 1, characterized in that said plastics material sheets are interconnected through the openings of said grid structure.

3. A compound material according to claim 1 or 2, characterized in that a mesh structure of finer mesh and thinner than said grid structure is interposed between at least one said plastics sheet and said grid structure so as to overlie the grid openings.

4. A method for producing a compound laminated material comprising the steps of arranging a plastics heat-shrinkable sheet on both sides of a grid structure consisting of intersecting metal rods for forming a carrying framework in a parallel and aligned relationship for enclosing said grid structure, heat-shrinking said plastics shrinkable sheets onto both sides of said grid structure and further thereby welding and interconnecting said plastics heat-shrinkable sheets through the openings of said grid structure. 201447

5. A method as claimed in claim 4, which includes arranging a mesh structure of finer mesh and thinner than said grid structure onto said grid structure so that the said plastics heat-shrinkable sheets enclose said mesh and grid structure, shrinking said plastics heat-shrinkable sheets by use of heat and thereby fixing said plastics sheets onto said mesh and grid structures and further thereby interconnecting said plastics sheets on both sides through the openings of said mesh and grid structures.

6. A method as claimed in claim 4 or 5, characterized in that the employed materials are continuously withdrawn from a supply thereof and fed into a connecting device in superimposed arrangement.

7. A method as claimed in any one of claims 4 to 6, characterized by heating and shrinking said plastics heat-shrinkable sheets with a heated gas stream and pressing said sheets onto said grid structure.

8. A method as claimed in any one of claims 4 to 7, characterized by passing said grid structure through a flattening and straightening device.

9. An apparatus for making a compound laminated material consisting of a grid structure consisting of intersecting metal rods as a carrying framework and plastics heat-shrinkable sheets shrunken on both sides of said grid structure comprising a first feed path for said grid " 10 " 201447 fP* structure and for said plastics sheets, and at least one supply roller as well as guide rollers for feeding, aligning and superimposing said plastics sheets and said grid structure, and by a second feed path for feeding the 5 superimposed grid structure and plastics sheets towards a heat-shrinking and welding apparatus for shrinking the plastics sheets and thereby interconnecting said plastics sheets and said grid structure by the application of heat.

10. An apparatus as claimed in claim 9, which is also 10 arranged to feed a mesh structure along the first feed path with said grid structure, and said plastics sheets, and includes at least one further supply roller as well as further guide rollers for feeders, aligning and superimposing said mesh structure with said grid structure 15 and plastics sheets, said second feed path also enabling the feeding of the mesh structure with the grid structure and plastics sheets towards the shrinking and welding apparatus for interconnecting the superimposed materials by the application of heat. 20

11. An apparatus as claimed in claim 9 or 10, characterized in that said shrinking and welding apparatus includes at least one heated gas generator for generating a heated gas stream to be directed onto each surface of the compound material formed by plastics heat-shrinkable 25 sheet.

12. An apparatus as claimed in claim 11, 12 or 13, characterized in that a flattening and straightening device for at least said grid structure is provided upstream of said heat-shrinking and welding apparatus.

.•W 3Q0Jn>. 13 • A compound material substantially as herein described — i\ ■Da v^ii with reference to any one of the embodiments shown in f JAN 1986y Figures 1 to 4 of the accompanying drawings " 11 " . 201447

14. A method of producing a compound material substantially as herein described with reference to any one of the embodiments shown in Figures 1 to 4 of the accompanying drawings.

15. An apparatus for making a compound material substantially as herein described with reference to Figure 5 and 6 of the accompanying drawings. I3 ? JAM 1986