GB2190036A

GB2190036A - Sheeting manufacture

Info

Publication number: GB2190036A
Application number: GB08706377A
Authority: GB
Inventors: Francis Hanning-Lee
Original assignee: Fibrelite Ltd
Current assignee: Fibrelite Ltd
Priority date: 1986-04-01
Filing date: 1987-03-18
Publication date: 1987-11-11
Also published as: GB2190036B; GB8706377D0

Abstract

A method of and apparatus (10) for the manufacture of a double skin sheeting (23) is provided. A first quantity of curable sheet forming material is forwarded at a first forwarding speed between bands (14,16) into a heating chamber (12), the bands (14,16) passing alternately over and under spaced laterally extending tubes (18,29). The rollers (18,29) are driven so that the material and bands (14,16) travel at a slower speed than the first speed so that the material becomes corrugated and cured. It is then cut longitudinally by a cutter (15) into corrugated strips (24) which are passed on another conveyor belt (30) through the heating chamber (12) in contact with and spaced laterally of a second sheet of material which is cured and bonded to the strips (24). The strips (24), with one sheet of material (25) bonded thereto, are then passed again through the heating chamber (12) in contact with a third sheet of material which is cured and bonded to the strips (24) to form the double skin sheeting (23). <IMAGE>

Description

SPECIFICATION Sheeting manufacture This invention relates to the manufacture of sheeting, and in pa rticularto the manufacture of double skin glass-fibre sheeting for use in obscure windows, rooflights, greenhouses, "see through" fire doors and the like.

Sheeting ofthe abovementioned type is known and conventionally has been made in the requisite sized paneis by hand. This invoives the production of a honeycomb or otherform of spacing structure which isthen bonded between two sheets of glass-fibreto produce the sheeting panel. This is a time consuming and therefore costly method of production and leads to non-uniformityofthe product.

It is an object of the present invention to provide a method of manufacturing a double skin sheeting which avoids or substantially mitigatesthe aforementioned disadvantages, and a machine for performing the method.

The invention provides a method of manufacture of double skin sheeting comprising the steps of feeding a first quantity of curable sheetforming material into a heating zone at a firstforwarding speed, forwarding said sheet forming material through said heating zone along an undulating path at a second forwarding speed less than said first forwarding speed whereby laterally extending corrugations are formed in said material and said material is substantially cured, forwarding said corrugated material from said heating zone and cutting same longitudinally thereof into a plurality of corrugated strips, feeding a second quantity of curable sheet forming material into a heating zone with said corrugated strips in contact therewith and spaced laterally thereof to substantially cure said second sheet material and bond said corrugated strips thereto, and feeding a third quantity of curable sheetforming material into a heating zone with said corrugated strips in contact therewith and said second sheet material spaced therefrom to substantially cure said third sheet material and bond said corrugated strips thereto and form said double skin sheeting.

The invention also provides apparatus for performing the aforesaid method comprising at least one heating chamber, first conveying means operable to forward sheet forming material at a first forwarding speed into said heating chamberandto forward said sheet forming material along an undulating path through said heating chamber at a second forwarding speed less than said first forwarding speed, cutting means operable to cut said sheet material longitudinally into a plurality of strips, and at least one further conveying means operable to convey sheet forming material through a heating chamber.

Said first conveyor means may comprise a band or belt which is supported by a plurality of tubes extending laterallythereofand spaced longitudinally thereofwithin said heating chamber.

Said first and second conveying means may each comprise a band,a pair of rollers and meansfor driving one of said rollers in rotation to wind said band thereon and unwind said band from the other of said rollers. Said first conveying means may also comprise a second band disposed above the aforementioned band, a second pair of rollers and meansfordriving one of said second pairof rollers in rotation to wind said second band thereon and unwind said second band from the other of said second pair of rollers.

The invention will now be described with reference to the accompanying drawing in which Figure lisa schematic elevation ofapparatusfor performing the method of the invention, and Figure2 is a perspective view of double skin sheeting made by the method of the invention.

Referring now to Figure 1 there is shown double skin sheeting manufacturing apparatus 10 comprising a first conveying means 11,a heating chamber 12, a second conveying means 13, and a cutter 15.

The first conveying means 11 is operable to forward sheet forming material into the heating cha m ber 12 at a fi rst forwa rd i ng speed. The sheet forming material comprises a suitable quantity of glass fibre reinforced molten resin, for example polyester resin. The first conveyor 11 comprises a band of polyethylene terephthalate 14 which passes from one roller 27 to a driven roller 28. The conveyor 11 also comprises a second band 16 of polyethylene terephthalate disposed above the band 11 and passing from a roller 17to a driven roller 19. The sheetforming material is placed between the bands 14,16 and is fed into the heating chamber 12 at a first forwarding speed, a speed of approximately 60cm/min being suitable. The sheet forming material is partially solidified after entering the heating chamber 12.The bands 14,16 are supported by and pass beneath a pluralityoftubes 18,29 respectively extending laterallyofthebands 14,l6andspaced apart longitudinally thereof. One or more ofthe tubes 18,29 is driven in rotation so that the bands 14,16forward the material at a second forwarding speed which islessthanthefirstforwardspeed.The retardation ofthesheetforming material andthe disposition ofthe tubes 18,29 causes the material to travel an undulating path between the tubes 18,29 and thus becomes corrugated. The temperature within the heating chamber 12 is maintained atan appropriatetemperature so that the corrugated sheet is substantially cured as it passes out ofthe heating chamber 12.Cutting means 15 in the form of a plurality of laterally spaced knives or rotary cutters cuts the corrugated sheet issuing from the heating chamber 12 longitudinally into a plurality of corrugated strips.

The second conveying means 13 comprises a band 30 of polyethylene terephthalate which is unwound from a supply roller 20 and onto a driven take-up roller21.

A second quantity of glass fibre reinforced molten polyester resin is placed on the band 30 at the heating chamber inlet 22, with the corrugated strips placed on their edges thereon spaced apart laterally of the band 30. The band 30 conveys the second sheetforming material and the corrugated strips thereon through the heating chamber 12so asto substantially cure the second sheet material and bond the corrugated strips thereto.

Athird quantity of glass fibre reinforced molten polyester resin is then placed on the band 30 at the heating chamber inlet 22, with the free edges ofthe corrugated strips in contact with the third sheet forming material and the second sheet spaced therefrom. The band 30 then conveys the third sheet forming material, the corrugated strips and the second sheetthrough the heating chamber 12 so as to substantially cure the third sheet material and bond the corrugated strips thereto. In this way a double skin sheeting 23 as shown in Figure 2 is formed, comprising a first sheet material formed and cut into corrugated strips 24to the opposed longitudinal edges of which strips are bonded second and third sheets 25,26. The sheeting 23 is manufactured in a simple and quick mannerwhich provides for good uniformity of the product.By suitable choice ofthethickness of each sheet formed and the width of the corrugated strips, any particular thickness, strength and insulation properties ofthe sheeting 23 can be provided. For example, with sheets of approximately lmmthicknessand corrugated strips of approximately 8mm width a sheeting of 1 Omm thickness suitable for insertion in glazing bars is produced. For rooflights 25m m thick sheeting is suitable, and this has a weight of approximately 1/6 that of glass. The sheeting thus produced does not melt and therefore presents less of a hazard in case of fire than PVC, acrylic or polycarbonate sheet materials.In addition the sheeting is considerably stronger than glass and will not break when hit by stones, air rifle pellets orthe like. The sheeting is particularly suited for rooflights as its light transmittance is comparable with clear glass, e.g. 84to 77% but unlike glass it is substantially opaqueto infra-red solar radiation. In addition the sheeting has good sound insulation properties.

Other embodiments of apparatus for performing the method ofthe invention will be readily apparent to persons skilled in the art. For example a third -.,nveyor may be provided for conveying of the third sheetforming material, the corrugated strips and the second sheet material through the heating chamber 12 instead of using the second conveyor 14 a second time forthis operation. Alternatively separate heating chambers with their respective conveyors may be provided for each of the three curing operations.

Claims

1. A method of manufacture of double skin sheeting comprising the steps offeeding a first quantity of curable sheet forming material into a heating zone at a first forwarding speed, forwarding said sheet forming material through said heating zone along an undulating path at a second forwarding speed less than said first forwarding speed whereby laterally extending corrugations are formed in said material and said material is substantially cured, forwarding said corrugated material from said heating zone and cutting same longitudinally thereof into a plurality of corrugated strips, feeding a second quantity of curable sheet forming material into a heating zone with said corrugated strips in contact therewith and spaced laterallythereofto substantially cure said second sheet material and bond said corrugated strips thereto, and feeding a third quantity of curable sheet forming material into a heating zone with said corrugated strips in contacttherewith and said second sheet material spaced therefrom to substantially cure said third sheet material and bond said corrugated strips thereto and form said double skin sheeting.

2. A method according to claim 1 wherein each of said forwarding through a heating zone steps is performed in a common heating zone.

3. A method according to claim 1 orclaim2 wherein said first sheet forming material is fed along an undulating path alternately over and beneath a plurality of tubes spaced along said path and extending laterally thereof.

4. A method according to claim 3 comprising driving in rotation at least one of said tubes.

5. A method according to any one of claims 1 to 4 wherein each of said forwarding steps is performed by piacing said material on a moving band.

6. A method according to any one of claims 1 to 5 comprising placing said corrugated strips on said second quantity of sheet forming material each with an edge in contact therewith.

7. A method of manufacture of double skin sheeting substantially as hereinbefore described with reference to the accompanying drawing.

8. A double skin sheeting when manufactured by the method of any one of claims 1 to 7.

9. Adoubleskinsheeting accordingtoclaim8 wherein said sheet forming material comprises a glass fibre reinforced molten polyester resin.

10. Apparatusforthemanufactureofadouble skin sheeting comprising at least one heating chamber, first conveying means operable to forward sheet forming material at afirstforwarding speed into said heating chamber and to forward said sheet forming material along an undulating path through said heating chamber at a second forwarding speed less than said first forwarding speed, cutting means operable to cut said sheet material longitudinally into a plurality of strips and at least onefurther conveying means operable to convey sheet forming material through a heating chamber.

11. Apparatus according to claim 10wherein each conveying means comprises a respective band.

12. Apparatus according to claim 11 wherein said first conveying means comprises a pair of rollers, one of which is driven to wind said band onto said one rollerfromthe other of said rollers.

13. Apparatus according to claim 12 wherein said first conveying means comprises a plurality oftubes extending laterally of said band and spaced apart longitudinallythereof.

14. Apparatus according to claim 13wherein said band passes alternately over and beneath said tubes.

15. Apparatus according to claim 130reclaim 14 wherein at least one of said tubes is driven in rotation.

16. Apparatus according to any one of claims 12 to 15 wherein said first conveying means comprises a second pair of rollers, one of which is driven and a second band disposed above said band and passing between said second pair of rollers.

17. Apparatus according to any one of claims 11 to 16 wherein the or each further conveying means comprises a band supply roller, a band take-up roller and a respective band passing therebetween.

18. Apparatus for the manufacture of double skin sheeting substantially as hereinbefore described with reference to and as illustrated in Figure 1 ofthe accompanying drawings.