GB1602592A

GB1602592A - Moisture impermeable and reflecting panels

Info

Publication number: GB1602592A
Application number: GB44564/76A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1978-01-25
Filing date: 1978-01-25
Publication date: 1981-11-11

Description

(54) MOISTURE IMPERMEABLE & REFLECTING PANELS (71) I, GEORGE LESLIE ROBINSON, a British Subject, of 239 Ditchfield Road, Hough Green, Widnes, Cheshire, do hereby declare the invention, for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement:- The present invention relates to composite panels for use as building panels.

More particularly, the present invention relates to a wide variety of composite panels, suitable for use as building panels, having good vapour/moisture impermeability and heat and cold reflectivity and which are not provided for in the market as yet.

At the present time it is common, for vertical cavity type construction, for example in new or prefabricated buildings, to utilize the following insulating techniques: (i) to leave an air cavity; (ii) to use glass fibre quilts, for example, as made by Pilkington-fibreglass Ltd., (iii) to use mineral wool quilts, for example, Rocksil mineral wool made by Cape Building Products ("Rocksil" is a Trade Mark), or (iv) to use thick, expanded, high void, open cell plastics sheets.

Most substrates are water sensitive and can absorb moisture through the insulating material should there be damp present or should condensation form on the face within the cavity by there being temperature disparities between the inside and outside of the cavity panel and the dew point being reached. In these cases the insulating material can act as a bridge across the cavity. Consequently, a polythene sheet is sometimes provided between the insulating material and the substrate to act as a moisture barrier.

The substrates normally used are plasterboard, hardboard, chipboard, wood fibre insulation board, plywood, asbestos, asbestos-free substrates or plastics based, high void substrates, for example, expanded polystyrene and rigid, open cell urethane foams, all of which are porous or of open cell construction.

The principle in using, thick, expanded, high void plastics sheets or glass fibre or mineral wool quilts as insulators is to create as much still air as possible within the sheet or quilt, the still air acting as the insulator within the cavity.

It is also common to use insulating plasterboard which comprises a thin, fragile, pure aluminium foil applied to a face of the plasterboard panel, the aluminium foil coated face being the face facing the cavity in use. As in the use of thick, expanded, open cell constructed plastics sheets, a moisture or vapour barrier may also be provided. The provision of the moisture barrier will, however, add to the cost of producing the panel. The principle in using aluminium foil for insulating purposes is that the aluminium is used as a reflecting surface for radiation (when new approximately 80% heat radiation can be achieved).This form of panel, however, suffers from the disadvantage that the aluminium foil is subject to slow oxidation and is hygroscopic, particularly when subject to vapour or condensing moisture deposits building up on the surface, and consequently the efficiency of the insulating panel deteriorates over a period of time.

There is, therefore, the need for a panel having good vapour/moisture impermeability and heat and cold reflectivity and which does not lose its efficiency over a period of time.

According to the present invention there is provided a composite for use as a building panel, which comprises a substrate, a polyester film on at least one surface of the substrate, the polyester film being adhered to the substrate using an adhesive, a vacuum deposited aluminium coating on the surface of the polyester film remote from the substrate, and a protective plastics material layer on the surface of the aluminium coating remote from the polyester film, the protective plastics material layer being light-transparent and substantially transparent to radiant heat.

According to the present invention there is also provided a process for preparing a composite, which comprises adhering a laminate to at least one surface of a substrate using an adhesive and at a sufficient temperature and pressure, the laminate comprising a polyester film, a vacuum deposited aluminium coating on one surface of the polyester film and a protective plastics material layer on the exposed surface of the aluminium coating, the protective plastics material layer being light-transparent and substantially transparent to radiant heat and the polyester film of the laminate being adjacent to the substrate.

Although the present invention will hereinafter be described with reference to the use of a laminate of the polyester film, aluminium coating and protective plastics material layer, it is to be understood that the polyester film may be adhered to the substrate and the aluminium coating and the protective plastics material layer subsequently added in separate stages.

By practice of the present invention the "U" values of the substrate may be substantially improved.

The terms "moisture impermeability" and "moisture barrier", as used herein, are merely intended to refer to substances having low or substantially no vapour/moisture permeability under normal building conditions.

The protective plastics material layer and the polyester film have good clarity, although the protective plastics material layer is generally more transparent than the polyester film when using thicknesses greater than 12 microns.

Any radiation striking the composite panels of the present invention will only have to pass through the protective plastics material layer before being reflected by the aluminium coating, thereby resulting in a high efficiency of reflection (a reflectivity of up to 92% emissivity values 0.08 at 5W100 F).

Thepolyester film may be from 12 to 25 microns thick, preferably substantially 12 microns thick.

A suitable polyester film is marketed as "Melinex S" ("Melinex" is a Trade Mark) by ICI and is 12 microns in thickness. Melinex S is supplied in rolls of up to approximately 51 inches (1300 mm) wide. A suitable clear film is also manufactured by Dupont.

Laminates which may be used in accordance with the present invention and comprising a metallized polyester film of approximately 12 microns in thickness were found to have the following water vapour/oxygen permeabilities.

Water Vapour Permeability

Test Method: BS 3177 MVTR in test conditions g/mV24 hours 12 micron metallised polyester 0.2-1.0 25"C 75% RH 2.5 38"C 90 O RH 12 micron polyester -- clear 18 25"C 750d RH 40 38 C 90 , RH 12 micron metallised polyester 0.2 25"C 75% RH laminated to 50 micron LDPE 2.-2.8 38"C 90%, RH Oxygen Permeability

Test Method: BS 2782 O2 transmission in method 514A cc/m2/24 hours/atm. test conditions 12 micron metallised polyester 1--2 250C 0% RH 12 micron polyester -- clear 110--130 25"C 0% RH 12 micron metallised polyester severely creased for I minute 20--55 25"C 45% RH 12 micron metallised polyester laminated to 50 micron LDPE 2 25"C 0 /O RH Thus such laminates provide a very effective moisture/vapour barrier.

Suitable substrates for use in the present invention include wood fibre insulation board, asbestos, asbestos-free panels, chipboard, plywood, hardboard or plasterboard, any of which may be plain or decorated. Further suitable substrates include laminate structures, for example, Formica or bonded panels, mineral tiles for ceiling use, composites or monolithic panels, e.g. Marinite, Echostop, Plaster and glass fibre. "Formica" and "Marinite" are Trade Marks. Composites using a combination of any of these bonded to expanded polystyrene (i.e. beaded) and with the protective foil laminate on the reverse or both sides may also be used.

Any adhesive which does not attack the substrate and polyester may be used.

Suitable adhesives for bonding the substrate to the laminate are PVA waterbased adhesives formulated for PVC bonding and epoxy adhesives. An example of a PVA water-based adhesive is Crodafix, manufactured by Croda. The adhesive can be applied either manually or mechanically.

The protective plastics material layer provides an antioxidation barrier in the composite panel according to the present invention.

Suitable protective plastics materials for use in the composite panels of the present invention are manufactured by Chamberlain Plastics Ltd and are known as R100 and 101C.

The substrates may be of any suitable size and thickness, although chipboard building panels are normally manufactured in sizes of 2440x 1220 millimetres or 2440x610 millimetres, the latter mostly for flooring. Composite panels in accordance with the present invention and with the width of the substrate being 1220 mms can be mass produced readily on a roller press since the laminate used may be produced commercially in a width of 1300 mms by any practical length.

When adhering the laminate to the substrate, it is preferable to leave an overlap of the laminate around the edges of the substrate so that, when an edge of the panel is placed against a further panel or any other surface, the overlap wraps round the edge of the panel thereby providing an efficient seal for the edge and can be trimmed to the face when jointing has been completed. For example, when tongued and grooved joints are used to join panels according to the present invention together, the overlap of the laminate is trapped by the tongued and grooved joints when placed together, thereby providing a seal having a high moisture impermeability which can be left untrimmed or trimmed. A floor thus constructed with the laminate on the underside of the floor over a still air cavity, e.g. basements or upper floors, may reduce heat losses by up to 43% and also acts as a vapour barrier.

The composite panels of the present invention may be prepared using roller presses or flat or platen presses. Further, these presses may be hot or cold presses.

Where panels of considerable length are required on materials which do not require high pressures or careful examination of each panel, for example where the panel is to be used as a flooring or walling panel and the laminate will be on the surface of the substrate out of view, roller presses are preferred because of the high production speeds. Roller presses, may, however, also be used to prepare short panels.

The presses which may be utilized in preparing the composite panels of the present invention may be operated at pressures ranging from 30 to 120 Ibs per square inch and at temperatures up to 1400F. However, temperatures above 140"F may be used provided the temperature utilised is not deleterious to the properties of the substrate and laminate. There is nothing to be gained by applying heat except to speed up the adhesive setting time because, unlike PVC polyester does not stretch.

Pressures in the range of 30 to 80 Ibs per square inch are preferred and pressures in the range of 40 to 45 Ibs per square inch are especially preferred. The pressure used, will, of course, depend on such factors as the type of substrate used.

the type of press being used to apply the pressure needed to bond the laminate to the substrate and in the case of asbestos substrates, on whether the asbestos is used in a compressed or semi-compressed form. If semi-compressed asbestos is used, a pressure of 100 Ibs per square inch is preferably not exceeded. For plasterboard. a pressure of from 30 to 80 Ibs per square inch is preferably used, especially a pressure of 30 to 40 Ibs per square inch.

A pressure of 30 to 120 Ibs per square inch is generally sufficient to remove all air pockets from between the laminate and the substrate, this being the main consideration. However the pressure also provides the means to keep the adhesive in continual contact, with both the substrate and laminate surfaces.

If a cold press is used in preparing the composite panels of the present invention, the operating temperature, i.e. the temperature of the surrounding environment, is likely to be in the range of 60 to 800 F. If, however, a hot press is used the operating temperature can be any temperature from ambient temperature up to 1400 F. A hot press will, preferably, be operated at a temperature in the upper region of this range, for example 100" to 140 F, since it would not be economical to supply energy to raise the temperature of the press to just above that of the surrounding environment.

The substrate used in the composite panels of the present invention may be a panel produced according to my British Patent Specification No. 1,558,964. For example, the substrate may have the fibre reinforced, synthetic veneer on one surface thereof and the laminate adhered to the other surface of the substrate. In this way a panel which is at least fire retardant, decorative and highly efficient as a moisture barrier and insulator is produced. All the components of such a panel may be bonded together at the same time.

When adhering the laminate to a substrate in accordance with my British Patent Specification No. 1,558,964 it is essential that the cauls used in the presses be cleanand smooth otherwise imperfections will register in the panels produced.

The production of imperfections in the finished panels by cauls which are not satisfactorily clean and smooth may be reduced by placing a clean protective film, for example, polythene, between the cauls and the material being pressed. Subject to the press, heat is kept low enough to avoid melting the separation film. This protective film will absorb any small faults in the cauls. Larger faults must be removed to avoid disfigurement of the faces of the panel. A metallized foil may also be used between the cauls and the material being pressed in order to avoid temperature disparities. In many cases a metalised foil is preferred since higher temperatures may be used.

When utilizing the panels according to the present invention as flooring, for example using chipboard as the substrate, the panel is laid such that the laminate is on the underside. A cavity is formed between the chipboard/laminate combination and the plasterboard of the ceiling below. The effect of this combination is to form a cavity to obtain an efficient radiator and reflect up to 92% of the radiation downwards from the floor, thereby saving up to 43% of heat loss. This may be particularly important in basement cover floors in old houses.

The use of the aluminium foil laminate on the underside of the floor is a reversal to common practice where the aluminium foil of insulating plasterboard (used as ceiling) is fixed aluminium face upwards collecting dust and dirt by gravity and losing its radiation value progressively.

Further, the common practice of using the aluminium foil on the upper surface of the plasterboard is also ineffective, the warm air rising only passes through the plaster to the back of the aluminium foil i.e. the glue line, not the foil, is in contact with the warm air. The aluminium foil of the insulating plasterboard will also oxidize in time, resulting in a further lowering of the efficiency to substantially zero over a period of time. It can be seen, therefore, that the aluminium foil is technically placed on the wrong side of the plasterboard to conserve energy.

When it is necessary to produce panels which have a highly satisfactory appearance, it is preferred to use flat or platen presses which allow individual panel attention during pressing. Further. in this case it is necessary to lay the reflective laminate carefully on the adhesive-coated substrate. One method of applying the laminate would be to have a roll of laminate mounted on a rotatable spindle at one end of the press. The foil may then be rolled across the lower pressing plate (having the adhesive coated substrate thereon), maintaining the laminate a short distance above the adhesive coated substrate, and then lowering carefully the laminate onto the adhesive coated substrate.An alternative and more satisfactory method for ensuring that there is even tension over the laminate, when placing it on the adhesive-coated substrate, would be to have a simple mobile arm on movable stands which can pass back and foward from the roll to the opposite end of the press, the laminate being draped over the arm. Utilizing this alternative, the movable arm need only be approximately 1 to 3 inches above the height of the lower pressing plate because the laminate is very light in weight. None of these conditions apply to roller presses.

By practice of the present invention it is, therefore, possible to obtain an efficient vapour/moisture barrier with wrapped around edges and a highly efficient radiating surface from a laminate having very little bulk, very little weight, and which is low in static attraction. Further, the good vapour/moisture barrier properties of the composite panels according to the present invention may result in the production of building panels conforming to the Building (second amendment) Regulations, 1974 (Part F3).

When the laminate is formed prior to the adhesion to the substrate it is found to have good tensile strength and this strength is superior to that of aluminium foils previously adhered to substrates, although tearing along an edge is possible.

The present invention will now be further; illustrated by way of the following Examples: Example 1 A predecorated, i.e. painted or veneered, standard hardboard panel was bonded to a metallized polyester. The polyester was 12 microns thick and had a vapour deposited aluminium coating thereon. The exposed surface of the aluminium carried a protective plastics material layer.

The metallized polyester was bonded to the hardboard panel using a PVA adhesive formulated for PVC bonding (e.g. Crodafix) and a roller press operated at a temperature of 90"F and a pressure of 40 p.s.i.

The resulting panel was found to produce a predecorated panel having an effective vapour resistant reverse.

By allowing an overlap of the metallized polyester over the edges of the hardboard panel, protection of the edges of the panel may be achieved when the panel was fixed in place.

Example 2 The procedure utilized in this Example is identical to that of Example 1 except that a predecorated hardboard panel which had been impregnated to produce an at least fire-retardant specification was substituted for the standard hardboard panel.

A panel was produced having a Class 0, and the presence of the metallized polyester was also found to inhibit loss of the fire-retardant salts from the hardboard by leaching when exposed to moisture present in the surrounding environment.

WHAT I CLAIM IS: 1. A composite for use as a building panel, which comprises a substrate, a polyester film on at least one surface of the substrate, the polyester film being adhered to the substrate using an adhesive, a vacuum deposited aluminium coating on the surface of the polyester film remote from the substrate, and a protective plastics material layer on the surface of the aluminium coating remote from the polyester film, the protective plastics material layer being light-transparent and substantially transparent to radiant heat.

2. A composite as claimed in Claim 1, in which the polyester film is from 12 to 25 microns in thickness.

3. A composite as claimed in Claim 2, in which the polyester film is substantially 12 microns in thickness.

4. A composite as claimed in any of Claims 1 to 3, in which the adhesive is a PVA water-based adhesive.

5. A composite as claimed in any of Claims 1 to 4, in which the substrate is wood fibre insulation board, asbestos, an asbestos-free panel, chipboard, plywood, hardboard, plasterboard or a laminate.

6. A composite as claimed in Claim 5, in which the substrate is asbestos, chipboard, plywood, hardboard or a laminate.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. laminate would be to have a roll of laminate mounted on a rotatable spindle at one end of the press. The foil may then be rolled across the lower pressing plate (having the adhesive coated substrate thereon), maintaining the laminate a short distance above the adhesive coated substrate, and then lowering carefully the laminate onto the adhesive coated substrate. An alternative and more satisfactory method for ensuring that there is even tension over the laminate, when placing it on the adhesive-coated substrate, would be to have a simple mobile arm on movable stands which can pass back and foward from the roll to the opposite end of the press, the laminate being draped over the arm.Utilizing this alternative, the movable arm need only be approximately 1 to 3 inches above the height of the lower pressing plate because the laminate is very light in weight. None of these conditions apply to roller presses. By practice of the present invention it is, therefore, possible to obtain an efficient vapour/moisture barrier with wrapped around edges and a highly efficient radiating surface from a laminate having very little bulk, very little weight, and which is low in static attraction. Further, the good vapour/moisture barrier properties of the composite panels according to the present invention may result in the production of building panels conforming to the Building (second amendment) Regulations, 1974 (Part F3). When the laminate is formed prior to the adhesion to the substrate it is found to have good tensile strength and this strength is superior to that of aluminium foils previously adhered to substrates, although tearing along an edge is possible. The present invention will now be further; illustrated by way of the following Examples: Example 1 A predecorated, i.e. painted or veneered, standard hardboard panel was bonded to a metallized polyester. The polyester was 12 microns thick and had a vapour deposited aluminium coating thereon. The exposed surface of the aluminium carried a protective plastics material layer. The metallized polyester was bonded to the hardboard panel using a PVA adhesive formulated for PVC bonding (e.g. Crodafix) and a roller press operated at a temperature of 90"F and a pressure of 40 p.s.i. The resulting panel was found to produce a predecorated panel having an effective vapour resistant reverse. By allowing an overlap of the metallized polyester over the edges of the hardboard panel, protection of the edges of the panel may be achieved when the panel was fixed in place. Example 2 The procedure utilized in this Example is identical to that of Example 1 except that a predecorated hardboard panel which had been impregnated to produce an at least fire-retardant specification was substituted for the standard hardboard panel. A panel was produced having a Class 0, and the presence of the metallized polyester was also found to inhibit loss of the fire-retardant salts from the hardboard by leaching when exposed to moisture present in the surrounding environment. WHAT I CLAIM IS:

1. A composite for use as a building panel, which comprises a substrate, a polyester film on at least one surface of the substrate, the polyester film being adhered to the substrate using an adhesive, a vacuum deposited aluminium coating on the surface of the polyester film remote from the substrate, and a protective plastics material layer on the surface of the aluminium coating remote from the polyester film, the protective plastics material layer being light-transparent and substantially transparent to radiant heat.

7. A composite as claimed in Claim 1 and substantially as hereinbefore

described with reference to either of the Examples.

8. A process for preparing a composite, which comprises adhering a laminate to at least one surface of a substrate using an adhesive and at a sufficient temperature and pressure, the laminate comprising a polyester film, a vacuum deposited aluminium coating on one surface of the polyester film and a protective plastics material layer on the exposed surface of the aluminium coating, the protective plastics material layer being light-transparent and substantially transparent to radiant heat and the polyester film of the laminate being adjacent to the substrate.

9. A process as claimed in Claim 8, in which the polyester film is from 12 to 25 microns in thickness.

10. A process as claimed in Claim 9, in which the polyester film is substantially 12 microns in thickness.

11. A process as claimed in any of Claims 8 to 10, in which the adhesive is a PVA water-based adhesive.

12. A process as,claimed in any of Claims 8 to 11, in which the pressure is 30 to 120 Ibs/in2.

13. A process as claimed in Claim 12, in which the pressure is 30 to 80 Ibs/in2.

14. A process as claimed in Claim 13, in which the pressure is 40 to 45 Ibs/in2.

15. A process as claimed in any of Claims 8 to 14, in which the temperature is up to 1400F.

16. A process as claimed in Claim 15, in which the temperature is 60 to 800 F.

17. A process as claimed in Claim 15, in which the temperature is 100" to 140"F.

18. A process as claimed in any of Claims 8 to 17, in which the substrate is wood fibre insulation board, asbestos, an asbestos-free panel, chipboard, plywood, hardboard, plasterboard or a laminate.

19. A process as claimed in Claim 18, in which the substrate is asbestos, chipboard, plywood, hardboard or a laminate.

20. A process as claimed in Claim 8 and substantially as hereinbefore described with reference to either of the Examples.

21. A composite whenever produced by a process as claimed in any of Claims 8 to 17 or 19.

22. A composite whenever produced by a process as claimed in Claim 18 or Claim 20.

23. A process for preparing a composite, which comprises adhering a polyester film to at least one surface of a substrate using an adhesive and at a sufficient temperature and pressure, vacuum depositing an aluminium coating on the exposed surface of the polyester film and applying a protective plastics material layer to the exposed surface of the aluminium coating, the protective plastics layer being light-transparent and substantially transparent to radiant heat.

24. A process as claimed in Claim 23, in which the polyester film is from 12 to 25 microns in thickness.

25. A process as claimed in Claim 24, in which the polyester film is substantially 12 microns in thickness.

26. A process as claimed in any of Claims 23 to 25, in which the adhesive is a PVA water-based adhesive.

27. A process as claimed in any of Claims 23 to 26, in which the pressure is 30 to 120 Ibs/in2.

28. A process as claimed in Claim 27, in which the pressure is 30 to 80 Ibs/in2.

29. A process as claimed in Claim 28, in which the pressure is 40 to 45 Ibs/in2.

30. A process as claimed in any of Claims 23 to 29, in which the temperature is up to 1400F.

31. A process as claimed in Claim 30, in which the temperature is 60 to 80" F.

32. A process as claimed in Claim 30, in which the temperature is 100" to 140"F.

33. A process as claimed in any of Claims 23 to 32, in which the substrate is wood fibre insulation board, asbestos, an asbestos-free panel, chipboard, plywood, hardboard, plasterboard or a laminate.

34. A process as claimed in Claim 33, in which the substrate is asbestos, chipboard, plywood, hardboard or a laminate.

35. A process as claimed in Claim 23, and substantially as hereinbefore particularly described.

36. A composite whenever produced by a process as claimed in any one of Claims 23 to 32, 34 or 35.

37. A composite whenever produced by a process as claimed in Claim 33.