Multi-layer panel and method of manufacturing such a panel

Abstract

A method of manufacturing a multi-layer panel having a curved reflective and/or transmitting facing layer, the method comprising the steps of: increasing and/or decreasing the pressure on a side of the thin membrane to form a pressure differential across a thin membrane to cause the thin membrane to deform to a required shape; and applying a first layer of material to an outer surface of the thin membrane whilst the thin membrane is maintained in the required shape by the increase and/or decrease in pressure, and allowing the first layer of material to cure for a pre-determined time.

1 . A method of manufacturing a multi-layer panel having a curved reflective and/or transmitting facing layer, the method comprising the steps of:
 increasing and/or decreasing the pressure on a side of a thin membrane to form a pressure differential across the thin membrane that deforms the thin membrane to a required shape; and   applying a first layer of material to an outer surface of the thin membrane whilst the thin membrane is maintained in the required shape by the increase and/or decrease in pressure, and allowing the first layer of material to cure for a pre-determined time.   
     
     
         2 . The method according to  claim 1 , wherein the thin membrane comprises a thin plastic film or a thin foil. 
     
     
         3 . The method according to  claim 1 , further comprising applying a second layer of material to the first layer of material whilst the thin membrane is maintained in the required shape by the increase and/or decrease in pressure and allowing the second layer of material to cure for a pre-determined time, the second layer of material used to reinforce the multi-layer panel. 
     
     
         4 . The method according to  claim 1 , wherein forming the pressure differential further comprises sealing the thin membrane to a pressure chamber, the pressure chamber being pressurised or de-pressurised to deform the thin membrane to the required shape. 
     
     
         5 . The method according to  claim 4 , wherein a sealing device is placed on the thin membrane to assist in sealing the pressure chamber to the thin membrane. 
     
     
         6 . The method according to  claim 4 , further comprising at least one frame to which the thin membrane is attached to, the at least one frame attached to the pressure chamber by at least one clamp to form a seal between the at least one frame and the pressure chamber. 
     
     
         7 . The method according to  claim 4 , wherein sealing either the thin membrane to the pressure chamber or the at least one frame to the pressure chamber comprises attaching an o-ring to either the thin membrane or the at least one frame. 
     
     
         8 . The method according to  claim 4 , wherein when the pressure chamber is pressurised the thin membrane forms a concave shape and when the pressure chamber is depressurised the thin membrane forms a convex shape. 
     
     
         9 . The method according to  claim 1 , wherein the required shape of the thin membrane is a parabolic shape. 
     
     
         10 . The method according to  claim 1 , further comprising abrading the outer surface of the thin membrane whilst still under a pressure differential to provide a mechanical key to the outer surface of the thin membrane. 
     
     
         11 . The method according to  claim 1 , wherein the first layer of material comprises a plastic material that is cured by the application of a catalyst or low heat. 
     
     
         12 . The method according to  claim 1 , wherein the first layer of material comprises any one of the group of materials comprising polyesters, epoxies, silicones, or polyurethanes. 
     
     
         13 . The method according to  claim 1 , wherein the first layer of material is a slow curing material. 
     
     
         14 . The method according to  claim 1 , wherein the first layer of material comprises filler to increase the viscosity of the first layer material. 
     
     
         15 . The method according to  claim 14 , wherein the filler is aluminium. 
     
     
         16 . The method according to  claim 1 , wherein the first layer of material comprises a black dye added to the first layer of material to enhance the reflectivity of the multi-layer panel. 
     
     
         17 . The method according to  claim 3 , wherein the second layer of material comprises a fibre glass mat impregnated with a polyester resin, the polyester resin cured by mixing the polyester resin with a suitable catalyst. 
     
     
         18 . The method according to  claim 1 , wherein the predetermined time is from a few minutes up to 24 hours. 
     
     
         19 . A mirror comprising:
 a concave thin foil membrane stiffened by a first layer placed on an outer surface of the thin foil membrane to provide structural rigidity to the mirror.   
     
     
         20 . The mirror according to  claim 19 , wherein the required shape of the thin membrane is a parabolic shape. 
     
     
         21 . The mirror according to  claim 19 , wherein the first layer of material comprises any one of the group of materials comprising polyesters, epoxies, silicones or polyurethanes. 
     
     
         22 . The mirror according to  claim 19 , wherein the wherein the first layer of material is a slow curing material. 
     
     
         23 . The mirror according to  claim 19  wherein the first layer of material comprises filler to increase the viscosity of the first layer material during curing. 
     
     
         24 . The mirror according to  claim 23  wherein the filler is aluminium. 
     
     
         25 . The mirror according to  claim 19 , wherein the first layer of material further comprises a black dye added to the first layer of material to enhance the reflectivity of the mirror. 
     
     
         26 . The mirror according to  claim 19 , further comprising a second layer of material, the second layer of material used to reinforce the mirror. 
     
     
         27 . The mirror according to  claim 19 , wherein the second layer of material comprises a fibre glass mat which is impregnated with a polyester resin. 
     
     
         28 . An apparatus for producing a multi-layer panel having a curved reflective and/or transmitting facing layer, the apparatus comprising:
 at least one frame to which a thin membrane is attachable;   a pressure chamber adapted to allow a seal to form between the at least one frame and the pressure chamber; and   wherein the pressure chamber is arranged to create a pressure differential across the thin membrane to deform the thin membrane to a required shape, when the frame containing the thin membrane is attached to the pressure chamber; and   a means for applying a first layer and a second layer to the thin membrane to form the multi-layer panel whilst the multi-layer panel is maintained in the pressure differential state by the pressure chamber.