GB2383295A

GB2383295A - Repairable solid surface laminate

Info

Publication number: GB2383295A
Application number: GB0130308A
Authority: GB
Inventors: Michael Ghahari
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-12-19
Filing date: 2001-12-19
Publication date: 2003-06-25
Also published as: GB0130308D0

Abstract

A repairable solid surface laminate for kitchen work surfaces and wall panelling comprises a solid surface material which is of a thickness suitable for its application to chipboard or other substrate 3 either as a material storable in a roll on a supply roller or as a rigid tile. It may comprise a solid surface layer 1 comprising a mixture of aluminium tri-hydrate mineral filler, a hardening filler for example aluminium oxide, polymerised coloured particles and a thermosetting resin carrier and a layer 2 consisting of a consolidated glass fibre matting, a pigmented resin and a thermosetting resin carrier. The laminate has the advantages of repairability and seamless joints. Contrasting patterns may be created in the surface of the laminate to individualise it.

Description

Repairable solid surface laminate.

The invention relates to the manufacture of a solid surface laminate which, when the surface is damaged, can be repaired.

Various materials are used in fabricating kitchen worktops and similar items, including wall panelling. The cheapest of these commonly known as Formica, which is a registered Trade Mark (RTM), and has been in use for many years. The Formica (RTM) laminate is stuck onto a sheet of wood, or similar material, to give it the mechanical strength required to fabricate kitchen furniture.

The decorative effect on the Formica (RTM) laminate is provided by printed-paper covered by a thin layer of transparent melamine. The printed-paper may be damaged by abrasion during normal use as a work surface and its appearance gradually becomes more shabby. Formica (RTM) is regularly damaged by, for example, kitchen fitters using wood screws which are too long beneath the surface of the laminate. In this case the point of the screw erupts from beneath the laminate and cracks the work surface, resulting in the laminate being scrapped. Another disadvantage is that, because the decorative printed-paper is a thin layer, the joints between the laminated sections are normally unsightly. When constructing kitchen units for example, it is necessary to connect pieces of laminate together to form"L"shaped work surfaces. In best practice a proprietary filler is used in the joint to render the work surface hygienic, but this is unsightly and it would be an advantage if the joint could be made as inconspicuous as possible. Similarly, when an edging strip made of laminate is stuck onto the chipboard, an unsightly joint is left where the brown coloured laminate substrate of Formica (RTM) is exposed. Suitably coloured fillers may be used to disguise this but obviously it would be an advantage if the substrate were the same colour as the surface of the laminate.

The above are important drawbacks of Formica (RTM), as surface appearance is a major selling point.

Apart from this, the mechanical properties of Formica (RTM) are fit for purpose.

In the late 1960's, so called "solid surface" materials were developed. With these materials the general pattern remains intact throughout the thickness of the material, typically 12 mm. However the mechanical properties of this material are such that it breaks, even when only lightly loaded, and is therefore not fit for purpose when fabricating kitchen units and similar items of furniture. It cannot be stuck onto a wooden sheet using a thin layer of adhesive, as it is likely to crack because of differential expansion. Nevertheless it is possible to attach this material, for example, to a wooden or similar sub-frame, using small discs of a flexible silicone based adhesive, and thereby achieve the desired mechanical properties. The major advantages of this material are that it is extremely hardwearing, and fabricated worktops can be made with joints, which are virtually invisible to the naked eye. Also it can be seamlessly repaired. However the cost of kitchen units fabricated in this way may be many times that using Formica (RTM) and hence it is not widely used.

More recently materials known as solid surface veneers have been developed. These use a solid surface material, similar to that described above, of the order of 3 mm thick which is rigidly attached to chipboard, or other substrate, using a thin layer of adhesive. Although this is cheaper than the 12 mm thick solid surface material, there have been mechanical problems and failures caused by differential expansion between the solid surface veneer and the chipboard.

Solid surface laminates are now being developed in which a layer of solid surface material of the order of 1.5mm thick is stuck onto a layer of a high strength material of similar thickness, to provide the mechanical properties necessary for the fabrication of kitchen furniture. An example of this is described in EP 1 043 147 where the process involves batch making, and therefore changes in colour cannot be easily made. Since the product is acrylic based (thermoplastic), the manufacturing process requires bonding of the high strength layer to the solid surface layer by applying heat and pressure. Expensive machinery in the form of a heated press and extruders are required to produce this material.

The objective of all the developments described above is to provide a material suitable for fabricating kitchen units and the like, which looks attractive, is hardwearing, and is cheap to make. The successful development of a solid surface laminate is likely to satisfy these criteria and will therefore provide a substantial advantage in the marketplace.

According to the present invention there is provided a composite solid surface laminate which can be stuck onto chipboard, or other substrate, using a thin layer of adhesive.

For batch production the solid surface material is deposited on to the surface of a mould by spraying, to achieve optimum control of thickness, and is subsequently reinforced by glass fibre and resin to provide adequate mechanical strength. The spraying of the solid surface material allows a thin coating of only 1 mm thickness to be applied evenly over the mould area. The coating of solid surface material is allowed to harden and then the glass fibre matting is consolidated onto the solid surface material, using a pigmented bonding resin to match the colour of the surface. The total thickness of the glass reinforcement at the time of application is typically 1 mm. Once the pigmented resin material is fully hardened, the solid surface laminate sheet is taken off the mould and approximately 0.5 mm is sanded off the pigmented resin material to achieve a uniform thickness together with the provision of a key for better adhesion to the chipboard, or similar substrate.

In the method for continuous production for large volume manufacture, a non-stick polyester film under constant tension running along a conveyor replaces the moulds. The solid surface material is sprayed onto the non-stick polyester film, and cured when it passes through a heating tunnel. Pigmented resin solution is then deposited in a uniform thickness over the solid surface material and, instead of using glass fiber matting to reinforce the solid surface material, a continuous glass filament is chopped into lengths of typically 30 mm and sprinkled evenly to form a"carpet"on the pigmented resin solution. A second layer of non-stick polyester film is then placed on top of the"carpet"which prevents the glass fibre adhering to the rollers used to consolidate the"carpet". The composite solid surface layer then passes through a heating chamber to cure the pigmented resin solution, followed by a cooling chamber and then passes from the conveyor to a coiling machine, from which it can be subsequently cut to any suitable length.

The glass fibre reinforcement of the solid surface material provides the strength necessary to allow the lamination to be handled during the process of applying the adhesive and attaching it to the substrate, to form a material suitable for fabricating kitchen units and decorative surfaces of other similar products. The result of using a thinner layer of solid surface material makes the product much less expensive than previous prior art processes, and enables it to be used for large volume applications.

The present invention is a low cost material that can be produced in large volumes to compete with other low cost laminates, which are long established in the marketplace. The process does not require expensive equipment, and in small batch production changes in colour of the solid surface laminate can easily be made. Also the product is polyester based (thermoset), which provides greater surface hardness and heat resistance than an acrylic based material.

The invention also provides unique advantages of repairability and seamless joints. Surfaces can be repaired using a pack containing the ingredients, which form the solid surface material, and used to fill any holes, gaps, or other imperfections in the kitchen unit work surface. The repaired surface is left to cure in the normal way for thermoset materials and then smoothed, using conventional hand or machine tools, to obtain the required surface finish.

Another feature of the present invention is that contrasting patterns may be created in the surface of the laminate, to individualise kitchen unit surfaces. A conventional hand held routing machine is used to create a pattern of grooves in the solid surface laminate, and a similar solid surface material of a contrasting colour is used to fill the grooves as described above. The result is an attractive decorative pattern, which cannot be provided by current state of art low cost laminates.

A specific embodiment of the invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 shows a cross section through a solid surface laminate stuck onto a piece of substrate Figure 2 is a flowchart summarising the method of manufacture of the solid surface laminate, suitable for batch production Figure 3 shows a typical diagrammatic layout of a batch production facility for manufacturing the composite solid surface laminate Figure 4 illustrates the design of a rectangular mould, and method of preparation prior to spraying on the solid surface laminate Figure 5 is a diagram of the spray set up Figure 6 is a diagram of the mechanism for applying the fibreglass matting and consolidating the resin Figure 7 shows a typical diagrammatic layout for continuous production of the composite solid surface laminate.

Figure 8 illustrates the method for repairing cracks in the solid surface laminate Figure 9 shows how a joint between two laminated surfaces can be rendered inconspicuous The solid surface laminate shown in cross section in Figure 1 consists of a solid surface material, here in after referred to as a solid surface material layer 1 and a layer of glass fibre and pigmented resin 2 to reinforce the solid surface layer 1. For the construction of kitchen work surfaces for example, the solid surface laminate is stuck onto a piece of chipboard (or similar material) 3 to achieve the required mechanical properties. The solid surface layer 1 is a mixture of Aluminium Tri-hydrate mineral filler, a hardening filler, for example Aluminium Oxide, polymerised coloured particles, and a thermosetting resin carrier. The layer of glass fibre and pigmented resin 2 consists of a consolidated layer of glass fibre matting and a pigmented resin with a thermosetting resin carrier. The combined thickness of both the solid surface layer 1 and the glass fibre and pigmented resin 2 is of the order of 1.5 mm.

Figure 2 is a flowchart summarising the method of manufacture of the solid surface laminate suitable for batch production. The first stage is to prepare the mould 4 (see figure 2 box A), and this process is described in Figure 4. The second stage (see figure 2 box B) is to spray solid surface material onto the mould 5, and the equipment used for this is described in Figure 5. The third stage (see figure 2 box C) is the process of the removal of the top layer of masking tape from the mould 6 (shown in figure 4) before the solid surface layer 1 (shown in figure 1) starts to cure. The fourth stage (see figure 2 box D) is the curing of the solid surface material 7, and the time required for this in the batch production process is illustrated by the lengths of the dotted lines 12 in Figure 3. The fifth stage (see figure 2 box E) is the application of pigmented resin onto the solid surface material and then deposit glass fibre matting 8; the machine for doing this is illustrated in Figure 6. The sixth stage (see figure 2 box F) is the curing of the pigmented resin consolidated in the glass fibre matting 9. The final stage (see figure 2 box G) is to remove the finished laminate from mould 10, which is a manual operation.

Figure 3 shows a typical diagrammatical layout of a small batch production facility for manufacturing the composite solid surface laminate. The various stages of the process shown in figure 3 are the same as those shown in figure 2, apart from the curing of the solid surface material 7, and the curing of the pigmented resin consolidated in the glass fibre matting 9 (both shown in figure 2). These two curing processes take place at room temperature over a period of time as each rectangular mould 11 (shown in figure 6) passes slowly along the conveyor belt 12. The period of time is indicated by the length of the dotted lines which represent the conveyor belt 12 in figure 3, and the curing processes are completed prior to the process of applying the pigmented resin and deposit of the glass fibre matting 8, and removal of the laminate from the mould 10.

Figure 4 illustrates the design of the rectangular moulds 11 (shown in figure 6) and the method of preparation prior to spraying solid surface material onto the mould 5. The sub-frame 13 (shown in Figure 4) can be made of wood or any other suitable material. The surface of the mould 14 may be made of any suitable material having a very smooth surface. The surface of the mould 14 is secured by any suitable

means, in this case by screws 15, onto the sub-frame 13. Two layers of masking tape 16, one on top of the other, are applied around the perimeter of the surface of the mould 14 covering the screws 15. An appropriate release agent (not shown) is sprayed onto the surface of the mould 14.

Figure 5 is a diagram of the spray set up. The compressor 17 supplies compressed air (not shown) via the compressed air lines 18 to the first resin and solid surface mixture tank 19, the second resin and solid surface mixture tank 20, the catalyst tank 21, and catalyst manifold 22. The catalyst (not shown) is atomised by injecting it through an orifice 23 into the catalyst manifold 22. The mixture of resin and solid surface granules, (not shown) in the resin and solid surface mixture tanks 19 and 20, is delivered via the resin manifold 24 to the spray heads 25 together with atomised catalyst (not shown) from the catalyst manifold 22. As each mould 11 (shown in figure 6) passes along the smoothly running conveyor belt 12 under the spray heads 25 (shown in figure 5) in the direction of the arrow 26, an atomised mixture of resin and solid surface granules (not shown) is deposited on the surface of the mould 14 (shown in figure 4).

Since each mould 11 passes under the spray heads 25 (shown in figure 5) at a controlled speed, a coating of a controlled thickness (not shown) is deposited. The design of the spray heads 25 (shown in figure 5) is such as to ensure efficient dispersion of the atomised mixture of resin and solid surface granules (not shown), which is of a consistency similar to liquid mud. Strict control and timing of this process is necessary according to the consistency of the atomised mixture of resin and solid surface granules which is achieved by a series of pneumatic valves (not shown) actuated by a programmable logic controller (not shown). When one of the resin and solid surface mixture tanks 19 or 20, becomes empty, there is an arrangement (not shown) whereby it can be recharged without interrupting the process.

Figure 6 is a diagram of the machine for applying resin and consolidating the glass fibre matting onto the solid surface laminate. Each rectangular mould 11 is transported along the conveyor belt 12 and pigmented resin solution 27 deposited over each mould 11 in a continuous stream (not shown). Since each mould 11 passes under the continuous stream (not shown) at a controlled speed, a coating of a controlled thickness (not shown) is deposited.

The glass fibre matting 28 and non-stick polyester film sheet 29 are fed onto each rectangular mould 11 from roller 30. The purpose of the non-stick polyester film sheet 29 is to prevent the glass fibre matting 28 adhering to the rollers 31,32, 33. Each rectangular mould 11 travels in the direction of the arrow 34, firstly under a spiral cut roller 31, and then under a fine scrolled roller 32, and finally under a plain scrolled roller 33 to consolidate the glass fibre matting 28 onto the deposited solid surface layer 1 (shown in figure 1).

Once the pigmented layer 2 (shown in figure 1) is fully hardened, the composite solid surface laminate (not shown) is taken off the rectangular mould 11 (shown in figure 6) and approximately 0.5 mm is sanded off the pigmented layer 2 (shown in figure 1) to achieve a uniform thickness (not shown) and provide a key (not shown) for better adhesion to the chipboard 3, or similar substrate.

In figure 7 is the method for continuous production for large volume manufacture of the solid surface laminate. For this process the rectangular moulds 11 (shown in figure 6) are replaced by a non-stick polyester film under constant tension 35 running along a conveyor belt 12. The solid surface material (not shown) is sprayed 36 (shown in figure 7) onto the surface of the non-stick polyester film under constant tension 35, as it moves at a controlled speed under the spray heads 25. (The spray set up is similar to that shown in figure 5). The non-stick polyester film under constant tension 35 continues along the conveyor belt 12 and passes through a heating tunnel 37 to cure the solid surface material 7 (see figure 2 box D. ) The heating medium in the heating tunnel 37 may be by ultra violet light, hot air, or electric elements (not shown). When the non-stick polyester film under constant tension 35 emerges from the heating tunnel 37, the solid surface material layer 1 (shown in figure 1) is sufficiently cured for the pigmented resin solution 27 to be deposited in a uniform thickness (not shown) over the solid surface material layer 1 (shown in figure 1) (see figure 2 box E). However, instead of using glass fibre matting 28 (shown in figure 6) to reinforce the solid surface laminate layer 1 (shown in figure 1), a continuous glass filament 38 is chopped by machine 39 (shown in figure 7) into lengths of typically 30 mm and sprinkled evenly from a defined height 40 to form a"carpet" (not shown) on the deposited pigmented resin solution 27. A second layer of non-stick polyester film sheet 41 is placed on top of the"carpet" (not shown). The

purpose of the second layer of non-stick polyester film sheet 41 is to prevent the glass fibre "carpet" (not shown) adhering to the rollers 31,32, 33. The glass fibre "carpet" (not shown) passes under the spiral cut roller 31, fine scrolled roller 32, and plain scrolled roller 33 to consolidate the glass fibre"carpet" (not shown) and then on to a heating chamber 42 to cure the pigmented resin solution 27, followed by a cooling chamber 43. The lower reel 44 and upper reel 45 then remove the two layers of non-stick polyester film sheet 29 and 41 which sandwich (not shown) the composite solid surface laminate (not shown). The composite solid surface laminate (not shown) then passes from the conveyor belt 12 to a coiling machine 46 from which it can be subsequently cut to any suitable length and the pigmented layer 2 (shown in figure 1) is sanded (not shown), principally to provide a key for better adhesion (not shown) to the chipboard 3 or similar substrate, but also to ensure a uniform thickness (not shown).

In figure 8 is illustrated the method of repairing cracks in the solid surface laminate. The damaged material 47 is removed down to the surface of the pigmented layer 2 (shown in figure 1) to form a hole 48 (shown in figure 8) by machine or hand tools (not shown). A pack containing the ingredients which form the solid surface material, (not shown) is mixed with the resin (not shown) and used to fill the hole 48, and project above the surface of the solid surface laminate 49. Once the resin (not shown) has cured, the projection above the surface of the solid surface laminate 49 is sanded flush leaving an almost invisible repaired area 50.

In figure 9 is illustrated how a butt joint between two sheets of solid surface laminate can be made inconspicuous. The joint between the two pieces of solid surface laminate 51 is covered with a colour matched adhesive paste (not shown). The joint 51 is then mechanically secured, by some suitable means, and clamped (not shown) until the adhesive paste (not shown) has cured. The surplus colour matched adhesive paste 52 which has been squeezed out of the joint 51 and allowed to cure, is then sanded flush leaving an almost invisible joint 53.

Claims

Ref: GB0130308. 0 Claims 1. A repairable solid surface laminate material for kitchen work surfaces, wall panelling, and like applications, wherein the laminate material comprises a solid surface material, as here in before defined, which is of a thickness suitable for its application either as a rigid tile or as a material storable in a roll on a supply roller.
2. A repairable solid surface material as claimed in claim 1 wherein the said material is reinforced with glass fibre mats or by an even carpet of chopped glass fiber filaments.
3. A repairable solid surface material as claimed in claim 2 wherein the said filaments are of the order of 30 mm in length.
4. A repairable solid surface material as claimed in any preceding claim wherein the said material is sandwiched between two layers of non-stick polyester film.
5. A repairable solid surface laminate material as claimed in claim 1 and substantially as described and as illustrated in the accompanying drawings.
6. A method of producing a solid surface material, the method being substantially as described and as illustrated in the accompanying drawings.