Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05D7/00—Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials
  • B05D7/06—Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials to wood

Definitions

• the invention relates to a method for surface treating engineered composite board to produce a grain effect similar to that found in wood.
• the invention has particular, although not exclusive, utility in relation to producing architraves and skirting boards that have the appearance of wood from engineered composite board.
• forest wood is used to make skirting boards and architraves. These items were originally manufactured from hard woods such as Jarrah. Recently, the increasing cost of forest woods such as Jarrah and the environmental push to preserve forests have made this practice uneconomical. Further, even where forest wood is available, difficulties arise in producing long, straight lengths of timber for purposes such as architraves and skirting boards.
• Engineered composite board also referred to as engineered wood panelled product, is a man made product.
• engineered composite boards include particle board and medium density fibre board (MDF).
• Engineered composite boards have achieved only partial success in acting as a forest wood substitute for architraves and skirting boards. This is primarily because the engineered composite board, even when stained, does not produce a realistic imitation of wood. Although the engineered composite board can be stained to achieve a similar colour to wood, the engineered composite board is a uniform colour and does not imitate the grain of the wood.
• This process takes advantage of the fact that grain in wood is recessed from the surface of the wood. Thus, one colour is applied to the grain and the other colour is applied to the remainder of the surface of the wood. Whilst these processes are effective on wood, they are not effective on engineered composite boards because the boards have a uniformed surface texture and do not have an existing grain.
• UK Patent 591 , 213 discloses a method for producing a grain-like effect on a surface which uses a pre-formed rubber stamp with a grain-like pattern etched thereon to stamp a simulated grain onto a surface.
• the use of a fixed stamp leads to repetitious appearance of the grain which yields unrealistic results. Further, the use of a stamp creates difficulties when working with moulded products such as architraves and skirting boards.
• a method for surface treating engineered composite board comprising the steps of:
• said method further comprises the step of sanding the material prior to the distribution of the first surface treatment.
• said method further comprises the steps of:
• said method further comprises the step of applying a fifth surface treatment to the material after application of the fourth surface treatment.
• the first surface treatment comprises stain and/or colouring.
• the first surface treatment comprises a pigment colour.
• the second surface treatment comprises stain and/or colouring.
• the finishing surface treatment comprises one of a lacquer, acrylic or eurathane/polyurethane.
• Figure 1 is a flow chart of the method for surface treating engineered composite board in accordance with the preferred embodiment of the invention.
• the embodiment is directed towards a method for surface treating medium density fibre board (MDF) to produce skirting boards and architraves.
• MDF medium density fibre board
• other forms of engineered composite board can be used as desired.
• the method can be applied to products other than architraves and skirting boards.
• Figure 1 is a flow chart of the method of surface treating engineered composite board according to the preferred embodiment. The method comprises the following steps:
• the MDF is sanded prior to any surface treatment being applied.
• One of the difficulties with conventional sanding is that it can further disturb the fibres and therefore not provide any advantage.
• polishing discs ordinarily used to buff metal a fine sanding and buffing is achieved.
• the discs are cut to the same profile as the MDF moulding, since this assists the dust and fibres sanded from the surface to fill any gaps in the surface and produce a smoother surface.
• a first surface treatment in the form of pigment colour is applied to the MDF in an irregular manner and distributed in a predetermined direction. This achieves a grain-like effect.
• Pigment colour is preferred since it does not fade. It is also preferred that the pigment colour is darker than the remaining colours applied in subsequent steps to emulate the generally darker grain colours in wood. By applying the pigment to the MDF prior to applying a sealer, the pigment colour soaks in to the MDF better.
• the pigment colour can be applied in a number of different ways. However, it is important that the effect is relatively random and appears to be straight in a single direction similar to the grain of wood. It has been found that by applying the pigment stain with a brush which has a small amount of pigment stain on it and which is lightly passed over the surface of the MDF, good results are achieved. However, other processes can be used, so as long as they produce the desired grain-like appearance.
• a second surface treatment in the form a pre colour is then applied to the upper surface and edges of the MDF.
• the pre colour comprises a mix of pigment stain and thinners.
• the pre colour is applied using one or more spray guns provided at an angle so that spray covers both the edge and the upper surface of the MDF.
• a sealer is applied to the MDF.
• the sealer acts as a primer on any remaining waxed surfaces of the MDF, which assist subsequent lacquer treatments to adhere to MDF. Further, the sealer makes the fibres of the MDF become erect and rigid. Although this is generally considered an inconvenience, in this instance it is considered desirable because it permits the fibres to be sanded off in a subsequent step and leave a smooth, uniform surface.
• the sealer also acts as a protective coat over the pigment colour distributed as grain so that the grain effect is not removed during the subsequent sanding step.
• the MDF is again sanded and buffed using the same polishing discs used in previous step 10. Because the fibres of the MDF have become ridged with the application of the sealer at step 40, the light sanding and buff allows these fibres to be removed to leave a smooth surface.
• the finish coat is a mixture of two colours, Jarrah and Burnt Umber, combined with lacquer.
• moulding such as a traditional federation skirting board and architrave have narrow "V" shaped crevices, which are not adequately covered using conventional spray techniques. If the amount of colouring is increased to adequately cover the crevices, then the remaining areas of the MDF are flooded and over filled. To avoid this problem, the finished coat applied at step 60 is applied in a generally light coat to provide a uniform coat to the majority to the surface of the MDF. Then, a narrow beam spray is used to apply highlight lines, or shadowing, in any crevices of the moulding.
• Burnt Umber is used in this step to achieve a dark appearance. It has been found that this step can considerably improve the aesthetic appearance of the finished product whilst simultaneously avoiding shortcomings in current spray technology. - o -
• a top colour comprised of a mixture of stain and thinners is then applied using a spray gun. An even coat of the top colour is applied to achieve the final colouring.
• the embodiment produces MDF products which provide a good copy of jarrah wood.
• producing a grain-like effect which is distributed in direction significantly enhances the realism of the product.
• the pigment colour in step 30 is replaced with liming. If desired, the liming can also be applied in the crevices at step 30.
• a clear lacquer is used as the first finish coat applied in step 60.
• the top colour in step 80 uses a suitably light pigment colour and thinners, and the finish coat used at step 90 is a clear lacquer.

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• 1998
  • 1998-09-15 AU AUPP5940A patent/AUPP594098A0/en not_active Abandoned
• 1999
  • 1999-09-15 EP EP99945786A patent/EP1154885A1/de not_active Withdrawn
  • 1999-09-15 WO PCT/AU1999/000779 patent/WO2000015400A1/en not_active Application Discontinuation

Non-Patent Citations (1)

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