METHOD OF FABRICATING A PROTECTED CONSTRUCTION PANEL

Abstract

A method of fabricating a protected construction panel prior to the construction panel being used in construction, the method comprising applying a removable coating onto a surface of the construction panel to form a removable coating layer on said construction panel. A construction panel for use in the construction of a building or the like comprising a removable coating layer located on a surface of said construction panel.

Claims

1. A method of fabricating a protected construction panel prior to the construction panel being used in construction, the method comprising: applying a removable coating onto a surface of the construction panel to form a removable coating layer on said construction panel.

2. A method of fabricating a protected construction panel prior to the construction panel being used in construction according to claim 1, further comprising: applying a curable sealant coating onto the surface of the construction panel and curing the curable sealant coating to form a cured sealant layer on the surface of the construction panel prior to applying the removable coating.

3. A method of fabricating a protected construction panel prior to the construction panel being used in construction according to claim 2, wherein the curable sealant coating is UV curable and the curing is performed at a wavelength of from about 200 nm to about 500 nm.

4. A method of fabricating a protected construction panel prior to the construction panel being used in construction according to claim 2, wherein the curable sealant coating is UV curable and the curing comprises a first curing step performed at a wavelength of from about 200 nm to about 350 nm and a second curing step performed at a wavelength of from about 400 nm to about 500 nm.

5. A method of fabricating a protected construction panel prior to the construction panel being used in construction according to claim 1, wherein the applying the removable coating onto the surface of the construction panel comprises spraying or roller coating the removable coating onto the surface.

6. A method of fabricating a protected construction panel prior to the construction panel being used in construction according to claim 1, further comprising applying the removable coating onto the surface of the construction panel at a coat weight of from about 80 to about 160 grams per square metre.

7. A method of fabricating a protected construction panel prior to the construction panel being used in construction according to claim 1, further comprising applying the removable coating onto the surface of the construction panel at a coat weight of from about 100 to about 140 grams per square metre.

8. A method of fabricating a protected construction panel prior to the construction panel being used in construction according to claim 1, further comprising applying the removable coating onto the surface of the construction panel at a temperature of from about 50 C. to about 200 C.

9. A method of fabricating a protected construction panel prior to the construction panel being used in construction according to claim 1, further comprising applying the removable coating onto the surface of the construction panel at a temperature of from about 125 C. to about 150 C.

10. A method of fabricating a protected construction panel prior to the construction panel being used in construction according to claim 1, wherein the removable coating comprises a vinyl acrylate polymer.

11. A method of fabricating a protected construction panel prior to the construction panel being used in construction according to claim 2, wherein the applying the curable sealant coating onto the surface of the construction panel comprises spraying or roller coating the curable sealant coating onto the surface.

12. A method of fabricating a protected construction panel prior to the construction panel being used in construction according to claim 2, further comprising applying the curable sealant coating onto the surface of the construction panel at a coat weight of from about 5 to about 140 grams per square metre.

13. A method of fabricating a protected construction panel prior to the construction panel being used in construction according to claim 2, further comprising applying the curable sealant coating onto the surface of the construction panel at a coat weight of from about 10 to about 15 grams per square metre.

14. A method of fabricating a protected construction panel prior to the construction panel being used in construction according to claim 2, wherein the curable sealant coating comprises an acrylate polymer.

15. A construction panel for use in the construction of a building or the like, the construction panel comprising a removable coating layer applied to a surface of said construction panel.

16. A construction panel for use in the construction of a building or the like according to claim 15, further comprising a cured sealant layer applied between the removable coating layer and the surface of said construction panel.

17. A construction panel for use in the construction of a building or the like according to claim 15, wherein the removable coating layer is a peelable coating layer.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Some embodiments of the present invention are described more fully hereinafter with reference to the accompanying figures. In the figures, dimensions may be exaggerated for clarity of illustration.

[0032] FIG. 1 illustrates an exemplary process flow diagram wherein a removable coating is applied to the surface of a construction panel.

[0033] FIG. 2 illustrates a UV coating application station and roller used to apply a UV sealant coating to the surface of a construction panel.

[0034] FIG. 3 illustrates a UV curing station and lamp used to cure a UV sealant coating applied to the surface of a construction panel.

[0035] FIG. 4 illustrates a heater roller coater used to apply a removable coating to the surface of a construction pane.

[0036] In the following detailed description, only certain embodiments of the present invention have been shown and described, simply by way of illustration. As those skilled in the art would realise, the described embodiments may preferably be modified in various different ways, all without departing from the spirit or scope of the present invention. Accordingly, the drawings and description are to be regarded as illustrative in nature and not restrictive.

DETAILED DESCRIPTION

[0037] FIG. 1 illustrates an exemplary process flow diagram wherein a protective film is applied to the surface of a construction panel.

[0038] Construction panels (not shown) are delivered and loaded on to a feed conveyor system (1). Where the construction panels are delivered in packaging (e.g. bearers, slats, strapping, identification or labels), before being removed, which is done manually. The panels are loaded, using a forklift truck or any other suitable means, onto the feed conveyer system (1) in either single stack or multiple stack arrangements. The feed conveyor system (1) transports the construction panels automatically towards an in-feed vacuum pick-and-place stacking system (2) which in turn transfers the construction panels onto a machine bed (16). Again, the construction panels are loaded on to the machine bed (16), automatically, in either single stack or as multiple stack arrangement.

[0039] An in-feed panel pusher (3) then conveys the construction panels along the machine bed (16) and into an in-feed nip roller (4). The construction panels are then conveyed through a brush roller (5) which cleans the surface of the panels. The brush roller (5) is also fitted with an extraction system to remove any dust on the panel surface. The dust is removed and taken away via an extraction pipe.

[0040] The construction panels are then automatically conveyed from the brush roller (5) into a governor roller (6). The governor roller (6) drives the construction panels along the remainder of the machine bed (16) and controls the line speed. The panels are automatically conveyed from the governor roller (6) into the UV coating application station (7) where a UV coating is applied to the surface of the panels. The UV coating is then cured at UV curing station (8). The application and curing of the UV coating is described in more detail with reference to FIGS. 2 and 3 below. From the UV coating application station, the panels are then fed into the heated coating application station (9) where the removable coating is applied. The removable coating, which may be a peelable coating, is supplied to the heated coating application station (9) via heated hoses (15) from melt tank (14). The application of the removable coating is described in more detail with reference to FIG. 4 below.

[0041] The panels are then automatically conveyed from the heated coating application station (9) to an inspection and quality control table (10) where the panels and their coatings are quality checked.

[0042] The construction panels are then automatically conveyed from the inspection and quality control table (10) to an outfeed nip roller (11) which directs the construction panels to an outfeed pick and place stacking system (12) where the panels are restacked on to outfeed conveyors (13) in either single stack or multiple stack arrangements.

[0043] The stacks are then conveyed from the outfeed conveyor (13) to a packing station, preferably via a forklift truck, where the packs are repackaged into their original/alternative packaging.

[0044] FIG. 2 illustrates an example of a UV coating application station (7) as described above. The UV coating application station (7) is made up of an ethylene propylene diene terpolymer (EPDM) coated application roller (A) and a steel dosing roller (B). The two doctor blades are included in the UV coating application station. These doctor blades run along the length of the rollers to prevent the coating flooding the board when run in reverse, they also help with the consistency of the coat weights of the UV coating being applied to the surface of the panels (P). A gap (G) is provided between the steel dosing roller (B) and the EPDM coated application roller (A) which can be adjusted to control the coat weight of the UV coating being applied to the surface of the panels (P). Typical gaps (G) have a measurement of from about 0 to about 3 millimetres depending on the specific requirements of the final construction panel. A heavy coat weight can be achieved by using a larger gap (G) as compared to a lighter coat weight. Typical coat weights that can be achieved by the EPDM coated application roller (A) and steel dosing roller (B) set up range from about 5 to about 100 grams per square metre depending on the type of UV coating being used.

[0045] In use, a UV coating is pumped continually into the space between the EPDM coated application roller (A) and the steel dosing roller (B). The UV coating is retained and prevented from spilling from the sides of the rollers by two stainless steel side plates (not shown) situated at each end of the rollers to create a well. Any excess UV coating that flows over the side plates may be recirculated using a pump back to the pump area which applies the UV coating on to the EPDM coating application roller and the steel dosing roller (B).

[0046] The EPDM coated application roller (A) rotates in the opposite direction to the steel dosing roller (B) to force the UV coating between the rollers, down the well, through the gap (G) between the rollers and on to the surface of a panel (P) located beneath. The steel dosing roller (B) can be run in either direction to the application roller, however, when run in reverse, lower coating weights are obtainable.

[0047] As the machine beds, shown by (16) in FIG. 1, moves the panel (P) along the production line (in the direction of the arrow shown in FIG. 2) the UV coatings applied to the surface of the panel (P) via the EPDM coated application roller (A) at a coat weight corresponding to the gap (G) between the rollers panel (P). As it will be appreciated, UV coatings may be applied to the surface of a panel using one or more UV coating application station. In addition, UV coating application stations suitable for applying a UV coating to the surface of a panel may also include one or more set of application rollers to maximise the coverage of the UV coating on the panel surface and to improve the efficiency of the method. For example, there may be 1, 2, 3, 4 or 5 sets of application rollers for applying UV coating to the surface of the panel.

[0048] FIG. 3 illustrates an example of a UV curing lamp used in UV curing station (8) as described above. The UV curing station (8) is made up of three UV curing lamps, the first two UV curing lamps are mercury (H-type) lamps and the third UV curing lamp is a mercury/gallium (V-type) lamp. FIG. 3 shows that a typical UV lamp includes a UV lamp element (17) contained within an outer casing (19). As the UV coated panels move along the machine bed (as shown in FIG. 1) the panels enter the UV curing station and are exposed to the first two mercury lamps having a short UV range of from 220 to 320 nanometres and a spike energy in the longwave range of about 365 nanometres. These lamps are used to cure the UV coatings on the surface of the panels and produce a flat hard surface on which a removable coating (e.g. peelable coating) is applied.

[0049] The panels then pass through a third lamp which is a mercury/gallium V-type lamp which yields a strong output in the longwave range of from about 400 to about 450 nanometres. This lamp is used to ensure that the UV coating on the surface of the panels is fully cured. This is especially important where the UV coatings contain heavy pigment or titanium dioxide which may block the shortwave UV exposure provided by the first two mercury lamps. The UV lamp elements may be stored with reflectors (18) to enhance reflection of the UV radiation towards the UV coating on the surface of the panel that is being cured. They UV curing lamps are also fitted with an extraction fan at one end (20) to pull air across the UV lamp element to keep the lamp cool. As it will be appreciated, the UV coatings may be cured using one or more UV curing application station. In addition, UV curing application stations suitable for curing a UV coating on the surface of a panel may also include one or more UV lamps to maximise UV light exposure to the surface of the panel and improve the efficiency of the UV curing step. For example, a suitable UV curing application station may include, but is not limited, 1, 2, 3, 4 or 5 UV lamps each of which may emit UV light at wave length of from 220 to 320 nanometres or of from about 400 to about 450 nanometres.

[0050] FIG. 4 illustrates an example of the heated coating application system (9) described above. In particular, the heater roller coater is made up of a silicone coated application roller (D) and a steel dosing roller (C) which are both oil heated by an electric element that goes through the centre of each of the rollers. Each of the rollers may be independently heated at a temperature ranging from about 100 C. to about 150 C. depending on the type of removable coating (e.g. peelable coating) being applied.

[0051] A gap (G1) between the rollers (i.e. the distance between the silicone roller (D) and the steel dosing roller (C)) is adjusted to control the coat weight of the removable coating being applied to the surface of the construction panel. Typically gaps having a measurement of about from 0 to about 3 millimetres are used, but, generally, a heavy coat weight can be achieved by using a larger gap as compared to a larger coat weight. Typical coat weights, achieved by the heater roller coater shown in FIG. 4, range from about 80 to about 160 grams per square metre depending on the type of removable coating being applied.

[0052] In use, a removable coating is pumped on to the space between the silicone coated application roller (D) and the steel dosing roller (C). The removable coating is retained and prevented from spilling from the sides of the rollers by two pneumatic Teflon side plates (not shown) situated at each end of the roller to create a well. The steel dosing roller (C) rotates in the opposite direction to the silicon coated application roller (D) to force the removable coating between the rollers, down the well, through the gap (G1), between the rollers and on to the surface of a panel (P1) located beneath. As the machine bed (16) in FIG. 1, moves the panel (P1) along the production line (in the direction of the arrow shown in FIG. 4) the removable coating is applied to the surface of the panel (P1) by the silicon roller (C) as at a coat weight corresponding to the gap (G1) between the rollers.

[0053] It will be appreciated that the methods, materials and equipment/machinery described in relation to FIGS. 1 to 4 above, may be suitably modified by the skilled person to carry out the method of fabricating a protected construction panel prior to the construction panel being used in construction as described herein.