GB2394433A

GB2394433A - A polishing line

Info

Publication number: GB2394433A
Application number: GB0311473A
Authority: GB
Inventors: Anthony Coyle; James Stanley Carleton
Original assignee: COYLE JOHN E
Current assignee: COYLE JOHN E
Priority date: 2002-10-24
Filing date: 2003-05-19
Publication date: 2004-04-28
Anticipated expiration: 2023-05-19
Also published as: GB2394433B; GB0311473D0

Abstract

A polishing line (1) for polishing a plurality of timber panels (3) of different types of wood which require different types of lacquers and stains comprises a conveyor (4) for conveying the panels (3) through the polishing line (1). Two pairs of stain applicators (12a to 12d) selectively apply a dark stain and a blonding agent to dark timber and lighter timber panels, respectively. Four primary lacquer applicators (20a, 20b, 20c, 20d) selectively apply UV curable lacquers of different tinted shades for the panels of different timber. Secondary lacquer applicators (28a, 28b) apply clear lacquer to all the panels. A post-treatment lacquer applicator (32) selectively applies clear UV curable lacquer to the panels, while a first final lacquer applicator (40) selectively applies a water based tinted lacquer to the panels and a pair of second final lacquer applicator rollers (44) selectively apply a UV curable lacquer to the panels. Drying and curing stations (11, 19, 27, 29, 35, 42, 46) are located downstream of the respective stain and lacquer applicators for drying and/or curing the applied lacquers while a primary sanding station (10) initially sands the panels prior to the application of stain and secondary (30) and post-treatment sanding stations (36) lightly sand the lacquered panel. The stain and lacquer applicators (12, 20, 32, 40, 44) are selectively enabled and disabled depending on the colour, whether dark or light, of the timber panels being passed through the polishing line (1).

Description

HA polishing line" The present invention relates to a polishing line and

to a method for polishing a timber surface of a panel, for example, a timber panel, or a panel comprising a 5 timber veneer sheet laminated to a substrate, for example, fibreboard, blackboard, Shipboard, high density particle board, medium density particle board, low density particle board or any other suitable substrate.

Polishing lines for polishing timber surfaces of such panels are known. For example, lo such a polishing line is disclosed in British Patent Specification No. 2,281,232 of

John E. Coyle (R & D) Limited. In such polishing lines a UV curable lacquer is applied to timber panels and is subsequently cured. The polishing line of British Patent No. 2,281,232 comprises an upstream sanding station for sanding the surface of each panel to be polished. A pair of stain applicator rollers apply stain to the sanded surface, which is brushed into the stained surface, and a drying oven dries the stain. A first lacquer applicator roller applies a first coat of ultraviolet (UV) curable lacquer which is subsequently cured to a tacky state in a UV curing oven. A pair of second lacquer applicator rollers apply a further coat of lacquer to the timber surface which is subsequently cured to a fully dried state in another UV curing oven.

20 A downstream sanding station lightly sands the lacquered surface of the panel.

While this polishing line is suitable for lacquering panels of certain timber materials, for example, mahogany or other dark woods, it is unsuitable for lacquering a plurality of panels where some of the panels are of different timber material to others, for

example, where some of the panels are of a dark wood material, for example, mahogany, cherry and the like, and others are of a light colour, for example, maple, beech and the like. This is because the darker colour panels require different staining and different lacquering to that of the lighter colour panels, and it is not s feasible to switch the stain and lacquer applicators from one type of stain or lacquer to another.

There is therefore a need for a polishing line which overcomes this problem.

lo The present invention is directed towards providing such a polishing line, and the invention is also directed towards a method for polishing timber surfaces of respective timber panels in the polishing line.

According to the invention there is provided a polishing line for polishing a timber 15 surface of each of a plurality of panels with a polishing lacquer wherein the timbers defining the timber surfaces of the respective panels are different and require different polishing lacquers, the polishing line comprising: a pre-treatment area at an upstream end of the polishing line in which the timber surfaces of the respective panels are pre-treated, 20 a primary lacquering area downstream of the pretreatment area in which respective polishing lacquers are applied to the timber surfaces of the respective panels, a post-treatment area downstream of the primary lacquering area in which the lacquered timber surfaces of the respective panels are subjected to post

a treatment subsequent to lacquering, and a conveying means for conveying the panels through the polishing line from the pre-treatment area through the primary lacquering area to the post-treatment area, wherein s the primary lacquering area comprises a plurality of primary lacquer applicators for applying respective different primary lacquers to the timber surfaces of panels of different timber surfaces, each primary lacquer applicator being selectively and alternately operable in an enabled state for applying a primary lacquer to a timber surface of a passing panel, and a disabled state for preventing 10 application of a primary lacquer to a passing panel, and each primary lacquer applicator being selectively operable in the enabled state for applying the appropriate primary lacquer to the passing panel, while the other primary lacquer applicators are disabled.

1s In one embodiment of the invention a primary curing station is located in the polishing line downstream of the primary lacquering area for curing the primary lacquer applied to the panels in the primary lacquering area, the conveying means conveying the panels through the primary curing station. Preferably, the primary curing station is adapted for curing the primary lacquer applied to the panels to a 20 tacky state. Advantageously, the primary lacquer is an ultraviolet (UV) curable lacquer, and the primary curing station comprises a UV curing oven.

In one embodiment of the invention a secondary lacquer applicator is provided for applying a secondary lacquer on top of the primary lacquer on the panels, the

secondary lacquer applicator being provided downstream of the primary curing station, and the conveying means conveying the panels past the secondary lacquer applicator. 5 In another embodiment of the invention a secondary curing station is located downstream of the secondary lacquer applicator for curing the secondary lacquer applied to the panels by the secondary lacquer applicator, the conveying means conveying the panels through the secondary curing station. Preferably, the secondary curing station is adapted to cure the secondary lacquer and the primary 0 lacquer to a fully dried state. Advantageously, the secondary lacquer is a UV curable lacquer, and the secondary curing station is a UV curing station. Ideally, the secondary lacquer is a clear lacquer.

In another embodiment of the invention a pair of secondary lacquer applicators are 15 located sequentially in the polishing line for sequentially applying secondary lacquer to the panels, a first of the pair of lacquer applicators being located upstream of a second of the pair of lacquer applicators.

In a further embodiment of the invention the first secondary lacquer applicator 20 applies the secondary lacquer to the panels at a rate in the range of 25 gms per square metre to 45 gms per square metre of timber surface, and the second secondary lacquer applicator applies the secondary lacquer to the panels at a rate in the range of 15 gms per square metre to 25 gms per square metre of timber surface.

Preferably, the first secondary lacquer applicator applies the secondary lacquer to

s the panels at a rate in the range of 30 gms per square metre to 40 gms per square metre of timber surface, and the second secondary lacquer applicator applies the secondary lacquer to the panels at a rate in the range of 17 gms per square metre to 22 gms per square metre of timber surface. Advantageously, the first secondary 5 lacquer applicator applies the secondary lacquer to the panels at a rate of 35 gms per square metre of timber surface approximately, and the second secondary lacquer applicator applies the secondary lacquer to the panels at a rate of 19 gms per square metre approximately of timber surface.

to In one embodiment of the invention each secondary lacquer applicator comprises a lacquer applicator roller extending transversely of the polishing line, the lacquer applicator roller of each lacquer applicator being moveable between an upper disabled position spaced apart from the polishing line for preventing the application of secondary lacquer to a passing panel, and a lower enabled position with the roller 15 adjacent the polishing line for engaging a panel passing beneath the roller for applying the secondary lacquer thereto.

In another embodiment of the invention each primary lacquer applicator applies the primary lacquer to the panels at a rate in the range of 5 gms per square metre to 25 20 gms per square metre of timber surface. Preferably, each primary lacquer applicator applies the primary lacquer to the panels at a rate in the range of 10 gms per square metre to 20 gms per square metre of timber surface.

In one embodiment of the invention the primary lacquering area comprises four

primary lacquer applicators.

Preferably, one of the primary lacquer applicators is provided for applying a tinted lacquer of natural maple tint. Advantageously, one of the primary lacquer s applicators is provided for applying a tinted lacquer of honey maple tint. Preferably, one of the primary lacquer applicators is provided for applying a tinted lacquer of beech tint, and advantageously, one of the primary lacquer applicators is provided for applying a clear lacquer.

lo In one embodiment of the invention the primary lacquer applicator for applying the clear lacquer applies the clear lacquer at the rate of approximately 15 gms per square metre of timber surface.

In another embodiment of the invention the primary lacquer applicator for applying 15 the beech tint lacquer applies the beech tint lacquer at the rate of approximately 10 gms per square metre of timber surface.

In a further embodiment of the invention the primary lacquer applicator for applying the honey maple tint lacquer applies the honey maple tint lacquer at the rate of 20 approximately 10 gms per square metre of timber surface.

In a still further embodiment of the invention the primary lacquer applicatorfor applying the natural maple tint lacquer applies the natural maple tint lacquer at the rate of approximately 10 gms per square metro of timber surface.

In one embodiment of the invention each primary lacquer applicator comprises a lacquer applicator roller extending transversely of the polishing line, the lacquer applicator roller being moveable between an upper disabled position spaced apart s from the polishing line for preventing the application of the primary lacquer therefrom to a passing panel, and a lower enabled position for engaging a panel passing beneath the roller for applying the primary lacquer thereto.

In another embodiment of the invention the pre-treatment area comprises a plurality lo of stain applicators for applying stain to the timber surfaces of at least some of the panels, each stain applicator being selectively and alternately operable in an enabled state for applying stain to a passing panel and in a disabled state for preventing the application of stain to the passing panel. Preferably, four stain applicators are provided, two of the stain applicators being provided for applying a 15 dark stain, and the other two stain applicators being provided for applying a blending stain. Advantageously, each stain applicator comprises a stain applicator roller extending transversely of the polishing line, the stain applicator roller of each stain applicator being moveable between an upper disabled position spaced apart from the polishing line for preventing the application of stain therefrom to a passing panel, 20 and a lower enabled position with the roller adjacent the polishing line for engaging a panel passing beneath the roller for applying the stain thereto.

In another embodiment of the invention the pre-treatment area comprises a brush located downstream of the stain applicators for brushing the stain into the timber

surfaces of the panels. Preferably, the brush is a rotating brush extending transversely across the polishing line.

In another embodiment of the invention the pre-treatment area comprises a drying 5 oven downstream of the stain applicators, the conveying means conveying the panels through the drying oven for drying the stained panels. Preferably, the drying oven comprises an upstream hot air drying oven, and a downstream infrared radiation drying oven located sequentially in the polishing line.

lo In a further embodiment of the invention the pre-treatment area comprises a primary sanding station for sanding the timber surfaces of the panels prior to staining by the stain applicators, the conveying means conveying the panels through the primary sanding station. Preferably, the pre-treatment area comprises a pre-drying oven downstream of the primary sanding station for pre-drying the sanded panels prior to 15 staining. Advantageously, the pre-drying oven is an infrared radiation drying oven.

In one embodiment of the invention a secondary sanding station is provided in the post-treatment area for sanding the lacquered surface of each panel after the secondary curing station.

In another embodiment of the invention a post-treatment lacquer applicator is provided in the post-treatment area downstream of the secondary sanding station for applying lacquer to the timber surface of at least some of the panels subsequent to the panels being subjected to sanding in the secondary sanding station. Preferably,

the post-treatment lacquer applicator comprises a lacquer applicator roller extending transversely of the polishing line, the lacquer applicator roller being moveable between an upper disabled position spaced apart from the polishing line for preventing the application of lacquer therefrom to a passing panel, and a lower 5 enabled position with the roller adjacent the polishing line for engaging a panel passing beneath the roller for applying the lacquer thereto.

In another embodiment of the invention the post-treatment area comprises a post-

treatment curing oven located downstream of the post-treatment lacquer applicator ]() for curing the lacquer applied by the post-treatment lacquer applicator.

Advantageously, the post-treatment area comprises a post-treatment sanding station located downstream of the post-treatment curing oven for selectively sanding panels passing therethrough.

In one embodiment of the invention a first final lacquer applicator is provided in the post-treatment area, the first final lacquer applicator being selectively and alternately operable in an enabled state for applying lacquer to a passing panel and in a disabled state for preventing the application of lacquer to a passing panel.

In another embodiment of the invention a first final drying station is provided in the post-treatment area downstream of the first final lacquer applicator for selectively drying lacquer applied to panels by the first final lacquer applicator. Advantageously, the first final drying station is an infrared radiation oven.

In another embodiment of the invention a second final lacquer applicator is provided in the post-treatment area downstream of the first final applicator, the second final lacquer applicator being selectively and alternately operable in an enabled state for 5 applying lacquer to a passing panel and in a disabled state for preventing the application of lacquer to a passing panel.

In another embodiment of the invention a second final drying station is provided in the post-treatment area downstream of the second final applicator for selectively lo drying the lacquer applied to panels by the second final applicator. Preferably, the second final drying station is a UV curing oven.

In another embodiment of the invention each final lacquer applicator comprises a lacquer applicator roller extending transversely of the polishing line, the lacquer 5 applicator roller being moveable between an upper disabled position spaced apart from the polishing line for preventing application of lacquer therefrom to a passing panel, and a lower enabled position with the roller adjacent the polishing line for engaging a panel passing beneath the roller for applying lacquer thereto.

20 Additionally the invention provides a method for polishing timber surfaces of respective panels in a polishing line as claimed in any preceding claim, the method comprising the steps of enabling one of the primary lacquer applicators for applying the appropriate primary lacquer to the panel and disabling the remaining primary lacquer applicators, and sequentially passing the panels along the polishing line

sequentially through the pre-treatment area, the primary lacquering area and the post-treatment area for polishing thereof.

In one embodiment of the invention the method further comprises the step of s enabling one of the stain applicators for applying the appropriate stain to the panel and disabling the remaining stain applicators.

In another embodiment of the invention the method further comprises selectively enabling the post-treatment lacquer applicator, the posttreatment curing oven and lo the post-treatment sanding station.

In a still further embodiment of the invention one or both of the first and second final lacquer applicators and one of the first and second final curing ovens is selectively enabled. Preferably, the method further comprises selectively disabling those of the post treatment lacquer applicator, the post-treatment sanding station, the first and second final lacquer applicators and the first and second final curing ovens which are not required. Further the invention provides a panel having a timber surface polished using the apparatus according to the invention.

In one embodiment of the invention the timber surface of the panel is polished using

the method according to the invention.

The invention will be more clearly understood from the following description of a

preferred embodiment thereof, which is given by way of example only, with reference 5 to the accompanying drawings, in which: Fig. 1 is a schematic plan view of a polishing line according to the invention, Fig. 2 is a diagrammatic cross-sectional side elevational view of a portion of lo the polishing line of Fig. 1, Fig. 3 is an end elevational view of the portion of Fig. 2 of the polishing line of Fig. 1, and 15 Fig. 4 is a view similar to Fig. 3 of another portion of the polishing line of Fig. 1. Referring to the drawings, there is illustrated a polishing line indicated generally by the reference numeral 1 for polishing a timber surface 2 of respective panels 3 in 20 which the timber defining the timber surface 2 is different in some of the panels 3 to that of others of the panels 3, and in particular, where the timber defining the timber surface 2 of some of the panels 3 is of a light coloured wood, for example, maple or beech, and the timber defining the timber surface 2 of others of the panels 3 is a dark coloured wood, for example, mahogany or cherry. The polishing line 1

comprises a conveying means comprising a roller conveyor 4 for conveying the panels 3 in the direction of the arrows A through the polishing line 1 from a pre-

treatment area 5 through a primary applicator area 6, a secondary lacquer applicator area 7, and then through a post-treatment area 8. The roller conveyor 4 comprises a 5 plurality of powered rollers 9 for conveying the panels 3 therealong.

The pre-treatment area 5 comprises a primary sanding station 10 for sanding the timber surface of the panels 3 to be polished. A dust extraction system (not shown) is provided from the primary sanding station 10 for extracting dust therefrom. The to sanded panels are conveyed on the conveyor 4 from the primary sanding station 10 to a pre- drying oven, which in this embodiment of the invention is provided by an infrared radiation oven 11 for thoroughly drying the sanded panels. Four stain applicators 12 are provided in the pre-treatment area 5 downstream of the infrared radiation oven 11 for applying an appropriate colour stain to the panels. In this 15 embodiment of the invention the stain applicators 12 are arranged in pairs, the upstream pair of stain applicators 12a and 12b being provided for applying a dark colour stain to, for example, mahogany and cherry timber surfaced panels, and the two downstream stain applicators 12c and 12d being provided for applying a blending agent to lighter timber surfaced panels, for example, maple, beech and the 2() like. Each stain applicator 12 comprises an applicator roller 13, see Figs. 2 and 3, and each stain applicator 12 is selectively and alternately operable in an enabled state with the applicator roller 13 in an enabled position adjacent the conveyor 4 for engaging passing panels 3 for applying stain to a passing panel, and a disabled state with the applicator roller 13 in a disabled position spaced apart above the

conveyor 4 for preventing the application of stain to a passing panel.

Referring now in particular to Figs. 2 and 3, the stain applicator 12 comprises a main framework 14 which extends transversely over and across the conveyor 4, and is in s a fixed position relative to the conveyor 4. A sub-framework 15 is carried by a threaded screw jack 16 on the main framework 14, and in turn rotatably carries the applicator roller 13 extending transversely across the conveyor 4. The screw jack 16 is rotatably engaged and retained in the sub-framework 15, and engages a threaded bore (not shown) in the main framework 14 for raising and lowering the applicator lO roller 13 between the enabled position and the disabled position. Slots 17 in the main framework 14 accommodate movement of a shaft 13a of the applicator roller 13 between the enabled and the disabled positions. A stain reservoir (not shown) is provided in each stain applicator 12 for holding the corresponding stain, and for transferring the stain to the applicator roller 13. The transfer of stain from the stain 15 reservoir onto the applicator rollers 13 will be well known to those skilled in the art, and it is not intended to describe this aspect of the stain applicators 12 in further detail. Accordingly, when it is desired to apply stain to darker timber panels, the upstream 20 stain applicators 12a and 12b are enabled while the downstream stain applicators 1 2c and 1 2d are disabled, and vice versa for applying the blending agent to the lighter colour timber panels.

A pair of rotating brush rollers 18 extending transversely of the polishing line 1 are

located downstream of the stain applicators 12 for brushing the stain applied to the panels 3 by the applicator rollers 12 into the surface 2 of the panels. Drive motors (not shown) rotate the brush rollers 18.

5 A drying oven 19 downstream of the brush rollers 18 dries the stain. The drying oven 19 comprises an upstream hot air drying oven 21 and a downstream infrared drying oven 22. The panels 3 are resident in the hot air drying oven 21 for approximately 24 seconds. The air temperature in the hot air drying oven is maintained at a temperature in the range of 70 C to 75 C. The infrared drying oven lo 19 is operated at a temperature in the range of 30 C to 35 C and the resident time of the panels therein is approximately 8 seconds for finally drying the stain.

Four primary lacquer applicators 20a to 20d for selectively applying four primary UV curable lacquers to the panels 3 are located in the primary lacquering area 6. The primary lacquer applicator 20a applies a tinted lacquer of natural maple tint for lacquering a panel having a timber surface defined by natural maple. The primary lacquer applicator 20b applies a tinted lacquer of honey maple tint for applying to a panel, the timber surface of which is defined by honey maple. The primary lacquer applicator 20c applies a tinted lacquer of a beech tint which is suitable for applying to 20 a panel, the timber surface of which is defined by beech wood. The primary lacquer applicator 20d applies a clear lacquer which is suitable for applying to a panel, the timber surface of which is defined by mahogany or cherry. The primary lacquer applicators 20a, 20b and 20c apply the respective primary lacquers at the rate of approximately 10 gms per square metre of timber surface, while the primary lacquer

applicator 20d applies the clear lacquer at a rate of approximately 15 gms per square metro of timber surface.

Referring now to Fig. 4, the operating principle of the primary lacquer applicators 20 s is substantially similar to that of the stain applicators 12. Each primary lacquer applicator 20 is selectively and alternately operable in an enabled state for applying primary lacquer to a passing panel and in a disabled state for preventing application of primary lacquer to a passing panel. Each lacquer applicator 20 comprises a framework 23 extending across and over the conveyor 4, and in a fixed position lo relative to the conveyor 4. A sub-framework 24 is carried on the main framework 23 by a screw jack 25 in similar fashion as the subframework 15 is carried on the main framework 14 of the stain applicators 12. An applicator roller 26 is carried on the sub-framework 24 for applying the corresponding one of the primary lacquers to the panels 3. The screw jack 25 operates the sub-framework 24, and in turn, the 15 applicator roller 26 between a lower enabled position corresponding to the enabled state of the primary lacquer applicator 20, and a raised disabled position corresponding to the disabled state of the primary lacquer applicator 20, in similar fashion to that of the stain applicators 12. Slots (not shown) similar to the slots 17 in the main framework 14 of the stain applicators 12 are provided for accommodating 20 movement of a roller shaft 26a of the applicator roller 26 in the main framework 23 between the enabled and the disabled positions of the applicator roller 26, corresponding to the enabled and the disabled states, respectively, of each of the primary lacquer applicators 20. A primary lacquer reservoir (not shown) is located in each primary lacquer applicator 20 for supplying the primary lacquer to the applicator

roller 26. The transfer of lacquer from a reservoir to an applicator roller will be well known to those skilled in the art.

Accordingly, when it is desired to apply a natural maple tinted lacquer to a natural 5 maple panel, the primary lacquer applicator 20a is operated in the enabled state by lowering the applicator roller 26 to the enabled position for engaging the passing panels 3, for in turn applying the natural maple tinted lacquer to the passing panel.

Similarly, when it is desired to apply a honey maple tinted lacquer to a honey maple panel the primary lacquer applicator 20b is operated in the enabled state, and so on.

lo While any one of the primary lacquer applicators 20 is being operated in the enabled state, the other three primary lacquer applicators 20 are operated in the disabled state. A primary lacquer curing station comprising a primary UV curing oven 27 is provided 15 downstream of the lacquer applicators 20 for curing the primary lacquer applied by the primary lacquer applicators 20 to a tacky state. Each panel 3 is resident in the UV curing oven 27 for approximately 4 seconds, and is subjected to heat energy in the range of 500 millijoules to 560 millijoules per square metre of timber surface of the panel to be cured.

A pair of secondary lacquer applicators 28, namely, first and second secondary lacquer applicators 28a and 28b, respectively, extend transversely across the polishing line 1 for applying a secondary UV curable lacquer on top of the tacky primary lacquer applied by the primary lacquer applicators 20 and cured to the tacky

state by the primary UV curing oven 27. The secondary lacquer applicators 28 are identical to the primary lacquer applicators 20 and are operable in an enabled and a disabled state for selectively applying the secondary UV curable lacquer. However, in general, both secondary lacquer applicators 28a and 28b are operated in the s enabled state. The secondary lacquer is a clear lacquer, and is applied to all panels In this embodiment of the invention the first secondary lacquer applicator 28a which is upstream of the second secondary lacquer applicator 28b applies the secondary lacquer at a rate of approximately 35 gms per square metre of timber surface, while the downstream second secondary lacquer applicator 28b applies the secondary lo lacquer at a rate of approximately 19 gms per square metro of timber surface.

A secondary curing station comprising a secondary UV curing oven 29 is provided downstream of the secondary lacquer applicators 28 for curing the secondary lacquer applied by the secondary lacquer applicators 28, and also the primary 15 lacquer applied by the primary lacquer applicators 20 to a fully dried state. Each panel 3 is resident in the UV curing oven 29 for approximately 8 seconds, and is subjected to heat energy in the range of 500 millijoules to 560 millijoules per square metre of timber surface of the panel to be cured. 20 A pair of secondary sanding stations 30 is located downstream of the

secondary UV curing oven 29 in the post-treatment area 8 for lightly sanding and denibbing the lacquered panels from the secondary UV curing oven 29. A dust extraction system (not shown) is provided from each secondary sanding station 30 for extracting dust therefrom. A pair of air cleaning stations 31 located downstream of the respective

l secondary sanding stations 30 removes any remaining dust on the sanded panels from the secondary sanding stations 30.

A post-treatment lacquer applicator 32 is provided in the post-treatment area 8 for s selectively applying a UV curable clear lacquer to some of the panels after the secondary sanding station 30. The post-treatment lacquer applicator 32 is similar to the primary lacquer applicators 20, and is selectively and alternately operable between an enabled state for selectively applying the UV curable clear lacquer to passing panels, and a disabled state for preventing the application of the UV curable lo clear lacquer to the passing panels. The post-treatment lacquer applicator 32 when operating in the enabled state applies the UV curable clear lacquer to the passing panels at a rate in the range of 20 gms per square metro of timber surface to 25 gms per square metre of timber surface, and preferably, at a rate of 22 gms per square metre of timber surface.

A post-treatment curing oven is located in the post-treatment area 8 downstream of the post-treatment lacquer applicator and is provided by a post-treatment UV curing oven 35 which cures the UV curable clear lacquer applied by the post-treatment lacquer applicator 32 to a fully dry state. Each panel 3 is resident in the UV curing go oven 35 for approximately 8 seconds, and is subjected to heat energy in the range of 500 millijoules to 560 millijoules per square metre of timber surface of the panel to be cured.

A post-treatment sanding station 36 is located in the post-treatment area 8

downstream of the post-treatment curing oven 35 for selectively and lightly sanding some of the panels 3 to which the UV curable clear lacquer is applied by the post-

treatment lacquer applicator 32.

s An air cleaning station 38, which is similar to the air cleaning stations 31 is located downstream of the post-treatment sanding station 36 for removing any residual dust remaining on the panels after sanding in the post-treatment sanding station 36.

A first final lacquer applicator 40 for selectively applying a honey maple tinted water lo based lacquer to the lighter coloured panels is located downstream of the air cleaning station 38 in the post-treatment area 8. The first final lacquer applicator 40 is similar to the primary lacquer applicators 20 and is operable between an enabled state and a disabled state in similar fashion as are the primary lacquer applicators 20. The first final lacquer applicator when operating in the enabled state applies the is honey maple tinted water based lacquer to the panels at a rate in the range of 6 gms per square metro of timber surface to 10 gms per square metre of timber surface, and preferably, at a rate of approximately 8 gms per square metro of timber surface.

In general, panels to which the honey maple tinted water based lacquer is to be applied are subjected to sanding in the post-treatment sanding station 36.

2() A first final drying station, namely, an infrared drying oven 42 is located in the post treatment area 8 downstream of the first final lacquer applicator 40, and is selectively operable for curing the water based lacquer applied by the first final lacquer applicator 40 to a fully dried state. The infrared drying oven 42 is operated at a

temperature in the range of 30 C to 35 C, and preferably, at a temperature of approximately 33 C. The resident time of each panel to be cured in the infrared drying oven 42 is approximately 8 seconds.

s A pair of second final lacquer applicators 44a and 44b are provided downstream of the infrared drying oven 42 for selectively applying lacquer to the panels. The upstream second final lacquer applicator 44a applies a tinted UV curable lacquer which is suitable for beech and maple timber, while the downstream second final lacquer applicator 44b applies a clear UV curable lacquer which is suitable for Jo applying to mahogany and cherry timber. The second final lacquer applicators 44 are similar to the primary lacquer applicators 20 and are selectively and alternately operable in a disabled state and an enabled state for selectively applying the respective lacquers to passing panels. When operated in the enabled state the respective second final lacquer applicators 44a and 44b each apply their respective IS lacquers to the panels at a rate in the range of 15 gms per square metre to 25 gms per square metro, and preferably, at a rate of approximately 20 gms per square metre of timber surface.

A second anal drying station provided by a second final UV curing oven 46 is located 20 in the post-treatment area 8 downstream of the second final lacquer applicators 44 for curing the lacquer applied by the respective second final lacquer applicators 44.

The second final UV curing oven 46 is selectively operable for curing the lacquer applied by the respective second final lacquer applicators 44. Each panel 3 is resident in the UV curing oven 46 for approximately 8 seconds, and is subjected to

heat energy in the range of 500 millijoules to 560 millijoules per square metre of timber surface of the panel to be cured.

In general, polishing of the darker colour panels is completed after the lacquer 5 applied by the post-treatment lacquer applicator 32 has been cured in the post-

treatment UV curing oven 35, and when such panels are passing along the conveyor 4 the post-treatment sanding station 36 and the remaining first and second final lacquer applicators 40 and 44 as well as the first and second final drying stations 42 and 46 are disabled. However, in general, the lighter timber panels typically require l o the application of the honey maple tinted water based lacquer which is applied by the first final lacquer applicator 40, and in general, these panels also require a final application of clear UV curable lacquer which is applied by one or both of the second final lacquer applicators 44. Thus, when such lighter coloured panels are passing through the conveyor, the post-treatment sanding station 36 and the air cleaning 15 station 38 as well as the first and second final lacquer applicators 40 and 44 and the first and second final drying stations 42 and 46 are operated.

In use, when a batch of dark timber panels, for example, panels in which the timber surface is defined by mahogany or cherry wood, the following stain and lacquer 20 applicators are enabled, namely, the stain applicators 12a and 12b, the primary lacquer applicator 20d, the secondary lacquer applicators 28 and the post-treatment lacquer applicator 32, and depending on the panels, the second final lacquer applicator 44b may be enabled. Thus, the stain applicators 12c and 12d are disabled, the primary lacquer applicators 20a, 20b and 20c are disabled, as is the

first final lacquer applicator 40, and depending on the panels, the second final lacquer applicator 44a or the second final lacquer applicators 44a and 44b are disabled. In cases where the second final lacquer applicators 44 are both disabled, the post-treatment sanding station 36 is also disabled, since the last operation to 5 which the dark wood panels should be subjected is a cure after the last lacquer application, and the curing is carried out in the post-treatment UV curing oven 35.

However, should one of the second final lacquer applicators 44 be operated in the enabled state, then the post-treatment sanding station 36 and the air cleaning device 38 are activated.

lo When a batch of lighter wood panels are to be polished the stain applicators 12c and 12d for applying the blending agent are enabled while the stain applicators 12a and 12b are disabled. The appropriate one of the primary lacquer applicators 20a, 20b or 20c is operated into the enabled state, while the other three primary lacquer 15 applicators 20 are disabled. The secondary lacquer applicators 28 are also enabled.

In general, one of the first final lacquer applicators 40 and the second final lacquer applicator 44a will be operated in the enabled state for the lighter timber panels, and the appropriate one of the first final lacquer applicator 40 and the second final lacquer applicator 44a will be selected depending on the type of light colour timber 20 defining the timber surface of the panel. Once the first or second final lacquer applicator 40 or 44a is enabled, the post-treatment sanding station 36 and the air cleaning device 38 are also activated.

All panels irrespective of the timber defining the timber surface are subjected to

lacquering by the two secondary lacquer applicators 28 and the posttreatment lacquer applicator 32.

The appropriate drying and curing stations are operated depending on the lacquer 5 applicators which are selected. Additionally, all panels are initially subjected to primary sanding in the primary sanding station 10 and all panels are subjected to drying in the pre-drying oven 11.

When the appropriate stain and lacquer applicators have been enabled and disabled lo the conveyor 4 is activated and the panels sequentially fed along the conveyor 4 from the pre-treatment area 6 through the primary and secondary lacquering areas 6 and 7 and the post-treatment area 8.

In general, once set up the polishing line 1 is set up for a relatively large batch size 15 comprising a relatively large number of panels, although in certain cases, the polishing line 1 may be set up for relatively small batch quantities of panels.

Claims

1. A polishing line for polishing a timber surface of each of a plurality of panels with a polishing lacquer wherein the timbers defining the timber surfaces of the respective panels are different and require different polishing lacquers, the polishing s line comprising: a pre- treatment area at an upstream end of the polishing line in which the timber surfaces of the respective panels are pre-treated, a primary lacquering area downstream of the pre-treatment area in which respective polishing lacquers are applied to the timber surfaces of the respective lo panels, a post-treatment area downstream of the primary lacquering area in which the lacquered timber surfaces of the respective panels are subjected to post treatment subsequent to lacquering, and a conveying means for conveying the panels through the polishing line from 15 the pre- treatment area through the primary lacquering area to the post-treatment area, wherein the primary lacquering area comprises a plurality of primary lacquer applicators for applying respective different primary lacquers to the timber surfaces of panels of different timber surfaces, each primary lacquer applicator being 20 selectively and alternately operable in an enabled state for applying a primary lacquer to a timber surface of a passing panel, and a disabled state for preventing application of a primary lacquer to a passing panel, and each primary lacquer applicator being selectively operable in the enabled state for applying the appropriate primary lacquer to the passing panel, while the other primary lacquer

applicators are disabled.

2. A polishing line as claimed in Claim 1 in which a primary curing station is located in the polishing line downstream of the primary lacquering area for curing the s primary lacquer applied to the panels in the primary lacquering area, the conveying means conveying the panels through the primary curing station.

3. A polishing line as claimed in Claim 2 in which the primary curing station is adapted for curing the primary lacquer applied to the panels to a tacky state.

l()

4. A polishing line as claimed in Claim 2 or 3 in which the primary lacquer is an ultraviolet (UV) curable lacquer, and the primary curing station comprises a UV curing oven.

15

5. A polishing line as claimed in any of Claims 2 to 4 in which a secondary lacquer applicator is provided for applying a secondary lacquer on top of the primary lacquer on the panels, the secondary lacquer applicator being provided downstream of the primary curing station, and the conveying means conveying the panels past the secondary lacquer applicator.

6. A polishing line as claimed in Claim 5 in which a secondary curing station is located downstream of the secondary lacquer applicator for curing the secondary lacquer applied to the panels by the secondary lacquer applicator, the conveying means conveying the panels through the secondary curing station.

7. A polishing line as claimed in Claim 6 in which the secondary curing station is adapted to cure the secondary lacquer and the primary lacquer to a fully dried state.

5

8. A polishing line as claimed in Claim 6 or 7 in which the secondary lacquer is a UV curable lacquer, and the secondary curing station is a UV curing station.

9. A polishing line as claimed in any of Claims 5 to 8 in which the secondary lacquer is a clear lacquer.

10. A polishing line as claimed in any of Claims 5 to 9 in which a pair of secondary lacquer applicators are located sequentially in the polishing line for sequentially applying secondary lacquer to the panels, a first of the pair of lacquer applicators being located upstream of a second of the pair of lacquer applicators.

11. A polishing line as claimed in Claim 10 in which the first secondary lacquer applicator applies the secondary lacquer to the panels at a rate in the range of 25 gms per square metro to 45 gms per square metre of timber surface, and the second secondary lacquer applicator applies the secondary lacquer to the panels at a rate in 20 the range of 15 gms per square metre to 25 gms per square metro of timber surface.

12. A polishing line as claimed in Claim 11 in which the first secondary lacquer applicator applies the secondary lacquer to the panels at a rate in the range of 30 gms per square metro to 40 gms per square metro of timber surface, and the second

secondary lacquer applicator applies the secondary lacquer to the panels at a rate in the range of 17 gms per square metre to 22 gms per square metre of timber surface.

13. A polishing line as claimed in Claim 12 in which the first secondary lacquer s applicator applies the secondary lacquer to the panels at a rate of 35 gms per square metre of timber surface approximately, and the second secondary lacquer applicator applies the secondary lacquer to the panels at a rate of 19 gms per square metre approximately of timber surface.

to

14. A polishing line as claimed in any of Claims 11 to 13 in which each secondary lacquer applicator comprises a lacquer applicator roller extending transversely of the polishing line, the lacquer applicator roller of each lacquer applicator being moveable between an upper disabled position spaced apart from the polishing line for preventing the application of secondary lacquer to a passing panel, and a lower I s enabled position with the roller adjacent the polishing line for engaging a panel passing beneath the roller for applying the secondary lacquer thereto.

15. A polishing line as claimed in any preceding claim in which each primary lacquer applicator applies the primary lacquer to the panels at a rate in the range of 20 5 gms per square metre to 25 gms per square metre of timber surface.

16. A polishing line as claimed in Claim 15 in which each primary lacquer applicator applies the primary lacquer to the panels at a rate in the range of 10 gms per square metre to 20 gms per square metre of timber surface.

17. A polishing line as claimed in any preceding claim in which the primary lacquering area comprises four primary lacquer applicators.

s

18. A polishing line as claimed in Claim 17 in which one of the primary lacquer applicators is provided for applying a tinted lacquer of natural maple tint.

19. A polishing line as claimed in Claim 17 or 18 in which one of the primary lacquer applicators is provided for applying a tinted lacquer of honey maple tint.

20. A polishing line as claimed in any of Claims 17 to 19 in which one of the primary lacquer applicators is provided for applying a tinted lacquer of beech tint.

21. A polishing line as claimed in any of Claims 17 to 20 in which one of the 15 primary lacquer applicators is provided for applying a clear lacquer.

22. A polishing line as claimed in Claim 21 in which the primary lacquer applicator for applying the clear lacquer applies the clear lacquer at the rate of approximately 15 gms per square metre of timber surface.

23. A polishing line as claimed in any of Claims 20 to 22 in which the primary lacquer applicator for applying the beech tint lacquer applies the beech tint lacquer at the rate of approximately 10 gms per square metre of timber surface.

24. A polishing line as claimed in any of Claims 19 to 23 in which the primary lacquer applicator for applying the honey maple tint lacquer applies the honey maple tint lacquer at the rate of approximately 10 gms per square metro of timber surface.

5

25. A polishing line as claimed in any of Claims 18 to 24 in which the primary lacquer applicator for applying the natural maple tint lacquer applies the natural maple tint lacquer at the rate of approximately 10 gms per square metro of timber surface. lo

26. A polishing line as claimed in any preceding claim in which each primary lacquer applicator comprises a lacquer applicator roller extending transversely of the polishing line, the lacquer applicator roller being moveable between an upper disabled position spaced apart from the polishing line for preventing the application of the primary lacquer therefrom to a passing panel, and a lower enabled position for l engaging a panel passing beneath the roller for applying the primary lacquer thereto.

27. A polishing line as claimed in any preceding claim in which the pretreatment area comprises a plurality of stain applicators for applying stain to the timber surfaces of at least some of the panels, each stain applicator being selectively and 20 alternately operable in an enabled state for applying stain to a passing panel and in a disabled state for preventing the application of stain to the passing panel.

28. A polishing line as claimed in Claim 27 in which four stain applicators are provided, two of the stain applicators being provided for applying a dark stain, and

the other two stain applicators being provided for applying a blending stain.

29. A polishing line as claimed in Claim 27 or 28 in which each stain applicator comprises a stain applicator roller extending transversely of the polishing line, the s stain applicator roller of each stain applicator being moveable between an upper disabled position spaced apart from the polishing line for preventing the application of stain therefrom to a passing panel, and a lower enabled position with the roller adjacent the polishing line for engaging a panel passing beneath the roller for applying the stain thereto.

30. A polishing line as claimed in any of Claims 27 to 29 in which the pre treatment area comprises a brush located downstream of the stain applicators for brushing the stain into the timber surfaces of the panels.

15

31. A polishing line as claimed in Claim 30 in which the brush is a rotating brush extending transversely across the polishing line.

32. A polishing line as claimed in any of Claims 27 to 31 in which the pre-

treatment area comprises a drying oven downstream of the stain applicators, the 20 conveying means conveying the panels through the drying oven for drying the stained panels.

33. A polishing line as claimed in Claim 32 in which the drying oven comprises an upstream hot air drying oven, and a downstream infrared radiation drying oven

l located sequentially in the polishing line.

34. A polishing line as claimed in any of Claims 27 to 33 in which the pre-

treatment area comprises a primary sanding station for sanding the timber surfaces s of the panels prior to staining by the stain applicators, the conveying means conveying the panels through the primary sanding station.

35. A polishing line as claimed in Claim 34 in which the pre-treatment area comprises a pre-drying oven downstream of the primary sanding station for pre 10 drying the sanded panels prior to staining.

36. A polishing line as claimed in Claim 35 in which the pre-drying oven is an infrared radiation drying oven.

IS

37. A polishing line as claimed in any of Claims 6 to 36 when dependent on Claim 6, in which a secondary sanding station is provided in the post-treatment area for sanding the lacquered surface of each panel after the secondary curing station.

38. A polishing line as claimed in Claim 37 in which a post-treatment lacquer 20 applicator is provided in the post-treatment area downstream of the secondary sanding station for applying lacquer to the timber surface of at least some of the panels subsequent to the panels being subjected to sanding in the secondary sanding station.

39. A polishing line as claimed in Claim 38 in which the post-treatment lacquer applicator comprises a lacquer applicator roller extending transversely of the polishing line, the lacquer applicator roller being moveable between an upper disabled position spaced apart from the polishing line for preventing the application s of lacquer therefrom to a passing panel, and a lower enabled position with the roller adjacent the polishing line for engaging a panel passing beneath the roller for applying the lacquer thereto.

40. A polishing line as claimed in Claim 38 or 39 in which the posttreatment area l comprises a post-treatment curing oven located downstream of the post-treatment lacquer applicator for curing the lacquer applied by the post-treatment lacquer applicator.

41. A polishing line as claimed in Claim 40 in which the post-treatment area 15 comprises a post-treatment sanding station located downstream of the post-

treatment curing oven for selectively sanding panels passing therethrough.

42. A polishing line as claimed in any of Claims 38 to 41 in which a first final lacquer applicator is provided in the post-treatment area, the first final lacquer 20 applicator being selectively and alternately operable in an enabled state for applying lacquer to a passing panel and in a disabled state for preventing the application of lacquer to a passing panel.

43. A polishing line as claimed in Claim 42 in which a first final drying station is

provided in the post-treatment area downstream of the first final lacquer applicator for selectively drying lacquer applied to panels by the first final lacquer applicator.

44. A polishing line as claimed in Claim 43 in which the first final drying station is 5 an infrared radiation oven.

45. A polishing line as claimed in any of Claims 42 to 44 in which a second final lacquer applicator is provided in the post-treatment area downstream of the first final applicator, the second final lacquer applicator being selectively and alternately l o operable in an enabled state for applying lacquer to a passing panel and in a disabled state for preventing the application of lacquer to a passing panel.

46. A polishing line as claimed in Claim 45 in which a second final drying station is provided in the post-treatment area downstream of the second final applicator for 15 selectively drying the lacquer applied to panels by the second final applicator.

47. A polishing line as claimed in Claim 46 in which the second final drying station is a UV curing oven.

20

48. A polishing line as claimed in any of Claims 42 to 47 in which each final lacquer applicator comprises a lacquer applicator roller extending transversely of the polishing line, the lacquer applicator roller being moveable between an upper disabled position spaced apart from the polishing line for preventing application of lacquer therefrom to a passing panel, and a lower enabled position with the roller

l adjacent the polishing line for engaging a panel passing beneath the roller for applying lacquer thereto.

49. A polishing line for polishing a timber surface of each of a plurality of panels 5 with a polishing lacquer wherein the timbers defining the timber surface of the respective panels are different and require different polishing lacquers, the polishing line being substantially as described herein with reference to and as illustrated in the accompanying drawings.

10

50. A method for polishing timber surfaces of respective panels in a polishing line as claimed in any preceding claim, the method comprising the steps of enabling one of the primary lacquer applicators for applying the appropriate primary lacquer to the panel and disabling the remaining primary lacquer applicators, and sequentially passing the panels along the polishing line sequentially through the pre-treatment 15 area, the primary lacquering area and the post-treatment area for polishing thereof.

51. A method as claimed in Claim 50 in which the method further comprises the step of enabling one of the stain applicators for applying the appropriate stain to the panel and disabling the remaining stain applicators.

52. A method as claimed in Claim 50 or 51 in which the method further comprises selectively enabling the post-treatment lacquer applicator, the post treatment curing oven and the post-treatment sanding station.

' r

53. A method as claimed in any of Claims 50 to 52 in which one or both of the first and second final lacquer applicators and one of the hrst and second final curing ovens is selectively enabled.

s

54. A method as claimed in any of Claims 50 to 53 in which the method further comprises selectively disabling those of the post-treatment lacquer applicator, the post-treatment sanding station, the first and second final lacquer applicators and the first and second final curing ovens which are not required.

55. A method for polishing timber surfaces of respective panels, the method being substantially as described herein with reference to and as illustrated in the accompanying drawings.

56. A panel having a timber surface polished using the apparatus as claimed in 15 any of Claims 1 to 49.

57. A panel as claimed in Claim 56 in which the timber surface of the panel is polished using the method as claimed in Claims 50 to 56.