WO2007065442A1

WO2007065442A1 - Apparatus for providing surface structure

Info

Publication number: WO2007065442A1
Application number: PCT/DK2006/000697
Authority: WO
Inventors: Nina Himmer
Original assignee: Amanda Patent & Licensing Sia
Priority date: 2005-12-09
Filing date: 2006-12-08
Publication date: 2007-06-14
Also published as: DK200501747A

Abstract

The invention relates to a system of providing a structured surface on a preferably elongate, essentially flat workpiece (100) comprising at least one polymer surface, said system comprising a conveyor device with a plane of conveyance, wherein conveyor means for conveying said object in a direction of conveyance are configured in connection therewith, structuring means (4) having a direction of rotation following essentially the direction of conveyance and being configured above the plane of conveyance for providing the structured surface comprising a plurality of evenly distributed recesses. The system is particular by the structuring means (4) being configured for being moved sideways from side to side relative to the direction of conveyance when surface structure is imparted to the workpiece. The invention further relates to a method of providing a surface structure on a preferably elongate, essentially flat workpiece comprising at least one polymer surface.

Description

Apparatus for providing surface structure

The present invention relates to a system for providing a structured surface on a preferably elongate, essentially flat workpiece comprising at least one polymer surface, said system comprising: a conveyor device with a plane of conveyance, where conveyor means for conveying said workpiece in a direction of conveyance "F" is configured in connection there with, and structuring means with a direction of rotation "R" following essentially the direction of conveyance "F" and being configured above the plane of conveyance for providing the structured surface, comprising a plurality of evenly distributed, elongate recesses.

Systems for forming a wood-like surface on preferably elongate workpieces are known from ia US 6,066,367 that describes a method of providing a structured surface on composite materials and an apparatus for executing the method. The apparatus comprises transverse, rotating sanding drums configured for abrading an essentially flat, elongate workpiece conveyed in a direction of conveyance through the apparatus. By this abrading process a coarse surface is provided that has elongate recesses that are subsequently filled with dye. By a further abrading process excess paint is removed, whereby primarily the grinding marks remain filled with paint. Subsequently a print is applied to the surface featuring a vein pattern from a desired kind of wood and finally a layer of transparent paint/varnish is applied to the printed surface.

However, the process is inconvenient in the sense that the finished wood-like surface is unnecessarily complex to manufacture and, moreover, it imparts an inauthentic appearance to the treated surface. It is therefore the object of the invention to provide a system and a method of forming a structured surface on a preferably elongate, essentially flat workpiece. According to the invention this is accomplished in that the structuring means are configured for being moved sideways from one side to another relative to the direction of conveyance "F" when surface structure is imparted to the workpiece.

Hereby surface structure is imparted to the surface which yields an authentic appearance in that the recesses formed in the surface and imitating the vein pattern on a piece of wood are provided with an alternating course and hence a more natural course. Moreover, a method for providing surface structure is provided which is uncomplicated compared to the prior art. According to a preferred embodiment said structuring means comprise one or more drum brushes with a first radius and a surface, along which a plurality of rotating steel brushes are configured. Hereby a particularly advantageous surface structure is provided. According to a further preferred embodiment, the system comprises control means for determining the speed of the transverse movement of the structuring means compared to a rate of conveyance, and the control means comprise means for determining a random work area on the transverse movement of the structuring means relative to the rate of conveyance. Hereby an advantageous manner of controlling the transverse movement of the structuring means is accomplished and hence a desired pattern (vein pattern) is accomplished in the surface of the workpiece.

According to yet a preferred embodiment the system comprises control means for setting a speed of rotation on said drum brushes, preferably for steplessly setting rates of rotation within an interval of between 500 and 3000 revolutions per minute. Hereby an advantageous way of providing desired recesses in the surface is accomplished in case a particular "vein pattern" is desired. According to yet a preferred embodiment the workpiece is made of plastics, since a particularly advantageous structure is hereby accomplished.

Other advantageous embodiments will appear from the dependent subclaims.

In the following, the invention will now be described with reference to the drawing, wherein Figure 1 shows a part of a system according to the invention.

In the following reference is made to Figure 1, where a system 1 is shown for providing a surface structure on a preferably elongate, essentially flat workpiece, indicated in the figure by reference numeral 100 and comprising a surface shown by reference numera) 101.

The system comprises a conveyor device with a plane of conveyance "P", to which conveyor means (not shown) are provided that have a direction of advancement "F", and preferably driven and/or drivable conveyor rolls or an endless conveyor belt opposite which a structuring device 1 with structuring means is provided. Relative to the direction of conveyance, an inlet side is defined in a plane of conveyance "P" in front of the means of conveyance, and an outlet side is defined in the plane of conveyance "P" after the means of conveyance relative to the direction of conveyance.

The structuring device 1 comprises a suspension fitting 9 with a vertically oriented axis of rotation 10 connected to the suspension fitting 9 at an upper and a lower end 19, 20. From the upper and lower ends 19, 20 an upper, torque rigid arm 16 and a lower arm, respectively, extend in the direction of conveyance "F", wherein the lower arm 8 is further configured with a charnier 8a (hinge), whereby the lower arm 8 can be moved in a vertical plane relative to the plane of conveyance "P". At a free end 8b opposite the chamier 8a and from an upwardly facing side of the lower arm 8, two parallel, vertically extending mounting fittings 11 , 12 are configured at a distance from each other. The mounting fitting 11 , 12 comprises an elongate, vertically oriented, through-going hole 13, intended for cooperating with a transverse latch 14 in connection with a vertically configured thread bar 14 with which the lower arm 8 is movably suspended in the upper arm 16 and is moreover secured relative thereto. At the upper side of the upper arm 16, the threaded bar 15 is taken through a tilting disc 17 and moreover configured with thread to cooperate with height adjustment means 18 (in the figure shown in the shape of an adjustment screw 18) and being connected thereto for setting of a working height of the structuring means. In this context it will be understood that the maximal vertical travelling of the lower arm 8 is determined by the expanse of the hole 13 in vertical direction, the transverse latch 14 being able to move between two extreme points constituted by the upper and lower edges of the hole. That may be in connection with the continuous adaptation of the structuring means/drum brushes to a profiled surface on the workpiece to which a structure is to be imparted. A drive means, preferably in the form of an electromotor 7, is configured on the underside of the lower arm 8 at the free end 8b. The electromotor 7 comprises a horizontally configured drive shaft 6 with a direction of rotation "R" following essentially the direction of conveyance (F) and on which a cylinder shaped drum brush 4 is configured. Said drum brush 4 is configured with a circular surface 42 along which a number of rotating steel brushes 41 are configured to be rotationally stable. In this context, the radius of the drum brush 4 is defined as the distance from the centre of rotation 5 of the drum brush 4 to the surface 42 of the rotating steel brushes 41. An oscillator device (guide means) 25 is configured for moving the abrasive brush 4 in a transverse direction relative to the direction of conveyance "F". The oscillator device 25 comprises an electromotor 22 and a gearbox 23 associated therewith and, at the output shaft of the gear box 23, it is further connected to means configured for determining rate and frequency of the oscillating, ie transverse, movement. By an arm 21 , the oscillator device is connected to the lower arm 8, whereby the transverse movement of the drum brush 4 is provided by the simultaneous rotation/movement of the upper - and lower- arm (16, 8) about the axis of rotation 10.

It will further be understood that the oscillator device could be configured with guide means by which a random oscillation could be provided, ie the surface is provided with an abraded structure corresponding to the vein pattern of any type of wood. The abraded structure may be eg a structured surface comprising a plurality of evenly distributed elongate recesses. Moreover, the guide means may comprise pressure means by which the drum brush can be caused to operate with variably adjustable operating pressure/abutment pressures since a more random depth is imparted the recesses formed thereby,

If a particular structure is desired for the surface of the workpiece, further structuring means 1 or further drum brushes can be provided in extension of the above-described first structuring device 1. This second, further structuring device may advantageously be provided with separate guide means or be provided with a control configured for cooperating with the guide means configured for the first structuring device. This second drum brush (not shown) may advantageously have a diameter which differs from the first one, and the steel brushes as such may have some other configuration or be configured with another grade and/or else be of some other nature.

Alternatively the second drum brush may be replaced by a drum coated with eg sanding paper around the circular surface and wherein protruding flaps of sanding paper are configured around the circular surface. They may advantageously be evenly distributed around the entire circumference. Advantageously the rates of conveyance of the endless conveyor can be determined to be within an interval of between 1 and 30 meters per minute. The rates of rotation of the drum brushes 4 will preferably be set steplessly and will be within an interval of from 500 to 3000 rotations per minute.

The workpieces processed with the device for providing structure to thereby provide at least one surface of the piece with structure are preferably elongate workpieces (profiles) for use in the manufacture of eg door frames or window frames. The pieces are completely or partially made of a synthetic material or comprise at least one outer coating with one polymer surface (eg plastics) and a subjacent core will be made of any suitable material, eg wood, fibre plate or composite material. Moreover, the workpiece may be reinforced to further increase its flexing strength. In accordance with the idea behind the invention the term "structure" is to be understood as a treatment of the surface in such a manner that grooves/traces are provided in the surface, whereby an appearance is imparted to the surface resembling or corresponding to the surface structure/vein pattern on a corresponding piece of wood. The grooves in the surface may, depending on the desired effect, be elongate (ie relative to the sanding direction) depending on the desired vein pattern.

The workpieces to be treated by structuring according to the invention are preferably elongate workpieces for use in connection with the manufacture of door frames or frames for a window.

The method of structuring a surface on a preferably elongate, essentially flat workpiece with at least one polymer surface comprises the following steps: The workpiece to be provided with structure is, at the inlet side in the direction of conveyance, to be taken on the endless conveyor belt to a first drum brush (the structuring means), where the surface of the workpiece that faces towards the drum brush is treated by its surface being swept, whereby structure is imparted to the surface, ie evenly distributed recesses are provided on that part of the workpiece that faces towards the drum brush.

Then the surface of the brushed workpiece is treated by sanding with sanding paper whereby burrs, if any, are removed from the surface and the surface is cleaned of brushing/sanding dust, if required. By the treatment of the workpieces with the steel brushes, a structured surface is provided with evenly distributed recesses that may advantageously be elongate due to a particular configuration of the abrading brushes.

If a particular structure is desired, the workpiece may furthermore be provided with structure by another (further) drum brush, which is preferably carried out following the structuring with the above-described first drum brush, but before sanding with sanding paper. The second drum brush may have a radius that differs from or is equal to the first drum brush.

Subsequently the workpiece is treated by application of a layer of base colour which preferably dries partially prior to non-sticking colour/paint being wiped off, the recesses in the surface being filled with base colour and a sticking part of the base colour further remaining on the surface of the workpiece.

In the next step in the method, a coat of surface colour is applied that may be entirely or partially covering. Preferably, the surface colour is lighter than the base colour, and advantageously the surface colour is of a lighter shade than the base colour.

According to the invention, other advantageous process steps can be used, eg the drum brush will be operated at variably adjustable contact pressure, thereby imparting to the recesses thus formed a more random depth.

Claims

C l a i m s

1. A system (1) for forming a structured surface on a preferably elongate, essentially flat workpiece (100), comprising at least one polymer surface (101), said system comprising:

- a conveyor device with a plane of conveyance (P), wherein conveyor means for conveying said workpiece (100) in a direction of conveyance (F) are configured in connection therewith;

- structuring means (2) with a direction , of rotation (R) which essentially follows the direction of conveyance (F) and is configured above the plane of conveyance (P) for forming the structured surface comprising a plurality of evenly distributed recesses, characterised in that the structuring means (2) are configured for being moved sideways from side to side relative to the direction of conveyance (F) when the workpiece (100) is being provided with structure.

2. A system according to claim 1 , characterised in that said structuring means (2) comprise a drum brush (4) with a first radius and a surface (42), along which a plurality of rotating steel brushes are configured.

3. A system according to claim 2, characterised in comprising a further drum brush (4) with a second radius and a second surface (42), along which a plurality of rotating steel brushes are configured.

4. A system according to any one of the preceding claims, characterised in comprising height adjustment means (18) for adjusting the working height of the structuring means (2).

5. A system according to any one of the preceding claims, characterised in that, in connection with the structuring means (2), means are configured for providing desired brush pressure on the workpiece (100) during the structuring.

6. A system according to any one of the preceding claims, characterised in comprising control means (25) for determining the speed of the transverse movement of the structuring means (2) relative to a speed of conveyance.

7. A system according to any one of the preceding claims, characterised in comprising control means (25) for setting a speed of rotation of said drum brushes (42), preferably for stepless setting of rotation speeds within an interval of between 500 and 3000 revolutions per minute.

8. A system according to any one of the preceding claims, characterised in that the control means (25) comprise means for determining a random working area on the transverse movement of the structuring means (2) relative to the speed of conveyance.

9. A system according to any one of the preceding claims, characterised in that said workpiece (100) is made of plastics.

10. A method for structuring a surface of a preferably elongate, essentially flat workpiece (100) comprising at least one polymer surface (101 ), characterised in that said workpiece (100) is structured on said at least one surface (100) by means of the system 1 according to any one of claims 1-9 for providing a structured surface.

11. A method according to claim 10, characterised in that the structured surface is sanded with a piece of sanding paper and is subsequently cleaned of sanding dust.

12. A method according to claim 10 or 11 , characterised in that a coat of base colour is applied to the structured surface; and that the structured surface is subsequently wiped to remove non-sticking colour.

13. A method according to claim 12, characterised in that a layer of surface colour is applied to the structured surface.

14. A method according to claim 12 or 13, characterised in that the surface colour is lighter than the base colour.