GB2319992A

GB2319992A - Pressing a wheel into a rigid PVC - UE fascia board to form a groove in its surface

Info

Publication number: GB2319992A
Application number: GB9624385A
Authority: GB
Inventors: Edward Vincent Richardson
Original assignee: Kestrel Building Products Ltd
Current assignee: Kestrel Building Products Ltd
Priority date: 1996-11-23
Filing date: 1996-11-23
Publication date: 1998-06-10
Anticipated expiration: 2016-11-23
Also published as: GB2319992B; IE970826A1; GB9624385D0

Abstract

A decorative groove 6 is formed in a supported PVC - UE fascia board 5 by pressing a profiled rotating wheel 7 into the skinned surface 2 of the board as it passes beneath the wheel. The pressure P applied to the wheel is controlled to ensure that the groove is formed without breaking the skin 2 of the board.

Description

METHOD AND APPARATUS FOR SHAPING PVC BOARDS The present invention relates to a method and apparatus for shaping rigid cellular PVC boards, particularly, but not exclusively, boards intended for use on or around the roof of a building as a so-called "roofline board", such as a fascias and bargeboards.

For convenience, rigid cellular PVC is referred to herein by its conventional designation PVC-UE.

Wood is the traditional material used for the production of roofline boards.

Wood does however have the disadvantage that it requires regular treatment (such as painting or varnishing) and, in any event, may eventually rot and require replacement.

There is thus now a trend to the use of boards of PVC-UE in place of wooden boards, since PVC-UE has the advantage that it does not rot and maintains its appearance without the need for regular maintenance.

Briefly, PVC-UE is an extruded product which comprises a core of cellular PVC and a PVC skin provided on at least some of its surfaces, e.g. surfaces that will either be visible or exposed to the elements. The skin has properties of UV and impact resistance and may be any variety of colours.

In spite of its disadvantages, wood does however have the advantage that it is relatively cheap and simple to shape and in particular to apply decorative features (e.g.

decorative profiles) to wooden boards using a variety of conventional techniques. In contrast, conventional methods for the production of PVC-UE boards require use of a particular dedicated extrusion tool for each shape. Such tools are expensive, so that the provision of boards with a variety of different decorative profiles by conventional techniques can be very expensive.

It is an object of the present invention to provide a method and apparatus for shaping PVC boards which overcomes the above disadvantage.

According to a first aspect of the present invnetion there is provided method of shaping a pre-formed PVC-UE board, the method comprising forming one or more depressions in a surface of the board by pressing at least one former into said surface.

Thus the invention provides a method that may be used to apply decoration to a pre-formed board.

In a preffered embodiment of the invention a rotatable wheel is used as a former and the board and wheel are moved translationally relative to one another so that the wheel rotates about its axis as it is pressed into the surface of the board, thereby forming a groove in the board.

Thus, for instance, a decorative groove may be formed along the edge of a fascia board or the like.

Preferably the or each former is held substantially stationary and the relative movement between the or each former and the board is provided by movement of the board.

The method according to the present invention may be performed on-line with an extrusion process used to fabricate the board but downstream of the extrusion process subsequent to cooling of the board to substantially ambient temperature. Such cooling ensures that the skin of the board will be sufficiently hardened to resist breaking under the or each former.

According to a second aspect of the present invention there is provided apparatus for shaping a pre-formed PVC-UE board, the apparatus comprising at least one former, means for supporting a board, and means for applying pressure to the or each former to press the or each former into a surface of the board thereby forming a depression in the board.

Preferably the or each former is a wheel mounted for rotation about an axis and said apparatus is adapted to receive a board travelling in a direction perpendicular to said axis such that the or each wheel forms a groove in the surface of the board as it travels through the apparatus.

A support member is preferably located beneath the or each wheel such that a space is defined between the support member and the or each wheel to receive said board, the support member providing support for the board as it passes through the apparatus to provide a reaction to the pressure applied to the or each wheel. The support member may, for instance, comprise a roller mounted for rotation about an axis parallel to said axis of rotation of the or each wheel.

Specific embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figs. la and ib are sections oftwo conventional PVC-UE fascia boards; Figs. 2a and 2b are perspective and end schematic illustrations of the shaping of a fascia board of Fig. 1 in accordance with the present invention.

Fig. 3 is a schematic end view illustrating on-line shaping of an extruded fascia board in accordance with the present invention; Fig. 4 is a front view of one embodiment of apparatus for shaping a PVC-UE board in accordance with the present invention; and Fig. 5 is a side view of the apparatus of Fig. 4.

Referring to the drawings, Figs. la and lb illustrate two conventional PVC-UE fascia boards. Each board is produced as an extrusion, using conventional techniques, and comprises a core 1 of cellular PVC and an outer skin 2 on one of its major faces (the thickness of the skin is exaggerated throughout the drawings for clarity). The skin 2, which forms as a result of the conventional extrusion process, provides the board with a smooth visible surface. The other major surface of each board is unskinned but will be hidden from view and will not generally be exposed to the elements. The board of Fig. la is of a design referred to as (bull nose) having a slot 3 formed along its length for receiving a soffit (not shown). The board of Fig lb is of an alternative design formed with a support flange 4 along one edge (which in use will be the lower edge of the board).

Turning now to Figs. 2a and 2b, these illustrate shaping of a conventionally fabricated board 5 (which in this case is a board of the type illustrated in Fig. lb) in accordance with the present invention to provide a decorative groove 6 along one edge (which in use will be the lower edge) of the skinned face 2. The groove 6 is formed in the skinned surface of the board by an appropriately profiled wheel 7. The board is passed under the wheel in the direction indicated by arrow 8 in Fig 2a and the wheel 7 is forced down onto the board 5 by the application of pressure in the direction indicated by arrow P. The wheel is mounted for rotation about an axis 9 which is perpendicular to the direction of travel 8 of the board 5 so that the wheel 9 rotates about its axis as the boards travels beneath it and in doing so "crimps" the surface of the board 5 to form the groove 6. The pressure P applied to the wheel is controlled to ensure that a groove of required depth is formed without breaking the skin 2.

It will be appreciated that the shaping of the board can be varied in accordance with the present invention by, for instance, using a wheel with a different (e.g. thicker) profile and varying the pressure applied to the wheel. Similarly, more than one wheel could be positioned side by side to form more than one groove along the length of the board. The wheel (or wheels if there is more than one) could be lifted from the board at periodic intervals to provide "breaks" in the groove formed in the board. In addition, the circumference of the wheel could be radially profiled to form a repeating pattern in the surface of the board.

It will be appreciated that the shaping method according to the present invention could be used as an additional shaping step on-line with a conventional extrusion process, or could be used to shape a board sometime subsequent to its manufacture.

It is conventional in the manufacture of PVC-UE boards to produce two boards from a single extrusion by cutting the board in two along its length. Fig. 3 is a schematic illustration of application of the present invention to provide decorative shaping to an extrusion 10 which is subsequently to be cut in two as indicated by the dotted line 11 to form two separate fascia boards of the type illustrated in the previous Figs. lb. Thus, in this case the invention is adapted to form grooves along both skinned edges of the extrusion 10 (which will form lower edges of respective fascia boards).

The invention as illustrated in Fig. 3, operates in essentially the same way as it is described above in relation to Figs. 2a and 2b in that grooves are formed in the surface of the board 10, without breaking the skin 12 using rotating wheels 13, 14 and 15 which are pressed into the surface of the board 10 under pressure applied in the direction of arrows P. In this particular illustrated embodiment, it will be seen that one half of the board 10 (which will ultimatly provide one fascia board) is provided with two grooves along its edge by using a pair of side by side wheels 14 and 15.

Furthermore, it will be seen that wheel 15 is somewhat thicker than wheel 14 so as to form a wider groove than that formed by wheel 14. This is illustrative of one of the above mentioned ways in which the decoration of the board can be varied.

In this case the shaping step according to the invention is on-line with the extrusion process, being performed on exit of the board from the extrusion apparatus.

Since the extrusion may be entirely conventional this will not be described in detail.

However, it should be noted that in later stages of a conventional extrusion process the board is cooled (generally under cold water jets in a vacuum tank) so that when the board reaches the shaping apparatus according to the present invention it will be at ambient temperature and thus the skin will be hardened and so will not easily break.

In the forgoing description no particular detail has been described as to how the shaping wheels could be mounted, how pressure could be applied to the wheels, or how the board could be supported during the shaping process. However, the appropriately skilled person will readily be able to construct apparatus for performing the method according to the present invention to suit particular circumstances and will appreciate that the invention is not limited to any particular form of apparatus.

However, an example of apparatus in accordance with the present invention suitable for forming decorative grooves in and extruded PVC-UE board (for instance a board that is subsequently to be cut in two to form two fascia boards) is illustrated in Figs. 4 and 5.

The illustrated apparatus comprises two rollers 16 and 17 arranged one above the other in a support frame 18. The axis of rotation of the rollers 16 and 17 are parallel such that a space 19 is defined therebetween to receive a PVC-UE board (not shown). The top roller 17 is mounted to the support frame 18 within a sub-frame 20 which is vertically slidable within frame 18 under operation to prepare of screwjack members 21 and 22 which are turned by turning wheels 23 and 24 respectively. The top roller 17 is provided with shaping wheels 25 and 26 adjacent each of its ends.

In use, a board is passed through the space 19 between the rollers 16 and 17 with its skinned face uppermost. The top roller 17 is then pressed down on to the board by rotation of wheels 23 and 24 so that the shaping wheels 25 and 26 are pressed into the surface of the board which is supported upon lower roller 16. The amount of pressure applied is controlled by the degree of rotation of wheels 23 and 24 which operate the screw-jacks 21 and 22. As the board travels through the apparatus, the above rollers 16 and 17 will rotate and wheels 25 and 26 will form grooves in the upper skinned surface of the board.

The upper roller 17 can be constructed so that the wheels 24 and 25 can be interchanged with alternatively sized or profiled wheels to vary the shaping of the board, and furthermore could be adapted to receive more than one shaping wheel at each of its ends to allow for multiple grooves to be formed adjacent either edge of a board.

As mentioned above, it will be appreciated by the skilled man that many other forms of apparatus could be constructed to carry out the shaping method according to the present invention. For instance, in the embodiment described in Figs. 4 and 5 application of pressure is by way of mechanical screw-jacks 20 and 21. In alternative embodiments pressure could, for instance. be applied hydraulically or pneumatically.

Other possible modifications to the particular examples of the invention described above will be apparent to the skilled person.

In addition, it will be understood that the invention is not limited to applications in shaping boards for use as roofline boards, such as the fascias described above, but rather can be used in the shaping of any PVC-UE board.

Claims

1. A method of shaping a pre-formed PVC-UE board, the method comprising forming one or more depressions in a surface of the board by pressing at least one former into said surface.

2. A method according to claim 1, wherein a rotatable wheel is used as a former and the board and wheel are moved translationally relative to one another so that the wheel rotates about its axis as it is pressed into the surface of the board, thereby forming a groove in the board.

3. A method according to claim 2. wherein the or each former is held substantially stationary and the relative movement between the or each former and the board is provided by movement of the board.

4. A method according to any preceding claim, wherein one or more substantially continuous grooves is/are formed in the board.

5. A method according to claim 4. wherein one or more grooves is/are formed along the board adjacent one of its edges.

6. A method according to any preceding claim, wherein the method is performed on-line with an extrusion process used to fabricate the board but downstream of the extrusion process subsequent to cooling of the board to substantially ambient temperature.

7. A method according to any preceding claim, wherein the board is elongate and a plurality of grooves are formed along the length of the board subsequent to which the board is cut along its length into two or more separate parts at least some of which include said grooves.

8. A method according to any preceding claim, wherein the or each depression is formed in a skinned surface of the board without breaking said skin.

9. Apparatus for shaping a pre-formed PVC-UE board, the apparatus comprising at least one former, means for supporting a board, and means for applying pressure to the or each former to press the or each former into a surface of the board thereby forming a depression in the board.

10. Apparatus according to claim 9, wherein the or each former is a wheel mounted for rotation about an axis and said apparatus is adapted to receive a board travelling in a direction perpendicular to said axis such that the or each wheel forms a groove in the surface of the board as it travels through the apparatus.

11. Apparatus according to claim 10, wherein a support member is located beneath the or each wheel such that a space is defined between the support member and the or each wheel to receive said board, the support member providing support for the board as it passes through the apparatus to provide a reaction to the pressure applied to the or each wheel.

12. Apparatus according to claim 11, wherein said support member comprises a roller mounted for rotation about an axis parallel to said axis of rotation of the or each wheel.

13. Apparatus according to any one of claims 10 to 12, wherein the or each wheel is mounted concentrically upon a roller.

14. A method of shaping a pre-formed PVC-UE board, substantially as hereinbefore described, with reference to the accompanying drawings.

15. Apparatus for shaping a pre-formed PVC-UE board, substantially as hereinbefore described, with reference to the accompanying drawings.