GB2221407A

GB2221407A - Application of adhesive to elongate members

Info

Publication number: GB2221407A
Application number: GB8818710A
Authority: GB
Inventors: Robert Ronald Botham; Leslie Whithorn
Original assignee: BKL Extrusions Ltd
Current assignee: BKL Extrusions Ltd
Priority date: 1988-08-05
Filing date: 1988-08-05
Publication date: 1990-02-07
Also published as: GB8818710D0

Abstract

An adhesive substance, e.g. for adhering a lamina in a profile wrapping process, is applied to an elongate member (10). The elongate member may be a metal or plastics extrusion intended for use as a window or door frame member. The elongate member (10) is moved lengthwise past a spraying means (14) by which the substance is applied and subsequently past a spreading means (22) by which the adhesive substance is spread over the surface of the elongate member. The spraying means (14) is movable towards and away from the member (10) and angularly. The spraying means is of the venturi type wherein the quantity of adhesive delivered is controlled by a supply of compressed air. Spreading means (22) comprises a porous pad e.g. of felt. <IMAGE>

Description

APPLICATION OF ADHESIVE TO ELONGATE MEMBERS This invention relates to a method of, and apparatus for, applying an adhesive substance in flowable form to the surface of an elongate member.

The invention has been developed in relation to the application of a lamina to the surface of an elongate member by a profile wrapping process. A profile wrapping process, as is well known, involves passing the elongate member through a machine wherein an adhesive is applied thereto, after which the lamina is introduced to the surface of the member and caused to conform to the surface shape thereof by successive profiled rollers.

The lamina may, for example, be of a plastics material and be used to give a required surface finish to the elongate member which may be a metal or plastics extrusion, e.g. intended for use as a window or door frame member.

In a machine, presently commercially available, for carrying out a profile wrapping process, adhesive is applied to the required surface of the elongate member by one or more pads of porous material, e.g. felt, which contact the surface of the member as the member passes lengthwise thereby, the adhesive being delivered at a controlled rate to the pad or pads. A problem has been found with this, namely inconsistency of the supply and application of the adhesive. A supply of adhesive by gravity at a low rate, e.g. by a drip feed type of arrangement, can readily become clogged due to a tendency for the adhesive to dry up, and the result is unsatisfactory adhesion of the applied lamina. Constant attention to the arrangement for supplying adhesive has been found to be necessary, and frequent cleaning thereof.

It is the object of the present invention to overcome or reduce these disadvantages. Although the invention is advantageously used in conjunction with a profile wrapping process, it is to be appreciated that it is valuable in other circumstances where similar problems arise.

According to one aspect of the invention, we provide a method of applying an adhesive substance in flowable form to a surface of an elongate member, comprising moving the elongate member lengthwise past a spraying means whereby the adhesive substance is applied by spraying to the surface of the member, and subsequently past a spreading means by which the adhesive substance is spread over the surface of the member.

The invention also provides apparatus for applying an adhesive substance in flowable form to a surface of an elongate member, comprising spraying means for spraying the substance onto the surface of the member and spreading means for spreading the substance thus applied over said surface, the spraying means and spreading means being mounted or adapted to be mounted in relation to a means for moving the elongate member lengthwise such that the member is moved past the spraying means followed by the spreading means.

The spraying means is preferably a spray nozzle of venturi type, wherein a flow of gas (usually air) through a venturi section is used to draw the adhesive substance from a supply thereof and spray it onto the surface of the elongate member. Preferably the supply of adhesive substance is below the level of the nozzle, so that no flow thereof occurs except when air is supplied to the nozzle, and the supply of the adhesive substance can be controlled solely by controlling the supply of air.

The spreading means may comprise one or more porous pads contacting the surface of the elongate member.

Advantages of the invention are primarily that it has been found that the supply of adhesive is more consistent than with the previously known methods above described. Less attention and maintenance time has been found to be required. Further, the application of the adhesive substance by spraying means that, if required, an underneath surface of the elongate member can have adhesive applied to it, which is not possible with a gravity feed arrangement for adhesive supply. Two or more sprays may be utilized to ensure effective application to surfaces of complex shape.

The invention will now be described by way of example with reference to the accompanying drawing, which is a diagrammatic perspective view of apparatus according to the invention.

In the drawing, there is shown an elongate member 10 which is caused to move in the direction of its length as indicated by arrow 11. The member 10 may be moved by any conventional means, e.g. a succession of rollers spaced along a feed path. The member 10 may be an extrusion of a metal or a plastics material. The illustrated member 10 has a flat upper surface 12 with a bevelled edge 13 and it is to this surface and edge that adhesive is required to be applied, e.g. as preparation for the application of a lamina to the member in a profile wrapping process.

Adhesive is applied to the member 10, on its upper surface 12 and edge 13, by spraying from a nozzle assembly indicated generally at 14. The assembly 14 is movable towards and away from the member 10, and angularly, as indicated by the arrows on the nozzle assembly, to cause the adhesive to be directed to the required part of the member and to be applied in the correct quantity as the member moves lengthwise past the nozzle assembly.

The nozzle assembly is supplied with compressed air through pipe 15, and with adhesive through pipe 16 from a reservoir 17 which is disposed below the level of the nozzle assembly. As shown in the inset to Figure 1, the nozzle assembly is of the type which has a body 23 which defines a venturi section so that the compressed air issuing from a jet 18 draws the adhesive from a passage 19 perpendicular thereto, and delivers a spray of the adhesive from a divergent outlet passage 20. The quantity of the adhesive delivered in spray form is controlled by the supply of compressed air to the nozzle assembly, under the control of a valve 21.

After the nozzle assembly 14, the member 10 travels past a spreader 22. This may be in the form of a porous pad, e.g. of felt, either touching or in close proximity to the surface 12 and edge 13 of the member so as to spread the adhesive uniformly thereon. The combination of spray application of adhesive to the member followed by spreading thereof ensures consistent application of the adhesive to the member.

Claims

1. A method of applying an adhesive substance in flowable form to a surface of an elongate member, comprising moving the elongate member lengthwise past a spraying means whereby the adhesive substance is applied by spraying to the surface of the member, and subsequently past a spreading means by which the adhesive substance is spread over the surface of the member.

2. Apparatus for applying an adhesive substance to a surface of an elongate member, comprising spraying means for spraying the substance onto the surface of the member and spreading means for spreading the substance thus applied over said surface, the spraying means and spreading means being mounted or adapted to be mounted in relation to a means for moving the elongate member lengthwise such that the member is moved past the spraying means followed by the spreading means.

3. Apparatus according to Claim 2 wherein the spraying means is a spray nozzle of venturi type, comprising a supply of gas under pressure for drawing the adhesive substance from a supply thereof and delivering it as a spray to the surface of the elongate member.

4. Apparatus according to Claim 3 wherein the supply of adhesive substance is below the level of the spray nozzle.

5. Apparatus according to any one of Claims 2 to 4 wherein the spreading means comprises at least one porous pad contacting the surface of the elongate member.

6. A method of applying an adhesive substance, substantially as hereinbefore described.

7. Apparatus for applying an adhesive substance, substantially as hereinbefore described with reference to the accompanying drawing.