IE981040A1 - Veneer edging manufacture - Google Patents

Abstract

The process comprises cutting veneer sheets into veneer strips of desired size; joining the veneer strips end to end forming a veneer web; applying adhesive to a rear face of the veneer web; applying a flexible backing sheet to the adhesive covered face of the veneer web; pressing the backing sheet and web together; and sanding the veneer web. The process includes the step of partially drying the adhesive on the web prior to application of the backing sheet.

Description

BACKGROUND OF THE INVENTION £®ibl5fo.

This invention relates to apparatus and a process for manufacturing veneer edging.

Wooden veneer edging has been used in furniture manufacture for a long number of years. It is usually only applied to a flat surface as the bending of the veneer tends to crack the veneer. Where it is necessary to cover a curved surface or a profiled surface it is either usually left bare and stained or else covered with a plastic edging strip. This obviously does not look as good as a natural wood veneer.

The present is directed towards overcoming these problems.

SUMMARY OF THE INVENTION According to the invention there is provided a process for producing a veneer edging strip comprising a veneer sheet with a flexible backing sheet attached to a rear face of the veneer sheet. Advantageously the application of a flexible backing sheet to the rear of the veneer sheet enables the wooden veneer sheet to be curved and bent without cracking of the veneer itself. Thus advantageously the edging strip can be applied to curved surfaces and even profiled surfaces. It will be appreciated that the natural wood veneer gives a much higher quality finish than either a stained edge or a plastic coated edge.

In one embodiment of the invention there is provided a process for producing a veneer edging strip, comprising the steps: selecting veneer sheets of a desired moisture content and delivering the 0 selected veneer sheets to a cutting station, cutting each of the selected veneer sheets into a number of rectangular veneer strips of a predetermined length and width, INT CL - 2 delivering a plurality of the rectangular veneer strips to a joining apparatus, feeding the rectangular veneer strips end to end through a cutter in the joining apparatus, the cutter cutting complementary edge profiles in adjacent ends of adjoining rectangular veneer strips, interengaging said edge profiles of adjoining rectangular veneer strips and gluing said complementary edge profiles together to interconnect the rectangular veneer strips, a plurality of the rectangular veneer strips being thus joined end to end to form a veneer web, delivering the veneer web through a backing sheet applicator, in said backing sheet applicator leading the web to a gluing station, applying adhesive in a controlled manner onto a surface of the veneer web at the gluing station, overlaying a flexible backing sheet on to the adhesive coated surface of the veneer web, pressing the backing sheet and the veneer wfeb together and curing the adhesive for securely bonding the backing sheet to the veneer web to form a composite flexible veneer web having on one side a veneer face and on the other side a backing sheet face, delivering the composite flexible veneer web to a sanding station and sanding the veneer face of the composite flexible veneer web to provide a desired surface finish on the veneer face thus forming the veneer edging strip.

In a particularly preferred embodiment the process includes the step of partially drying the adhesive on the web prior to application of the backing sheet.

In a further embodiment the process includes the step of storing the veneer sheets in a raw material store prior to use, controlling the climate within the raw material store to maintain a moisture content of at least 11% in the veneer sheets, selected veneer sheets being delivered from the raw material store to the cutting station.

In another embodiment the process includes the step of sanding the veneer face of the web to reduce the web to a preset desired thickness. - 3 The process may further include the application of an adhesive to a backing sheet face of the veneer edging strip after formation of the edging strip.

The backing sheet may be of any suitable flexible material. A cellulose based material has been found to work well.

In another embodiment the process includes the step of back lighting the web for detecting faults in the web.

In a further embodiment the process includes drawing the backing sheet from a supply reel onto the adhesive coated surface of the veneer web, and pressing the backing sheet and veneer web together by delivering them between a set of press rollers comprising a number of pairs of rollers between which the backing sheet and web pass.

In another embodiment the process includes applying a second backing sheet to the web before sanding the web.

In another embodiment the process includes leading the veneer edging strip to a gluing station, applying an adhesive to the backing sheet face of the veneer edging strip, blowing drying air on to the adhesive coated surface of the veneer edging strip for forced drying of the adhesive immediately downstream of the gluing station and reeling the veneer edging strip.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be more clearly understood by the following description of some embodiments thereof, given by way of example only, with reference to the accompanying drawings, in which:Fig. 1 is a schematic flowchart illustrating a manufacturing process accading to the invention; J - 4 Fig. 2 is a perspective view of a guillotine apparatus used in the process; Fig. 3 is a perspective view of cut veneer strip storage racks; Fig. 4 is a perspective view of an end joining apparatus for the veneer strips; Fig. 5 is a schematic elevational view of apparatus for applying a backing sheet to a veneer web; y Fig. 6 is a detail view of portion of the apparatus shown in Fig. 5; Fig. 7 is a detail view of another portion of the apparatus shown in Fig. 5; Fig. 8 is a detail elevational view showing a veneer web and associated backing sheet joined in the apparatus of Fig. 5; Fig. 9 is a schematic elevational view of sanding station used in the process; Fig. 10 is a perspective view of adhesive applicating apparatie; Fig. 11 is a perspective view of a reeling apparatus used in a process according to the invention; Fig. 12 is a detail elevational view of portion of the reeling apparatus; Fig. 13 is a detail sectional elevational view of a spooling bar forming portion of the apparatus of Fig. 11; and Fig. 14 is an elevational view of a reel of veneer edging formed using the apparatus of Fig. 11.

DETAILED DESCRIPTION OF ΤΗ E PREFERRED EMBODIMENTS Referring to the drawings, a process and apparatus for manufacturing veneer edging J - 5 will be described.

Veneer sheets are inspected and suitable veneer sheets having a desired quality and flexibility are selected. The selected sheets are retained in a veneer sheet store 10. Within the store 10, the climate is controlled to maintain the moisture content of the veneer sheets in the range 11-13%.

Selected veneer sheets are delivered to a cutting station having a guillotine 12 for cutting the veneer sheets into rectangular strips of a required size. At the guillotine 12, a stack of the veneer sheets have their opposite ends cut square to provide sheets of a desired length. Then, opposite sides of the stack of sheets are cut square with the ends and leaving veneer strips 14 of a desired width and length. These cut veneer strips 14 are mounted on a storage rack 15 awaiting further processing.

A stack of veneer strips 14 is then delivered to end joining apparatus 16 for joining the strips 14 end to end to form a veneer web 18 which is wound on a spool 19. The strips 14 are advanced end to end to a cutter 20 which cuts a serrated edge along the adjoining ends 21,22 of two adjacent strips 14. These serrated edges are then interengaged and glued together to form a substantially invisible joint. After joining the strips 14 to form the web 18, the web 18 is passed over a light box 23 to back-light the web 18 to check for defects which can be marked for later correction.

Downstream of the joining apparatus 16, the spool 19 is mounted at an inlet end of a backing sheet applicator 25. The veneer web 18 is drawn from the spool 19 and passed through a gluing station 27. At the gluing station 27, the web 18 passes around gluing rollers 28, 29 at which an adhesive from a pool 26 is applied to an upper surface of the web 18. The glued web 18 is then delivered through a dryer 30 at which the glue is partially dried to a desired tacky consistency.

Downstream of the dryer 30, a flexible backing fleece 32 of, in this case, a cellulose based material is drawn from a supply reel 33 and applied to the glued upper surface of the web 18. After application of the backing fleece 32 to the web 18, the fleece 32 and web 18 are delivered between a set of press rollers 35 comprising a number of pairs of rollers between which the fleece 32 and web 18 pass to press the fleece 32 - 6 and web 18 together securely binding the fleece 32 to the web 18 to form a composite web 36. This composite web 36 is delivered over a lamp 38 for back-lighting the composite web 36 to show up any defects in the composite web 36 which can be marked on the composite web 36 prior to reeling the composite web 36 on a spool 40.

The spool 40 is then delivered to a fine sanding station 45. At th§ sanding station 45, the composite web 36 is drawn from the spool 40 and passed through a sander 47 within which the veneer sheet is sanded to reduce the veneer sheet to a desired thickness, for example, 0.3 mm. Any suitable thickness may be selected depending on the thickness of the veneer in the composite web 36 and the nature of the wood in the web. Also, the sanding machine 47 may be set up to provide either a smooth or a coarse finish on the veneer of the composite web 36 as desired. Downstream of the sander 47, the sanded web 36 is passed over a light table 49 which back-lights the web 36 to show up any defects in the web 36. These can be marked for later correction. The web 36 is then wound up on a reel 50.

The reels 50 may then be packaged for dispatch to furniture manufacturers or the like. Alternatively, the reels 50 may be further treated by applying an adhesive to an underside of the web 36 for subsequent application of the web to a surface. Preferably, the adhesive is a thermally activated adhesive such that upon application of the web to a surface and subsequent heating of the web, the adhesive melts to bond the web to the surface on which it is mounted.

In an alternative arrangement, the web 36 may be cut into thinner strips of veneer edging prior to applying adhesive to the rear surface. Fig. 10 shows apparatus for applying adhesive to a number of thin strips of veneer edging simultaneously. Veneer strips 60 are drawn from reels 61 through a gluing station 62 at which adhesive is applied to a rear surface of the strips 60. Immediately downstream of the gluing station 62, dryers 64 direct airstreams onto the glued surface of the strip 60 for drying the glue. The strips are then wound up on reels 65 prior to packing.

Prior to packing, the veneer strip on each reel 65 may be subdivided into a number of smaller reels for the DIY market. Figs. 11 to 13 show apparatus for carrying out this operation. Because of the flexibility imparted to the veneer strip by the backing fleece, - 7 it is possible to tightly wind the veneer on a core 70 of relatively smaller diameter, typically in the order of 25 mm. A number of the reels 65 can be transferred simultaneously. The strips are drawn from each reel 65 through guides 72,73,74 J which keep each strip separate and then wound up on spools 70 mounted on a 5 spooling bar 75. The spooling bar 75 is generally cylindrical. A clamp bar 77 is mounted within an associated re-entrant slot 78 extending along one side of the bar 75. The clamp 77 is retractable within the slot 78 to slide the spools 70 onto and off the spooling bar 75. To securely hold the spools 70 for winding up the veneer strips, the clamp 77 can be moved outwardly by bolts 79 at each end. A pivoting guide 80 which is pivotally mounted on a support frame of the apparatus keeps the veneer strips separate as they are wound up on the spools 70, the guide 80 being free to move outwardly as the diameter of the reels of veneer strips increase.

It will be appreciated that the invention provides a process and apparatus for manufacturing a veneer edging strip with a relatively high degree of flexibility such that it can be tightly wound for packaging and such that in use it can be moulded around and attached to profiled edges without cracking of the veneer itself.

The invention is not limited to the embodiments hereinbefore described which may be 0 varied in both construction and detail.

Claims (13)

1. A process for producing a veneer edging strip, comprising the steps: selecting veneer sheets of a desired moisture content and delivering the selected veneer sheets to a cutting station, cutting each of the selected veneer sheets into a number of rectangular veneer strips of a predetermined length and width, delivering a plurality of the rectangular veneer strips to a joining apparatus, feeding the rectangular veneer strips end to end through a cutter in the joining apparatus, the cutter cutting complementary edge profiles in adjacent ends of adjoining rectangular veneer strips, interengaging said edge profiles of adjoining rectangular veneer strips and gluing said complementary edge profiles together to interconnect the rectangular veneer strips, a plurality of the rectangular veneer strips being thus joined end to end to form a veneer web, delivering the veneer web through a backing sheet applicator, in said backing sheet applicator leading the web to a gluing station, applying adhesive in a controlled manner onto a surface of the veneer web at the gluing station, overlaying a flexible backing sheet on to the adhesive coated surface of the veneer web, pressing the backing sheet and the veneer web together and curing the adhesive for securely bonding the backing sheet to the veneer web to form a composite flexible veneer web having on one side a veneer face and on the other side a backing sheet face, delivering the composite flexible veneer web to a sanding station and sanding the veneer face of the composite flexible veneer web to - 9 provide a desired surface finish on the veneer face thus forming the veneer edging strip.

2. A process as claimed in claim 1 wherein the process includes the step of storing the veneer sheets in a raw material store prior to use, controlling the climate within the raw material store to maintain a moisture content of at least 11 % in the veneer sheets, selected veneer sheets being delivered from the raw material store to the cutting station. -/

3. A process as claimed in claim 1 or 2 wherein the moisture content of the selected veneer sheets is in the range 11% to 13%.

4. A process as claimed in any preceding claim wherein the process includes the step of partially drying the adhesive on the web prior to application of the backing sheet.

5. A process as claimed in any preceding claim, wherein the process includes the step of sanding the veneer face of the composite flexible veneer web to reduce the web to a preset desired thickness.

6. A process as claimed in any preceding claim, wherein the process includes the application of an adhesive to a backing sheet face of the veneer edging strip after formation of the edging strip.

7. A process as claimed in any preceding claim wherein the backing sheet comprises a cellulose based material.

8. A process as claimed in any preceding claim wherein the process includes the step of back lighting the web for detecting faults in the web.

9. A process as claimed in any preceding claim wherein the process includes drawing the backing sheet from a supply reel onto the adhesive coated surface of the veneer web, and pressing the backing sheet and veneer web together by delivering them between a set of press rollers comprising a - ίο number of pairs of rollers between which the backing sheet and web pass.

10. A process as claimed in any preceding claim wherein the process includes applying a second backing sheet to the web before sanding the web.

11. A process as claimed in any preceding claim wherein the process includes leading the veneer edging strip to a gluing station, applying an adhesive to the backing sheet face of the veneer edging strip, blowing drying air on to the adhesive coated surface of the veneer edging strip for forced drying of the 10 adhesive immediately downstream of the gluing station and reeling the veneer edging strip. J

12. A veneer edging strip whenever produced by the process as claimed in any preceding claim, said veneer edging strip comprising a veneer sheet with a

13. 15 flexible backing sheet attached to a rear face of the veneer sheet.