GB2092475A - Flock coating of strip material - Google Patents

Abstract

Flocking of a strip is achieved by coating the strip in a layer of adhesive and then passing the strip through an applicator station where cut flock powder is applied. The powder is given a positive charge whilst the strip is given a negative charge which results in an even pattern of application of the flock powder. The strip is then dried.

Description

SPECIFICATION Flock coating of strip material The object of this invention is to apply a flock coating to strip material which may then be used, for example, in the construction of Venetian blinds.

Hitherto, strips for Venetian blinds have been made from the basic strip material, possibly with a decora tivecoating of paint or the like but no form of textured finish has been achieved.

According to the present invention, there is provided, from aspect, a method of forming a flock coated strip which comprises applying a polymeric solvent-based adhesive to a continuous strip substrate, dosing cut flock onto the adhesive on the substrate whilst applying an electrostatic charge to the cut flock to allow it to site itself in the adhesive carried by the substrate, and drying the adhesive to secure the flock to the substrate.

The type of adhesive employed will secure the flock to the strip substrate in such a way as to give good abrasion resistance. Also, the method of applying the flock powder by an electrostatic process ensures that a very even coating is achieved which enhances the adhesion of the flock and the visual appearance of the final product.

The substrate forming the strip will ideally comprise aluminium, polyvinylchloride orfibreglass. It is advisable to clean the strip prior to application of the adhesive.

The adhesive can be applied, for example, either by dipping the strip into a bath of the adhesive or by spraying the adhesive onto the top, bottom and sides of the strip with a spray gun. The preferred adhesive comprises an acrylic polymer or copolymer or polyurethane with a suitable cross-linking agent.

The solvent would generally be a cellulose-acetate ester.

It is of advantage to incorporate a conductive agent of phenolic character in the adhesive mixture.

The adhesive will be prepared so as to have a suitable open time such as two or three minutes.

The flocking material will ideally be chosen from a cut nylon, viscose, Taklun or other acrylic or polyester synthetic fibre. The flock itself will be chosen to have a suitable colour but added colouring effects can be achieved by tinting the adhesive with a solvent based pigment.

The electrostatic application of the flock is improved if the flock is initially treated with a cathionic or nonionic softening agents after dyeing. Excess surface flock which has not been secured by the adhesive may be removed at a subsequent stage by a suction device.

From a further aspect the invention provides apparatus for creating a flock coated strip comprising a conveying device for transporting a continuous strip substrate, means for applying a polymeric solvent based adhesive to the strip, a flock applicator station at which the strip will be covered with electrostatically charged flock, a discharge device for dispensing cut flock onto the strip at the applicator station, means for applying an electrostatic charge to the flock being dispensed at the applicator station, a dryer for curing the adhesive, a cooling station, and a station for taking up the flock coated strip.

The invention also extends to a flock coated strip as formed by a method or the apparatus of this invention as herein before defined.

The invention may be performed in various ways and one preferred embodiment thereof will now be described, by way of example, with reference to the accompanying drawing, in which: Figure 1 is a diagrammatic representation of an apparatus when coating a continuous strip with flock; and Figure2 is an enlarged cross-section through a portion of strip being subjected to the coating process.

A continuous strip 1 of aluminium, polyvinylchloride orfibreglass is unwound from a coil 2 by means of pinch rollers 3 and is then passed into a bath 4 containing a liquid adhesive 5. Prior to entering the bath 4, the strip 1 will be cleaned (by sprays or other means, not shown) to remove foreign matter from the surface. The adhesive is a conductive adhesive which is formulated from polyurethane chips dissolved in methyl glycol acetate for twenty hours at 20"C, and incorporating a conductive agent of a phenolic character. Polyester iso-cyanate dissolved in xylol is added as 50% of the total mixture, as a cross-linking agent. The solvent based adhesive is then diluted to the required viscosity to suit this method of application.Also, the adhesive is so formulated that an open time of two to three minutes is achieved when the strip leaves the bath 4 with a coating of adhesive thereon.

The adhesive coated strip 1 then passes to an applicator station where it is flocked with cut nylon of 11/2 denier and having a length of 0.75 mm. The nylon has been dyed previously and then treated with a cathionic softening agent to impart a good conductivity to the flock powder and this powder is discharged through holes 6 in dosing hoppers 7 by means of vibrators 8 so as to be directed towards the adhesive coated strip. An electrostatic positive charge is applied to the powder 9 and a negative charge is applied to the adhesive carried by the strip 1 so that an even pattern of application if the flock powder 9 on the strip 1 is achieved (as shown particularly in Figure 2).The coated strip is then passed through a drying chamber 10 where the adhesive is cured for five minutes at 185"C. This gives good abrasion resistance properties to the flocked strip and also fastness to washing and light.

If a thicker density of flock is required, the same process can be repeated but in the second stage, the drying time will be about three minutes at 120"C, otherwise there is danger of damage to the previous layer. Any excess flock is then removed by a vacuum cleaner and the coated strip is wound onto a take-off reel 11 and cooled down at room temperature for 48 hours before the strip is used.

The strip can be cut into lengths suitable for a Venetian blind and bent to have a curved form if desired. The strips are then connected in the usual way, vertically or horizontally, to produce a blind wherein the strips have a pleasing textured finish and with the sharp edges softened by the layer of powdered flock.

Whilst the application of the adhesive has been shown by means of dipping the strip in the bath 4, the adhesive could of course be sprayed on. If spraying techniques are concerned than a pattern could be applied to the substrate (for example, by masking techniques) so that the final product will have a patterned flocked appearance.

Furthermore, the adhesive can incorporate a solvent based pigment which will give it a tint of a desired colour. The flock powder itself will be dyed with a reactive colour direct, or sulphur colours.

CLAIMS (Filed 1 Feb 1982) 1. A method of forming a flock-coated strip which comprises applying a polymeric solventbased adhesive to a continous strip substrate, dosing cut flock onto the adhesive on the substrate whilst applying an electrostatic charge to the cut flock to allow it to site itself in the adhesive carried by the substrate, and drying the adhesive to secure the clock to the substrate.

2. A method according to claim 1, wherein the substrate forming the strip comprises aluminium, polyvinylchloride or fiberglass.

3. A method according to claim 1 or claim 2, wherein the strip is cleaned prior to application of the adhesive.

4. A method according to any one of claims 1 to 3, wherein the adhesive is applied by dipping the strip into a bath of the adhesive or by spraying the adhesive onto the top, bottom and sides of the strip with a spray gun.

5. A method according to any one of claims 1 to 4, wherein the adhesive comprises an acrylic polymer or copolymer or polyurethane with a suitable cross-linking agent.

6. A method according to claim 5, wherein the solvent is a cellulose-acetate ester.

7. A method according to any one of claims 1 to 6, wherein a conductive agent of phenolic character is incorporated in the adhesive mixture.

8. A method according to any one of claims 1 to 7, wherein the adhesive is prepared so as to have an open time of two to three minutes.

9. A method according to any one of claims 1 to 8, wherein the flocking material is chosen from a cut nylon, viscose, Taklun or other acrylic or polyester synthetic fibre.

10. A method according to any one of claims 1 to 9, wherein the adhesive is tinted with a solvent based pigment.

11. A method according to any of claims 1 to 10, wherein the flock is initially treated with a cathionic or nonionic softening agent after dyeing.

12. A method according to any of claims 1 to 11, wherein excess surface flock which has not been secured by the adhesive is removed at a subsequent stage by a suction device.

13. A method of forming a flock-coated strip substantially as herein described with reference to the accompanying drawings.

14. Apparatus for creating a flock-coated strip comprising a conveying devicefortransporting a continuous strip substrate, means for applying a polymeric solvent based adhesive to the strip, a flock applicator station at which the strip will be covered with electrostatically charged flock, a discharge device for dispensing cut flock onto the strip at the applicator station, means for applying an electrostatic charge to the flock being dispensed at the applicator station, a dryer for curing the adhesive, a cooling station, and a station for tasking up the flock coated strip.

15. Apparatus for creating a flock-coated strip substantially as herein described with reference to the accompanying drawings.

16. A flock-coated strip as formed buy a method or the apparatus according to any one of claims 1 to 15.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (16)

**WARNING** start of CLMS field may overlap end of DESC **. powdered flock. Whilst the application of the adhesive has been shown by means of dipping the strip in the bath 4, the adhesive could of course be sprayed on. If spraying techniques are concerned than a pattern could be applied to the substrate (for example, by masking techniques) so that the final product will have a patterned flocked appearance. Furthermore, the adhesive can incorporate a solvent based pigment which will give it a tint of a desired colour. The flock powder itself will be dyed with a reactive colour direct, or sulphur colours. CLAIMS (Filed 1 Feb 1982)

1. A method of forming a flock-coated strip which comprises applying a polymeric solventbased adhesive to a continous strip substrate, dosing cut flock onto the adhesive on the substrate whilst applying an electrostatic charge to the cut flock to allow it to site itself in the adhesive carried by the substrate, and drying the adhesive to secure the clock to the substrate.

2. A method according to claim 1, wherein the substrate forming the strip comprises aluminium, polyvinylchloride or fiberglass.

3. A method according to claim 1 or claim 2, wherein the strip is cleaned prior to application of the adhesive.

4. A method according to any one of claims 1 to 3, wherein the adhesive is applied by dipping the strip into a bath of the adhesive or by spraying the adhesive onto the top, bottom and sides of the strip with a spray gun.

5. A method according to any one of claims 1 to 4, wherein the adhesive comprises an acrylic polymer or copolymer or polyurethane with a suitable cross-linking agent.

6. A method according to claim 5, wherein the solvent is a cellulose-acetate ester.

7. A method according to any one of claims 1 to 6, wherein a conductive agent of phenolic character is incorporated in the adhesive mixture.

8. A method according to any one of claims 1 to 7, wherein the adhesive is prepared so as to have an open time of two to three minutes.

9. A method according to any one of claims 1 to 8, wherein the flocking material is chosen from a cut nylon, viscose, Taklun or other acrylic or polyester synthetic fibre.

10. A method according to any one of claims 1 to 9, wherein the adhesive is tinted with a solvent based pigment.

11. A method according to any of claims 1 to 10, wherein the flock is initially treated with a cathionic or nonionic softening agent after dyeing.

12. A method according to any of claims 1 to 11, wherein excess surface flock which has not been secured by the adhesive is removed at a subsequent stage by a suction device.

13. A method of forming a flock-coated strip substantially as herein described with reference to the accompanying drawings.

14. Apparatus for creating a flock-coated strip comprising a conveying devicefortransporting a continuous strip substrate, means for applying a polymeric solvent based adhesive to the strip, a flock applicator station at which the strip will be covered with electrostatically charged flock, a discharge device for dispensing cut flock onto the strip at the applicator station, means for applying an electrostatic charge to the flock being dispensed at the applicator station, a dryer for curing the adhesive, a cooling station, and a station for tasking up the flock coated strip.

15. Apparatus for creating a flock-coated strip substantially as herein described with reference to the accompanying drawings.

16. A flock-coated strip as formed buy a method or the apparatus according to any one of claims 1 to 15.