WO1998030898A1

WO1998030898A1 - Method and apparatus for applying stains to fabric

Info

Publication number: WO1998030898A1
Application number: PCT/GB1998/000041
Authority: WO
Inventors: Richard Docherty; Andrew Holmes; Nicola Young
Original assignee: Equest Market Research Limited
Priority date: 1997-01-09
Filing date: 1998-01-07
Publication date: 1998-07-16
Also published as: DE19882214T1; GB2335443B; GB9916001D0; GB2335443A; GB9700315D0

Abstract

A semi-automated method and apparatus is described for applying stains to test fabrics for use in the testing of detergent compositions and laundry methods. Fabric swatches (20) covered by a template (22) defining a 4 by 4 matrix travel on pallets (18) by means of a closed loop conveyor track (10) to a dispensing area, where there are four dispensing stations (32a, 32b, 32c, and 32d). Each station has four pots (40), each containing a stain material which is held under pressure by means of a compressed air supply (48). Stain material is passed from the pot (40) by a motorised valve (42) to a respective nozzle (34), under the control of a valve (44). At the same time, compressed air is supplied to the nozzle (34) under the control of the valve (44) to cause the stain material to be atomised, and projected towards the template (22) on the swatch (20).

Description

Method and Apparatus for Applying Stains to Fabrics

This invention relates to a method and apparatus for applying stains to fabrics .

One application of the present invention is in producing test fabrics for use in the testing of detergent compositions and laundry methods.

It is known to make use of test fabrics in the form of swatches each of which carries a number of stains produced by different soiling materials. These swatches are conventionally produced by means of applying the selected stains to a given swatch by hand, but it is difficult using manual application to produce consistent results.

It is also known to apply the stains by a mechanised method which does provide better consistency. However, the known mechanised method relies on the use of additives to apply the stains, and the use of additives adversely affects the test results.

According to one aspect of the present invention a method of applying staining to a test fabric comprises providing at least one reservoir containing a selected stain material in the form of a liquid, emulsion or fluid paste, and spraying the stain material onto a test fabric swatch from a nozzle by means of a pressurised gas which atomizes the stain material and projects it from the nozzle.

The pressurised gas may conveniently be compressed air.

Preferably, a plurality of stain materials are sprayed from a plurality of nozzles onto the swatch.

In a particularly preferred form of the invention, swatches are passed serially through a stain dispensing area, each swatch being covered by a template which defines a plurality of sample locations on the swatch. The template may for example define a matrix of 4 x 4 sample locations, with a row of four stain materials being sprayed in each of four spray stations .

From another aspect, the present invention provides apparatus for applying stains to a test fabric, the apparatus comprising at least one reservoir for containing a selected stain material in the form of a liquid, emulsion or flowable paste, location means for positioning a test fabric swatch, a nozzle positioned to spray the stain material on to a test fabric swatch in said location means, and means for supplying pressurised gas to the nozzle so as to atomize the stain material and project it from the nozzle.

The means for supplying pressurized gas may conveniently comprise a compressed air line.

A particular form of the invention comprises a conveyer track passing from a loading area through a stain dispensing area to an unloading area. The track is adapted to transport a series of pallets each of which carries a test fabric swatch overlaid by a template, the template defining a matrix of sample locations on the swatch, and the dispensing area having a plurality of spraying stations each of which comprises a plurality of said nozzles.

An embodiment of the present invention will now be described by way of example, with reference to the drawings, in which: -

Fig. 1 is a schematic plan view of one form of apparatus in accordance with the present invention. Fig 2. is a schematic end view of part of the apparatus taken in the direction of the arrows 2-2 in Fig. 1. Fig. 3 is a block diagram of part of the apparatus of Fig. 1.

The apparatus comprises a closed loop conveyer track 10 which passes from a loading area 12 through a dispensing area 14 to an unloading area 16. The track 12 carries a series of pallets 18. At the loading area 12 an operator covers each of the pallets 18 with a textile fabric swatch 20 which in turn is covered with a template 22 defining a 4 x 4 matrix of apertures 24. When ready, the pallets 18 is released from the loading area 12 by the operator depressing a foot switch 26 to release a pallet stop 28.

A further pallet stop 30 synchronises movements of the pallets 18 into the dispensing area 14.

The dispensing area 14, which may conveniently be enclosed in transparent sheet material (not shown), provides four dispensing stations 32a, 32b, 32c and 32d. In each of the dispensing stations 32 a row of four nozzles 34 dispenses sprays of stain material towards one row of template apertures 24. After all sixteen template locations have received sprayed material, the pallets pass on the conveyor 10 to the unloading area 16 where another operator removes the textile swatches 20, wipes any residue from the surface of the template 22, and releases the pallets 18 for re- use by means of a pallet stop 36 activated by a foot switch 38.

Referring more particularly to Figs. 2 and 3, each of the stain materials is held in a respective pot 40 under pressure, for example from a compressed air supply 48. At the appropriate point in the cycle stain material is passed from the pot 40 by a motorised valve 42 to the respective nozzle 34, and at the same time compressed air is supplied to the nozzle 34 under the control of a valve 44 to cause the stain material to be atomized and projected towards the swatch 20. Atomizing nozzles of this general type are known in the art.

It will be appreciated that this arrangement requires the stain material to be in a liquid or semi-liquid form. For example, if it is desired to produce a clay- based staining, then it will be necessary to disperse clay particles in water or another suitable liquid carrier.

Certain stain materials require to be heated to give good flow characteristics and accordingly heating means (not shown) may be incorporated in the system, which may conveniently be in the form of electric trace- heating tapes .

Other stain materials may be liable to settling out and accordingly selected storage pots may be provided with means to prevent this, such as a motor driven paddle, or a re-circulating pump as indicated at 46 in Fig. 3.

The operation of the system may suitably be controlled by a programmable logic controller (not shown) arranged to maintain the dispensing procedure in synchronism. The programmable logic controller may also conveniently monitor other factors such as low stain material levels and process temperatures, and generate warning or alarm signals accordingly.

Modifications may be made to the foregoing embodiment within the scope of the present invention.

Claims

1 A method of applying staining to a test fabric comprising providing at least one reservoir containing a selected stain material in the form of a liquid, emulsion or fluid paste, and spraying the stain material onto a test fabric swatch from a nozzle by means of a pressurised gas, which atomises the stain material and projects it from the nozzle.

2 A method according to claim 1, in which the gas is compressed air.

3 A method according to claim 1 or claim 2, in which a plurality of stain materials are sprayed from a plurality of nozzles onto the swatch.

4 A method according to claim 3, in which plurality swatches are passed serially through a stain dispensing area, each swatch covered by a template.

5 A method according to claim 4, in which the template defines a 4 by 4 matrix of sample locations, with a row of four stain materials being sprayed in each of four spray stations.

6 Apparatus for applying stains to a test fabric, comprising at least one reservoir for containing a selected stain material in the form of liquid, semi liquid or flowable paste, location means for positioning a test fabric swatch, a nozzle positioned to spray the stain material on to a test fabric swatch in the location means, and means for supplying pressurised gas to the nozzle so as to atomize the stain material and project it from the nozzle.

Apparatus according to claim 6 in which the means for supplying pressurised gas comprises of compressed air line.

Apparatus according to claim 6 or claim 7, including a plurality of nozzles positioned to spray a plurality of stain materials onto each swatch.

Apparatus according to claim 8, in which each swatch is mounted a pallet and covered by a template.

Apparatus according to claim 9, including a mechanism for transporting the pallets containing the swatches and templates in the form of a closed loop conveyor track passing from a loading area through a stain dispensing area to an unloading area.

Apparatus according to claim 10, in which synchronisation of the flow of pallets along the closed loop conveyor is by means of three pallet stops, one at the loading area, one before the dispensing area, and one at the unloading area.

Apparatus according to any of claims 6 to 11, including means for maintaining the stain material(s) in flowable form.

Apparatus according to claim 12, in which said means comprises electric trace heating tapes and/or a motor driven paddle.