WO2007086739A1

WO2007086739A1 - Method and device for finishing textile materials and floor covering

Info

Publication number: WO2007086739A1
Application number: PCT/NL2007/050026
Authority: WO
Inventors: Jakobus Hindriks; Richard Arnout Otto Pennekamp; Andreas Thomas Johannes Dorsch
Original assignee: Color Wings B.V.
Priority date: 2006-01-24
Filing date: 2007-01-23
Publication date: 2007-08-02
Also published as: NL1030990C1

Abstract

The invention relates to a method for finishing textile materials and floor covering, wherein print heads (6, 7, 8, 9) are placed above the material (2) and wherein liquid droplets are spayed at predetermined locations onto the material via nozzles arranged in the print heads, whereafter the liquid is dried and/or fixed. Between first periods in which textile materials and floor covering are printed there are according to the invention second periods in which no textile materials and floor covering are printed, but in which every nozzle is nevertheless periodically activated, thereby preventing drying-out and clogging of the nozzles.

Description

Method and device for finishing textile materials and floor coverinα

The invention relates to a method for finishing textile materials and floor covering, wherein print heads provided with spray nozzles are placed above the material and wherein liquid droplets are sprayed via the nozzles at predetermined locations onto the material, whereafter the liquid is dried and/or fixed. Finishing is for instance understood to mean bleaching, coating or printing of textile materials and floor covering after weaving. Such a method is preferably performed using digital print heads operating according to the so-called drop-on-demand principle. The problem here is that, when a print head has not been used for a time, one or more nozzles can become blocked. Taking into account that for the purpose of finishing textile materials and floor covering a large number of heads must co-act for a long period and that blockage of a single nozzle can make the product unsaleable, the known print heads are only suitable when textile materials and floor covering are printed continuously without interruption. Although this is a very attractive proposition from an economic viewpoint, it has been found impossible to realize this in practice. A manufacturer will often produce only five days a week in normal day shifts. Every evening/night and every weekend will therefore inevitably cause problems with clogging. In such a situation the machine must therefore be flushed and cleaned at the end of an operating run, and be re-filled with for instance ink at start-up. These are time-consuming processes wherein efforts must for instance be made on each occasion to restore the printing process to the same level as it was, particularly in respect of colour management. The mounting of a new roll of textile or essential machine maintenance also inevitably ensures that printing is sometimes not possible. When the method is then resumed, at least one nozzle is then often found to be clogged. A cleaning procedure then ensues which is time-consuming and often causes the first metres of printed textile to be of inferior quality because the colour of the product is not yet stable, whereby this part is unsaleable.

The method according to the invention almost completely solves this problem and has the feature that first periods in which textile materials and floor covering are printed are alternated with second periods in which no textile materials and floor covering are printed, but in which at least almost every nozzle is nevertheless periodically activated.

The print heads are preferably placed in a parking position during the second periods so that they do not make contact with a strip of textile. The liquid can then be collected and discharged or absorbed. For many ink or coating types it is found to be sufficient to activate each nozzle shortly once at least every hour, wherein each nozzle sprays liquid for at least one second. The cost of the amount of liquid which is lost here amounts to only a fraction of the cost necessary to clean the machine at the end of a working day or working week and to then restart the machine again until a stable, predictable print quality has been obtained.

The invention also relates to a device for finishing textile materials and floor covering, comprising a system of print heads which are placed above the material and which are provided with spray apertures and with piezo pressure wave elements or valves for opening and closing the spray apertures and with actuating members for actuating the piezo pressure wave elements or valves, in addition to transport means for moving the print heads and/or the textile materials and floor covering, a liquid supply to which the print heads are connected and control means for actuating the actuating members and the transport means. The inventive device has the feature that the control means have a first operational mode in which textile materials and floor covering are printed, and a second operational mode in which each valve is opened periodically for a predetermined time, thereby effectively preventing clogging of the nozzles.

A favourable embodiment of the device according to the invention has the feature that the device is provided with a parking location above which the print heads can be placed during the second periods, so that liquid droplets delivered during a second period do not drop onto a strip of textile. The parking location is preferably provided with liquid discharge means or with a liquid-absorbing layer.

A further favourable embodiment has the feature that in the second mode each valve is opened at least every hour, preferably for at least one second.

A further favourable embodiment has the feature that the device is provided with an emergency power supply so that the device can effectively also be placed and held in the second period during a power failure.

The invention will now be further elucidated with reference to the following figures, in which:

Fig. 1 shows schematically a top view of a possible embodiment of a device according to the invention; Fig. 2shows schematically a top view of an alternative embodiment of a device according to the invention.

Fig. 1 shows schematically a top view of a possible embodiment of a device according to the invention. A strip of textile 2 is carried over a table 1 in a direction indicated by an arrow 3. A yoke 4 moves reciprocally above material 2 in a direction indicated by an arrow 5. Placed on yoke 4 in the embodiment shown here are four groups of print heads 6,7,8,9 which spray droplets of liquid onto material 2. Print head 6 sprays for instance black ink, while print heads 7,8,9 spray for instance cyan, magenta and yellow. The speed of material 2 and yoke 4 is chosen in combination with the geometry and placing of print heads 6,7,8,9 in a manner which is further self-evident such that any conceivable pattern can be sprayed onto material 2. The size of a sprayed droplet depends on the type of material; a droplet can be relatively large, particularly for deep-pile materials. It is roughly the case that a droplet has a volume of several picolitres to hundreds of nanolitres. Once the ink has dried the strip of textile 2 is carried through a fixing unit 10 where a further treatment takes place which ensures that the printing is friction-resistant, wash- resistant, UV-resistant or otherwise improved, or is absorbed to a considerable extent into the fibres of material 2, thereby obtaining a good wear-resistance of the pattern. The device further comprises an ink cartridge 11 where the ink is filtered, brought to a predetermined temperature and carried through the heads. Filtering is essential because otherwise the nozzles of print heads 6,7,8,9 can become clogged, whereby lines of a different colour can result on material 2. The temperature must be constant because temperature changes can affect the viscosity of the ink, and thereby the size of an ink droplet, this causing a change in the colour of the pattern. Finally, the device comprises an actuating member 12, generally a computer together with an interface, with which heads 6,7,8,9 and the diverse drives (not shown) for moving the strip of textile 2 and yoke 4 are controlled. Because the ink present in the nozzles of print heads 6,7,8,9 can dry out during a longer period in which the device is not being used, whereby print heads 6,7,8,9 may possibly no longer function properly, a parking location 13 is provided above which yoke 4 can be placed. Actuating member 12 can then periodically control print heads 6,7,8,9 such that each nozzle delivers ink for a short time. This takes place for instance every hour, so that the quantity of ink which is lost is in fact negligible. In order to prevent this periodic spraying being interrupted in the case of power failure, the device is preferably provided with an emergency power supply 14.

Fig. 2 shows schematically a top view of an alternative embodiment of a device according to the invention. A strip of textile 2 is carried over a table 1 in a direction indicated by an arrow 3. Placed above material 2 is a fixed yoke 4 on which in the embodiment shown here four groups of print heads 6,7,8,9 are placed which extend over the full width of material 2 and which spray droplets of liquid onto material 2. Print head 6 sprays for instance black ink, while print heads 7,8,9 spray for instance cyan, magenta and yellow. Any conceivable pattern can be sprayed onto material 2 with the wide print heads 6,7,8,9 in a manner which is further self-evident. The size of a sprayed droplet depends on the type of material; a droplet can be relatively large, particularly for deep-pile materials. It is roughly the case that a droplet has a volume of several picolitres to hundreds of nanolitres. Once the ink has dried, the strip of textile 2 is carried through a fixing unit 10 where a further treatment takes place which ensures that the printing is friction-resistant, wash-resistant, UV- resistant or otherwise improved or is absorbed to a considerable extent into the fibres of material 2, thereby obtaining a good wear-resistance of the pattern. The device further comprises an ink cartridge 11 where the ink is filtered, brought to a predetermined temperature and carried through the heads. Filtering is essential because otherwise the nozzles of print heads 6,7,8,9 can become clogged, whereby lines of a different colour can result on material 2. The temperature must be constant because temperature changes can affect the viscosity of the ink, and thereby the size of an ink droplet, this causing a change in the colour of the pattern. Finally, the device comprises an actuating member 12, generally a computer together with an interface, with which heads 6,7,8,9 and the drive for moving the strip of textile 2 is controlled. Because the ink present in the nozzles of print heads 6,7,8,9 can dry out during a longer period in which the device is not being used, whereby print heads 6,7,8,9 may possibly no longer function properly, a parking location 13 is provided above which yoke 4 can be placed. Actuating member 12 can then periodically control print heads 6,7,8,9 such that each nozzle delivers ink for a short time. This takes place for instance every hour, so that the quantity of ink which is lost is in fact negligible. In order to prevent this periodic spraying being interrupted in the case of power failure, the device is preferably provided with an emergency power supply 14.

Claims

1. Method for finishing textile materials and floor covering, wherein print heads provided with spray nozzles are placed above the material and wherein liquid droplets are sprayed via the nozzles at predetermined locations onto the material, whereafter the liquid is dried and/or fixed, characterized in that first periods in which textile materials and floor covering are printed are alternated with second periods in which no textile materials and floor covering are printed, but in which at least almost every nozzle is nevertheless periodically activated.

2. Method as claimed in claim 1 , characterized in that the print heads are placed in a parking position during the second periods.

3. Method as claimed in claim 1 or 2, characterized in that each nozzle is activated shortly once at least every hour.

4. Method as claimed in claim 3, characterized in that each nozzle is activated at least every hour for at least one second.

5. Device for finishing textile materials and floor covering, comprising a system of print heads which are placed above the material and which are provided with spray apertures and with piezo pressure wave elements or valves for opening and closing the spray apertures and with actuating members for actuating the piezo pressure wave elements or valves, in addition to transport means for moving the print heads and/or the textile materials and floor covering, a liquid supply to which the print heads are connected and control means for actuating the actuating members and the transport means, characterized in that the control means have a first operational mode in which textile materials and floor covering are printed, and a second operational mode in which each valve is opened periodically for a predetermined time.

6. Device as claimed in claim 5, characterized in that the device is provided with a parking location above which the print heads can be placed during the second periods.

7. Device as claimed in claim 6, characterized in that the parking location is provided with liquid discharge means or with a liquid-absorbing layer.

8. Device as claimed in claim 5, characterized in that in the second mode each valve is opened at least every hour for the predetermined time.

9. Device as claimed in claim 8, characterized in that in the second mode each valve is opened at least every hour for at least one second.

10. Device as claimed in any of the claims 5-9, characterized in that the device is provided with an emergency power supply.