GB2030183A - Wet heat treatment of textiles - Google Patents

Abstract

Textiles are continuously wet heat treated in a high pressure steamer, in which the textile is transported through the steamer under no tension and supported in a series of vertical loops by guide means arranged so that only one surface of the looped textile material contacts the guide means. The guide means may be an endless belt (Figure 1) passing around a plurality of guide rolls provided alternately in the upper and lower parts of the steamer body so as to follow a zigzag path. Alternatively (Figure 2) the textile may be transported within the steamer by passage over a plurality of guide rolls in the upper part of the steamer body so that the textile hangs between the rolls in a series of loops. <IMAGE>

Description

SPECIFICATION Wet heat treatment of textiles This invention relates to the wet heat treatment of textiles, and is particularly concerned with continuous treatment of elongate textile products such as cloths, belts, tapes and fasteners under substantially no tension using a high temperature and high pressure steamer. Textile processing steps such as dyeing, scouring, bleaching, felting and weight reduction can be effectively carried out in such steamers.

The processing (for example, dyeing) of elongate textile products such as cloth lengths and belts is conventionally carried out discontinuously by a batch process but a discontinuous process has various drawbacks in that it is not suitable for mass production, it involves high consumption of heat energy and dyes and, moreover, the waste liquid can cause pollution problems.

In an attempt to overcome these drawbacks, processes and apparatuses have been proposed for subjecting textile products to continuous wet heat treatment in a high temperature and high pressure steamer. Although such continuous wet heat treatment has various merits, sufficient time is needed for the wet heat treatment to effect dyeing and other operations in a high pressure steamer, so that it is usual to transport the textile product on a continuous zigzag path by guiding it around a plurality of guide rolls to prolong the time that the textile product spends with the steamer.

In transporting a long textile product continuously through a high pressure steamer using a plurality of guide rolls, it is inevitable that the textile product is placed under tension, and this causes problems in that the textile product is stretched and deformed, and the meshes thereof are distorted. This is a particular problem when treating an easily expandable thin cloth, or knitted goods. Moreover, in colour developing a printed cloth or in dyeing textile products such as fasteners which have numerous projecting convex teeth, special difficulties are encountered when the printed surface or the teeth of the fastener directly contact the guide rolls in the steamer; the printed surface may be stained and spoiled or the dye adhering to the teeth is removed, and consequently in each case the processing is unsatisfactory.

Accordingly, in one aspect this invention provides a process for continuously wet heat treating a textile product in a high pressure steamer, in which the textile product is transported through the steamer under substantially no tension and supported in a series of substantially vertical loops by guide means arranged so that only one surface of the looped textile material contacts the guide means.

According to one embodiment of the invention there is provided a process for continuously wet heat treating a textile product in a high pressure steamer, in which the textile product is transported through the steamer under substantially no tension and supported in a series of substantially vertical loops by an endless guide belt passing around a plurality of guide rolls alternately in the upper and the lower portions of the steamer body, so that the guide belt contacts one face only of the textile product.

In an alternative embodiment the process of the invention there is provided a process for continuously wet heat treating a textile product in a high pressure steamer, which comprises transporting the textile product through the steamer under substantially no tension and supporting the textile product on a plurality of guide rolls provided in the upper part of the steamer body so that the textile product hangs between the guide rolls in a series of substantially vertical loops.

The invention also provides apparatus for use in continuously wet heat treating a textile product in a high pressure steamer according to the processes of the invention. In one embodiment the apparatus comprises a high pressure steamer body provided with an endless guide belt for supporting a textile product under substantially no tension in a series of substantially vertical loops, the guide belt passing around a plurality of guide rolls alternately in the upper and the lower parts of the steamer body so that the guide belt follows a zigzag path having substantially vertical runs, and a water tank adapted to supply water to the guide belt and positioned within the steamer body so that the guide belt passes therethrough.

An alternative embodiment of the apparatus of the invention comprises a high pressure steamer provided with an endless guide belt positioned within the steamer adjacent to the inlet for a textile product and adapted to lift the textile product entering the steamer body and transport the textile product towards a plurality of guide rolls provided in the upper part of the steamer body, which guide rolls are adapted to support the textile product by contacting one surface thereof so that the textile product hangs under substantially no tension as a series of substantially vertical loops, and a water tank adapted to supply water to the guide belt and positioned within the steamer body so that the guide belt passes therethrough.The guide rolls are advantageously provided with a plurality of upstanding pins on the surface of the rolls to prevent slip between the rolls and the textile product. Alternatively, suction may be used to prevent the textile product slipping relative to the rolls. Thus, each guide roll may comprise a non-rotatably mounted vacuum roll in the form of a tube adapted to be maintained with a reduced internal pressure (relative to the steamer body) and having one or more holes through the tube wall allowing communication of the reduced internal pressure to the surface of the tube, and a perforate drum rotatably mounted concentric with and around the vacuum roll. In use, the textile product contacts the perforate drum which rotates to allow the textile product to move over the guide roll.The textile product is sucked towards the perforate drum by the reduced pressure communicated from the vacuum tube and is prevented from slipping relative to the perforate drum.

The invention will now be described in detail, but only by way of illustration, with reference to the accompanying drawings, in which: Figure 1 shows schematically, in part crosssection, one embodiment of apparatus of the invention.

Figure 2 shows schematically, in part crosssection, a second embodiment of apparatus of the invention; and Figure 3 is a cross-section of a guide roll used in the apparatus of Figure 2.

Figure lisa side view of the apparatus of the invention for continuously wet heat treating a textile product in the form of a high pressure steamer comprising a high pressure steamer body 2 in which the textile product 1 (for example, a cloth length, belt or fastener) is processed in a high temperature and high pressure atmosphere of wet heat. The steamer body 2 is provided with an inlet 3 and an outlet 4 for the textile product 1, and the inlet 3 and the outlet 4 are provided respectively with an inlet sealing mechanism 5 and an outlet sealing mechanism 6 to allow passage of the textile product therethrough while preventing the leakage of the atmosphere in the steamer body 2.

Various types of the sealing mechanism for high pressure steamer bodies have been proposed, and any of these sealing mechanisms can be applied to the present invention. The structures of the sealing mechanisms 5 and 6 will not therefore be described further, since the choice of suitable mechanisms is believed to be within the competence of one skilled in the art.

A plurality of guide rolls 11, 11' are provided within the steamer body 2 in two series, one in the upper part (rolls 11) and one in the lower part (rolls 11') of the steamer body being equally spaced within these series in the transverse direction. The rolls are driven by a motor (not shown in the Figure), so that they in turn drive an endless guide belt 12 which is mounted around rolls 11, 11' so that it follows a zigzag path up and down within the steamer body 2 as shown in the Figure. The endless guide belt 12 mounted around the guide rolls 11, 11' is continuously circulated in the direction shown by the arrow in Figure 1. It is desirable that the guide belt 12 is heat resistant and capable of retaining a sufficient amount of water.For instance, the guide belt 12 may be formed from a cotton cloth, a polypropylene net, or a metal wire gauze.

The textile product 1 to be processed is supported by the endless guide belt 12 so that it forms loops under substantially no tension and is transported along a zigzag path through the high pressure steamer body 2. It is pointed out that the textile product 1 passes over rolls 11, but does not pass around rolls 11' so that it is not tensioned. Thus, the zigzag path followed by the textile product 1 is not the same as the zigzag path followed by the endless guide belt 12, although the two zigzag paths do coincide over a large part of their lengths.

Provided within the steamer body 2 is a water tank 7 and subsidiary water tanks 7', through which the guide belt 12 is circulated. The belt 12 is therefore immersed in water contained in tanks 7, 7' so that a sufficient amount of water is supplied thereto to obtain adequate adhesion between the guide belt 12 and the textile product, while the textile product is transported. Awater pipe 8 supplies water to the water tank 7; and an umbrella-type protecting plate is provided in the upper portion of the steamer body 2 above rolls 11 to protect the textile product 1 from water drops falling from the uppermost art of the steamer body.

A liquid tank 13 supplies a processing liquid such as a dye solution to the textile product 1, and before the textile product 1 enters the steamer it is passed through an intermediate drier 14. After leaving the steamer the textile product is passed through a washing tank 15 and dried in a drier 16. The devices 13 to 16 are not essential features of the invention and will not therefore be described in any detail.

Such devices are well known in the art and their selection is within the competence of the skilled worker.

Although not shown in the Figure, superheated steam is passed through the steamer body to maintain in the interior the desired atmosphere of wet heat at the desired temperature. Again this aspect of the steamer is well-known.

The wet heat treating of a textile product using the apparatus just described will be illustrated in respect of a dyeing operation.

By opening the steamer body 2, one end portion of an elongate textile product 1 such as a cloth, belt or fastener is passed successively through the various parts of the high pressure steamer to follow the path shown in Figure 1, and then the steamer body 2 is closed. The textile product rides freely on the guide belt 12 (in turn mounted on guide rolls 11,11') to form loops under substantially no tension in the zigzag arrangement shown. When the textile product is both long and thin as in the cases of a belt or fastener, it is possible to treat a plurality of such textile products en bloc by passing them in parallel through the steamer.

The interior of the steamer is maintained with an atmosphere of wet heat at a suitable temperature for instance, 1 500C to 1 60 C - by passing superheated steam therethrough.

By circulating the guide belt 12 in the direction of the arrow as shown in the Figure by driving guide rolls 11, 11', the textile product 1, riding on the guide belt 12, forms loops and is transported along a zigzag path through the steamer under substantially no tension. The textile product 1 is soaked with a dye solution in the liquid tank 13 and half dried by passage through the intermediate drier 14 before it is brought into the steamer body 2 through the inlet 3 provided with the inlet sealing mechanism 5.

In the steamer body 2, the guide belt 12 is immersed successively in water tanks 7 and 7', and the wetted guide belt adheres closely to the textile product so that the textile product 1 is transported smoothly on the guide belt 12 under substantially no tension without the shape of the loop changing.

After wet heat treatment in the steamer body 2, the textile product 1 is withdrawn therefrom through the outlet 4 provided with the outlet sealing mechanism 6, then washed in the washing tank 15 and finally dried in the drier 16.

In this way, the textile product previously soaked with a dye solution is continuously wet heat treated in the steamer body under substantially no tension, so enhancing the effect of the wet heat treatment.

Furthermore, in the apparatus described only one of the surfaces of the textile product contacts with the guide belt in the steamer body, leaving the other surface untouched by the guide belt. Therefore, this apparatus is particularly suitable for operations such as colour printing in which only one surface is printed as the printed surface is then untouched by the guide belt and undesirable staining and spoiling of that surface can then be avoided. A fastener can also be carefully dyed by setting the fastener so that the teeth thereof do not contact with the guide belt, and in this way loss of dye from the teeth can be prevented.

Figure 2 is a side view of another example of the apparatus of the invention for use in wet heat treating a textile product according to the invention.

In the Figure, where components are the same as in the embodiment of Figure 1 they are given the same reference numeral, and these components may be as described herein before. Superheated steam is again passed through the steamer body to maintain the interior thereof in an atmosphere of wet heat.

A plurality of guide rolls 21 are provided in the upper part of the steamer body 2 spaced at equal intervals in the transverse direction and are driven by a motor (not shown in the Figure) to transport the textile product 1 continuously through the steamer body 2. The textile product 1 hangs from the rolls 21 in a series of loops, so that in passing through the steamer the textile product is under substantially no tension (other than that resulting from the weight of the loops of textile) and yet follows a zigzag path. To prevent slip between the rolls 21 and the textile product, the rolls may be specially adapted -for instance, the roll may have numerous closely spaced pins outwardly projecting from the surface thereof to increase the frictional coefficient of the surface.

Alternatively, the guide roll 21 may employ a vacuum to increase adhesion of the textile product thereto as shown in Figure 3. In the roll shown in Figure 3, vacuum holes 24 are provided in the upper portion of a fixed vacuum tube 25, and a mesh drum 26 is concentrically and rotatably mounted around the vacuum tube 25.

A guide belt 22 provided at the inlet 3 of the steamer body 2 is supported for continuous circulation around guide rolls 23 and 23' provided in the lower part of the steamer body and the first of the textile product guide rolls 21. The textile product 1 descending from the textile inlet 3 is lifted by the belt 22 and transferred to the textile product guide rolls 21. The guide belt 22 is desirably heat resistant and capable of retaining a sufficient amount of water to enhance adhesion between the belt 22 and the textile product. The guide belt 22 passes through a water tank 7 from which it takes up water to achieve this desired adhesion.

The embodiment of Figure 2 may also employ such devices as a liquid tank 13, an intermediate drier 14, a washing tank 15 and a drier 16 as described in relation to Figure 1.

The wet heat treatment of a textile product using the apparatus of Figure 2 employs substantially the same techniques as described in relation to the embodiment of Figure 1. The textile product 1 descends continuously at a uniform rate from the textile product inlet 3, and is pulled up by means of the guide belt 22 and fed to the guide rolls 21. The textile product 1 hangs from the guide rolls 21 to form loops and is thus transported along a zigzag path through the steamer body 2 under substantially no tension by driving the guide rolls 23 and 23' at a uniform rate. The apparatus is thus eminently suitable for wet heat treatment of textile products.

A plurality of guide rolls provided at equal intervals as in this embodiment is particularly advantageous in that this arrangement may be used to treat a textile product in the form of loops of a definite length notwithstanding its simple structure, and is remarkablytroublefree over long periods. The arrangement can also be applied to the transport of textile products under substantially no tension in an apparatus operating at ordinary (room) tempera tures.

The term "high pressure steamer" as used herein means a closed vessel in which it is possible to maintain temperatures in excess of the boiling point of water and high relative humidity at superatmospheric pressures, and references herein to "high temperature", "high pressure" and "wet heat" are to be construed accordingly.

Claims (10)

1. A process for continuously wet heat treating a textile product in a high pressure steamer, in which the textile product is transported through the steamer under substantially no tension and supported in a series of substantially vertical loops by guide means arranged so that only one surface of the looped textile material contacts the guide means.

2. A process for continuously wet heat treating a textile product in a high pressure steamer, in which the textile product is transported through the steamer under substantially no tension and supported in a series of substantially vertical loops by an endless guide belt passing around a plurality of guide rolls alternately in the upper and the lower portions of the steamer body so that the guide belt contacts one face only of the textile product.

3. A process for continuously wet heat treating a textile product in a high pressure steamer, which comprises transporting the textile product through the steamer under substantially no tension and supporting the textile product on a plurality of guide rolls provided in the upper part of the steamer body so that the textile product hangs between the guide rolls in a series of substantially vertical loops.

4. A process for continuously wet heat treating a textile product substantially as described herein with reference to and as illustrated in either of Figures 1 and 2.

5. An apparatus for use in continuously wet heat treating a textile product, which apparatus comprises a high pressure steamer provided with an endless guide belt adapted to transport a textile product through the steamer under substantially no tension in a series of substantially vertical loops, the guide belt passing around a plurality of guide rolls alternately in the upper and the lower parts of the steamer body so that the guide belt follows a zigzag path having substantially vertical runs, and a water bath adapted to supply water to the guide belt and positioned within the steamer body so that the guide belt passes therethrough.

6. An apparatus as claimed in Claim 5 substantially as described herein with reference to and as illustrated in Figure 1 of the accompanying drawings.

7. An apparatus for use in continuously wet heat treating a textile product, which apparatus comprises a high pressure steamer provided with an endless guide belt positioned within the steamer adjacent the inlet for a textile product and adapted to lift the textile product entering the steamer body and transport the textile product towards a plurality of guide rolls provided in the upper part of the steamer body, which guide rolls are adapted to transport the textile product through the steamer by contacting one surface of the textile product so that the textile product hangs under substantially no tension as a series of substantially vertical loops, and a water tank adapted to supply water to the guide belt and positioned within the steamer body so that the guide belt passes therethrough.

8. An apparatus as claimed in Claim 7, in which one or more of the guide rolls are provided with a plurality of pins upstanding from the surface thereof.

9. An apparatus as claimed in Claim 7, in which one or more of the guide rolls comprise a nonrotatably mounted vacuum tube adapted to be maintained with a reduced internal pressure (relative to the steamer body) and having one or more holes through the tube wall, and a perforate drum rotatably mounted concentrically with and around the vacuum tube.

10. An apparatus as claimed in Claim 7, and substantially as described herein with reference to and as illustrated in Figure 2 or in Figure 3.