EP0535288B1 - Method and apparatus for crimping of fabrics - Google Patents

Abstract

The material web (3) to be treated is laid in the loose state onto an endlessly rotating air-permeable conveyor band (13). It is thereafter moved violently to and fro alternately in portions, on the one hand by means of blowing nozzles (16) which are directed towards the material-web supporting surface of the said conveyor band, until they bear against this material-web supporting surface (13), and on the other hand, from the other side of the material web, by means of blowing nozzles (17) which are directed through the conveyor band (13) away from this supporting surface towards an air-permeable material-web compression surface spaced from the said supporting surface and limiting a transport channel (14), until the said blowing nozzles respectively bear against the said material-web compression surface, the said material web (3) thereby being dried. <IMAGE>

Description

The invention relates to a method for the continuous shrinking of textile fabrics according to the preamble of claim 1 and a device for carrying out this method according to the preamble of claim 10.

From DE-A 2 918 833 a generic device for shrinking textile knitted fabrics has become known. It is provided with opposing hot air chambers with heating air nozzles facing each other, which form an elongated flow channel for the knitted fabric. An air-permeable transport cloth led through the flow channel serves as a support for the knitted fabric. The opposite nozzle tubes are offset from one another and spaces are formed between the nozzle tubes, so that the hot air blowing out from one row of nozzles can escape through the spaces between the other row of nozzles. Due to the continuous, alternating air currents impinging on the knitted fabric, the knitted fabric is moved in a wave-like manner, drying and shrinking in the process.

When finishing textiles, in particular plush and terry cloth, it would often be desirable to obtain a product with even less residual shrinkage potential.

The object of the present invention is in particular to create a method by means of which this can be achieved.

This task is carried out in a method of the type mentioned at the beginning Art solved according to the invention according to claim 1.

Advantageous further developments of the method according to the invention are the subject of claims 2 to 9.

The invention further relates to a device for carrying out the method according to the invention as claimed in claim 10.

Appropriate further developments of the device according to claim 10 are the subject of claims 11 to 20.

Fig.1

einen Längsabschnitt durch eine beispielsweise Ausführungsform einer erfindungsgemässen Vorrichtung;

Fig.2

in vergrössertem Massstab einen Bauteil der in Fig. 1 dargestellten Vorrichtung;

Fig.3

in vergrössertem Massstab einen Längsschnitt durch den Führungs- und Beschleunigungskanal des in Fig. 2 dargestellten Bauteiles; und

Fig.4

den Ausschnitt A in Fig. 1 in vergrössertem Massstab.

The invention is explained below with reference to the drawing, for example. It shows

Fig. 1

a longitudinal section through an example embodiment of a device according to the invention;

Fig. 2

on an enlarged scale a component of the device shown in Fig. 1;

Fig. 3

on an enlarged scale, a longitudinal section through the guide and acceleration channel of the component shown in FIG. 2; and

Fig. 4

the section A in Fig. 1 on an enlarged scale.

As can be seen in particular from FIGS. 1 and 2, the device shown, after the two shrink dryers 9, 9 ', has two approximately U-shaped web store 1 and 2 for loosely accommodating one web section 3' and 3 "and one between these two web stores 1,2 arranged, connecting these and in its longitudinal direction on its two end faces delimited by a web impact surface 4 and 4 'each web guide and acceleration channel 5.

Pneumatic conveying means 6 and 6 'connected to the latter 5, in the two opposite longitudinal directions of which can be switched in effect, serve for the alternating conveyance of a web section of the web 3 to be treated in the opposite longitudinal directions 7,7' (FIG. 3) of the guide and acceleration channel 5 against the respective web impact surface 4 or 4 ′ arranged at the end and from this into the respectively assigned web store 2 or 1 arranged below the latter.

This component 8 can also be omitted or, as in the illustrated embodiment, e.g. can be combined with two shrink dryers 9 and 9 'arranged on the inlet side, the latter also serving as a feed arrangement 9' for the continuous feed of the web 3 to be treated into the first web store 1.

To control the conveying direction of the pneumatic conveying means 6, 6 ', optical scanning means 10 and 10' are provided in the lower deflection areas of the two web stores 1 and 2 to determine the degree of filling of the two web stores 1 and 2 with sections 3 'and 3 "of the web to be treated 3 to scan.

In order to achieve the opposite directions of conveyance of the goods 3 to be treated, the pneumatic conveying means assigned to the acceleration channel 5 are like 3, divided into two pneumatic conveying means groups (blowing nozzles) 6 and 6 'acting in opposite directions of the acceleration channel 5. These two blow nozzle groups 6 and 6 'are connected to one another in alternating fashion, for example via a flip-flop switchover element 11 (see FIG. 2) which operates on the principle of the Coanda effect (see FIG. 2). Depending on the material, the air used can have a temperature in the range of, for example, approximately 80 to 200 ° C.

As can be seen in particular from FIGS. 1 and 4, the two shrink driers 9 and 9 'are for receiving and transporting the goods 3 to be treated through the shrink driers and for delivering the goods 3 emerging from the shrink dryer 9' into the first web store 1 provided with a common, continuously drivable, air-permeable, endlessly rotating conveyor belt 13, which with a conveying speed of about 40 to 50m / min. is driven. An upper, stationary and air-permeable boundary wall 15 is arranged in the latter to form a transport channel 14 which is limited in the vertical direction at the top and bottom and serves to receive and support the goods 3 to be treated 3 and which is penetrated by blow nozzles 16 which are directed downwards and run transversely to the web conveying direction is.

In order to achieve the lowest possible residual shrinkage potential, the upper, air-permeable perforated boundary wall 15 has at least approximately the shape of a shed roof in a vertical section running longitudinally to the web transport direction (see in particular FIG. 4), with between two mutually adjacent angular sections 15 ', 15 '', 15 '''etc. each facing downwards Blowing nozzle 16 is arranged, which are simultaneously designed to support the associated sections 15 ', 15'',15''' etc.

For optimal individual adaptation of the flow conditions to the tissue to be dried, the distance a between the upper blowing nozzles 16 and thus the upper boundary wall 15 supported on them is opposite the bearing surface b of the conveyor belt 13, e.g. adjustable in a range from about 10 to 80mm.

Viewed in a horizontal plane, two lower blowing nozzles 17, which support the upper run of the conveyor belt 13 and are directed upward into the associated angular sections 15 ′, 15 ″, 15 ″ ″ etc. of the upper boundary wall 15, are provided between two upper blowing nozzles 16 .

The lateral horizontal spacing of the upper blowing nozzles 16 is approximately 190 mm and that of the lower blowing nozzles 17 is approximately 95 mm.

The upper and the lower, blowing air supplying blow nozzles 16 and 17 are each divided into groups and can be connected alternately and in a pulsating manner about 2 times per second via switching means 18 to a hot air source 19. The subdivision and switchover is designed such that each active blow nozzle group is opposed by an inactive blow nozzle group and the blow nozzle groups immediately adjacent to the side of an active blow nozzle group are inactive. In this way it is ensured that, alternately, a section of the goods 3 passing through a shrink dryer 9 or 9 'is always pressed down by upper blow nozzles 16 onto the bearing surface b of the endlessly rotating conveyor belt 13 and thus inevitably is conveyed together with this through the corresponding shrink dryer 9 or 9 '.

The pulsating and alternating loading of the goods moving through the shrink dryer from below and from above with hot air blows, the resulting fluttering movement of the goods 3 in the vertical direction of the transport channel 14 and the simultaneous compression of the passing goods 3 in the approximately angular, air-permeable sections 15 ', 15' ', 15' '' etc. of the upper boundary wall 15 results in an extremely effective drying, shrinking and relaxing of the goods 3 passing through.

The pretreated fabric 3 emerging continuously from the second shrink dryer 9 'reaches the first fabric web storage 1 with a residual moisture content of preferably less than 20%, but at least 6%, and is stored there in sections in a loose state. From the latter, the web 3 is, as already mentioned, removed pneumatically in sections with the aid of the nozzle arrangement 6, accelerated in the acceleration channel 5 to a speed of approximately 600 to 800 m / min, depending on the type of goods, and at the end of this acceleration section 5 hurled against the grid-like and arched impact surface 4 and compressed there. The lattice-like and thus air-permeable design of the impact surface 4 makes it impossible to form an air cushion that dampens the impact between the impacting web section and the impact surface 4.

The same process is then carried out with the aid of the nozzle arrangement 6 'acting in the opposite conveying action second web store 2 repeated over the baffle 4 'in the second web store 1, but with a lower web length feed, these back and forth movements repeated alternately, and the feed difference occurring between these back and forth web length sections continuously from the second web store 2 in the then removed second shrink dryer 10 for final treatment. The same treatment steps are then repeated in a subsequent, analog component 8 '.

In order to be able to easily accelerate both light and heavy goods through the acceleration channel 5, the two pneumatic conveying means groups 6, 6 'on both sides of the acceleration channel 5 are mutually offset by the distance from one another by the angle y directed obliquely to the web transport plane, which means that the wave through the acceleration channel 5 against the impact surface 4 to be transported 3 in the area of the active blowing nozzle group 6 (FIG. 3 right), whereby the transport air in this area attacks the goods 3 to be transported extremely efficiently and a very good transport effect on it.

Since the two blow nozzle groups 6, 6 ', viewed in the direction of transport, are arranged in the respective end region of the acceleration channel 5, any upsetting and jamming of the goods 3 during transport through the acceleration channel 5 becomes perfect as a result of the tensile force acting on the goods 3 to be transported in this way avoided.

Depending on the type of goods 3, it may also be expedient to supply saturated steam to the nozzle arrangement 6 and / or 6 'when they are used, in order to additionally achieve the passing goods 3 before they enter the second shrink dryer 9' in order to achieve an even stronger and more uniform shrinkage exposed to saturated steam treatment.

Depending on the type of goods 3 and the desired degree of treatment, it may be advantageous in some circumstances to connect one or more shrink dryers analogous to the last component 8 ′ to the shrink dryers 9 and 9 ′.

Claims (21)

1. A process for the continuous shrinkage of textile fabrics, in particular of knitted fabrics, wherein the fabric web (3) to be treated is laid loose on a continuously revolving, air-permeable conveyor belt (13) and is then dried by being jerked to and fro in a conveyor channel (14) by means of blast nozzles (16, 17) disposed opposite one another with reference to the passing fabric web (3) and oriented towards the fabric web surface (6), characterised in that mutually opposite blast nozzles arranged in groups are switched on and off alternately, and in that the fabric web is brought into abutment with an air-permeable fabric web compression face (15) by means of the blast nozzles (17) acting through the conveyor belt.
2. Process according to claim 1, characterised in that the switching frequency of mutually opposite blast nozzle groups is in the range of 1 to 6, preferably 1 to 3 revolutions per second, and the fabric web forward feed speed is in the range of 10 to 80, preferably 30 to 50 m/sec.
3. Process according to either of claims 1 or 2, characterised in that before and/or after the stages defined in claim 1, the fabric web (3) to be treated is fed continuously to a first fabric web store (1) where it is stored in lengths, is removed therefrom by pneumatic conveying, and is hurled against a first baffle face (4) so as to be compressed, whereupon the fabric (3) thus compressed is fed to a second fabric web store (2) where it is stored in lengths, and then the same process is carried out in the reverse direction of conveying from the second fabric web store (2) against a second baffle face (4'), and then into the first fabric web store (1), but with a slower forward feed, and these reciprocating motions are repeated alternately, and the forward feed differential between these lengths of fabric web being passed to and fro is continuously derived from the second fabric web store (2).
4. Process according to claim 3, characterised in that the product (3) taken from the second fabric web store (2) is then subjected to the same procedure as in the characterising part of claim 3 at least once more.
5. Process according to claim 3 or 4, characterised in that the fabric web (3) to be treated is hurled against the respective baffle face (4, 4') at a speed in the range of 400 to 1000 m/min, preferably at a speed in the range of 600 to 800 m/min.
6. Process according to one of claims 3 to 5, characterised in that the product (3) to be treated is temporarily stored in lengths in at least approximately U-shaped fabric web stores (1, 2), wherein the product (3) to be treated and temporarily stored is introduced continuously into one of the arms (1') of the first U-shaped fabric web store (1), is continuously alternately removed in lengths from the other, second arm (1"), is fed back into same again in the opposite direction of conveying, being removed therefrom and so on, the treated product (3) being inserted continuously alternately and in lengths into the one arm (2') of the second fabric web store (2), being removed therefrom in the opposite conveying direction, fed back into same, and so on, and the finished goods (3) are removed continuously from the other, second arm (2") of the second U-shaped fabric web store (2).
7. Process according to one of claims 3 to 6, characterised in that the pneumatic conveying of the fabric web (3) to be treated between the two baffle faces (4, 4') is effected by means of blast nozzles disposed on either side of the fabric web and laterally staggered relative to one another, oriented obliquely to the plane of transport of the fabric web and disposed directly in front of the respective baffle faces (4, 4') to be acted on (Fig. 3).
8. Process according to one of claims 3 to 7, characterised in that the regions of the product to be treated entering the first fabric web store for the first time have a residual moisture content of at most 35%, preferably less than 20%, but at least 6%.
9. Process according to one of claims 3 to 8, characterised in that the goods to be treated are subjected to a saturated steam treatment while being conveyed from one fabric web store (1, 2) to the baffle face (4 and 4' respectively) acting in series.
10. Apparatus for carrying out the process according to claim 1, comprising a continuously drivable, air-permeable, continuously revolving conveyor belt (13) and a conveyor channel (14) defining the upper strand of the conveyor belt above and below, the conveyor belt forming a fabric web support face (b) for the fabric web and wherein, on both sides of the conveyor channel, blast nozzles (16, 17) are provided, which are staggered opposite one another and are oriented towards the fabric web support face (b), characterised in that the upper defining wall of the conveyor channel is formed as an air-permeable fabric web compression face (15), which is penetrated by downwardly oriented blast nozzles (16) and which has, in a vertical section (Fig. 4) extending longitudinally to the conveying direction of the product, at least approximately a corrugated or shed roof form, preferably in the form of consecutive wall sections (15, 15', 15" etc.) extending transverse to the direction of travel and having an at least approximately corner-shaped cross-section, between which wall sections a respective downwardly oriented blast nozzle (16) is disposed.
11. Apparatus according to claim 10, characterised in that the upper and lower blast nozzles (16, 17) are divided into groups and are connected via switching means (18) to a blower (19), this division and switching being so contrived that each active blast nozzle group (16) is associated with an opposite inactive blast nozzle group (17), and the blast nozzle group or optionally groups immediately laterally adjacent to an active blast nozzle group is or are inactive, and the switching of the respective blast nozzle groups between the active and inactive states is effected in a pulsating manner.
12. Apparatus according to either of claims 10 or 11, characterised in that the vertical distance (a) between the discharge apertures of the upper and lower blast nozzles (16, 17) is adjustable, preferably in a range of approximately 10 to 80 mm.
13. Apparatus according to one of claims 10 to 12, characterised in that the lateral distance between the upper blast nozzles (16) is in the range of 140 to 220 mm, preferably at least approximately 185 mm, and the lateral distance between the lower blast nozzles (17) is in the range of 70 to 110 mm, preferably at least approximately 95 mm.
14. Apparatus according to claim 10 for carrying out the process according to claim 3, characterised in that it comprises two fabric web stores (1, 2) for the loose storage of a respective fabric web length, a fabric web guiding and accelerating channel (5) disposed between these two fabric web stores (1, 2) so as to join them together and defined in its longitudinal direction at both end faces by a respective fabric web baffle face (4, 4'), pneumatic conveying means (6, 6') connected to said accelerating channel and capable of being set in action alternately in the two opposite longitudinal directions thereof for the alternating conveying of a fabric web length in the two opposite longitudinal directions (7, 7') of the guiding and accelerating channel (5) towards the respective fabric web baffle face (4, 4') at respective end faces and thence into the respectively associated fabric web store (2, 1), a feed device (3, 3') for continuously feeding the fabric web to be treated into the first fabric web store (1), and a discharge device (3, 3") for continuously discharging the treated fabric web from the second fabric web store (2).
15. Apparatus according to claim 14, characterised in that the two fabric web stores (1, 2) are at least approximately U-shaped and are preferably provided in their interior with optical sensors (10, 10') for detecting the level to which the stores are filled with lengths of the fabric web (3) to be treated, wherein the one arm (1') of the U-shaped first fabric web store (1) is formed for continuously temporarily receiving lengths of the product (3) to be treated and the other arm (1") is formed for continuously, alternately removing lengths of the product (3), returning the product in the opposite direction of conveying, removing it again, and so on, and the one arm (2') of the U-shaped second fabric web store (2) is formed for continuously, alternately receiving the lengths of fabric web, removing them in the opposite direction, receiving them again and so on, and the other arm (2") of the second fabric web store (2) is formed for continuously removing the treated product (3).
16. Apparatus according to claim 14 or 15, characterised in that the pneumatic conveying means associated with the accelerating channel (5) is divided into two groups (6, 6') of pneumatic conveying means acting in two opposite directions (7, 7') of the accelerating channel (5), and these two groups (6, 6') are connected to a compressed air source (12), separately from one another and alternatingly via a switching element (11) operating preferably according to the principle of the coanda effect, these two groups having on either side of the accelerating channel (5) blast nozzles (6, 6') oriented obliquely to the fabric web conveying plane and disposed alternately and laterally staggered with respect to one another and, viewed in their respective conveying direction, are disposed in the end region of the accelerating channel (5).
17. Apparatus according to either of claims 15 or 16, characterised in that the feed and discharge devices (3', 3") are so contrived as to be capable of operating independently of one another in respect of their conveying speed.
18. Apparatus according to one of claims 14 to 17, characterised in that the fabric web baffle faces (4, 4') have a grid structure and are formed for receiving in a compressing manner a fabric web length which becomes bent outwards and downwards as it is hurled against the baffle faces.
19. Apparatus according to claim 14, characterised in that a plurality of arrangements according to the characterising part of claim 14 are connected in series.
20. Apparatus according to one of claims 14 to 19, characterised in that at least one shrink dryer (9) is connected upstream of the first fabric web store (1) and/or at least one shrink dryer (9) is connected in series to the last fabric web store (2).
21. Application of the process according to claim 1 for treating pile and terry fabrics.

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