DESCRIPTION

TECHNICAL FIELD

The present invention relates to textile ennobling treatments and more in particular to a treatment line for finishing fabrics, in particular knitted fabrics, preferably but not exclusively in open width. The invention also relates to a treatment method having the same aims.

State of the art

Finishing of cotton or cellulose fiber in general, but also of synthetic fiber knits, must be carried out with the objective of complementing the dimensional stability of the fabric, which is important for manufacture of the finished garment.

At the state of the art, methods for continuous and open width finishing of knitted fabric produce a product with decidedly of hand, i.e. a fabric that does not have an effect of thickness of the knit. To obtain a knitted fabric with dimensional stability and a soft and voluminous hand of acceptable quality, there is currently used a discontinuous process in rope form which takes place in drums or tumblers of the same type as those used in the launderette.

This type of finish has high costs due to high consumptions and manual labor, as each bolt of fabric must be inserted in the machine, treated and subsequently extracted from the machine.

All these steps imply a high dissipation of energy and long, and consequently costly, manual operations, which must also be carried out by skilled workers. Due to the discontinuous nature of the process it is not possible to obtain adequate uniformity of the final finishing effects on the various bolts.

There are also continuous treatments in rope form, which however have some problems caused by the generation of creases and knots on the fabric. Moreover, as also occurs in discontinuous treatments in rope form, it is necessary to subject the treated fabric to a process to open out the rope using special machines in order to return the fabric to its spread out condition. Continuous treatments in rope form are also extremely expensive from the viewpoint of energy consumption. There are treatment machines that provide for the insertion of fabric in chambers in which the fabric is vibrated in order to enable shrinkage of the knit. A machine of this type is shown, for example, in the patent WO2010/064130. However, the shrinkage and increase in volume of the fabric is not satisfactory.

There are also machines that provide for passage of the fabric in a chamber in which the fabric is made to pass through tanks of water and through vibrating rollers onto which water is sprayed, so that wet steam is present in the chamber; this machine, which enables expansion of the fabric, is shown in the patent JP1314777. Also in this case, the shrinkage and increase in the volume of the fabric is not satisfactory.

Object and summary of the invention

The object of the present invention is that of providing a line for the continuous treatment of a fabric, particularly of knitted type, which makes it possible to obtain optimal shrinkage and swelling or volume of said fabric.

Another important object of the present invention is that of producing a line for continuous and open width treatment of a fabric, particularly of knitted type, which is particularly compact.

Yet another important object of the present invention is that of providing a method for continuous and open width treatment of a continuous fabric, preferably of knitted type, which makes it possible to obtain optimal shrinkage and swelling or volume of said fabric.

These and other objects, which will be more apparent below, are achieved with a line and a method for continuous and open width treatment of a fabric according to the appended claim 1 and the appended independent claim 42.

Brief description of the drawings

Further features and advantages of the invention will be more apparent from the description of three preferred but non-exclusive embodiments thereof, illustrated by way of non-limiting example in the accompanying drawings, wherein:

Fig. 1 is a schematic view of a first embodiment of treatment line according to the invention; Fig. 2 is a schematic view of a second embodiment of treatment line according to the invention;

Fig. 3 is a schematic view of a third embodiment of treatment line according to the invention;

Fig. 4 is a schematic view of a fourth embodiment of treatment line according to the invention;

Fig. 5 is a schematic view of a fifth embodiment of treatment line according to the invention;

Fig. 6 is a schematic view of a sixth embodiment of treatment line according to the invention;

Fig. 7 is a schematic view of a seventh embodiment of treatment line according to the invention;

Fig. 8 is a schematic view of an eighth embodiment of treatment line according to the invention;

Fig. 9 is a detail of a roller for handling the fabric between two supports according to the method of the embodiments of Figs. 5, 7 or 8;

Fig. 10 is a detail of a roller for moving the fabric between two supports according to the method of the embodiments of Figs. 6 to 8;

Fig. 1 1 is a schematic view of a fabric accumulation support highlighting the vibration means of the support according to one or more embodiments of the invention;

Detailed description of an embodiment of the invention

With reference to the aforesaid figures, in the description below the same numbers will refer, in different embodiments, to substantially corresponding parts.

Fig. 1 shows a first embodiment of textile ennobling treatment line according to the invention, indicated as a whole with 10. This line treats knitted fabric in a continuous bolt, preferably spread out in width. The continuous bolt can be open or tubular and is indicated with T.

The heart of the line is a chamber 11 into which the fabric is fed and from which the fabric is extracted. According to the invention, in this chamber 1 1 the fabric is subjected to steaming and simultaneous vibration, thereby enabling optimal shrinkage of the knitted fabric and a simultaneous increase in the volume of the fabric, i.e. a swelling of the fabric, as better described below.

Preferably, upstream of the steaming and vibration chamber 11 , there are present preheating means 12 for the fabric, such as a preheating chamber 13 in which there are present a battery 14 for heating the air (of known type, in practice a heat exchanger) preferably arranged on the bottom of the chamber, and fan means 15 that pick up the hot air adjacent to the battery 14 and reintroduce it preferably into the top part of the chamber.

In the preheating chamber 13 there are present rollers for guiding and moving the fabric T, in which the fabric is arranged in loose folds T1.

At the inlet 13A of the preheating chamber 13 there is preferably arranged a centering-spreading unit 16, of known type, such as a roller with symmetrical involutes with respect to the centerline thereof, which cause correct positioning, with respect to the axis of the roller and spreading out, with respect to the height of the bolt T, of the fabric.

Preferably, from the outlet 13B of the preheating chamber, the fabric T enters the steaming and vibration chamber 1 1 directly, through the inlet 1 1A, positioned in the top part of said chamber.

In the steaming and vibration chamber 11 there is arranged a plurality of supports 18 for accumulation of the fabric, for example arranged in folds on each support. On these supports the fabric is exposed to steam.

Preferably, the supports 18 are arranged at different heights from one another, for example superimposed on one another, preferably to form a column of superimposed supports through which the fabric T travels.

More in particular, the supports 18 have a feed zone 18A to the support and a pick up zone 18B from the support, so that between said zones 18A and 18B there is defined the accumulation zone of the folds of fabric.

In the example being described, the fabric T therefore moves in cascade from the top to the bottom with a "zigzag" trend, preferably with the pick up zone 18B of a top support approximately superimposed on the feed zone 18A of a bottom support. The movement means of the fabric in the chamber 1 1 preferably comprise drive rollers 19 arranged over the pick up zones 18B of the supports 18, in practice pick up rollers. For example, a first drive roller 19' (in practice a feed roller) is arranged over the feed zone 18A of the top support 18', i.e. the first support through which the fabric travels, and drive rollers 19 are arranged over the pick up zones 8B of all the supports 8, so that the fabric is picked up from the pick up zone 18A of one support 18, driven upward on the drive roller 19 above and, by means of partial winding thereon, the direction of movement of the fabric is reversed causing it to fall back toward the feed zone 18A of the support 18 below, aided by an optional chute or containing partition 20. In practice, the drive (pick up) roller 19 is arranged both over the pick up zone of one support and over the feed zone of the support below, with the part of the roller 19 destined for descent of the fabric which can be superimposed on the bottom support but not on the top support. It is understood that in other embodiments, these drive rollers can also not be superimposed on the pick up/feed zones. These rollers will preferably be at least partly at a greater height with respect to the pick up/feed zones, but can also be positioned laterally to these zones.

The pick up roller 19" relating to the bottom support 18" pulls the fabric T, through the outlet 1 1 B, out of the chamber 1 1 , arranging it on a conveyor belt 21 or transfer hopper that carries the fabric simply resting thereon, without any substantial pulling or tension on the fabric, toward an optional zone for any further treatment, such as a drying or storage station.

As explained below, the vibration of the supports also enables movement of the folds of fabric.

As stated, dry steam V is delivered into the chamber 1 1 , preferably at a temperature above 130°C and more preferably comprised between 140°C and 155°C and even more preferably approximately equal to 150°C.

The delivery means 22 of the steam in the chamber are preferably provided on the bottom part of the chamber 1 1 and comprise, for example, a distributor 23 with nozzles.

Advantageously, there are present means 24 for recirculation of the steam-air gaseous mixture inside the chamber 1 1 (air is present as the chamber is not sealed at the fabric inlet 1 1A and outlet 1 1 B of said chamber), which preferably operate continuously, in order to prevent water condensation and related stains on the fabric traveling through the chamber. For example, these recirculation means can comprise a duct 24A that draws in the gaseous mixture, for example in the top wall of the chamber 1 1 i.e. from the part opposite the delivery means 22, and returns it, for example in the lower part of the chamber. The recirculation means also comprise fan means 24B (of known type) operatively connected to, or arrange in, the duct 24A, which force the gaseous mixture along the duct 24A, and heating means, such as a heating battery 24C, which heat the mixture traveling through the duct 24A, preferably to a temperature greater than 130°C and more preferably comprised between 140°C and 155°C and even more preferably approximately equal to 150°C. Heating of the recirculation mixture prevents it from causing a decrease in the temperature of the mixture in the chamber, when it returns to the chamber, with consequent risk of water condensation and stains on the fabric. In case of need, means can be present to restore the air in the chamber, not indicated in the figures, optionally associated with heating means.

The supports 18 for the fabric T can have various shapes and can be formed by substantially rigid structures, such as tubs or trays, or also by flexible structures, such as mats or belts, appropriately constrained.

These structures can also be flat surfaces or have portions with flat surfaces; in general they can also be formed by, or comprise grill or mesh or perforated structures, or in any case such as to enable air and/or steam to pass through.

In the example being described, the supports 18 are formed by rigid trays with containing sides, with the bottom of the trays inclined or with the sides having an increasing height, with the highest zone of the sides in proximity of the pick up zone 18B of the fabric.

In general, according to the various embodiments of the invention, the supports 18 can have a fixed orientation in space. For example, they can be horizontal, or, more preferably, be inclined downward, i.e. with inclination that follows the downward movement of the fabric (for example the feed zone 18A is higher than the pick up zone 18B).

Advantageously, in this example, or in the other examples, the supports 18 can vary their inclination (for example from a horizontal position to a downwardly inclined position, and vice versa), preferably through rotation "f about an axis horizontal and transverse (preferably orthogonal) to the direction of movement of the fabric, in the example being described, for example, the axis X orthogonal to the plane of the sheet of the accompanying figures. In practice, these supports 18 are pivoted through this axis X to the chamber. The pivot X is defined in this example in proximity of one end of the related support 18 and preferably in the feed zone 18A. In other embodiments these pivots X can be arranged in an intermediate zone of the support 18, comprised between the zones 18A and 18B. The inclination of the supports 18 enables adjustment of the tension of the fabric being picked up from said support, or adjustment of the sliding of the folds of the fabric from the feed zone 18A to the pick up zone 18B according to need.

Naturally, to adjust the inclination there are present suitable means, not shown in the figures, but which are immediately understood by those skilled in the art.

In other embodiments, the supports can also be inclined upward (for example with the feed zone 18A lower than the pick up zone 18B).

To vibrate the fabric while it is being steamed, as mentioned above, there are present in the chamber 1 1 vibration means 25 adapted to transmit vibrations to the supports 18 and consequently to the fabric contained therein.

These means can be of various type, such as an eccentric element (for example an eccentric motorized connecting rod/crank system) connected to, or adapted to come into contact with, the support 18, transmitting thereto in a reciprocating manner a small thrust or movement from the top to the bottom, according to a given frequency, i.e. causing it to perform, for example, small oscillations about the pivot axis.

An example of these vibration means is given, for example, in Fig. 1 1 . These means comprise, for example, a connecting rod 25A pivoted at the ends respectively to the respective support 18 and to a motorized crank 25B. A bracket 18B which forms part of the support 18 (in practice, it sustains this latter on the structure of the chamber) supports the motor 25C that moves the connecting rod 25A. The tray 18A of the support 18 containing the fabric in folds is constrained by arms 18C to the bracket 18B which form an articulated parallelogram with the tray so as to enable the oscillation due to the connecting rod 25A.

It is possible to associate a torque measuring device, such as a torque meter (not shown in the figures), with the shaft of the crank 25, to measure the weight of the fabric contained on the support 18. In fact, the torsion applied by the load on the support to the crank of the vibrating system is a function of the weight on said support.

There are present means adapted to vary the frequency of the vibrations or oscillations, not indicated.

Therefore, when the fabric T is in the chamber 1 1 , it is immersed in an atmosphere of air and recirculated dry steam and is simultaneously vibrated while it is accumulated on the supports 18 (it must be noted that, according to the invention, the fabric in this steaming and vibration chamber is never immersed in water or liquids but simply surrounded by air and steam, and in particular, when it is on the supports, the fabric is exposed only to steam and air). Steaming with simultaneous vibration enables excellent shrinkage of the knitted fabric with a simultaneous optimal effect of increase in volume or swelling, thus providing the fabric with considerable dimensional stability and a soft and voluminous hand.

There are present means adapted to always maintain a same quantity of fabric substantially constant on the supports 18 and also to maintain the quantity of fabric processed in the steaming and vibration chamber constant in a predetermined period of time, taking into consideration shrinkage of the fabric and the consequent decrease in measurement during the treatment process.

For example, there can be present photocells 26, associated with electronic means for management and control of the line, arranged over the supports, preferably over the feed zone of the fabric, which act as sensors for detecting the folds of fabric. In practice, these photocells are means that assess the length of the fabric present in the support. An estimate of the length of the fabric corresponds to a certain density of crests of the folds. Therefore, when the number of folds present on the support varies, the drive rollers 19 are controlled to increase or decrease their speed, i.e. to vary the quantity entering or exiting from the supports, for example to maintain the length of the fabric in the tank more or less constant.

There can be present means for assessing the quantity of fabric that also or only assess the weight of the fabric on each single support (for example by means of means for measuring the weight of the fabric in the support, such as the torque measuring device on the crank 25B, as described above).

Fig. 2 shows a second embodiment of the line according to the invention, indicated as a whole with 100. This line 100 substantially comprises all the elements already described in the preceding example, and differs therefrom for the fact that the fabric T enters the steaming and vibration chamber, indicated here with 1 1 , from the bottom part of the chamber, at the inlet 1 1 1 A, exiting from the top part thereof through the outlet 1 1 1 B.

The supports 18 are superimposed on one another preferably in a column and the fabric is fed between the supports with a zigzag path from the bottom toward the top. In this case, a drive roller 1 19 is arranged over the feed zone 18A and pulls the fabric upward directly from the pick up zone of the support below, taking it to the related support. In this case, the bottom support 18", i.e. the first encountered by the fabric, has no drive rollers.

At the outlet 1 1 B of the steaming and vibration chamber 1 1 1 , there is present a drying station 27 of the fabric, which comprises, for example, heating means 28, for example of the type with air plenum blowing on the fabric, arranged over a conveyor belt 29 on which the fabric T is laid (preferably arranged simply resting thereon, without any substantial pulling or tension on the fabric). A drive roller 1 19' is placed at the inlet of the drying station 27 and pulls the fabric exiting from the chamber 1 1 1 (directly from the pick up zone 18B of the top support 18') directly onto the belt 29.

At the outlet from the drying station 27 there is present, for example, a further conveyor belt 21 or transfer hopper, which carries the fabric simply laid thereon, without any pulling or tension on the fabric, toward a cross lapper device 30.

Fig. 3 shows a third embodiment of line according to the invention, indicated as a whole with 200. With respect to the first example described, this embodiment varies substantially due to the fact that the accumulation supports of the fabric 218 in the steaming and vibration chamber 21 1 , are in the form of flat surfaces (also associated with means that enable adjustment of the upward or downward inclination f, for example about the axis X) and that the movement means of the fabric comprise, over the supports, respective devices for uniform feed and stabilization 31 , which comprise a plurality of slats 32 movable in the direction of movement of the fabric and having an orientation transverse (in this example orthogonal) to said direction, adapted to be arranged between the folds of the fabric laid on the related support. These slats adjust the fluctuation of the fabric in the direction of movement, preventing overlapping and superimposing of adjacent folds; in practice, they act as dividers for the folds during the movement thereof on the supports, to the full benefit of uniformity of movement, so that no unwanted folds are formed and the quantity of material traveling therethrough is regular. For example, these slats are fixed to a conveyor belt or closed loop chain 33 that moves, for a stretch, parallel to the support in the direction of movement of the fabric. The fabric T falls from the pick up zone 218B of a support toward the feed zone 218A of the support below, optionally aided by a chute or partition 220.

Fig. 4 shows a fourth embodiment of line according to the invention, indicated as a whole with 300. In this embodiment, the line provides for a "caffettiera" [Italian coffee maker"] shaped outer structure, and comprises at the inlet to the steaming and vibration chamber 31 1 , a first drying unit 340, in this example of the air type provided with a drying plenum 341 arranged blowing over a first upwardly inclined conveyor belt 342A on which the fabric is laid (preferably simply resting thereon, without any substantial pulling or tension on the fabric), which discharges directly into the top part of the chamber 3 1 , over the top support. The first conveyor belt 342A is arranged in a first tunnel 342. The line also comprises a second drying unit 343 at the outlet of the chamber 31 1 , in this example also of the air type provided with a drying plenum 344 arranged blowing over a second partially upwardly inclined conveyor belt 345A-345B on which the fabric is laid (preferably simply resting thereon, without any substantial pulling or tension on the fabric), that starts directly from the bottom part of the chamber 31 1 . The second conveyor belt is arranged in a second tunnel 345. Preferably, the second conveyor belt has a first upwardly inclined part 345A that starts from the bottom part of the chamber 1 1 , and a second substantially horizontal part 345B, which ends on a cross lapper 346, which arranges the fabric in folds. Preferably, the second drying unit 343 has a structure following both the inclined part and the horizontal part of the second conveyor belt.

Preferably, the first drying unit 340 and the second drying unit 343 are partly defined inside the chamber 31 1 , with the first conveyor belt 342A ending (in the sense that the end part thereof is contained) in the top part of the chamber 31 1 and the second conveyor belt starting (in the sense that the initial part thereof is contained) in the bottom part of the chamber 31 1. According to another point of view, the tunnels 342 and 345 form part of a same environment with the chamber 31 1 .

Just as in the preceding examples, there can also be present in this version recirculation means of the steam-air mixture (not shown).

Figs. 5 to 10 show other four embodiments of the invention, associated by a different method of steaming the fabric with respect to the preceding examples.

In fact, in these examples the drive rollers arranged between fabric supports subsequent to one another are also the means that enable steaming of the fabric.

For example, with reference to Fig. 9 or 10, there are visible two supports 18 arranged superimposed on one another, as in Fig. 9, or aligned with one another, as in Fig. 10, and a respective drive roller 419. This drive roller is also a steaming roller (or steamer roller), i.e. the surface thereof is perforated (the holes are not visible in the figures), that is, it has a plurality of passages communicating with an internal cavity (not represented in the figures), which is operatively connected, through a related pipe 419A, to a steam generation system (not shown in the figures).

The fabric is wound partly on the perforated surface of the drive and steaming roller. During operation, the roller 419 rotates and pulls the fabric T, picking it up from the pick up zone 18B of one support 18 and sending it to the feed zone 18A of the subsequent support. During rotation, from the inside of the roller 419, through the passages on the surface thereof, the steam (indicated by small arrows f in Figs. 9 and 10), coming from the steam generation system through the pipe 4 9A, reaches the fabric wound on the roller, impregnating it.

In practice, with respect to the preceding examples, the steaming means do not emit steam freely inside the treatment chamber, but emit a substantial part thereof directly in contact with the fabric by means of each drive/steaming roller comprised between two fabric supports 18. This system enables more accurate control of the quantity of humidity absorbed by the fabric in the treatment chamber, and more uniform and homogeneous humidification to be obtained.

Advantageously, immediately above and adjacent to each drive roller there is arranged a respective suction device 450, such as a suction hood, preferably provided with heating means 450A, for example electric heating elements, of the fluid drawn in, i.e. a fluid containing most of the quantity of steam coming from the roller 419 below and not retained by the fabric. This suction device 450 makes it possible to prevent drops of condensation of the steam in the chamber and consequently on the fabric, which could create a lack of uniformity in the surface appearance of said fabric. The outlet pipe of the fluid drawn in is schematically indicated with the number 450B. If necessary, the fluid drawn in, still hot, can be re-used for drying units (for example heating the battery that heats the drying air) or used in preheating modules, or the like.

It is understood that in other embodiments, the steaming rollers and the drive rollers can be separate, i.e. there can be present both rollers having the sole function of driving and rollers having the sole function of steaming the fabric, arranged in different positions to those shown or described. Moreover, these steaming and drive rollers can also be used together with systems for direct steaming in the chamber, such as those of the examples in Figs. 1 -4.

Moreover, steaming and driving rollers 419 can, for example, be used in the configurations of line of the examples of Figs. 1 -4 to replace the drive rollers 19, 1 19, without the presence of a common nozzle distributor 22.

All the examples of Figs. 5 to 8 show a line with steaming and drive rollers similar to those of Figs. 9 and 10. Each of these examples preferably has a first drying unit 440 positioned at the entrance to the line, upstream of the treatment zone produced by the vibrating supports 18 with the steaming and drive rollers 419.

Preferably, each embodiment of Figs. 5-8 also has a second drying unit 443 upstream of the treatment zone produced by the vibrating supports 18 with the steaming/drive rollers 419.

For example, in Fig. 5 the fabric T is accumulated folded at the entrance to the line/machine that performs the treatment according to the invention. A motorized cylinder 451 is present, which lifts the fabric T and deposits it freely (preferably simply resting, without any substantial pulling or tension on the, fabric) on the first part of a first conveyor belt 442A. The second part of the first conveyor belt enters the first drying unit 440; here, above the second part of first conveyor belt there is a further conveyor belt 442B, parallel to the first belt in the drying path. The fabric is therefore limited and contained between these, two conveyor belts, which move concordantly. In the drying unit, hot air blowers 440A (preferably thermoregulated) blow from above and from below the second part of the first conveyor belt (which therefore enables, just as the upper belt 442B, air to pass through).

From the outlet of the first drying unit 440, the fabric T, appropriately dried, i.e. dried until it has a desired degree of humidity before the subsequent treatment (in general, for all the embodiments, it is possible to include, upstream of the first support 18', measurement means of the quantity of humidity present on the fabric; in the case of a drying unit 440, these means will be downstream of this unit), enters the treatment chamber 4 1 and is lowered, always continuously, onto a first support 18', in the feed zone thereof. The fabric is then accumulated in folds on the support 18' and vibrated with a predetermined vibration frequency for a predetermined time, by means of operation of the vibration means associate with the support, such as those described above (connecting rod-motorized crank 25A, 25B 25C) and shown in Fig. 1 1 . The vibration means are preferably present on each support 18. In Figs. 5 to 10, the connecting rod 25A is shown on a single support 18, but it must be understood that a similar connecting rod is present on all the supports.

Then, as described above, the fabric is picked up from the pick up zone 18B due to the action of the steaming and drive roller 419. As already stated, the fabric, for the part wound on the roller 419 is impregnated by the steam, preferably saturated, with temperature preferably of approximately 100°C. (also the temperature of the chamber 41 1 is maintained at an analogous temperature, for example by means of recirculation means such as those described for the examples of Figs. 1 to 4).

The fabric is lowered by the steaming and drive roller onto the underlying feed zone of the support 18. The path of the fabric continues analogously between the subsequent supports 18 and the steaming and drive rollers 419, to the last support 18". From here the fabric is deposited freely (preferably simply resting, without any substantial pulling or tension on the fabric) on a second conveyor belt 445A of the second drying unit 443; here, above the second conveyor belt there is a further conveyor belt 445B, parallel to the second belt in the drying path. The fabric is therefore limited and contained between these two conveyor belts, which move concordantly. In the drying unit, hot air blowers 440A (preferably thermoregulated) blow from above and below the second conveyor (which therefore enables, just as the upper belt 445B, air to pass through).

There are associated with the steaming and drive rollers 419 the suction devices 450, as described above. Advantageously, the fluid drawn in is sent to the battery (not shown in the figures) which enables heating of the air of the blowers 440A of the two drying units, so as to enable a saving of energy.

At the output of the second drying unit 443, the fabric is made to arrive at a further output conveyor belt 460, from which the fabric is then collected, for example by means of a cross lapper 446 (or other known devices, such as an accumulation J-box).

Just as in the preceding examples, there are present means 26 adapted to maintain a same quantity constant on at least one said support 18, for example a same length (the width of the fabric is substantially constant along its steaming and vibrating treatment path in the line/machine).

For example, photocells 26 (or other sensors of optical or other type) can be present, for example with operation analogous to that of the preceding examples, associated with electronic means for management and control of the line/machine (not shown in the figures), arranged over the supports, preferably over the feed zone of the fabric, which act as sensors for detecting the folds of fabric, so that when the number of folds present on the support varies, the drive rollers 419 are controlled to increase or decrease their speed, i.e. to vary the length of the fabric entering or exiting from the supports.

With the electronic management and control means there can also be associated sensors adapted to measure the weight of the fabric in the supports, for example by means of the torque measuring device or torque meter associated with the shaft of the crank 25B described above. There can be present an electronic program that enables, by means of these means for assessing the weight, calculation of the variation in weight of the fabric deposited in the related support 18 due to the variation of humidity and/or to the overfeed required at the inlet to the support to avoid emptying this in the continuous feed process of the fabric, which, in view of the objective of the treatment, shrinks (i.e. becomes shorter) during the various steps on the supports 18.

In practice, before starting the machine/line, the fabric is arranged through the line, in the supports 18, in folds, with a more or less constant length on each support. During operation of the line, vibration and steaming of the fabric on the supports causes a shrinkage of said fabric, this means that the weight of the fabric on the support remains constant, but that it varies in length. The variation in length is, for example, assessed by the photocells 26 (or other means). To prevent a support 18 from being emptied, when the length of the fabric varies, as explained above, the steaming and drive roller 419 at the inlet (i.e. which feeds the fabric to the support in question) is operated to overfeed fabric (i.e. it is made to increase the speed of the roller; knowing the dimensions of the rollers, it is possible to know, on the basis of the speed, how much fabric has been fed to the support), restoring more or less the desired length of fabric on the support (in general, the means for assessing the length can have a measurement error, which although high, is nonetheless adequate for the type of processing). The weight of the fabric on the support 18 will increase as a consequence of the length of overfed fabric and can be calculated on the basis of the request for overfeed to the rollers 419. Naturally, the opposite is also possible, in the case in which, for any reason, the fabric in the support 18 should increase, the photocells 18 are able to decrease the speed of the roller 419 at the input to the support, the quantity of fabric fed.

To obtain optimum treatment, it is preferable for the humidity absorbed by the fabric to be substantially constant during the whole of the vibration treatment, i.e. through the passage between the supports 18.

To maintain the humidity absorbed constant, it is possible, advantageously, to control the weight of the fabric in the various supports 18. In fact, as stated, during the vibration process, the fabric is also steamed. Part of the weight of the fabric is therefore also given by the humidity absorbed by the fabric during steaming.

By knowing the weight as a function of the length of the fabric (as stated, the width is more or less constant throughout the treatment), for example the dry weight, and by knowing the quantity of humidity absorbed by the fabric, for example before entering the first support 18' (as explained above), it is possible, by measuring the weight of the fabric in a support, to calculate the fraction of weight due to the humidity and the fraction due to the dry weight of the fabric (given that, as explained above, the system always knows the length of fabric present in a support 18).

Therefore, by measuring a variation in the weight of the fabric on the support, considering that the machine/line maintains a constant length of fabric in the support 18 (or in any case knows the length of the fabric in a support), the machine/line in practice measures a variation in humidity on the fabric in that support.

To maintain the level of humidity absorbed by the fabric on the support constant, it is therefore possible to control, through adjustment means, the quantity of steam emitted by each steaming roller. Therefore, at the moment in which the machine/line measures a negative variation in weight (the fabric is lighter), this means that the humidity of the fabric has decreased in proportion to the variation in weight measured. At this point, the management software of the machine/line controls the steaming and drive roller 419 that feeds the fabric to the support 18 in question, to increase the quantity of steam emitted through said roller, by a quantity that is a function of the decrease in weight measured. Vice versa, in the case in which the variation in weight measured on the support is positive, it is necessary to decrease the quantity of steam emitted by the roller 419.

Therefore, according to what has been stated, it is possible to control the overall weight of the fabric on a given support, the length of the fabric on a given support and the quantity of humidity or steam absorbed by the fabric on a given support. ! ^'

Moreover, as stated, it is possible both to vary the feed speed (acting on the speed of the steaming and drive rollers 419), and to vary the quantity of steam emitted by each roller 419 adjusting the emission rate thereof (for example by means of appropriate "modulating" valves).

In this configuration of line/machine, the supports 18 are substantially superimposed on one another in a column, similarly to the case of Fig. 4. More in particular, the column of supports 18 is comprised, in the vertical direction, between the first drying unit, at the top, and the second drying unit, at the bottom.

The examples of Figs. 6, 7 and 8 differ from that of Fig. 5 only in the layout of the various components, these being identical to one another.

For example, in Fig. 6, the supports 18 are aligned with one another according to a horizontal direction and are comprised, in the vertical direction, between the first drying unit 440, at the top, and the second drying unit 443, at the bottom. The fabric travels through the first drying unit according to a first direction, is treated and moved through the supports 18 according to a second direction opposite to the first, and is moved again from the second drying unit in the first direction.

In Fig. 7, the layout of the line/machine is a mixture of examples 5 and 6, i.e. the supports 18 are partly aligned with one another and partly superimposed in vertical direction. In the specific example, the line of Fig. 7 differs from that of Fig. 6 in that a first support 18' is at a height more or less analogous to the outlet of the first drying unit 440 while the others are aligned with one another and at a lower level than the first 18'.

Fig. 8 shows another example of line/machine in which the supports 18 are partly aligned with and partly superimposed on one another. In this case, unlike the case in Fig. 7, there are two lines of supports 18 superimposed on one another, comprised in vertical direction, between the two drying units. In this case, the direction in which the fabric exits from the line/machine is opposite that of the preceding cases, so that the inlet and outlet of the line/machine are on the same side.

It is understood that, as in the examples, the line described can take the form of a compact machine comprised between the inlet zone and the outlet zone represented in the various figures. Therefore, the invention also relates to a machine for the continuous treatment of a fabric, adapted to perform shrinkage and swelling of said fabric, the heart of which is given by the treatment chamber for vibration and steaming and which preferably also comprises drying units at the inlet and/or at the outlet.

The continuous and, preferably, open width treatment method of a continuous knitted fabric according to the invention, which is implemented by the lines described above, in order to obtain shrinkage and swelling or volume of said fabric, comprises the following steps:

- continuous feeding and extraction of the fabric into and from a chamber, such as the one described above, in which the fabric is surrounded solely by air and steam, - steaming and simultaneous vibration of the fabric in the chamber.

Preferably, the steaming with simultaneous vibration of the fabric takes place with the fabric accumulated in folds on one or more supports, as in the examples described above.

Advantageously, steaming takes place with dry steam, preferably with a temperature exceeding 130°C and more preferably comprised between 140°C and 155°C and even more preferably equal to approximately 150°C.

To obtain an optimal result, the air and the steam in the chamber are recirculated continuously in the aforesaid chamber.

Advantageously, before entering the chamber, the fabric is preheated, preferably in a loose fold, for example with means as described in the preceding examples.

According to other preferred embodiments, the method provides that steaming takes place with saturated steam, preferably around approximately 100°C.

According to preferred embodiments, the method provides that the steaming step takes place substantially by placing the fabric in contact with at least one steaming roller.

Advantageously, the method can provide for suction of most of the quantity of steam emitted in contact with the fabric not absorbed thereby in a zone adjacent to the steaming roller (at a distance preferably no greater than the diameter of said roller).

Preferably, the method provides for drying the fabric to a predetermined degree of humidity before starting vibration and steaming.

Preferably, the method provides for drying the fabric to a predetermined degree of humidity after the vibration and steaming step.

Preferably, the method provides for adjusting, when required, the quantity of steam emitted by the steaming roller.

Preferably the method provides for pulling the fabric also by means of said at least one steaming roller.

Preferably, the method provides for weighing the fabric inside at least one support and, preferably, for maintaining the weight of the fabric constant in said support.

Preferably, the method provides for maintaining the length of the fabric constant in said at least one support, varying the feed speed of the fabric in the support when a decrease in length (or weight) of the fabric is detected.

Preferably, the method provides for maintaining the length of the fabric and/or the weight of the fabric more or less constant on said at least one support varying the feed speed of the fabric in the support and varying the quantity of steam emitted by said at least one steaming roller.

In general, the method provides, on the basis of parameters associated with the type of fabric to be treated, for setting the frequency at which the fabric is vibrated, setting the time interval for which the fabric is vibrated and setting the quantity of humidity to be impregnated in the fabric.

Preferably, this setting can be made for each fabric support that is vibrated, independently, or the same for all the supports and analogously, for each steaming roller, independently, or the same for all the rollers.

It is understood that the drawing only shows possible non-limiting embodiments of the invention, which can vary in forms and arrangements without however departing from the scope of the concept on which the invention is based. Any reference numerals in the appended claims are provided purely to facilitate the reading thereof, in the light of the above description and accompanying drawings, and do not in any way limit the scope of protection.