Description

Technical field

[0001] The present invention relates to the field of industrial systems for producing and treating fabric. More in particular, the invention refers to a treatment machine for shrinking and dimensionally stabilizing fabric and also to a treatment method for shrinking and dimensionally stabilizing a fabric. The fabric treated can be a weft/warp fabric, an open-width or tubular knitted fabric or a nonwoven fabric.

Background art

[0002] As is known, the finishing of knitwear made of cotton or cellulose fiber in general, but also of synthetic fiber, in addition to providing the knitwear with an aesthetic and tactile characterization, also has the purpose of providing the fabric with substantial dimensional stability, fundamental for manufacturing the finished garment.

[0003] Currently, the methods for continuous and open-width finishing of knitted fabric result in a product with a decidedly poor hand, i.e., a fabric that does not have an effect of depth of the knit.

[0004] To obtain a knitted fabric with dimensional stability and a soft and light hand of acceptable quality, a discontinuous procedure in rope form is currently used, which is carried out in rotating drums, or tumblers, of the same type as those used in the laundry.

[0005] This type of finishing has high costs due to high energy consumption and the use of labor, as each bolt of fabric must be inserted into the machine, treated and subsequently removed from the machine. All these steps lead to a high energy loss and lengthy and consequently costly manual operations, which moreover must be carried out by specialized personnel. [0006] Moreover, due to the discontinuous nature of the process, it is not possible to obtain adequate uniformity of the final effects of finishing on the various bolts of fabric.

[0007] There are treatment machines in which the fabric is inserted into chambers in which it is vibrated in order to allow shrinkage of the fibers. A machine of this type is illustrated, for example, in the patent document W02010/064130. However, the result of the shrinkage and bulking of the fabric is not completely satisfactory.

[0008] There are also machines in which the fabric is made to pass through a chamber containing tanks of water and vibrating rollers onto which water is sprayed, so that moist steam is present in the chamber. This machine, which allows expansion of the fabric to take place, is illustrated in the patent document JP1314777. Once again in this case the result of the shrinkage and bulking of the fabric is not satisfactory.

[0009] There are also known continuous treatments in which the fabric is moved in rope form (i.e., continuous fabrics “twisted” around a longitudinal axis in the fashion of a strand) through treatment stations, which however have some drawbacks due to the production of creases in the fabric. Moreover, a longitudinal tension is generated on the fabric, making the aim of dimensional stability practically impossible.

Summary

[0010] The main object of the present invention is to produce a finishing treatment machine for fabrics that also allows excellent dimensional stabilization to be obtained.

[0011] Another important object of the present invention is to produce a finishing treatment machine for fabrics that allows excellent shrinkage of the fabric treated to be obtained.

[0012] A further important object of the present invention is to produce a finishing treatment machine for fabrics that allows soft fabrics with an excellent “hand” to be obtained.

[0013] Yet another important object of the present invention is to produce a treatment machine for finishing fabrics that allows fabrics with good bulk to be obtained. [0014] One more important object of the present invention is to develop a treatment method of fabric that allows optimum shrinkage and stabilizing of the fabric, and optimum tactile characteristics, to be obtained.

[0015] These and other objects, which will be more apparent below, are achieved with a treatment machine for shrinking and dimensionally stabilizing fabric, provided with at least one module comprising a first fabric accumulation station and a second fabric accumulation station, an alternating movement path of the fabric between the two accumulation stations so that the fabric is moved from the first accumulation station to the second accumulation station and vice versa, and an air distribution system on the fabric along the movement path at least between the accumulation stations; the distinctive characteristic of the machine lies in the fact that it comprises, in an intermediate position of said movement path, a forming zone of a free loop of the fabric, and a detection device of a loop of fabric in said forming zone, such that during the alternating movement of the fabric between said accumulation stations, the fabric is moved maintaining a free loop inside said forming zone

[0016] The fact that the fabric has a free loop along its movement path means that, between the accumulation stations, the fabric has a very low longitudinal tension, i.e., is not taut.

[0017] Free loop is meant as a portion of fabric that forms, in this forming zone, a convex curve (with convexity facing downward), mainly as a result of gravity.

[0018] Advantageously, an alternating movement device is provided along said movement path, comprising two intermediate movement surfaces on which the fabric is adapted to be supported; these movement surfaces are separated from each other by a zone that does not support the fabric, thereby defining the free loop forming zone, so that the fabric is arranged continuously on the intermediate surfaces and has a free loop portion between these surfaces.

[0019] Preferably, the movement device comprises two movement members that define the intermediate movement surfaces, preferably moving the fabric concordantly, that is the two movement members move the fabric in the same overall direction between the two accumulation stations, even if with eventual different inclinations. [0020] Preferably, the movement members are conveyor belts, preferably closed in a loop, defining on the upper active portion thereof the intermediate movement surfaces, on which the fabric is supported.

[0021] Preferably, the conveyor belts are inclined from the bottom up in the directions from the accumulation stations to the loop forming zone.

[0022] Preferably, the conveyor belts comprise a device for adjusting their inclination relative to the ground, so as to be able to adjust the distance of the lower end relative to the accumulation tanks of the accumulation stations, which are arranged below these lower ends, with consequent adjustment of the curvature of the fabric in this lower end of the belt.

[0023] Advantageously, in preferred embodiments, the machine comprises a control of the speeds of at least one of the intermediate movement surfaces, such that if the loop detection device detects a lack or an excess of loop in this forming zone, the control modifies the speed of at least one of said intermediate movement surfaces to restore the correct amount of loop in the forming zone. For example, if the free loop detection device detects that the loop is not present, the machine can increase the speed of the first intermediate movement surface slightly, or decrease the speed of the second intermediate movement surface slightly (i.e., create a difference in speed between the two surfaces); in this way a small amount of fabric will accumulate in this forming zone, lengthening the free loop in downward direction until the detection device detects the loop and commands the intermediate surface whose speed was varied to return to normal speed. Moreover, the loop detection device can verify that there is an excess of loop in downward direction and therefore the machine varies (in the opposite manner to what was described above) the speed of one of the intermediate movement surfaces.

[0024] For example, the loop detection device is, for example, a device with an optical sensor. For example, this optical sensor is provided with a laser with direct reading of the loop of the fabric, for example through a window positioned under the loop or with axis inclined relative to the fabric, or with an indirect reading system using an optical fiber suitable for operating at high temperature. [0025] Another type of loop detection device can, for example, be produced with a position transducer of ultrasonic type to mount under the loop.

[0026] Other examples of loop detection devices can comprise mechanical feelers that detect the presence of the loop.

[0027] According to preferred embodiments, the air distribution system has air ejectors facing on the intermediate movement surfaces of the fabric and suction areas, operatively connected to facing suction ducts, placed opposite these ejectors relative to the movement surfaces, so that air is ejected from the ejectors to pass through the fabric placed on these surfaces and be drawn by the suction ducts; the effect of the air on the fabric is that of delicately pushing the fabric onto the intermediate movement surfaces, blocking them relative to these surfaces, so that the fabric is in practice stationary with respect to these surfaces, moving more or less together therewith between the respective accumulation station and the forming zone of the loop and vice versa.

[0028] Advantageously, in the preferred embodiments, the air ejectors are operatively connected to an air heating device. Preferably, this heating device has an intake pipe operatively connected to the environment surrounding the accumulation stations so that at least part of the air heated by the device is taken from the environment in which the stations are enclosed: Preferably, this intake pipe is provided with a fan to move the air inside the pipe toward the ejectors.

[0029] Preferably, the suction ducts are operatively connected to a suction fan operatively connected to an exhaust air outlet flue, so that at least part of the air drawn is extracted from the environment in which the accumulation stations are enclosed.

[0030] According to preferred embodiments, the module of the machine has a moisture sensor of the fabric; more preferably, the machine comprises a control of the amount and/or speed of the air fed toward the fabric, and/or a control of the heating temperature of the air fed into the movement path based on the moisture value detected by this moisture sensor. This allows optimal adjustment of the time, i.e., the effect, of drying of the fabric during the alternating movement between the two accumulation stations. [0031] In the preferred embodiments, a module of the machine comprises only two accumulation stations, an insertion device of the fabric into the first accumulation station and an extraction device of fabric from the second accumulation station, both adapted to move the fabric with a same movement speed, lower than the speed of alternating movement of the fabric between said two accumulation stations by means of movement of said support surfaces of the fabric; advantageously hereinafter, the speed of alternating movement is also referred to as first speed, while the speed of insertion into and extraction from the module is defined as second speed.

[0032] Preferably, the first speed of alternating movement between the two accumulation stations is at least three times the second speed, and more in particular is at least five times the second speed and even more preferably is between nine times and eleven times the value of the second speed; in other examples, the first speed can be greater than eleven times the value of the second speed.

[0033] Preferably, the insertion device comprises an initial movement surface of the fabric on which the fabric is adapted to be arranged; preferably the insertion device comprises a movement member that defines the initial movement surface, which moves the fabric toward the first accumulation station; preferably the movement member is a conveyor belt, preferably closed in a loop, defining on the upper active portion the initial movement surface, preferably the conveyor belt is inclined from the top down in the direction of insertion of the fabric, preferably with the possibility of adjusting this inclination.

[0034] Preferably, the extraction device comprises a final movement surface of the fabric on which the fabric is adapted to be arranged; preferably this extraction device comprises a movement member that defines the final movement surface, which moves the fabric from the second accumulation station toward the outside of the module; preferably the movement member is a conveyor belt, preferably closed in a loop, defining on the upper active portion the final movement surface, preferably this conveyor belt is inclined from the bottom up in the direction of extraction of the fabric, preferably with the possibility of adjusting this inclination.

[0035] In preferred embodiments, the machine comprises a plurality of the aforesaid modules arranged in series relative to one another, and wherein the fabric is adapted in each module, to be moved alternately between the first and the second accumulation station with a first speed, between said modules, to be moved in a single direction of forward movement with a second speed, lower than the first speed, so that as a whole the fabric passes through the machine with the second speed.

[0036] Preferably, between consecutive modules the fabric is adapted to pass from a final movement surface of an extraction device of the module from which the fabric exits, to an initial movement surface of an insertion device of the module into which the fabric enters, and wherein a further forming zone of a free loop of the fabric and a further detection device of a loop of fabric in this further forming zone are present between the extraction device and insertion device, so that during movement of the fabric between the extraction and insertion devices of two consecutive modules, the fabric forms a free loop in the forming zone.

[0037] Preferably, the air distribution system has further air ejectors facing on the initial and final movement surfaces of the fabric and further facing air suction ducts placed opposite the further ejectors relative to the initial and final movement surfaces, so that air is ejected from the further ejectors to pass through the fabric placed on the initial and final movement surfaces, and be drawn by said further suction ducts, so that the fabric is stationary with respect to these surfaces, i.e., moves together with these surfaces; preferably, the further air ejectors are operatively connected to an air heating device.

[0038] Preferably, also in this case the machine comprises a control of the speed of at least one between the final movement surface and the initial movement surface of the extraction and insertion devices of two adjacent modules, so that if the further loop detection device detects a lack or an excess of loop in said further forming zone, the control adjusts the speed of at least one of the final and initial movement surfaces to restore the correct amount of loop in said further forming zone.

[0039] According to preferred embodiments, the distribution system includes a control of the air temperature fed into each module, such that in each module it is possible to distribute air onto the fabric at a desired temperature, independent from the temperature of the air distributed in the other modules. [0040] According to preferred embodiments, the machine comprises a device for managing the reserve of fabric in the accumulation stations that generates a command to reverse the movement of the fabric between the accumulation stations; preferably, this device for managing the reserve comprises a device for assessing the amount of fabric in the accumulation stations adapted to command reversal of the movement between the accumulation stations upon reaching a given minimum value of accumulated fabric, or a device for assessing the tension of the fabric exiting from the accumulation station, so that upon reaching a tension value equal to or greater than a threshold value, reversal is commanded, or a combination of said devices for assessing the amount of fabric and for assessing the tension of the fabric. For example, a device for assessing the tension of the fabric exiting from the accumulation station is described in the international patent application PCT/EP2020/067091.

[0041] For example, this device for managing the reserve of fabric in the accumulation stations comprises

-the device for assessing the amount of fabric comprised in the related station, so that, when said device detects an amount of fabric in the station lower than a limit threshold, a command is generated to reverse the movement of the fabric extracted from said station,

-a device for assessing the tension of said fabric, and

-an electronic program adapted to change the value of said limit threshold based on the tension of the fabric detected by said device for assessing the tension.

[0042] Preferably, if when the device for assessing the amount of fabric detects an amount of fabric lower than said limit threshold, said device for assessing the tension of said fabric verifies a critical state of tension for said fabric, said program modifies said limit threshold of amount of fabric in the station, increasing it by a predetermined value.

[0043] Preferably, the device is adapted to memorize the number of events in which said assessment device detects an amount of fabric in the station lower than a limit threshold, i.e., the number of reversals associated with the decrease of fabric in the related station; if said device detects a predetermined consecutive number of said events, said electronic program modifies said limit threshold of amount of fabric in the station, decreasing it by a predetermined value.

[0044] In practice, advantageously, control of the reserves of fabric on the accumulation stations for insertion and extraction takes place by means of devices for assessing the amount of fabric, for example weight measuring devices such as load cells, which, by means of appropriate settings, determine when the accumulation stations are empty and therefore the device reverses the movement of the fabric; if the control values of the load cells are not adjusted with the correct value, two situations can occur: either too large a reserve of fabric remains on the accumulation stations or the fabric is tensioned; by means of a device for assessing the tension, for example of the type operated mechanically, tensioning of the fabric is detected and, in this case, the control value of the load cell of the accumulation station in question is automatically increased; if during the subsequent reversal, the device for assessing the tension is triggered again, the control value of the load cell will be further increased and so forth, until the device for assessing the tension is no longer triggered; in this way, tensioning of the fabric is avoided. However, at the same time, there could be too large a reserve of fabric in the accumulation station; to remedy this, after a certain number of reversals of fabric feed have been successfully concluded, i.e., without the device for assessing the tension being triggered, the control value of the load cell is decreased; after the same number of reversals successfully concluded, the control value of the load cell will be further decreased. This will continue until the device for assessing the tension is triggered again and consequently the control value of the load cell is once again increased.

[0045] With this system, the control values of the load cells self-adjust so that the reserves of fabric on the accumulation stations are not too large and so as to prevent the fabric from being subjected to stretching and tensioning.

[0046] Preferably, modification of said limit threshold of amount of fabric in the station takes place by equal incremental or decremental values.

[0047] Preferably, each accumulation station comprises an accumulation tank with which the management device is associated. [0048] Preferably, the accumulation tank is articulated according to a horizontal axis, allowing the inclination of this tank.

[0049] Preferably, the device for assessing the amount of fabric in an accumulation station comprises at least one load cell connected to said accumulation tank, preferably by means of a connection member. Preferably, the load cell is arranged over the accumulation tank, fixed to a support structure and connected to said tank by means of a connection member, such as a rope or a rod, so that said load cell is adapted to act in traction, or said load cell is arranged below said accumulation tank, fixed to a support structure and connected to said tank by means of a connection member, so that said load cell is adapted to act in compression.

[0050] Preferably, the device for assessing the tension of said fabric comprises a movable stop, constrained to a support structure and adapted to move from an idle position to an activated position, and vice versa, and a sensor element adapted to identify the movement of said movable stop from said idle position.

[0051] According to preferred embodiments, the machine comprises one or more modules, and a device for the continuous insertion of the fabric from outside the machine to a first module, and a device for the continuous extraction of the fabric from the last module (in the case of machine with a single module, first and last module coincide), so that the machine processes fabric continuously and can be advantageously inserted in a continuous fabric production line.

[0052] According to preferred embodiments, each module defines a proper treatment chamber, with an inlet for continuous feed of the fabric and an outlet for continuous extraction of the fabric.

[0053] According to other preferred embodiments, the machine is adapted to process, during a work cycle, a single portion of fabric accumulated in said accumulation stations, i.e., to process fabric discontinuously.

[0054] According to another aspect, the invention concerns a treatment method for shrinking and dimensionally stabilizing a fabric preferably carried out by a machine according to one or more of the preferred embodiments and examples described above, wherein, in at least one treatment chamber, fabric is accumulated alternately in a first accumulation station and in a second accumulation station by means of an alternating forward and return movement of the fabric between the two accumulation stations along a movement path, and wherein, during movement, the fabric is impacted by a flow of air, preferably hot.

[0055] Preferably, along the movement path, the fabric is supported on two movement surfaces and is not supported in in a free loop forming zone between said movement surfaces, so that during movement, a free loop is formed through gravity in said forming zone (i.e., not supported from below).

[0056] Preferably, during movement of the fabric, the presence of the free loop of fabric between said movement surfaces is monitored.

[0057] Preferably, if a lack or an excess of free loop is detected in said forming zone, the speed of at least one of said movement surfaces is modified to restore the correct amount of loop in said forming zone

[0058] Preferably, the moisture of the fabric in said chamber is detected, and, if this value is outside a given operating range, the amount and/or speed of the air fed toward the fabric is modified, and/or the temperature of the air is modified.

[0059] Preferably, the air that heats the fabric passes through the fabric arranged on said movement surfaces, and is drawn from below said surfaces, so that the fabric arranged on said surfaces, during movement of the surfaces, remains substantially stationary with respect thereto.

[0060] Preferably, the reversal of motion of the fabric between said accumulation stations takes place when in a said station an amount of accumulated fabric equal to or lower than a threshold value is measured or a tension of the fabric exiting from the accumulation station equal to or greater than a threshold value is measured, or takes place according to the operation of the device for managing the reserve described above.

[0061] Preferably, the fabric is moved continuously through one or more chambers, with the input and output speed of the fabric into/from said chambers lower than the movement speed of the fabric between said accumulation stations of each chamber; preferably, the speed of alternating movement between said two accumulation stations being at least three times higher than the input and output speed of the fabric into/from said chambers, and more in particular being at least five times higher than the input and output speed of the fabric into/from said chambers and ever more preferably being between nine times and eleven times the value of the input and output speed of the fabric into/from said chambers, preferably said speed of alternating movement being greater than eleven times the value of the input and output speed of the fabric into/from said chambers.

[0062] According to preferred embodiments, forming zones of a free loop of the fabric are present between two consecutive treatment chambers defined between movement surfaces of the fabric respectively for extraction and insertion of the fabric from and into the chambers; preferably during movement of the fabric, the presence of the free loop of fabric between said movement surfaces is monitored; preferably, if a lack or an excess of free loop in said forming zone is detected, the speed of at least one of said movement surfaces is modified to restore the correct amount of loop in said forming zone.

[0063] According to other preferred embodiments, the method is adapted to process, during a work cycle, a single portion of fabric accumulated in said accumulation stations, or to process fabric discontinuously in a said chamber, so that all the fabric to be treated is inserted into the chamber and subsequently treated and then extracted from the chamber.

[0064] Both as regards the treatment machine, and as regards the method, the fabric treated can be of various types, for example a weft/warp fabric, an open-width or tubular knitted fabric or a nonwoven fabric.

[0065] Moreover, the fabric can be treated in open width inside the treatment machine, i.e., the fabric is treated keeping the ends (selvages) open at the maximum height so that it takes a spread out configuration.

[0066] The fabric can also be treated in rope form, i.e., the fabric is treated “compressing” the selvages along the transverse axis. During treatment the fabric is twisted along the longitudinal axis. [0067] The fabric can also be treated in half-rope form, i.e., the fabric is treated "compressing" the selvages along the transverse axis. During treatment the fabric is accompanied so as to prevent twisting thereof along the longitudinal axis.

Brief description of the drawings

[0068] The invention will now be better understood by following the description and the accompanying drawings, which illustrate a non-limiting example of embodiment of the invention. More in particular, in the drawing:

Fig. 1 represents a schematic view of a machine module according to the invention;

Fig. 2 represents a schematic view of a machine formed by a plurality of modules as in Fig. 1;

Fig. 3 represents a schematic view of a machine according to the invention formed by several modules that share a common chamber;

Fig. 4 represents a schematic view of a further machine according to the invention formed by several modules that share a common chamber, in a variant with respect to the case of Fig. 3;

Fig. 5 represents a schematic top view of a further machine according to the invention formed by several modules in sequence which define a C-shaped movement path for the fabric.

Detailed description of embodiments

[0069] With reference to the aforesaid figures, a treatment machine for shrinking and dimensionally stabilizing fabric according to the invention is indicated as a whole with the number 10.

[0070] This machine can be modular and thus be formed by a single module, or formed by a plurality of modules arranged in succession to one another, with the fabric that passes continuously from one module to the other. [0071] Fig. 1 shows the example of a machine module, indicated as a whole with 10A. This module 10A can be part of a machine with a single module (as in Fig. 1), or of a machine with several identical modules (as in Fig. 2).

[0072] Each module 10A is defined by a chamber 11, provided with walls that delimit the treatment environment, inside which two accumulation stations of fabric T in folds are present, respectively a first accumulation station 12 and a second accumulation station 13. In other examples, a machine with several modules in succession can have several modules provided with two respective accumulation stations arranged in series inside a single chamber, as for example indicated in Fig. 3 or in Fig. 4 (in this case the modules share at least part of the air heating system and of the exhaust air outlet, as will be more apparent below).

[0073] Each accumulation station for example comprises a respective accumulation tank 12A and 13A, preferably hinged at one end 12A’, 13A’ thereof, according to a horizontal axis, to a structure integral with the chamber.

[0074] An alternating movement path 14 of the fabric T is present between the two accumulation stations 12 and 13, so that the fabric is moved from the first accumulation station 12 to the second accumulation station 13 and vice versa, according to a logic explained below.

[0075] A system 15 for distributing air on the fabric along the movement path 14, i.e., between the accumulation stations 12 and 13 and, as explained below, preferably also at the inlet and outlet of the module, is also associated with the module 10A.

[0076] An alternating movement device 16 of the fabric is present along the movement path 14 of the fabric T between the accumulation stations 12 and 13, which comprises members for moving the fabric in the form of conveyor belts 17 and 18, for example of closed loop type, defining on their upper active portion, movement surfaces of the fabric 17A and 18B, hereinafter defined intermediate movement surfaces of the fabric. Hereunder, the conveyor belt 17 and the conveyor belt 18 will also be referred to as first conveyor belt and second conveyor belt, in association with the accumulation station to which they are dedicated. [0077] The conveyor belts 17 and 18 are inclined from the bottom up in the directions from the accumulation stations toward the other conveyor belt.

[0078] Characteristically, a zone that does not support the fabric is provided between the intermediate movement surfaces 17A and 18 A, or between the conveyor belts 17 and 18, i.e., in an intermediate position of the movement path, thus defining a forming zone 19 of free loop Tl, so that the fabric T is arranged continuously on the intermediate surfaces 17 A, 18A and has a portion in a free loop Tl between these surfaces, i.e., between the facing ends of the conveyor belts 17 and 18. The fact that the fabric has a free loop along the movement path 14 means that the fabric, between the accumulation stations 12 and 13, has a very low longitudinal tension, i.e. it is not taut.

[0079] It should be noted that the free loop forms, as a result of gravity, in this forming zone, a convex curve, with convexity facing downward.

[0080] Advantageously, a device 20 for detecting a loop di fabric is present in this forming zone 19, such that during the alternating movement of the fabric T between the accumulation stations 12 and 13, the fabric is moved maintaining a free loop Tl inside the forming zone 19. For example, the loop detection device is a device with an optical sensor provided with a laser with direct reading of the loop of the fabric, for example through a window positioned below the loop or with axis inclined relative to the fabric.

[0081] Advantageously, the conveyor belts 17 and 18 comprise a device for adjusting their inclination relative to the ground, so as to be able to adjust the distance of the lower end 17’ -18’ relative to the accumulation tanks 12A and 13A of the accumulation stations 12 and 13, which are arranged below these lower ends, with consequent adjustment of the curvature of the fabric at the lower end of the belt. For example, this inclination adjustment device comprises a hinge with horizontal axis for the respective conveyor belt, for example located at the rotation axis of the idler rotor provided at the upper end of this belt. Naturally, the inclination adjustment device also comprises a device for blocking the conveyor belt in the desired inclined position, not indicated in the figures. [0082] The intermediate movement surfaces 17A and 17B move the fabric with the same speed, therefore the amount of free loop in the forming zone 19 is substantially constant, at least during normal movement. The module 10A comprises a control of the speeds of at least one of the intermediate movement surfaces 17A and 17B, such that if the free loop detection device 20 detects a lack or an excess of loop T1 in the forming zone 19, the control modifies the speed of at least one of the intermediate movement surfaces 17A and 17B to restore the correct amount of loop T1 in the forming zone 19.

[0083] By way of example, if the free loop detection device 20 detects that the loop T1 is not present (or is present in an insignificant amount), the control allows a slight increase in the speed of the first conveyor belt 17, or a slight decrease in the speed of the second conveyor belt 18 (or, more in general, creates a difference in speed between the two intermediate movement surfaces 17A and 18 A). Consequently, fabric accumulates in the forming zone 19, lengthening the free loop T1 downward until the detection device 20 detects the loop and commands the intermediate surface whose speed was varied to return to the normal speed.

[0084] Moreover, the loop detection device 20 can verify that there is an excess of loop T1 in the downward direction and therefore the machine varies (in the opposite manner to what was described above) the speed of one of the intermediate movement surfaces.

[0085] The air distribution system 15 has air ejectors 21 facing the intermediate movement surfaces 17Ae 17B, i.e., arranged above the first and second conveyor belt 17 and 18, which allow drying of the fabric on this conveyor belt 17 and 18.

[0086] Moreover, the air distribution system 15 has suction areas 22, which are operatively connected to suction ducts 23 and are facing opposite the ejectors 21 relative to the movement surfaces 17A and 17B.

[0087] For example, each intermediate movement surface 17A and 17B comprises a respective group of ejectors 21 and a respective suction zone 22.

[0088] In practice, air f is ejected from the ejectors 21 toward the conveyor belts 17 and 18. This air passes through the fabric present thereon and their upper surface that supports the fabric, being thus drawn into the suction zones 22. From the suction zones, by means of a suction device 24, the air drawn passes into the suction ducts 23 and from here to an exhaust air outlet flue 25, so that at least part of the air drawn is extracted from the chamber 11, i.e., from the environment in which the accumulation stations are enclosed.

[0089] In addition to the drying effect, the effect of the air f on the fabric T arranged on the conveyor belts is that of delicately pushing this fabric on the intermediate movement surfaces, blocking them relative thereto, so that the fabric is in practice stationary relative to the surfaces 17A-18A, i.e., moves more or less jointly with them, thereby preventing the fabric from rubbing on these surfaces.

[0090] The air distribution system 15 comprises an air heating device 26 arranged along an intake pipe 27 that draws air from inside the chamber 11 and takes it to the ejectors 21, so that at least part of the air heated by the device 26 is taken from the environment in which the accumulation stations 12 and 13 are enclosed. A fan 28 is present along this intake pipe to move the air inside the intake pipe 27 toward the ejectors 21.

[0091] The module has a fabric moisture sensor 29 associated with a control of the amount and/or speed of the air fed toward the fabric by the air distribution system 15, and/or a control of the heating temperature of the air fed into the movement path by the heating device 26, based on the moisture value detected by the moisture sensor 29. This allows optimal adjustment of the drying time, i.e., the effect of drying of the fabric during the alternating movement between the two accumulation stations 12 and 13.

[0092] For example, to increase the drying speed, it is possible to increase the amount of air fed onto the fabric, for example increasing the amount of fabric or decreasing the speed of alternating movement of the fabric, or alternatively increasing the air temperature, or a combination thereof. Likewise, it is possible to operate in the opposite manner when wishing to reduce the drying speed.

[0093] Advantageously, each module 10A comprises an insertion device 30 of the fabric T inside the first accumulation station 12 and an extraction device 31 of fabric from the second accumulation station 13, both adapted to move the fabric with a same movement speed, lower than the speed of alternating movement of the fabric between the two accumulation stations by means of the movement produced by means of the first and second conveyor belt 17 and 18.

[0094] The speed of alternating movement between the accumulation stations 12 and 13 is defined first speed, while the speed of insertion into and extraction from the module is defined second speed. Therefore, the second speed corresponds to the speed with which the fabric T passes through the module 10 A.

[0095] For example, the first speed of alternating movement between the two accumulation stations 12 and 13 can be at least three times greater than the second speed, and more in particular be at least five times greater than the second speed and even more preferably be around ten times the value of the second speed; in other examples, the first speed can be ten times greater than the value of the second speed.

[0096] The insertion device 30 is advantageously similar to the members that move the fabric with an alternating movement between the accumulation stations 12 and 13, i.e., is a third conveyor belt closed in a loop (hereunder also indicated with the number 30), the active section of which defines an initial movement surface 30A of the fabric on which the fabric T is adapted to be arranged.

[0097] Also in this example, the third conveyor belt 30 is inclined from the top down in the direction of insertion of the fabric into the first accumulation station 12, for example with the possibility of adjusting this inclination in the same manner as for the second conveyor belt 18.

[0098] Likewise, also the extraction device 31 is advantageously similar to the members that move the fabric with an alternating movement between the accumulation stations 12 and 13, i.e., is a fourth conveyor belt closed in a loop (hereunder also indicate with the number 31), the upper active section of which defines a final movement surface 31 A of the fabric on which the fabric T is adapted to be arranged.

[0099] Also in this example, this fourth conveyor belt 31 is inclined from the bottom up in the direction of extraction of the fabric from the second accumulation station 13, for example with the possibility of adjusting this inclination in the same manner used for the first conveyor belt 17. [0100] The air distribution system can have further air ejectors 121 facing on the initial and final movement surfaces 30A and 31A of the insertion and extraction devices 30 and 31, and further facing suction ducts 123 placed opposite the further ejectors 121 relative to the initial and final movement surfaces 30A and 31 A, so that air is ejected from the further ejectors 121 to pass through the fabric placed on the initial and final movement surfaces, and be drawn by said further suction ducts 123, which are operatively connected, for example, to the flue 25, to eliminate the moist air. Advantageously, the further air ejectors 121 are operatively connected to the air heating device 26, so as to feed heated air onto the fabric.

[0101] In the case of a machine with several modules 10A arranged in series, the fabric is adapted, in each module, to be moved alternately between the first and the second accumulation station 12 and 13 with a first speed, while, between the subsequent modules, and at the inlet to first module of the series and at the outlet from the last module of the series, the fabric is adapted to be moved in a single forward direction with the aforesaid second speed (lower than the first speed) so that as a whole the fabric passes through the machine with the second speed.

[0102] Therefore, in this series of several consecutive modules, between two consecutive modules 10A, the fabric is adapted to pass between a final movement surface 31A of an extraction device 31 of the module from which the fabric exits, to an initial movement surface 30A of an insertion device 30 of the subsequent module in which the fabric enters.

[0103] Advantageously, a further forming zone 119 of a free loop Tl’ of the fabric T is present between the extraction device 30 and insertion device 31, with which a further detection device 120 of a loop of fabric in this further forming zone 119 is associated, so that during the movement of the fabric between the extraction and insertion devices of two consecutive modules, the fabric forms a free loop inside the forming zone, thus avoiding tensioning of the fabric, to the advantage of the finishing effect.

[0104] Just as in the case of the loop detection device 20, also in this case the machine comprises a control of the speed of at least one between the final movement surface 31A and the initial movement surface 30A of the extraction and insertion devices of two adjacent modules, so that if the further loop detection device 120 detects a lack or an excess of loop in the further forming zone 119, the control modifies the speed of at least one of the final and initial movement surfaces 31 A and 30A to restore the correct amount of loop in this forming zone.

[0105] In some embodiments of machine with several modules in series, the distribution system can be provided with a control of the temperature of the air fed into each module 10A, such that in each module it is possible to distribute air on the fabric at a desired temperature, independent from the temperature of the air distributed in the other modules (as, for example, in Figs. 2 and 3). Fig. 4 shows the case of several modules, for example inside a single chamber, in which the exhaust air extraction system 23-25 is common for all the stations. Again in the example of Fig. 4, the heating system can be common for the stations of all the modules or independent for each station).

[0106] Fig. 5 shows the case of several modules 10A placed side by side laterally in pairs Cl, C2, C3 in the direction transverse to the direction of forward movement of the fabric. Each pair can be formed of modules that share part of the walls of their chambers or modules simply placed side by side. In this example there are six modules that define a path formed by a first section in a first direction, in which the fabric passes through three modules in sequence belonging to three distinct pairs, and a second section in a second direction, opposite the first, in the sequence opposite to the case of the first section, an arc-shaped movement belt G being present to reverse the direction of movement between the modules of the two sections. This configuration allows optimization of the spaces and structures forming the modules.

[0107] For each module 10A (i.e., both in the case of a single module and in the case of several modules in series), the machine comprises a device 40 for managing the reserve of fabric in the accumulation stations 12 and 13 that generates a command to reverse the movement of the fabric between the accumulation stations.

[0108] For example, this device 40 for managing the reserve comprises a device 41 for assessing the amount of fabric in the accumulation stations adapted to command reversal of the movement between the accumulation stations upon reaching a given minimum value of accumulated fabric. [0109] Alternatively, this device 40 for managing the reserve comprises a device 42 for sensing the tension of the fabric exiting from the accumulation station, so that upon reaching a tension value equal to or greater than a threshold value, reversal is commanded.

[0110] In this example, the device 40 for managing the reserve comprises a combination of these devices for assessing the amount of fabric 41 and fabric tension sensor 42.

[OHl] For example, a device for assessing the tension of the fabric exiting from the accumulation station is described in the international patent application PCT/EP2020/067091.

[0112] Therefore, this device 40 for managing the reserve of fabric in the accumulation stations 12 and 13 comprises the device 41 for assessing the amount of fabric comprised in the related station, so that, when the assessment device 41 detects that the amount of fabric in the station is lower than a limit threshold X, a command is generated to reverse the motion of the fabric exiting from said station.

[0113] Moreover, the device for managing the reserve of fabric 40 further comprises the device for sensing the tension of said fabric 42, and an electronic program adapted to adjust the value of the limit threshold X based on the state of tension of the fabric detected by the tension sensor device 42.

[0114] If when the device for assessing of the amount of fabric 41 detects an amount of fabric lower than the limit threshold X, the device for assessing the tension of the fabric verifies a critical state of tension for the fabric, the program modifies the limit threshold of amount of fabric in the station, increasing it by a predetermined value.

[0115] Advantageously, the device for managing the reserve of fabric 40 is adapted to memorize the number of events in which the assessment device 41 detects an amount of fabric in the station lower than a limit threshold, i.e., the number of reversals associated with the decrease of fabric in the related station; if the device detects a predetermined consecutive number of said events, the electronic program modifies the limit threshold of amount of fabric in the station, decreasing it by a predetermined value. [0116] In practice, advantageously, control of the reserves of the fabric on the accumulation stations for insertion and extraction takes place by means of devices for assessing the amount of fabric, for example weight measuring devices such as load cells, which, by means of appropriate settings, determine when the accumulation stations are empty and therefore the device reverses the movement of the fabric; if the control values of the load cells are not adjusted with the correct value, two situations can occur: either too large a reserve of fabric remains on the accumulation stations or the fabric is tensioned; by means of a device for assessing the tension, for example of the type operated mechanically, tensioning of the fabric is detected and, in this case, the control value of the load cell of the accumulation station in question is automatically increased; if during the subsequent reversal, the device for assessing the tension is triggered again, the control value of the load cell will be further increased and so forth, until the device for assessing the tension is no longer triggered; in this way, tensioning of the fabric is avoided. However, at the same time, there could be too large a reserve of fabric in the accumulation station; to remedy this, after a certain number of reversals of fabric feed have been successfully concluded, i.e., without the device for assessing the tension being triggered, the control value of the load cell is decreased; after the same number of reversals successfully concluded, the control value of the cell will be further decreased. This will continue until the device for assessing the tension is triggered again and consequently the control value of the load cell is once again increased.

[0117] With this system, the control values of the load cells self-adjust so that the reserves of fabric on the accumulation stations are not too large and so as to prevent the fabric from being subjected to stretching and tensioning.

[0118] Modification of the limit threshold of amount of fabric in the station takes place by equal incremental or decremental values.

[0119] The device for assessing the amount of fabric 41 in an accumulation station comprises at least one load cell connected to the accumulation tank 12A-13A. For example, the load cell is arranged above the accumulation tank, fixed to a support structure and connected to said tank by means of a connection member, such as a rope or a rod, so that said load cell is adapted to act in traction. Alternatively, the load cell is arranged below the tank, so that it is adapted to act in compression. [0120] The device for assessing the tension of the fabric 42 comprises, for example, a movable stop 42A, constrained to a support structure and adapted to move from an idle position to an activated position, and vice versa, and a sensor element 42B adapted to identify the movement of said movable stop from said idle position.

[0121] The machine 10, both in the case of being formed by a single module 10 A, and of a plurality of modules 10A arranged in succession, is capable of processing fabric continuously (with a speed corresponding to the second speed with which the fabric passes between the modules, and is continuously inserted into and extracted from the first and the last module), and can advantageously be inserted in a continuous fabric processing line. In this case, an apparatus for continuous insertion of the fabric from outside the machine into the first module and an apparatus for continuous extraction of the fabric from the last module will be present.

[0122] In other examples, the machine is adapted to process, during an operating cycle, a single portion of fabric accumulated in the accumulation stations, i.e., to process fabric discontinuously, so that all of the fabric is immediately arranged in the machine (with a single module or with several modules), for example manually, is subjected to the treatment cycle and is then extracted from the machine.

[0123] Therefore, the machine allows a treatment method for shrinking and dimensionally stabilizing a fabric carried out in at least one treatment module to be carried out. The fabric is accumulated alternately in the first accumulation station and in the second accumulation station by means of an alternating forward and return movement of the fabric between the two accumulation stations along the movement path 14, and wherein during movement, the fabric is impacted by a flow of air at a suitable temperature.

[0124] Along the movement path 14, the fabric is supported on the two movement surfaces 17A and 18 A, but is not supported in the free loop forming zone 19 defined between its movement surfaces, so that, during the movement, the free loop T1 is formed through gravity in this forming zone.

[0125] During the movement of the fabric, the presence of the free loop of fabric between the movement surfaces by means of the device 20 is monitored. [0126] If a lack or an excess of free loop T1 in this forming zone 19 is detected, the speed of at least one of said movement surfaces 17 A, 18A is modified to restore the correct amount of loop in the forming zone 19.

[0127] The moisture of the fabric in the chamber of the module can be detected, and, if this value is outside a given operating range, the amount and/or speed of the air fed toward the fabric is modified, and/or the temperature of the air fed is modified.

[0128] The heating air of the fabric passes through the fabric arranged on the movement surfaces 17A and 18 A, through suction from below these surfaces, such that the fabric arranged on these surfaces, during their movement, remains substantially stationary with respect thereto.

[0129] Advantageously, reversal of motion of the fabric between said accumulation stations 12 and 13 takes place when in a station an amount of accumulated fabric equal to or lower than a threshold value is measured or a tension of the fabric exiting from the accumulation station equal to or greater than a threshold value is measured, or takes place according to the operation of the device for managing the reserve described above.

[0130] The fabric is moved continuously through a module with the input and output speed of the fabric into/from the module lower than the movement speed of the fabric between the accumulation stations 12 and 13 of each module.

[0131] According to the treatment method, the speed of alternating movement of the fabric between the two accumulation stations is at least three times higher than the input and output speed of the fabric into/from the modules, and more in particular is at least five times higher than the input and output speed of the fabric into/from the modules, and even more preferably is between nine times and eleven times the value of the input and output speed of the fabric into/from the modules.

[0132] As said, forming zones of a free loop of the fabric are present between two consecutive treatment modules defined between movement surfaces of the fabric respectively for extraction and insertion of the fabric from and into the modules.

[0133] During movement of the fabric, the presence of the free loop of fabric between the insertion and extraction movement surfaces is monitored. If a lack or an excess of free loop in the forming zone is detected, the speed of at least one of said extraction and insertion movement surfaces is modified to restore the correct amount of loop in said forming zone.

[0134] It is understood that the above only represents possible non-limiting embodiments of the invention, which can vary in forms and arrangements without departing from the scope of the concept on which the invention is based. Any reference numbers in the appended claims are provided purely to facilitate their reading in the light of the description above and of the accompanying drawings and do not limit the scope of protection thereof in any way.