ROPE DYING MACHINE WITH MOTORISED DEPOSIT OF THE FABRIC FED BY A SYNCHRONISED ACCUMULATION SYSTEM AND RELATED PROCESS

The present invention refers to a rope dying machine with motorised deposit of the fabric fed by a synchronised accumulation system.

In particular, the device of the present invention concerns the accumulation and movement system of the "pack" of fabric contained in the drum of a dying machine of the aforementioned type, which allows the fabric to be deposited on a horizontal plane in prelapped form adjustable in relation to the type and amount of article treated. By the term rope dying, in the present invention we mean to indicate a dying process in which the cloth takes up a special rope-shaped structure during the course of the treatment operations. Currently, different types of dying machines are available on the market, which differ in their constructive and operative characteristics according to the type of fabric to be treated, the type of dye used (which may require operation under certain temperature and/or pressure conditions) , the possibility of operating continuously or discontinuously . One particular requirement of machines according to the

prior art consists of ensuring low bath ratios (the bath ratio being the ratio between the amount of goods present in the dying machine (expressed in kg) and the amount of bath water in use (expressed in litres) . Another particular requirement consists of ensuring that the loading and unloading time of the machines is low.

Italian patent no. 1108010 describes a machine for dying one or more ropes of fabric in the form of a closed loop, the purpose of which is to achieve low bath ratios. In particular, the dying machine comprises an impregnation area of the fabric with a dying liquid and a mobile mechanical transporter, with adjustable speed, in a closed loop and having a perforated surface for supporting the fabric, situated above the level of the dying liquid contained in a tank under the transporter, with an elbow-shaped tubular body with perforated walls being located between said impregnation area and said transporter. A reel picks up the fabric at the outlet of the transporter and feeds it to the impregnation area, from where the fabric passes back to the tubular body. The different speed of the reel and of the mechanical transporter ensure that, whilst crossing the tubular body, the fabric is shaped in laps. The perforated surfaces of the tubular body and of the support surface allow the excess dying

liquid to discharge from the fabric and to be collected in the tank.

The dying machine according to Italian patent no. 1108010 has a series of limitations, which have compromised its commercial success. Indeed, the lapped configuration system of the fabric through the fixed tubular body has little capability to optimise the arrangement of the fabric. For this reason, in the example embodiment of the invention according to patent no. 1108010, to increase the load two concentric loops have had to be foreseen, for the simultaneous treatment of two ropes. This solution does, however, have a second type of problem, since the two ropes, lying on the same surface on two concentric paths of different radius, are of different lengths. Consequently, the two concentric loops allow the treatment of different amounts of fabric.

Moreover, it has been noted that to reach acceptable loads, machines made according to the teachings of Italian patent no. 1108010 must have very large diameters, roughly 3350-3500 mm, with substantial transportation problems.

Moreover, the machine, as it has been conceived, does not allow the drum containing the fabric to be discharged, which means that the fabric loading and unloading steps require substantial amounts of time.

Italian patent no. 1227639 describes a dying machine the declared purpose of which is to reduce the treatment time, through mechanisation of the folding process and having it carried out separate from the actual machine. According to this solution, the fabric is folded outside of the machine, through a device suitable for carrying out the folding of the fabric in a perforated drum, reproducing the size and shape of the tank of the dying machine. Therefore, the drum already loaded with the fabric is introduced into the machine where dying is carried out, said machine being provided with a sealed inlet door. The drum can be removed at the end of the dying process, and immediately replaced with another drum containing ready prepared folded fabric.

The solution according to patent no. 1227639 also has some limitations, in particular due to the difficulty in moving the fabric inside the machine body and the low practicality of moving baskets that are 4-6 m long and about 600-800 mm wide.

It is easy to understand how both of the described solutions involve a series of limitations for this type of machine, in particular complicated operation, which also constitutes the main drawback, as well as limiting its maximum production capacity.

The purpose of the present invention is to make a rope

dying machine capable of working with a particularly low and constant bath ratio even as the load varies . Another purpose of the present invention is to provide a dying machine that allows the fabric loading and unloading operations to be carried out quickly.

Another purpose of the present invention is to make a dying machine capable of loading up to 200 kg of fabric and more in a single rope. A further purpose of the present invention is to provide a dying machine that is small in size, compared to its load capacity.

Another purpose of the present invention is to make a rope dying machine that is particularly simple and functional, with low manufacturing and operating costs. The last but not least purpose is to make a dying process in rope dying machines that allow various required steps to be performed so that a discontinuous production method is similar to a continuous production method . These purposes according to the present invention are accomplished by making a dying machine as outlined in claim 1.

Further characteristics of the dying machine of the present invention are foreseen in the dependent claims. The characteristics and advantages of a dying machine according to the present invention shall become clearer

from the following description, given as an example and not for limiting purposes, referring to the attached schematic drawings in which: figure 1 shows a top view of a dying machine according to the present invention, and figure 2 shows a top view of the dying machine of figure 1, seen from an angle rotated by about 90°. The invention is based upon a fabric moving, folding and synchrony control system. With reference to the figures, a rope dying machine 10 is shown, with a cylindrical shell 11 and an upper base plate 12, supported by at least three legs 13. The lower portion of the dying machine 10 consists of a lower base plate 14 on which a cylindrical drum 15 rests. The lower base plate 14 is slidably supported on the legs 13, so as to be able to take up a position in which it cooperates with the shell 11 to close the machine and so as to be able to be lowered in order to allow access to the drum 15, which can thus be removed without hindrance. The movement of the lower base plate 14 is controlled by a telescopic actuation arm 16 and is accompanied by guide means, consisting of wheels 17, rotatably coupled with tabs 18 fixed to form a unit with the lower base plate 14, which rotate on at least three tracks 19, each respectively present on one of the legs 13 for supporting the machine.

The system for moving fabric inside the dying machine 10 consists of a slatted or smooth dragging roll 20, a nozzle 21 fed with air and a transportation channel 22. The dragging of the fabric occurs by means of the airflow blown through the nozzle 21, therefore it is not necessary to have in the machine an amount of bath suitable for ensuring the head necessary for the operation of a centrifugal pump of 80-100 m ³ /h (which would, on the other hand, be necessary if the fabric were moved through a flow of water, like in known systems known as "jet" or "FLOW" or systems with nozzles having variable section) . The rope of fabric is passed over the dragging roller 20 and is then pushed into the transportation channel 22 by the airflow. On the end portion of the channel 22 for transporting the fabric an outlet mouth 23 is arranged that communicates with an accumulation duct 24, arranged perpendicularly and shaped with an end rotated to form a J, so that its outlet 25, which is located at the drum 15, is orientated on a horizontal axis. The width of the accumulation duct 24 is roughly equal to the radius of the drum 15, and its outlet 25 is arranged so as to occupy a portion of the drum 15 located between its centre and its side walls. The lapping of the fabric is carried out by the outlet mouth 23 of the transportation channel 22, which is made to translate

horizontally, perpendicular to the axis of the machine 10, with a back-and-forth movement. In this way, during its stroke, the outlet mouth 23 arranges the fabric in lapped form on the entire width of the duct 24. Moreover, to accumulate the fabric taking into account the different translation speeds of the "pack" of fabric on the circular-shaped drum 15, and therefore the different volumes that can be accumulated in the more central and more peripheral areas of the drum 15, the translation speed of the mouth 23 must be suitably varied. In particular, the mouth 23 shall move faster at the central area and slower at the peripheral area. The control of the translation speed of the mouth 23 is carried out by automatic control means. Thanks to the optimisation of the fabric lapping operations in the different sections, it is possible to obtain a very good degree of accumulation of the fabric . Moreover the dying machine 10 can be fed with fabric that has not yet been lapped or else that is pre- lapped. In the first case the fabric can be fed to the dying machine 10, to undergo a first lapping step even before starting the actual dying treatment. In this case, the fabric already shaped into a rope can be introduced into the dying machine 10 through a manhole 33 and cross the various components of the fabric moving system, going onto the drum 15 for the

subsequent dying step. Alternatively, the fabric is pre- lapped in the drum 15 by a lapping machine that differs from the dying machine 10 only in that it does not have the components needed for dying (which shall be illustrated with reference to the dying machine 10 later on in the description) . In particular, this lapping machine is equipped with the same lower base plate sliding along the vertical axis of the machine, so as to be able to be lowered until it allows access to the drum 15, which can thus be removed without hindrance, at the end of the lapping operations, to be sent to the dying machine 10.

With reference again to the figures illustrating the dying machine 10 according to the present invention, the drum 15 is made to rotate about its axis, through an actuation motor 26, which gives rotary motion to a support base 27 for the drum 15. The movement of the drum 15 allows the bath ratio to be reduced, since bath is not required to advance the "pack" of fabric deposited in the drum 15, as is on the other hand required in conventional machines, in which the drum is still and it is necessary to give relative motion between the fabric and the drum, through an amount of bath sufficient to ensure that the "pack" of fabric floats, and at the same time is dragged (necessary for machines with both horizontal and vertical extension) .

The dying bath is inserted in contact with the fabric through a nozzle 34 arranged in the fabric transportation channel 22.

The washing of the fabric, with water or other washing liquids, takes place through a special washing system, which comprises a series of nozzles 28, 35, 36. In particular, the nozzles 35, 36 subject the fabric to washing with water at the dragging roll 20 whereas the series of nozzles 28, arranged on one or more ducts 29 that lie over the drum 15 along its entire diameter, subject the fabric that is deposited in the drum 15 to washing.

Since the fabric is transported through an airflow, water is not necessary to move it forwards. The water can therefore be used exclusively for washing and is immediately separated from the fabric and then discharged from the dying machine 10, crossing a suitable perforation formed through a series of holes 30 on the surfaces of the drum 15 and a mouth 31 on the lower base plate 14.

The nozzles 28, 35, 36 can be fed with water coming from the mains or from a suitable preparation tank via pump.

Unlike conventional machines, the washing machines uses dedicated ducts and not the same ducts used for introducing the dye. The efficiency of this type of

washing is consequently very high, since the washing water, using the same circuit in which the dying bath passes, is prevented from being contaminated before it comes into contact with the fabric . The rotation mechanism and the mechanism for lifting the lower base plate 14 are independent .

The group of solutions proposed to move and impregnate fabric allow a constant bath ratio to be conserved even as the load varies. Indeed, as already seen, it is not necessary to have a part of the bath in the machine to be used to move forward the fabric and therefore the amount of bath that is loaded into the machine is just that which is necessary for dying, thus allowing the bath ratio to be maintained even with loads equal to just 10% of the maximum nominal load of the machine.

The dying machine 10 according to the present invention also comprises automatic control means, not shown. In particular, to determine the load of fabric possible without leaving the operator with the burden of having to suitably adjust the various parameters with the consequent inoperability of the machine itself, all of the adjustment parameters, like for example the speed of the dragging roll 20, the speed of the airflow of the nozzle 21, the rotation speed of the drum 15, the translation speed of the lapping mouth 23 according to the type and amount of fabric loaded, are completely

managed by automatic control means, managed by control software .

Thanks to the completely automated control software, the dying machine according to the present invention is easy to operate .

From what has been described, it is clear that the dying machine according to the present invention has a series of advantages compared to known machines of the same type . Firstly, the dying machine object of the present invention has the advantage of allowing the fabric to be deposited on a horizontal plane in lapped form, adjustable in relation to the type and amount of article treated. Moreover, the dying machine of the present invention can adapt to any type of article and work with constant bath ratios even as the load varies, in particular up to a reduction of the load such as to reach 10% of the nominal load of the machine . Moreover, the dying machine of the present invention allows the fabric loading and unloading steps to be carried out extremely quickly.

The aforementioned characteristics of the dying machine of the present invention make it possible to carry out the treatment cycle in distinct steps. It is thus possible to carry out the preparation of the fabric on

a machine equipped to carry out this particular step, the dying in another unit and the washing in yet another .

A further advantage of the dying machine of the present invention is the low bulk, in relation to the load capacity, which makes transportation possible with standard means. Indeed, the special lapping methods allow a substantial amount of fabric to be loaded in a small space (for example 200 kg of fabric in a drum having a diameter of less than 2.5 m) .

Moreover, the dying machine of the invention is easy to operate, thanks to the automatic control system. The dying machine thus conceived can undergo numerous modifications and variations, all of which are covered by the invention; moreover, all of the details can be replaced with technically equivalent elements. In practice, the materials used, as well as the sizes, can be whatever according to the technical requirements . Moreover, the invention also refers to a dying process in rope dying machines with processing cycle in steps able to be carried out with a machine as described above or similar in type.

The process consists of a first step in which some characteristics of the dying bath and of the fibre to be dyed are detected. For example, in this step a test is carried out on a laboratory machine with RGB

analysis of the bath suitable for determining a series of technological process information concerning behaviour (with particular reference to the speed at which the colour runs out) of the colour relative to the fibre to be dyed.

In a second step of the process of the invention, starting from the detected characteristics, a series of operative process parameters are determined and the setting of some significant variables of the system is calculated. For example, the dying cycle is worked out in terms of speed of temperature variation, speed of introduction of solids (salt, sulphate) and speed of introduction of alkalis/acids. The cycle depends upon the type of fibre and dye used in order to obtain a certain result (in terms of unity of the colour and reproduction of the laboratory sample) and can be repeated (reproducing the same colour in different times and loads) at the production stage. Such a cycle is automatically worked out by software that is based upon the date obtained in the first step, upon the characteristics of the production machine (rotation speed of the piece, rotation speed of the bath, product introduction system, etc.) and chemical-physical knowledge transferred in the software itself. Then follows a third step in which, during the course of the dying operations, the same significant variables

are detected in real time and some operative parameters are possibly modified to correct possible shifts of the measured values from the calculated values of the variables. Of course, according to the invention, since it can be successfully completed, the dying process can be advantageously carried out by means of a series of dying machines like those described above or similar, arranged in series with each other. For example, it is possible to foresee a series of machines suitable for carrying out one or more steps of the complete treatment cycle (preparations step, dying step, washing step) . In this way it is possible to foresee processing steps to be carried out in work stations if necessary arranged as occurs in a continuous process. In this case, after having studied the economic production lot, the amount to be produced is divided into so many economic production lots. Therefore, there is a predetermined amount of material that is transported in each processing unit or machine to carry out the relative step, transforming a discontinuous mode of production into a continuous production concept. It is thus clear that the better control of the process variables allows constant colour tones to be obtained even dividing the lot into many loads. Moreover, the

sharing out of the loads allows them to be divided so as to enter into the treatment line after one another, creating an almost continuous process. Therefore, the process consists, in short, of having developed a completely automated, predictive control system of the dying treatment .