Patent Publication Number: US-2012042455-A1

Title: Device for treating a yarn, system for the treatment of a yarn and method of treating a yarn

Description:
TECHNICAL FIELD OF THE INVENTION 
     The object of the present invention is a device for treating a yarn, a system for the treatment of a yarn and a method of treating a yarn. 
     In particular, the present invention is for application in the textile industry for dyeing a yarn or applying substances thereon. 
     BACKGROUND ART 
     In the state-of-the-art, if it is desired to apply dyes on a yarn, it is necessary to immerge hanks or reels thereof into dyeing baths and, afterwards, to subject it to thermal cycles in water, vapour and/or inside a plain oven to stabilize the applied substance. 
     Alternatively, the same yarns can be printed by applying spouts of dye either to the hanks laid over belts, or to threads stretched between a plurality of printing cylinders. 
     Likewise, if it is desired to apply powdery substances to the yarn, such as glitters or other chemical solutions, it is necessary using either typical vat- or bath-dyeing systems, or manual or automatic systems for spraying such substances onto the hanks stretched over belts or onto the yarns stretched between cylinders. 
     These standardized processes imply a considerable waste of dye as well as a significant cost for energy, inasmuch as they require baths of sensibly large quantities of substances; moreover, such processes are unable to control the dye pattern along the axis of the thread, as they can actually control it only along the surface of the hank or, at the most, along the axis of the yarn being cylinder-printed, but always with repetitive, invariable and uncontrollable motifs. 
     Besides, such standard processes do not allow using heat-stabilizations able to continuously treat the yarn through thermal cycles that would stabilize the nano-particles solutions within water or other solvents based on, for example, titanium dioxide of plain nature or doped with other elements (vanadium, silver, etc.) that would give the yarn photocatalytic and antibacterial properties. 
     DISCLOSURE OF THE INVENTION 
     In this context, the technical task on which the present invention is based is to propose a device for treating a yarn, and a system for the treatment of the yarn, which are able to overcome the above cited drawbacks of the prior art. 
     Moreover, the object of the present invention is to propose a method of treating a yarn to be made with said system in which the said device is included. 
     In particular, the object of the present invention is to provide a device for treating a yarn, said device being able to simplify the treatment thereof by avoiding waste of substances and reducing the consumption of energy required for the treatment. 
     A further object of the present invention is to propose a system and a method of treating a yarn which allow the pattern of the colour to be controlled along the axis of the thread in order to achieve the desired motifs. 
     Finally, the object of the present invention is to provide a method of treating yarns which makes it possible to thermally stabilize the yarn to give it photocatalytic and antibacterial properties. 
     The indicated technical task and specified objects are substantially achieved by a device for treating a yarn, a system for the treatment of the yarn and a method of treating the yarn which include the technical characteristics set forth in one or more of the appended claims. 
    
    
     
       Further characteristics and advantages of the present invention will appear more clearly from a reading of the indicative and thus non-limiting description of a preferred but non-exclusive embodiment of a device for treating a yarn and a system for the treatment of the yarn, as illustrated in the accompanying drawings, wherein: 
         FIG. 1  is a first side view of a device for treating a yarn according to the present invention; 
         FIG. 2  is a section view of the device shown in  FIG. 1 ; 
         FIG. 3  is a schematic representation of the system for the treatment of a yarn according to the present invention and including the device shown in  FIGS. 1 and 2 . 
     
    
    
     With reference to the attached figures, numeral  1  indicates as a whole a device for treating a yarn F according to the present invention. 
     In particular, the yarns that can be treated by the device which is an object of the present invention are of natural, or synthetic or blend fibres (wool, cotton, acrylic). 
     The device  1  comprises a main body  2 , preferably of cylindrical shape, having a treatment chamber  3  formed therein. 
     Said chamber  3  extends longitudinally throughout the axis  2   a  of the main body  2 , between a first  2   b  and a second  2   c  ends of body  2 . 
     The yarn F moves through the device  1  and enters the chamber  3  via an inlet section located in correspondence of the first end  2   b  of main body  2  and exits from an outlet section located in correspondence of the second end  2   c  opposite to the first one. 
     The device  1  also exhibits at least a first side channel  4 , located in fluid communication with the treatment chamber  3 . Introduced into the chamber  3  through such channel  4  is in fact at least one substance for treating the yarn F. 
     The substances that can be used are of liquid or powdery nature such as dyes, solutions of nano-particles, glitters or other chemical products to be applied on the yarn F inside the treatment chamber  3 , and are such as to give the same yarn F the desired effects. 
     The introduction of said treating substances in a controlled manner through one or more solenoid valves and one or more channels makes it possible to apply different substances over different stretches of the yarn by controlling the patterns and effects over the length of same yarn. 
     The main body  2  of device  1  further exhibits at least a second side channel  5  also being in fluid-communication with the treatment chamber  3 . 
     The second side channel  5  is intended for the admission of compressed air into the chamber  3 . 
     The first side channel  4  creates a fluid communication between the treatment chamber  3  and a relevant conduit  6  for the admission of the treating substances. 
     Advantageously, alternative embodiments provide for two or more side channels  4  connected to respective conduits  6  for the admission of more substances for treating either elements, such as fibres, or buttons, according to the effect to be obtained. 
     The first  4  and second  5  side channels are spaced apart along the axial development of main body  2 . 
     Preferably, the first channel  4  is located between the second end  2   c  and a central region of main body  2 , whereas the second channel  5  is between the central region and the first end  2   b  of the main body  2 . 
     Disposed externally around the main body  2  of device  1  is a sleeve  7 . 
     An annular chamber  8  is defined between the sleeve  7  and the main body  2 . 
     Said annular chamber is located to be in fluid communication with the treatment chamber  3  via the second channel  5 . 
     The sleeve  7  exhibits an inlet mouth  9  for the admission of compressed air into the annular chamber  8 . 
     A tight seal of sleeve  7  around the main body  2  is ensured by opposite gaskets  10 . 
     Advantageously, provision is made for two or more second side channels  5  able to put the treatment chamber  3  into fluid communication with annular chamber  8 . 
     The introduction of compressed air into the treatment chamber  3  generates a vacuum region  3   a  in proximity of the exit section  2   c  of treatment chamber  3 . 
     The vacuum region  3   a  is generated because inside the treatment chamber  3 , up to the level of introduction of compressed air, the air present therein has a velocity and a pressure, the latter being likely the atmospheric pressure and, therefore, less than that of the compressed air. Such pressure differential gives rise to a vacuum region and, at the opposite end close to the inlet section  2   b  of chamber  3 , to a pressurized region  3   b.    
     The compressed air is admitted into the chamber  3  by preferably directing it to the first end  2   b  of the main body  2 . 
     In proximity of the second channel  5 , instead, a region  3   c  of nebulization of the substance injected within the treatment chamber  3  is created in the middle of the latter, between the first side channel  4  and second side channel  5 . The nebulization of the introduced substance takes place because said substance is sucked up within the chamber  3  by the compressed air admitted therein, which is a consequence both of the difference between the pressure in the substance-admitting conduit  6  and the pressure inside the chamber  3 , and of the eddy current, as described above, which is generated inside the chamber. 
     The device  1  can be inserted in a system  11  for the treatment of the yarn F, schematically represented in  FIG. 3 . 
     The system  11  comprises at least one conduit  6  for feeding the substance to be used, possibly operated by systems for metering and controlling the solutions to be applied for the treatment of the yarn F, said conduit  6  leading up to the first side channel  4 . 
     Provision is also made for a delivery conduit  13  which admits compressed air and leads to the inlet mouth  9  on sleeve  7 , and for a conduit  12  discharging the compressed air blended with fibres detached from the yarn. 
     The discharge conduit  12  is in fluid communication with the first end  2   b  of the main body  2  of device  1 . 
     A suction nozzle  14  intercepts the discharge conduit  12 . Connected downstream of the suction nozzle  14  is at least one filtering apparatus  15  able to separate the textile fibres that have come off the yarn F during the treatment of the air. 
     Preferably, two filtering apparatuses are present in series: the first of them, named cyclone  15 , has the function of separating textile fibres of greater dimensions. 
     Located downstream of cyclone  15  is a second filtering apparatus, named scrubber  16 , able to filter fibres and particulates of smaller dimensions not retained by the cyclone  15 . 
     Finally, downstream of the outlet section  2   c  of treatment chamber  3 , the system exhibits at least one apparatus of heat-stabilization  17 . The yarn F going through the apparatus  17 , after having being subjected to the treatment, to stabilize the applied solution. 
     The preset system makes it possible to implement a method of continuously treating the yarn F, the method being able to apply simultaneously, along the axis of same yarn, one or more dyeing solutions, glitters or nano-solutions, or other liquid or powdery solutions, directly within the treatment chamber  3  into which compressed air is also introduced. 
     The device  1 , as will be described below, is supplied with compressed air and is provided with tubes  6 ,  13  controlled by solenoid valves operated by an automatic control system which allows the liquid solution to be withdrawn from one or more vessels over preset periods so as to apply selected solutions for controlled times, and consequently lengths, of yarn. 
     In this way, it is possible to produce a yarn F exhibiting different colours, patterns, designs, special effects or definite chemical properties (such as antibacterial property lent by nano-particles of titanium dioxide also doped with other elements, or magnetic properties lent by nano-particles of cobalt, ferrite, etc.) throughout its length. 
     The compressed air introduced into the device  1  generates, as above mentioned, a vacuum region  3   a  which pushes the air from the top of device  1 , which is vertically oriented as shown in  FIGS. 1 and 2 , that is, from the second end  2   c  of main body  2  to the bottom or first end  2   b . Introduced in proximity of the second end  2   c  of device  1 —in the very vacuum space created by the effect of the compressed air—are the chemical solutions to be applied to the yarn F via one or more feeding conduits  6  and a system, the latter being able to control the time of application of same solutions by presetting solenoid valves located on the feeding lines. This system can therefore define for how long every single solution is to be fed and applied to generate effects deriving from continuous, or discontinuous, or length-by-length treatments while selecting different solutions for each portion of the yarn F as desired. The introduction of the compressed air into the device  1  constructed with properly designed geometries, creates a vacuum that sucks the air from above and pushes it downward by nebulizing the injected solution and generating a confined atmosphere consisting of a downward vertical flow of air and nebulized solution. 
     The yarn F is introduced from the bottom of main body  2 , that is, from the first end  2   b , and travels in counterflow the region of the above described atmosphere. 
     By going through the treatment chamber  3 , the yarn F is impregnated with a chemical solution (nano-particles, dye, glitters, etc.) and exits upward from the second end  2   c  of main body  2 . 
     Thereafter, the yarn F keeps going upward and enters one or more apparatuses of thermal stabilization  17  which remove the water and solvent from the yarn F and allow the latter to undergo the thermal cycles necessary to stabilize the solution (nano-particles, dye, glitters, etc.) applied thereto. 
     The atmosphere of air and nebulized solution proceeds downwards, through a discharge conduit  12 , and is sucked up through the nozzle  14 , again by the effect of the compressed air, so as to never enter in contact with the external environment. 
     The atmosphere of air and nebulized solution is then introduced into the cyclone  15  which, as above mentioned, removes solution agglomerates and any residue of heavier yarn&#39;s fibres therefrom and, subsequently, the same atmosphere goes into a scrubber  16  which removes any particulate of minor dimensions not retained in the previous stage, thereby emitting clean air at the end of the process. 
     The filtering operated by the cyclone and the scrubber may also be omitted in case of a “disposable system”. 
     The described method is therefore a process under controlled vacuum for the application of solutions of nano-particles, dyes, glitters or other chemical products on a yarn F through a continuous treatment, able to controllably apply such solutions on the yarn, and, the subsequent introduction of same yarn into a heat-stabilization apparatus intended to fix the solutions thereon. 
     The invention achieves the envisaged objects and offers major advantages. 
     Actually, since the process of application of chemical solution (dye, glitter, nano-particles, etc.) on the yarn takes place within an ambient totally vacuum-confined and with controlled flow, the operating environment is fully isolated from the application system, with consequent improvement of safety for the operators. 
     The treatment of the yarn F is carried out within a chamber having an extremely reduced volume and, accordingly, the process results highly energy-efficient and of low consumption of reagents, with respect to the traditional print- or bath-processes, thereby having a minimum environmental impact per processed thread. 
     Since the solutions are vacuum-applied, the flow of air—in counter-direction to the thread on output from the device—operates a first drying thereof, thereby reducing the need of ovens. 
     The possibility of having controlled axial ovens within the stabilization apparatus, allows subjecting the yarn—as a function of its relative humidity and feeding velocity—to definite thermal cycles which are absolutely necessary for the application of both simple solutions, such as dyes and glitters, and complex solutions above all, such as nano-particles of different nature, which require—in order to achieve a sufficient level of solidity—extremely precise and sufficiently high thermal levels for the materials in question (100-150° C. and above). 
     The system for controlling the introduction of one or more solutions makes it possible to treat the yarn centimeter-by-centimeter in different way by obtaining, for example, controlled sequences of colour or of a plurality of colours (if dyeing solutions are used), sequences of effects (when using resins, glitters or other effect-lending solutions), sequences of different chemical-physical properties (if nano-particles solutions or powders are used). 
     Finally, the system could be also totally or in part fitted directly onto the heads of spinning machines (of rings, or open ends type, etc.) for the formation of the raw yarn, so as to perform a single process for the spinning and finishing thereof.