Patent Publication Number: US-11660854-B2

Title: Continuous sublimation transfer method using a vacuum suction roller

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation-in-part of co-pending U.S. patent application Ser. No. 17/493,193 filed on Oct. 4, 2021 to Kim et al., entitled “Continuous Printing Apparatus Using Vacuum Suction Roller and Method Thereof”, which claims the benefit of priority to Korean Patent Application No. 10-2021-0100693, filed on Jul. 30, 2021, both of which are incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present invention relates to a continuous printing apparatus using a vacuum suction roller and a method thereof, which achieve cost saving and productivity improvement by continuously printing on the surface of a woven fabric using the vacuum suction roller. 
     BACKGROUND ART 
     In general, a dyeing method of fabrics comprises dyeing a woven fabric by introducing it in a dye solution. However, this method generates a large amount of wastewater, which causes environmental pollution, and has problems in complicated process and poor workability. 
     In addition, in the case of partial dyeing, it is necessary to correspond to color pattern through individual yarn dyeing before weaving, and there is a limitation in that a yarn having a desired color must be prepared. As a method of improving the above problems, there is a sublimation transfer method. 
     The sublimation transfer method may be to print with salts by applying heat and pressure in a state in which the printed sublimation transfer film is laminated on the surface of the woven fabric. In the general sublimation transfer method, there was a difficulty in mass production because the structure of the jig or the way of working were not suitable for continuous production. 
     Accordingly, there is a need for a technology capable of solving the above-described problems, which is environmentally friendly and capable of reducing costs and improving productivity. 
     DETAILED DESCRIPTION OF THE INVENTION 
     Technical Problem 
     The present invention relates to a continuous printing apparatus using a vacuum suction roller, and more particularly to a continuous printing apparatus using a vacuum suction roller and a method thereof which is capable of reducing costs and improving productivity by continuously printing on the surface of a woven fabric using the vacuum suction roller. 
     The technical problems to be solved by the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those of ordinary skill in the art to which the present invention pertains from the following description. 
     Solution to Problem 
     A continuous printing apparatus using a vacuum suction roller of the present invention may comprise: 
     a first unwinding roller for unwinding an air permeable fabric to be printed; 
     a second unwinding roller for unwinding a printing film coated with dye on one side surface; 
     a first heating unit for preheating the air permeable fabric unwound from the first unwinding roller; 
     a vacuum suction roller configured so that while the printing film is laminated on one side surface of the air permeable fabric that has passed through the first heating unit the other side surface of the air permeable fabric is in contact with one side of the roller; 
     a second heating unit positioned to be spaced from the surface of the vacuum suction roller in contact with the air permeable fabric at a certain interval to heat the air permeable fabric and the printing film; 
     a first recovery roller for recovering the air permeable fabric that has passed through the vacuum suction roller; and 
     a second recovery roller for recovering the printing film that passed through the vacuum suction roller. 
     In the continuous printing apparatus using the vacuum suction roller of the present invention, the lateral surface of the vacuum suction roller in contact with the air permeable fabric is formed of an air permeable porous material having a plurality of pores, and the gas containing the sublimated dye on the surface of the vacuum roller may be sucked into the vacuum suction roller through the plurality of pores to bring the printing film into close contact with the air permeable fabric. 
     In the continuous printing apparatus using the vacuum suction roller of the present invention, the air permeable material having the plurality of pores and forming the lateral surface of the vacuum suction roller in contact with the air permeable fabric may be selected from porous SUS, ceramic and gypsum. 
     In the continuous printing apparatus using the vacuum suction roller of the present invention, the air permeable fabric may be a knitted fabric or a woven fabric manufactured by a weaving method. 
     In the continuous printing apparatus using the vacuum suction roller of the present invention, the first heating unit may be to preheat the air permeable fabric to a temperature of 100° C. to 200° C. 
     In the continuous printing apparatus using the vacuum suction roller of the present invention, the material of the printing film may be selected from PET, A-PET, PP, PE and paper. 
     In the continuous printing apparatus using the vacuum suction roller of the present invention, the second heating unit may be to heat the air permeable fabric and the printing film to a temperature of 130° C. to 250° C. 
     The continuous printing apparatus using the vacuum suction roller of the present invention may further comprise a cooling roller for cooling the air permeable fabric by contacting one side of the roller with the air permeable fabric between the vacuum suction roller and the first recovery roller. 
     In the continuous printing apparatus using the vacuum suction roller of the present invention, the vacuum suction roller may comprise an inner cylinder having a cylindrical shape, an outer cylinder whose inner circumferential surface is formed to be spaced apart from an outer circumferential surface of the inner cylinder, and a porous layer covering the outer circumferential surface of the outer cylinder, the outer circumferential surface of the inner cylinder and the inner circumferential surface of the outer cylinder may be spaced apart from each other to provide a vacuum forming space, the outer cylinder may be provided with a plurality of suction holes, the sublimated dye gas located outside the outer cylinder may be sucked into the vacuum forming space through the plurality of suction holes after passing through the porous layer. 
     In the continuous printing apparatus using the vacuum suction roller of the present invention, the vacuum forming space may be separated into a plurality of spaces by a plurality of partition walls, and each space of the vacuum forming space separated by the partition walls may be provided with a cooling flow path. 
     The continuous printing method using the continuous printing apparatus using the vacuum suction roller of the present invention may comprise: 
     a fabric preparation and preheating step of unwinding the air permeable fabric from the first unwinding roller and then preheating it through the first heating unit; 
     a printing film arrangement step of unwinding the printing film from the second unwinding roller and then laminating it on one side surface of the air permeable fabric; 
     a dyeing step using the vacuum suction roller of passing the air permeable fabric through the vacuum suction roller to bring the other side surface of the air permeable fabric into contact with one side of the vacuum suction roller; 
     a printing film separation step of separating the printing film from the air permeable fabric; and 
     a dyed fabric cooling step of cooling the air permeable fabric by the cooling roller. 
     In the dyeing step using the vacuum suction roller of the continuous printing method of the present invention, the air permeable fabric in close contact with the vacuum suction roller may be heated by the second heating unit. 
     Effect of the Invention 
     The continuous printing apparatus and method using the vacuum suction roller of the present invention may exclude the use of a dyeing solution, thereby preventing the generation of wastewater and enabling an eco-friendly production process. 
     The continuous printing apparatus and method using the vacuum suction roller of the present invention enables mass-production through continuous production, thereby contributing to cost reduction. 
     The continuous printing apparatus and method using the vacuum suction roller of the present invention can produce high-quality fabrics with stable dyeing. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1    is a conceptual diagram showing a continuous printing apparatus using a vacuum suction roller of the present invention. 
         FIG.  2    is an enlarged cross-sectional view of an area of the dash-dotted line of  FIG.  1   . 
         FIG.  3 A  is a cross-sectional diagram showing the vacuum suction roller. 
         FIG.  3 B  is a cross-sectional diagram showing the vacuum suction roller of another embodiment. 
         FIG.  4    is a block diagram showing the continuous printing method of the present invention. 
     
    
    
     BEST MODE FOR CARRYING OUT THE INVENTION 
     Hereinafter, embodiments according to the present invention will be described in detail with reference to the accompanying drawings. The size or shape of the components shown in the drawings may be exaggerated for clarity and convenience of explanation. In addition, terms specially defined in consideration of the configuration and action of the present invention may vary depending on the intention or custom of the user or operator. Definition of these terms should be made based on the content throughout this specification. 
     In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms “center”, “top”, “bottom”, “left”, “right”, “vertical”, “horizontal”, “inside”, “outside”, “one side”, “other side”, etc. is based on the orientation or positional relationship shown in the drawings or the orientation or positional relationship that is usually arranged when using the product of the present invention, and it is only for the description and brief description of the present invention and is not intended to be construed as limiting the present invention because it does not suggest or imply that the indicated apparatus or device necessarily has the specified orientation and must be configured or operated in the specified orientation. 
       FIG.  1    is a conceptual diagram showing a continuous printing apparatus using a vacuum suction roller of the present invention.  FIG.  2    is an enlarged cross-sectional view of an area of the dash-dotted line of  FIG.  1   .  FIG.  3 A  is a cross-sectional diagram showing the vacuum suction roller.  FIG.  3 B  is a cross-sectional diagram showing the vacuum suction roller according to another embodiment.  FIG.  4    is a block diagram showing the continuous printing method of the present invention. 
     The continuous printing apparatus using the vacuum suction roller of the present invention may be to print dyes on the air permeable fabric  11  which is air permeable on both sides. In the continuous printing apparatus using the vacuum suction roller of the present invention, a sublimation transfer film that can be used for various purposes may be used as the printing film  12 , and the dye of the sublimation transfer film may be transferred to the air permeable fabric  11  by bringing the sublimation transfer film into close contact with the air permeable fabric  11  using the vacuum suction roller  400 . 
     As shown in  FIG.  1   , the continuous printing apparatus using the vacuum suction roller of the present invention may comprise: 
     a first unwinding roller  100  for unwinding an air permeable fabric  11  to be printed; 
     a second unwinding roller  200  for unwinding a printing film  12  coated with dye on one side surface; 
     a first heating unit  300  for preheating the air permeable fabric  11  unwound from the first unwinding roller  100 ; 
     a vacuum suction roller  400  configured so that while the printing film  12  is laminated on one side surface of the air permeable fabric  11  that has passed through the first heating unit  300  the other side surface of the air permeable fabric  11  is in contact with one side of the roller; 
     a second heating unit  500  positioned to be spaced from the surface of the vacuum suction roller  400  in contact with the air permeable fabric  11  at a certain interval to heat the air permeable fabric  11  and the printing film  12 ; 
     a first recovery roller  700  for recovering the air permeable fabric  11  that has passed through the vacuum suction roller  400 ; and 
     a second recovery roller  800  for recovering the printing film  12  that passed through the vacuum suction roller  400 . 
     The air permeable fabric  11  may be printed. The air permeable fabric  11  is made of an air permeable material, and may be applicable without limitation to the material that is air permeable between one side surface to which the dye is transferred and the other side surface. 
     For example, the air permeable fabric  11  may be a knitted fabric or a woven fabric manufactured by a weaving method. There is no limitation on the weaving pattern of the air permeable fabric  11 , and one side surface of the air permeable fabric  11  to which dye is transferred may be applicable without limitation among flat surfaces or three-dimensional surfaces provided with protrusions and concave portions. 
     The air permeable fabric  11  may be prepared with being wound around the cylindrical first unwinding roller  100 . 
     Before the printing film  12  is laminated on one side surface of the air permeable fabric  11 , the air permeable fabric  11  may be preheated through the first heating unit  300 . 
     The first heating unit  300  may be preheated to a temperature at which the air permeable fabric  11  is not deformed or damaged by heat. For example, the first heating unit  300  may be to preheat the air permeable fabric  11  to a temperature of 100° C. to 200° C. 
     The first heating unit  300  is provided in the form of a chamber having a heating means  310  therein, and the air permeable fabric  11  may be preheated while passing through the first heating unit  300 . The heating means  310  may be an IR heater. 
     The printing film  12  may be a sublimation transfer film. A dye id applied to one side surface of the printing film  12 , and the dye of the printing film  12  may be transferred to one side surface of the air permeable fabric  11  by heat and pressure. The printing film  12  may be laminated on the preheated air permeable fabric  11  so that one side surface of the printing film  12  coated with dye faces one side surface of the air permeable fabric  11 . The printing film  12  may be printed (applied) in a predetermined pattern or color. 
     The material of the printing film  12  may be selected from PET, A-PET, PP, PE and paper. The printing film  12  is made of a non-air-permeable material and may be compressed on the surface of the vacuum suction roller  400  with the air permeable fabric  11  therebetween by the suction force of the vacuum suction roller  400 . 
     The material of the printing film  12  is determined in consideration of the weaving pattern of the air permeable fabric  11 . For example, when the surface of the air permeable fabric  11  is formed as a three-dimensional surface, the printing film  12  may be preferably made of a thermoplastic film such as A-PET. 
     The printing film  12  may be prepared while being wound around the cylindrical second unwinding roller  200 . 
     The vacuum suction roller  400  is provided in a cylindrical shape and the lateral surface may be in contact with the air permeable fabric  11  having the printing film laminated. Specifically, as shown in  FIG.  2   , while the air permeable fabric  11  and the printing film  12  are laminated so that one side surface of the air permeable fabric  11  is in contact with one side surface of the printing film  12  coated with dye  13 , the other side surface of the air permeable fabric  11  may be in close contact with the surface of the vacuum suction roller  400 . 
     A plurality of pores is formed on the lateral surface of the vacuum suction roller  400  in contact with the breathable fabric  11 , and the gas containing the sublimated dye on the surface of the vacuum suction roller  400  is sucked into the vacuum suction roller  400  through the plurality of pores to bring the printing film  12  into close contact with the air permeable fabric  11 . Specifically, the dye of the printing film  12  is sublimated by the second heating unit  500 , which will be described later, and then the sublimated gaseous dye is guided into the pores by the negative pressure formed inside the vacuum suction roller  400 . In the process, the dye may be stably adsorbed to the air permeable fabric  11 . 
     The air permeable material having the plurality of pores and forming the lateral surface of the vacuum suction roller  400  in contact with the air permeable fabric  11  may be selected form porous SUS, ceramic and gypsum. The air permeable material having the plurality of pores and forming the lateral surface of the vacuum suction roller  400  in contact with the air permeable fabric  11  is not limited thereto, and any air permeable material having heat resistance capable of withstanding the heat emitted from the second heating unit  500  may be used without limitation. 
     The vacuum suction roller  400  is formed of a cylindrical cylinder that is air permeable inside and outside, and the cylindrical cylinder is provided with suction holes or has a porous structure, so that there is air permeable inside and outside. When a vacuum is applied inside the cylindrical cylinder, the gas on the surface of the cylindrical cylinder is sucked into the cylinder, thereby adsorbing the air permeable fabric  11  and the printing film  12  on the surface. 
     Specifically, as shown in  FIG.  3 A , the vacuum suction roller  400  may comprise an inner cylinder having a cylindrical shape  410 , an outer cylinder  420  whose inner circumferential surface is formed to be spaced apart from an outer circumferential surface of the inner cylinder  410 , and a porous layer  430  covering the outer circumferential surface of the outer cylinder  420 . 
     The central axis of the inner cylinder  410  may be a rotation axis. The outer cylinder  420  is also provided in a cylindrical shape, and the outer cylinder  420  may be provided with a plurality of suction holes  421 . The external gas of the outer cylinder  420  may be sucked into the outer cylinder  420  through suction holes  421 . Specifically, the outer circumferential surface of the inner cylinder  410  and the inner circumferential surface of the outer cylinder  420  may be spaced apart from each other to provide a vacuum forming space  440 , and the sublimated dye gas located outside the outer cylinder  420  may be sucked into the vacuum forming space  440  through the hole  421  after passing through the porous layer. 
     At this time, in order to prevent the negative pressure from being concentrated at the suction hole  421  on the outer circumferential surface of the outer cylinder  420 , the outer circumferential surface of the outer cylinder  420  may be covered with an air permeable porous layer  430 . By providing the porous layer  430 , the entire surface of the vacuum suction roller  400  may have a constant air permeability. 
     The porous layer  430  may be formed to a thickness of 5 mm to 15 mm More preferably, the porous layer  430  may be formed to a thickness of 7 mm to 12 mm. The difference in air permeability for each portion of the porous layer  430  may be 1 cfm to 10 cfm. More preferably, the difference in air permeability for each portion of the porous layer  430  may be 2 cfm to 3 cfm. For example, the porous layer  430  between the vacuum forming space  440  and the outer space of the outer cylinder  420  may be formed to have the air permeability of 1 cfm to 10 cfm. 
     The porous layer  430  may be at least one selected from porous SUS, ceramic and gypsum. The porous layer  430  is manufactured by a template method, a replication method, a direct foaming method, etc. using ceramic or gypsum as a material, or manufactured by sintering metal powders or wires of SUS. 
     In another embodiment, as shown in  FIG.  3 B , the vacuum forming space  440  may be separated into a plurality of spaces by the partition walls  441 . By separating the vacuum forming space into a plurality of spaces by the partition walls  441 , when a local temperature or pressure imbalance occurs in the vacuum forming space  440 , the pressure or temperature of the individual space may be independently controlled. The partition wall  441  may extend in the direction of the central axis of the inner cylinder  410  and may be formed in a plane parallel to the radial direction of the inner cylinder  410 . 
     Each space of the vacuum forming space separated by the partition walls may be provided with a cooling flow path  442 . The cooling flow path  442  may be provided for temperature correction of the outer circumferential surface of the vacuum suction roller  400 . 
     The second heating unit  500  may heat the air permeable fabric  11  and the printing film  12 . The second heating unit  500  may include an IR heater as a heat source. 
     The second heating unit  500  may be provided in a semi-cylindrical shape corresponding to the surface of the vacuum suction roller  400 , and the inner circumferential surface of the vacuum suction roller  400  spaced apart from the outer circumferential surface by a predetermined distance. 
     The second heating unit  500  may be for accelerating the sublimation function of the printed sublimation transfer dye of the printing film  12 , Therefore, the second heating unit  500  may be to heat the air permeable fabric  11  and the printing film  12  to 130° C. to 250° C. 
     The printing apparatus using the vacuum suction roller of the present invention may further comprise a cooling roller for cooling the air permeable fabric  11  by contacting one side of the roller with the air permeable fabric  11  between the vacuum suction roller  400  and the first recovery roller  700 . 
     The dye transferred to the air permeable fabric  11  may be stabilized by the cooling roller  600  and the air permeable fabric  11  that has passed through the cooling roller  600  may be a printed product, which is recovered by the first recovery roller  700 . 
     The printing film  12  after use may be recovered by the second recovery roller  800 . 
     As shown in  FIG.  4   , the continuous printing method using the vacuum suction roller of the present invention may comprise: 
     a fabric preparation and preheating step (S 10 ) of unwinding the air permeable fabric  11  from the first unwinding roller  100  and then preheating it through the first heating unit  300 ; 
     a printing film arrangement step (S 20 ) of unwinding the printing film  12  from the second unwinding roller  200  and then laminating it on one side surface of the air permeable fabric  11 ; 
     a dyeing step (S 30 ) using the vacuum suction roller  400  of passing the air permeable fabric  11  through the vacuum suction roller to bring the other side surface of the air permeable fabric  11  into contact with one side of the vacuum suction roller  400 ; 
     a printing film separation step (S 40 ) of separating the printing film  12  from the air permeable fabric  11 ; and 
     a dyed fabric cooling step (S 50 ) of cooling the air permeable fabric  11  by the cooling roller  600 . 
     In the dyeing step using the vacuum suction roller  400 , the air permeable fabric  11  in close contact with the vacuum suction roller  400  may be heated by the second heating unit  500 . 
     Although the embodiments according to the present invention have been described above, these are merely exemplary, and those of ordinary skill in the art will understand that various modifications and equivalent ranges of embodiments are possible therefrom. Accordingly, the true technical protection scope of the present invention should be defined by the following claims. 
     EXPLANATION OF CODE 
     
         
         
           
               11  . . . air permeable fabric 
               12  . . . printing film 
               13  . . . dye 
               100  . . . first unwinding roller 
               200  . . . second unwinding roller 
               300  . . . first heating unit 
               310  . . . heating means 
               400  . . . vacuum suction roller 
               500  . . . second heating unit 
               600  . . . cooling roller 
               700  . . . first recovery roller 
               800  . . . second recovery roller