Patent Publication Number: US-2022212482-A1

Title: Image forming apparatus and image forming method

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This is a continuation application of International Application No. PCT/JP2020/036237 filed on Sep. 25, 2020 which claims the benefit of priority from Japanese patent application No. 2019-180441 filed on Sep. 30, 2019. The entire contents of the earlier applications are incorporated herein by reference. 
    
    
     BACKGROUND 
     When performing printing by ink on a cloth for which dyed chemical fibers are used, a heat treatment is performed so as to fix the ink. At this time, dye-transfer sublimation that dye transfers to an ink layer may occur. In order to suppress the dye-transfer sublimation, an image forming method of forming a dye-transfer sublimation suppression layer including activated carbon on a cloth by screen printing, ejecting ink thereon, and then performing a heat treatment is suggested. 
     When forming the dye-transfer sublimation suppression layer by screen printing, it is necessary to make a plate for screen printing for each of different images to be printed. Therefore, there is a problem that man-hours and costs are required to make the plates. 
     SUMMARY 
     An object of the present disclosure is to provide an image forming apparatus and an image forming method, which enable to print images of various designs while reducing an influence of dye-transfer sublimation. 
     A first aspect of the present disclosure is an image forming apparatus including a supplier and an inkjet head. The supplier is configured to supply, to a medium to be printed, a dye-transfer suppression agent that suppresses a dye or a pigment dyeing chemical fibers constituting the medium to be printed from transferring to a print surface formed on the medium to be printed. At least one of a platen on which the medium to be printed is placed or the supplier is moved to supply the dye-transfer suppression agent to the medium to be printed. The inkjet head is configured to eject ink for forming the print surface to an area to which the dye-transfer suppression agent is supplied. 
     In the image forming apparatus, the supplier is configured to eject the dye-transfer suppression agent to the medium to be printed. Thereby, it is possible to print various images while suppressing the dye or the pigment dyeing the chemical fibers from transferring to the print surface formed on the medium to be printed. 
     A second aspect of the present disclosure is an image forming method performed by an image forming apparatus including a supplier, an inkjet head and a controller. The supplier is configured to supply, to a medium to be printed, a dye-transfer suppression agent that suppresses a dye or a pigment dyeing chemical fibers constituting the medium to be printed from transferring to a print surface formed on the medium to be printed. At least one of a platen on which the medium to be printed is placed or the supplier is moved to supply the dye-transfer suppression agent to the medium to be printed. The inkjet head is configured to eject ink for forming the print surface. The controller performs the steps of causing the dye-transfer suppression agent to be supplied from the supplier to the medium to be printed, and causing ink for forming the print surface to be ejected to an area to which the dye-transfer suppression agent is supplied. 
     In the image forming method, the supplier is configured to supply the dye-transfer suppression agent to the medium to be printed. Thereby, it is possible to print various images while suppressing the dye or the pigment dyeing the chemical fibers from transferring to the print surface formed on the medium to be printed. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a side sectional view of a printing apparatus  1 . 
         FIG. 2  is a rear view showing an internal structure of a heater  4  of the printing apparatus  1 . 
         FIG. 3  is a plan view of a carriage  13 . 
         FIG. 4  is a block diagram showing a schematic electrical configuration of the printing apparatus  1 . 
         FIG. 5  is a flowchart of first print processing. 
         FIG. 6  is a plan view showing arrangement of the carriage  13  and a fabric  3 . 
         FIG. 7  is a plan view showing arrangement of the carriage  13  and the fabric  3 . 
         FIG. 8  is a flowchart of second print processing. 
         FIG. 9  is a sub-routine of first dye-transfer suppression agent ejection processing. 
         FIG. 10  is a sub-routine of second dye-transfer suppression agent ejection processing. 
         FIG. 11  is a plan view showing arrangement of the carriage  13  and the fabric  3 . 
     
    
    
     DETAILED DESCRIPTION 
     A printing apparatus  1  according to a first embodiment of the present disclosure will be described with reference to the drawings. In descriptions below, the right and left, the front and rear, and the upper and lower are indicated using arrows in the drawings. A direction facing from the front toward the rear is hereinafter referred to as “conveying direction”. 
     Structure of Printing Apparatus  1   
     A structure of a printing apparatus  1  is described with reference to  FIG. 1 . The printing apparatus  1  includes a printing unit  2 , an ink cartridge accommodating unit (not shown), a heater  4 , and the like. A front wall of a housing  9  of the printing unit  2  is provided with an opening  10  through which a platen  31  and a medium to be printed such as a fabric placed on the platen  31  can enter and exit. 
     A printing area  11  where printing on the medium to be printed is performed is provided in a part covered by the housing  9  of the printing unit  2 . In the printing area  11 , a printing head  12  and a carriage  13  are provided, and guide rods  14  and  15  are bridged in the right and left direction (front direction and inner direction on the drawing sheet). As shown in  FIG. 3 , the printing head  12  includes a pretreatment agent head  121 , a white head  122 , and a color head  123 . The pretreatment agent head  121  is also denoted as ‘P’ in  FIG. 3 . The white head  122  is also denoted as ‘W’ in  FIG. 3 . The color head  123  is also denoted as ‘C’ in  FIG. 3 . 
     The pretreatment agent head  121 , the white head  122 , and the color head  123  include a plurality of nozzle alignments in a main scanning direction (right and left direction), respectively. The nozzle alignments of the pretreatment agent head  121  are such that a plurality of nozzles (not shown) for ejecting droplets of a pretreatment agent, which will be described later, is aligned in a sub-scanning direction (front and rear direction). The nozzle alignments of the white head  122  are such that a plurality of nozzles (not shown) for ejecting droplets of white ink (white (W)), which will be described later, is aligned in the sub-scanning direction (front and rear direction). The nozzle alignments of the color head  123  are such that a plurality of nozzles (not shown) for ejecting droplets of color inks of black (B), yellow (Y), cyan (C) and magenta (M), which will be described later, is aligned in the sub-scanning direction (front and rear direction). As shown in  FIG. 3 , the carriage  13  is configured to mount thereon the pretreatment agent head  121 , the white head  122  and the color head  123  from an upstream side toward a downstream side with respect to the sub-scanning direction. In the first embodiment, a dye-transfer suppression agent, which will be described later, is mixed with the pretreatment agent. 
     As shown in  FIG. 1 , a carriage motor  18  is provided at a right end portion (an inner portion in the direction of the drawing sheet) of the printing area  11 . The carriage  13  is connected to a belt (not shown) extending in parallel to the guide rods  14  and  15 . The belt extends between a pulley (not shown) connected to the carriage motor  18  and a pulley (not shown) provided at a left end portion of the printing area  11 . Driving the carriage motor  18  causes the carriage  13 , on which the printing head  12  is mounted, to move in the main scanning direction (right and left direction) along the guide rods  14  and  15 . 
     The ink cartridge accommodating unit is configured to accommodate a plurality of ink cartridges. The respective ink cartridges store a pretreatment agent including a dye-transfer suppression agent, white ink, and color ink, respectively. The pretreatment agent, the white ink, and the color ink stored in the ink cartridges are supplied to the pretreatment agent head  121 , the white head  122 , and the color head  123  via a tube (not shown), respectively. 
     A guide rail (not shown) is provided in the front and rear direction at the center of the printing area  11  and a heating area  21 , which will be described later. The guide rail is configured to guide a platen support part  61  configured to support the platen  31  in the front and rear direction. The platen  31  has a plate shape lengthwise in the front and rear direction, as seen from above. 
     A platen motor  26  is provided near a front end portion of the guide rail. A pulley  16  is fixed to an output shaft of the platen motor  26 . A pulley  24  is rotatably supported on a bottom part ahead of the pulley  16 . A belt  17  extends over the pulley  16  and the pulley  24 . A pulley  28  is rotatably supported below the heating area  21 . A belt  25  extends over the pulley  24  and the pulley  28 . The platen support part  61  is connected to the belt  25 . The pulley  16  is configured to rotate by rotary drive of the platen motor  26 . The rotation of the pulley  16  causes the pulley  24  to rotate via the belt  17 . The rotation of the pulley  24  is transmitted to the belt  25 , so that the platen support part  61  moves in the sub-scanning direction (front and rear direction) along the guide rail. 
     The heater  4  is provided behind the printing unit  2 . A heating area  21  is provided in a housing  20  of the heater  4 . A heating mechanism  30  is provided in the heating area  21 . The heating mechanism  30  is configured to heat the medium to be printed so as to fix an image printed on the medium to be printed, for example. 
     As shown in  FIGS. 1 and 2 , the heating mechanism  30  includes an intermediate plate  40  at a horizontal posture, a heat press plate  34 , an elastic support mechanism  55 , an elevating drive mechanism  56 , and the like. 
     The heat press plate  34  includes a heat sheet part  32 , a heat insulating plate  33 , and the like. The heat insulating plate  33  is fixed to an upper surface of the heat sheet part  32 . The heat sheet part  32  includes a heat sheet  32 A and a heat storage material (not shown). The heat sheet  32 A is a heat generating body in which a nichrome wire is arranged. The heat storage material is an iron member configured to store heat generated by the heat sheet  32 A and arranged so as to sandwich the heat sheet  32 A therebetween. 
     The elastic support mechanism  55  is configured to elastically support the heat press plate  34  so as to be slidable in the upper and lower direction with respect to the intermediate plate  40 . The elastic support mechanism  55  is respectively provided at each of four corners of the heat insulating plate  33 . The elevating drive mechanism  56  is configured to drive up and down the heat press plate  34  so as to come into contact with and to separate from a surface of the medium to be printed placed on the platen  31 . The elevating drive mechanism  56  is configured to drive up and down by a rotary drive force of a heat press motor  47  (refer to  FIG. 2 ). 
     Electrical Configuration of Printing Apparatus  1   
     As shown in  FIG. 4 , the printing apparatus  1  includes a CPU  81 , a ROM  82 , a RAM  83 , a storage device  84 , an operation unit  85 , a display unit  86 , an input and output unit  87 , a communication unit  88 , drive circuits  90  to  97 , and the like, which are mutually connected via a bus. The CPU  81  is configured to control the printing apparatus  1 , to read various programs from the ROM  82 , to use the RAM  83  as a working memory, and to execute a variety of processing. 
     The storage device  84  is a non-volatile storage device such as a flash memory and an HDD. The storage device  84  is configured to store programs for first print processing, second print processing, first dye-transfer suppression agent ejection processing and second dye-transfer suppression agent ejection processing and the like, data of various setting screens, parameters, and the like, which will be described later. The operation unit  85  includes an operation panel and the like (not shown). An operator&#39;s instruction is input to the CPU  81  via the operation unit  85 . The display unit  86  is configured by a well-known display device or the like. The input and output unit  87  includes an SD memory card slot, a USB (registered trademark) port, and the like. A PC (personal computer)  100 , a camera  101  and the like may be connected to the input and output unit  87 . 
     The communication unit  88  has at least one of a wireless module (not shown) and a wired module (not shown), and can be connected to an external apparatus (not shown) such as a terminal apparatus via a network (not shown). 
     The drive circuit  90  is connected to the pretreatment agent head  121 , and is configured, under control of the CPU  81 , to eject droplets of the pretreatment agent including a dye-transfer suppression agent from the nozzles. The drive circuit  91  is connected to the white head  122 , and is configured, under control of the CPU  81 , to eject droplets of the white ink from each nozzle of the white head  122 . The drive circuit  92  is connected to the color head  123 , and is configured, under control of the CPU  81 , to eject droplets of the color ink from each nozzle of the color head  123 . The drive circuit  92  is connected to the carriage motor  18 , and is configured, under control of the CPU  81 , to drive the carriage motor  18 . The drive circuit  92  is connected to the platen motor  26 , and is configured, under control of the CPU  81 , to drive the platen motor  26 . The drive circuit  92  is connected to the heat press motor  47 , and is configured, under control of the CPU  81 , to drive the heat press motor  47 . The drive circuit  92  is connected to the heat sheet  32 A, and is configured, under control of the CPU  81 , to cause the heat sheet  32 A to generate heat. Note that, in a case of a second embodiment, which will be described later, the pretreatment agent does not include a dye-transfer suppression agent, and the printing apparatus  1  includes a drive circuit  97  and a dye-transfer suppression agent head  124 , in addition to the above-described electrical configuration. The dye-transfer suppression agent head  124  is connected to the drive circuit  97 , and is configured, under control of the CPU  81 , to eject droplets of the pretreatment agent including a dye-transfer suppression agent from the nozzles. In the first embodiment, the drive circuit  97  and the dye-transfer suppression agent head  124  are not necessary. 
     Pretreatment Agent 
     The pretreatment agent is a base coating agent that is applied before ink is applied to a fabric  3  (refer to  FIGS. 6 and 7 ) that is a medium to be printed. As an example, a multivalent metal salt (CaCl 2 , Ca(NO 2 ) 2  and the like) is included to make an expressed color of the ink vivid. 
     Dye-Transfer Sublimation 
     When performing printing by ink on a cloth for which dyed chemical fibers, particularly, polyester fibers are used, a heat treatment is performed so as to fix the ink. At this time, the heat treatment may cause a sublimation phenomenon in the dye dyeing the fibers, resulting in dye-transfer sublimation that the dye transfers to an ink layer. In order to solve this problem, a method of lowering a temperature of the heat treatment and performing the fixing is considered. However, when the temperature of the heat treatment is lowered, the fixing may become insufficient, resulting in a problem that an abrasion resistance of a coating film surface of the ink is lowered. Therefore, in the present embodiment, the dye-transfer suppression agent is ejected to the fabric  3 . 
     Dye-Transfer Suppression Agent 
     In the first embodiment, in order to suppress dye-transfer sublimation, the pretreatment agent including the dye-transfer suppression agent is ejected from the pretreatment agent head  121  to the fabric  3 . The dye-transfer suppression agent includes, for example, a porous member, a resin component, glycols, water, and a surfactant. Examples of the porous member include activated carbon, zeolite, MOF (METAL Organic Frameworks), or the like. Since activated carbon is porous, it has a large surface area for its volume and has an adsorption property of adsorbing a lot of substances. Zeolite also has a porous structure, has extremely small continuous cavities, and thus has an adsorption property. MOF is an artificially synthesized porous body and has an excellent adsorption property. A content of the porous member in the dye-transfer suppression agent is, for example, 5% to 20%. The dye-transfer suppression agent may be colored, and for example, the dye-transfer suppression agent including activated carbon is gray. In addition, the dye-transfer suppression agent including zeolite is milky white. Further, the porous member including MOF is blue when the MOF includes copper or iron. The porous member included in the dye-transfer suppression agent adsorbs the dye dyeing the fibers when dye-transfer sublimation occurs, and suppresses the dye from transferring to the ink surface. In addition, the porous member can suppress the pigment dyeing the fibers from transferring to a print surface. An example of an average particle size of activated carbon when the porous member is activated carbon is described. For example, WO2019/131209 discloses activated carbon having an average particle size of 20 μm or smaller ([0051] paragraph]. The average particle size of activated carbon may be equal to or smaller than a nozzle diameter of the pretreatment agent head  121 . An example of the resin component is a binder resin. A content of the binder resin in the dye-transfer suppression agent is, for example, 5% to 20%. The binder resin suppresses the ejected dye-transfer suppression agent from being peeled off due to washing of the fabric  3 , and enhances washing resistance. Examples of the binder resin include urethane, acrylic, styrene, or the like. The binder resin may also be a water-soluble emulsion. An example of glycols is glycerin. The pretreatment agent suppresses fluffing of the fabric  3  and also suppresses ink spreading. 
     First Print Processing 
     First print processing of the printing apparatus  1  is described with reference to  FIG. 5 . In the first print processing, as shown in  FIG. 6 , it is premised that the pretreatment agent head  121 , the white head  122 , and the color head  123  are arranged in the sub-scanning direction on the carriage  13  and the pretreatment agent head  121  ejects droplets of the pretreatment agent including the dye-transfer suppression agent. First, when the platen  31  is located at a set position P 1  shown in  FIG. 1 , the operator sets the fabric  3 , which is an example of the medium to be printed, on the platen  31 . An example of the fabric  3  is a shirt made of polyester. When the CPU  81  detects that a predetermined operation has been performed via the operation unit  85  by the operator, the CPU  81  reads a first print processing program from the ROM  82  and executes the first print processing. In addition, when the CPU  81  receives an instruction to start printing from the PC  100 , the CPU  81  also starts the first print processing. 
     As shown in  FIG. 5 , the CPU  81  first drives the platen motor  26  via the drive circuit  94  to convey the platen  31  on which the fabric  3  is placed from the set position P 1  (refer to  FIG. 1 ) to a printing position P 2  (refer to  FIG. 1 ) (S 1 ). The printing position P 2  is a position where the platen  31  reaches directly below the pretreatment agent head  121 . As shown in  FIG. 6 , the fabric  3  is placed at a predetermined position on the platen  31 . It is assumed that an image is printed in a rectangular area  3 A having P 11 , P 12 , P 13 , and P 14  as apexes on the fabric  3 . In this case, an area to which the white ink is ejected is the area  3 A. In addition, an area to which the color ink is ejected is also the area  3 A. The CPU  81  moves the platen  31  to a scanning position L 1  including the position P 11 , which is an ejection start position of the pretreatment agent by the pretreatment agent head  121 . At this time, a front end  121 A of the pretreatment agent head  121  is located at the scanning position L 1 . 
     Next, the CPU  81  executes ejection processing of the pretreatment agent and the dye-transfer suppression agent (S 2 ). The CPU  81  moves the carriage  13  rightward, and ejects the pretreatment agent including the dye-transfer suppression agent from the pretreatment agent head  121  to the area  3 A where the pretreatment agent and the dye-transfer suppression agent need to be applied. The CPU  81  sequentially moves the platen  31  rearward, reciprocally moves the carriage  13  in the main scanning direction (right and left direction), and ejects the pretreatment agent from the pretreatment agent head  121 . When the ejection of the pretreatment agent up to the position P 14  is completed, the CPU  81  ends the ejection of the pretreatment agent from the pretreatment agent head  121 . An amount of ejection of the dye-transfer suppression agent included in the pretreatment agent is a predetermined specified amount. Note that, when an instruction to perform first dye-transfer suppression agent ejection processing (refer to  FIG. 9 ) or second dye-transfer suppression agent ejection processing ( FIG. 10 ), which will be described later, to change the amount of ejection of the dye-transfer suppression agent has been input from the operation unit  85 , the CPU  81  executes a subroutine of the first dye-transfer suppression agent ejection processing or the second dye-transfer suppression agent ejection processing, in the processing of S 2 . 
     Next, the CPU  81  conveys the platen  31  to a heating position P 3  (S 4 ). As shown in  FIG. 1 , the heating position P 3  is a position in the heater  4  where the platen  31  reaches directly below the heat press plate  34 . When the platen  31  reaches the heating position, the CPU  81  performs a preheating treatment (S 5 ). The preheating treatment is a treatment for fixing the pretreatment agent and the dye-transfer suppression agent. For example, the CPU  81  drives the heat press motor  47  (refer to  FIG. 4 ) via the drive circuit  95  (refer to  FIG. 4 ) to push down the heat press plate  34  (refer to  FIG. 2 ) toward the platen  31 , thereby bringing the heat press plate  34  into contact with the fabric  3  (refer to  FIG. 6 ). The CPU  81  causes the heat sheet  32 A to generate heat for a predetermined time for preheating, via the drive circuit  96 . An example of the predetermined time is within  30  seconds. Thereafter, the CPU  81  drives the heat press motor  47  (refer to  FIG. 4 ) to move the heat press plate  34  (refer to  FIG. 2 ) upward. 
     Next, the CPU  81  drives the platen motor  26  to convey the platen  31  from the heating position P 3  (refer to  FIG. 1 ) to the printing position P 2  (refer to  FIG. 1 ) (S 6 ). Next, the CPU  81  executes white ink ejection processing (S 7 ). For example, the CPU  81  moves the platen  31  to a position where a front end portion  122 A of the white head  122  coincides with the scanning position L 1  including the position P 11 , which is an ejection start position of the white ink by the white head  122 . Next, the CPU  81  moves the carriage  13  rightward, and ejects the white ink from the white head  122  to the area  3 A (S 7 ). The CPU  81  sequentially moves the platen  31  rearward, reciprocally moves the carriage  13  in the main scanning direction (right and left direction), and ejects the white ink by the white head  122 . When the ejection of the white ink up to the position P 14  is completed, the CPU  81  ends the ejection of the white ink from the white head  122 . 
     Next, the CPU  81  executes color ink ejection processing (S 8 ). For example, the CPU  81  moves the platen  31  to a position where a front end portion  123 A of the color head  123  coincides with the scanning position L 1  including the position P 11 , which is an ejection start position of the color ink by the color head  123 . Next, the CPU  81  moves the carriage  13  rightward, and ejects the color ink from the color head  123  to the area  3 A (S 8 ). The CPU  81  sequentially moves the platen  31  rearward, reciprocally moves the carriage  13  in the main scanning direction (right and left direction), and ejects the color ink by the color head  123 . When the ejection of the color ink up to the position P 14  is completed, the CPU  81  ends the ejection of the color ink from the color head  123 . Note that, during a period after the front end portion  123 A of the color head  123  reaches the scanning position L 1  shown in  FIG. 6  until the front end portion  122 A of the white head  122  reaches the scanning position L 2 , the CPU  81  may perform the white ink ejection processing (S 7 ) and the color ink ejection processing (S 8 ) at the same time. In addition, the CPU  81  may move the platen  31  to a position where the scanning position L 2  including the position P 13  is directly below the white head  122 , sequentially move the platen  31  forward, reciprocally move the carriage  13  in the main scanning direction (right and left direction) and cause the white head  122  to eject the white ink. Similarly, the CPU may move the platen  31  to a position where the scanning position L 2  including the position P 13  is directly below the color head  123 , sequentially move the platen  31  forward, reciprocally move the carriage  13  in the main scanning direction (right and left direction) and cause the color head  123  to eject the color ink. 
     Next, the CPU  81  conveys the platen  31  to the heating position P 3  (S 9 ). Since the processing of S 9  is similar to the processing of S 4 , the description thereof is omitted. When the platen  31  reaches the heating position P 3 , the CPU  81  performs a main heating treatment (S 10 ). The main heating treatment is processing of fixing the white ink and color ink ejected on the fabric  3 . For example, the CPU  81  drives the heat press motor  47  (refer to  FIG. 4 ) via the drive circuit  95  (refer to  FIG. 4 ) to push down the heat press plate  34  (refer to  FIG. 2 ) toward the platen  31 , thereby bringing the heat press plate  34  into contact with the fabric  3 . The CPU  81  causes the heat sheet  32 A to generate heat for a predetermined time for main heating longer than the preheating treatment, via the drive circuit  96 . An example of the predetermined time is within  10  minutes. Thereafter, the CPU  81  drives the heat press motor  47  (refer to  FIG. 4 ) to move the heat press plate  34  (refer to  FIG. 2 ) upward. Note that, in the preheating treatment and the main heating treatment, the CPU  81  may cause the heat sheet  32 A to generate heat before pushing down the heat press plate  34  toward the platen  31 . 
     Next, the CPU  81  drives the platen motor  26  to convey the platen  31  to the set position P 1  (S 11 ). At the set position P 1 , the operator removes the fabric  3  from the platen  31 . 
     Second Embodiment 
     Next, a second embodiment of the present disclosure is described with reference to  FIGS. 7 and 8 . In the second embodiment, the pretreatment agent does not include a dye-transfer suppression agent, and the dye-transfer suppression agent is ejected from the dye-transfer suppression agent head  124  provided with nozzles for ejecting the dye-transfer suppression agent. For example, as shown in  FIG. 7 , the carriage  13  is configured to mount thereon the pretreatment agent head  121 , the dye-transfer suppression agent head  124 , the white head  122  and the color head  123  from an upstream side toward a downstream side with respect to the sub-scanning direction. The dye-transfer suppression agent head  124  is also denoted as ‘A’ in  FIG. 7 . 
     When the CPU  81  detects that a predetermined operation has been performed via the operation unit  85  by the operator or when an instruction to start printing is received from the PC  100 , the CPU  81  reads a second print processing program from the ROM  82  and executes the second print processing. 
     Second Print Processing 
     In the second print processing, since the processing of S 1  and S 4  to S 11  is the same as the processing of S 1  and S 4  to S 11  of the first print processing, only processing of S 2  and S 3  is described. When the CPU  81  conveys the platen  31  to the printing position P 2  (refer to  FIG. 1 ) (S 1 ), the CPU  81  executes pretreatment agent ejection processing (S 2 ). For example, the CPU  81  moves the platen  31  to the scanning position L 1  including the position P 11 , which is an ejection start position of the pretreatment agent by the pretreatment agent head  121 . At this time, the front end  121 A of the pretreatment agent head  121  is located at the scanning position L 1 . Next, the CPU  81  moves the carriage  13  rightward, and ejects the pretreatment agent from the pretreatment agent head  121  to the area  3 A. The CPU  81  sequentially moves the platen  31  rearward, reciprocally moves the carriage  13  in the main scanning direction (right and left direction), and ejects the pretreatment agent from the pretreatment agent head  121 . When the ejection of the pretreatment agent up to the position P 14  is completed, the CPU  81  ends the ejection of the pretreatment agent from the pretreatment agent head  121 . 
     Next, the CPU  81  executes dye-transfer suppression agent ejection processing (S 3 ). For example, the CPU  81  moves the platen  31  to a position where a front end portion  124 A of the dye-transfer suppression agent head  124  coincides with the scanning position L 1  including the position P 11 , which is an ejection start position of the dye-transfer suppression agent by the dye-transfer suppression agent head  124 . Next, the CPU  81  moves the carriage  13  rightward, and ejects the dye-transfer suppression agent from the dye-transfer suppression agent head  124  to the area  3 A. The CPU  81  sequentially moves the platen  31  rearward, reciprocally moves the carriage  13  in the main scanning direction (right and left direction), and ejects the dye-transfer suppression agent from the dye-transfer suppression agent head  124 . When the ejection of the dye-transfer suppression agent up to the position P 14  is completed, the CPU  81  ends the ejection of the dye-transfer suppression agent from the dye-transfer suppression agent head  124 . Note that, the CPU  81  may move the platen  31  to a position where the scanning position L 2  including the position P 13  is directly below the dye-transfer suppression agent head  124 , sequentially move the platen  31  forward, reciprocally move the carriage  13  in the main scanning direction (right and left direction) and cause the dye-transfer suppression agent head  124  to eject the dye-transfer suppression agent. An amount of ejection of the dye-transfer suppression agent is a predetermined specified amount. Note that, when an instruction to perform first dye-transfer suppression agent ejection processing (refer to  FIG. 9 ) or second dye-transfer suppression agent ejection processing ( FIG. 10 ), which will be described later, to change the amount of ejection of the dye-transfer suppression agent has been input from the operation unit  85 , the CPU  81  executes a subroutine of the first dye-transfer suppression agent ejection processing or the second dye-transfer suppression agent ejection processing, in the processing of S 3 . 
     Next, the first dye-transfer suppression agent ejection processing shown in  FIG. 9  and the second dye-transfer suppression agent ejection processing shown in  FIG. 10  are described. The first dye-transfer suppression agent ejection processing and the second dye-transfer suppression agent ejection processing are processing of changing an amount of ejection of the dye-transfer suppression agent to be ejected, in the processing of S 2  of the first print processing and the processing of S 3  of the second print processing. The CPU  81  may execute at least one of the first dye-transfer suppression agent ejection processing and the second dye-transfer suppression agent ejection processing, as a subroutine of the processing of S 2  of the first print processing and the processing of S 3  of the second print processing. The CPU  81  may also execute at least one of the first dye-transfer suppression agent ejection processing except S 26  and the second dye-transfer suppression agent ejection processing except S 36  in advance before the first print processing or the second print processing. 
     When the CPU  81  starts the first dye-transfer suppression agent ejection processing shown in  FIG. 9 , the CPU  81  first executes information acquisition processing (S 21 ) of the material of the fabric  3 . For example, the CPU  81  acquires information on the material of the medium to be printed input from the operation unit  85 . Examples of the information on the material include a type of the material, a color of the material, a dyeing method of the material, and the like. Examples of the type of the material include polyester, nylon, acrylic, other chemical fibers, cotton, and other natural fibers. Examples of a material in which it is easy for dye-transfer sublimation to occur include polyester. Examples of a material in which it is difficult for dye-transfer sublimation to occur include cotton or other natural fibers. Examples of the color of the material include a color in which it is difficult for dye-transfer sublimation to occur, and other colors. Examples of a color in which it is easy for dye-transfer sublimation to occur include red or black. Examples of the dyeing method of the material include cation dyeing and other dyeing methods. The cation dyeing is a dyeing method in which it is difficult for dye-transfer sublimation to occur. In the storage device  84 , a type of a material, a color of a material, and a dyeing method of a material in which it is difficult for dye-transfer sublimation to occur and a type of a material type, a color of a material, and a dyeing method of a material in which it is easy for dye-transfer sublimation to occur, which are input in advance by the operator, are stored. 
     Next, the CPU  81  determines whether the fabric  3  is a material in which it is difficult for dye-transfer sublimation to occur, based on the information acquired in the processing of S 21  (S 22 ). For example, in the determination processing of S 22 , the CPU  81  determines whether the type of the material acquired in the processing of S 21  is stored in the storage device  84  as a material in which it is difficult for dye-transfer sublimation to occur. When it is determined that the fabric is a material in which it is difficult for dye-transfer sublimation to occur (S 22 : YES), the CPU  81  reduces an amount of the dye-transfer suppression agent, as compared to a preset amount (S 23 ). The amount to be reduced is set in advance. The CPU  81  sets an amount of ejection of the dye-transfer suppression agent after reduction as a specified amount (S 25 ). In addition, when it is not determined that the fabric is a material in which it is difficult for dye-transfer sublimation to occur (S 22 : NO), the CPU  81  keeps the amount of the dye-transfer suppression agent at a preset value (S 24 ). Thereafter, the CPU  81  executes the dye-transfer suppression agent ejection processing (S 26 ), and ends the first dye-transfer suppression agent ejection processing. 
     Next, the second dye-transfer suppression agent ejection processing is described with reference to  FIG. 10 . First, the CPU  81  extracts a position where a color of an image to be formed in the area  3 A of the fabric  3  has a density value larger than a predetermined density or a brightness value smaller than a predetermined brightness, based on print data stored in the RAM  83  (S 31 ). The print data is received in advance from the PC  100  or an external memory connected to the input and output unit  87  by the CPU  81  before the first print processing and the second print processing, and is stored in the RAM  83 . The print data is data of an image that is printed on the fabric  3 . For the density value, for example, a saturation may be used. For the brightness value, a color value (L value) may be used. When there is a position where the density value is large or the brightness value is small (S 32 : YES), the CPU  81  reduces an amount of ejection of the dye-transfer suppression agent to the corresponding position, as compared to the preset value (S 33 ). The amount to be reduced is set in advance. The CPU  81  sets an amount of ejection of the dye-transfer suppression agent after reduction as a specified amount (S 35 ). When it is not determined that there is a position where the density value is large or the brightness value is small (S 32 : NO), the CPU  81  keeps the amount of the dye-transfer suppression agent at a preset amount (S 34 ). Thereafter, the CPU  81  executes the dye-transfer suppression agent ejection processing (S 36 ), and ends the second dye-transfer suppression agent ejection processing. Therefore, in the ejection processing (S 26 , S 36 ), the CPU  81  can change the amount of ejection of the dye-transfer suppression agent at each ejection timing of the dye-transfer suppression agent in the area  3 A having the apexes P 11  to P 14 . 
     Third Embodiment 
     Next, a third embodiment of the present disclosure is described with reference to  FIG. 11 . In the third embodiment, the alignment of the heads on the carriage  13  is different from the second embodiment shown in  FIG. 7 . As shown in  FIG. 11 , the carriage  13  of the third embodiment is configured to mount thereon the dye-transfer suppression agent head  124 , the pretreatment agent head  121 , the white head  122  and the color head  123  from the upstream side toward the downstream side with respect to the sub-scanning direction. Therefore, in the third embodiment, the dye-transfer suppression agent is first ejected from the dye-transfer suppression agent head  124  to the area  3 A of the fabric  3 , the pretreatment agent is ejected from the pretreatment agent head  121  to the area  3 A, the white ink is ejected from the white head  122  to the area  3 A, and then the color ink is ejected from the color head  123  to the area  3 A. The other processing is the same as the second embodiment. Note that, the positional relationship between the dye-transfer suppression agent head  124  and the pretreatment agent head  121  on the carriage  13  is not necessarily limited to that shown in  FIG. 11 . For example, the white head  122 , the color head  123 , the dye-transfer suppression agent head  124 , and the pretreatment agent head  121  may be arranged in corresponding order from the upstream side to the downstream side with respect to the sub-scanning direction. In addition, the white head  122 , the color head  123 , the pretreatment agent head  121 , and the dye-transfer suppression agent head  124  may be arranged in corresponding order. Further, the pretreatment agent head  121 , the white head  122 , the color head  123 , and the dye-transfer suppression agent head  124  may be arranged in corresponding order. Further, the dye-transfer suppression agent head  124 , the white head  122 , the color head  123 , and the pretreatment agent head  121  may be arranged in corresponding order. 
     Effects of Embodiments 
     The printing apparatus  1  of the first aspect of the present disclosure includes the pretreatment agent head  121  configured to eject, to the fabric  3 , the pretreatment agent including the dye-transfer suppression agent for suppressing the dye or the pigment dyeing the chemical fibers constituting the fabric  3  from transferring to a print surface formed on the fabric  3 . The printing apparatus also includes the white head  122  and the color head  123  configured to eject inks for forming the print surface to the area  3 A where the dye-transfer suppression agent is ejected. Therefore, in the printing apparatus  1 , the pretreatment agent head  121  ejects the dye-transfer suppression agent to the fabric  3 , so that the dye-transfer sublimation that the dye or the pigment dyeing the chemical fibers transfers to the print surface formed on the fabric  3  can be suppressed and various images can be printed. In addition, the printing apparatus  1  of the second aspect of the present disclosure includes the dye-transfer suppression agent head  124  configured to eject, to the fabric  3 , the dye-transfer suppression agent for suppressing the dye or the pigment dyeing the chemical fibers constituting the fabric  3  from transferring to the print surface formed on the fabric  3 . The printing apparatus also includes the white head  122  and the color head  123  configured to eject inks for forming the print surface to the area  3 A where the dye-transfer suppression agent is ejected. Therefore, in the printing apparatus  1 , the dye-transfer suppression agent head  124  ejects the dye-transfer suppression agent to the fabric  3 , so that the dye-transfer sublimation that the dye or the pigment dyeing the chemical fibers transfers to the print surface formed on the fabric  3  can be suppressed and various images can be printed. 
     The pretreatment agent head  121  is configured to eject the dye-transfer suppression agent including a resin component or having a color to the area  3 A where the white head  122  and the color head  123  eject ink. Therefore, since the dye-transfer suppression agent is ejected to the area to which the inks are ejected, the dye-transfer suppression agent is not ejected to an area to which the inks are not ejected, except the area  3 A. Therefore, when the dye-transfer suppression agent includes a resin component or the dye-transfer suppression agent is colored, a conspicuous application mark of the dye-transfer suppression agent is reduced. 
     The printing apparatus  1  of the second embodiment includes the white head  122 , the color head  123 , and the pretreatment agent head  121  configured to eject the pretreatment agent to the area  3 A to which the white ink is ejected from at least the white head  122 , before the dye-transfer suppression agent head  124  ejects the dye-transfer suppression agent. Therefore, since the pretreatment agent is ejected before the dye-transfer suppression agent is ejected to the area  3 A and then the dye-transfer suppression agent is ejected, it is possible to suppress the dye or the pigment dyeing the chemical fibers from transferring to the white ink. Therefore, a clear image is printed even when the white ink is ejected. The printing apparatus  1  of the third embodiment includes the white head  122 , the color head  123 , and the pretreatment agent head  121  configured to eject the pretreatment agent to the area  3 A after the dye-transfer suppression agent head  124  ejects the dye-transfer suppression agent. Therefore, since the pretreatment agent is ejected after the dye-transfer suppression agent is ejected to the area  3 A, the same effects as the printing apparatus  1  of the second embodiment can be realized. 
     Further, the printing apparatus  1  of the second embodiment includes the heater  4  configured to perform the heat treatment for the fabric  3 , and the heater  4  is configured not to perform the heat treatment after ejection of the pretreatment agent but to perform the heat treatment after ejection of the dye-transfer suppression agent. In this case, film formation of the pretreatment agent and fixing of the dye-transfer suppression agent by the heat treatment can be performed at the same timing. Therefore, the treatment time is shortened, as compared to a case where the film formation of the pretreatment agent and the fixing of the dye-transfer suppression agent are separately performed by the heat treatment. 
     Further, the printing apparatus  1  includes the dye-transfer suppression agent head  124  configured to eject the dye-transfer suppression agent, and the carriage  13  configured to mount thereon the dye-transfer suppression agent head  124 , the white head  122 , and the color head  123 . Therefore, since the dye-transfer suppression agent head  124 , the white head  122  and the color head  123  are mounted on the same carriage  13 , a positional deviation between a dye-transfer suppression agent ejection area and an ink ejection area is reduced. 
     The dye-transfer suppression agent includes porous fine particles (for example, activated carbon, zeolite, or MOF) having an adsorption property. In this case, the fine particles having the adsorption property can capture the dye or the pigment and suppress the dye-transfer sublimation. 
     Since the dye-transfer suppression agent includes activated carbon, the cost of the dye-transfer suppression agent can be reduced by using the low-cost activated carbon. 
     Further, the printing apparatus  1  includes the heater  4  configured to perform the heat treatment for the fabric  3  and the CPU  81  as a controller, and the CPU  81  performs the preheating treatment (S 5 ) for the fabric  3  before the white ink is ejected from the white head  122  to the fabric  3 , ejects the color ink from the color head  123  to the fabric  3  after the preheating treatment, and thereafter performs the main heating treatment (S 10 ), which takes longer than the preheating treatment. Therefore, by performing the preheating treatment and the long-time main heating treatment, it is possible to suppress the dye or the pigment dyeing the chemical fibers from transferring to the white ink layer by the dye transfer suppression member while improving an image quality. 
     Further, the CPU  81  of the printing apparatus  1  is configured to change the amount of the dye-transfer suppression agent that is ejected from the dye-transfer suppression agent head  124 , based on the material of the fabric  3 . In this case, when the fabric  3  is made of a material in which it is difficult for the dye or the pigment to transfer to the print surface formed on the fabric  3 , an amount of the dye-transfer suppression agent is reduced. Therefore, it is possible to reduce a possibility that the dye-transfer suppression agent will be ejected more than necessary. 
     Further, the CPU  81  of the printing apparatus  1  is configured to extract a position where the color of the image formed in the area  3 A of the fabric  3  has a density value larger than a predetermined density, and to change the amount of the dye-transfer suppression agent, which is ejected from the dye-transfer suppression agent head  124  to the fabric  3 , depending on the position on the print surface, in the second dye-transfer suppression agent ejection processing. In this case, since the amount of the dye-transfer suppression agent to be ejected can be reduced, depending on the position on the print surface, the amount of the dye-transfer suppression agent can be saved and the cost can be thus reduced. 
     At a position where the color of the image formed by the color ink has a density value larger than the predetermined density value or a brightness value smaller than a predetermined brightness, the CPU  81  may reduce the amount of the dye-transfer suppression agent, which is ejected from the dye-transfer suppression agent head  124  to the fabric  3 , to a predetermined amount or smaller. In this case, since a part where a printed color is deep or dark is less susceptible to an influence of an appearance of dye-transfer sublimation, the cost can be reduced by reducing the amount of the dye-transfer suppression agent. 
     An image forming method that is executed by the printing apparatus  1  of the present disclosure includes a step of dye-transfer suppression agent ejection processing (S 3 ) of causing the dye-transfer suppression agent to be ejected from the dye-transfer suppression agent head  124  to the fabric  3 , and a step of color ink ejection processing (S 8 ) of causing the color ink for forming a print surface to be ejected from the color head  123  to the area  3 A in which the dye-transfer suppression agent is ejected. Therefore, in the image forming method, the dye-transfer suppression agent head  124  ejects the dye-transfer suppression agent to the fabric  3 , so that the dye or the pigment dyeing the chemical fibers can be suppressed from transferring to the print surface formed on the fabric  3  and various images can be printed. 
     The present disclosure is not limited to the above embodiment, and can be variously changed. For example, the acquisition processing (S 21 ) of the material information on the medium to be printed in the first dye-transfer suppression agent ejection processing shown in  FIG. 9  is not limited to the acquisition of the information on the material of the medium to be printed input from the operation unit  85 , and the CPU  81  may use AI (Artificial Intelligence) or the like to determine the material of the fabric  3  from image data obtained by capturing the fabric  3  and input from the digital camera  101  (refer to  FIG. 4 ). In addition, the CPU  81  may acquire the material information of the fabric  3  included in the print data. 
     Further, in the second print processing, the dye-transfer suppression agent ejection processing (S 3 ) may also be performed before the pretreatment agent ejection processing (S 2 ). In the first print processing and the second print processing, the heating treatment is performed twice, i.e., the preheating treatment (S 5 ) and the main heating treatment (S 10 ), but is not necessarily limited to two times. The platen conveying processing (S 4 ) and the preheating treatment (S 5 ) are not necessarily required to be performed. The main heating treatment (S 10 ) may also be performed only once. In this case, the working time is shortened and the productivity is improved. Further, the heating treatment may also be each performed after ejection of the pretreatment agent, after ejection of the dye-transfer suppression agent, after ejection of the white ink, and after ejection of the color ink. In this case, each liquid is fixed, and therefore, the image quality is improved. 
     Further, the alignment of the pretreatment agent head  121 , the dye-transfer suppression agent head  124 , the white head  122  and the color head  123  in the sub-scanning direction on the carriage  13  is not limited to the first to third embodiments. For example, the pretreatment agent head  121  may be arranged behind the color head  123 . In a case where the alignment of the heads is different from the first to third embodiments, the CPU  81  may move the platen  31  according to the alignment of the heads, and eject the pretreatment agent, the dye-transfer suppression agent and the inks from each of the heads to the area  3 A on the fabric  3 . Further, the heads  121  to  124  may be mounted on separate carriages, respectively. A pretreatment unit configured to perform a pretreatment for the fabric  3  may be provided separately from the printing unit  2  configured to eject the white ink and the color ink, and the heater  4  may be provided between the pretreatment unit and the printing unit  2 . 
     Further, in the processing of S 24  of the first dye-transfer suppression agent ejection processing shown in  FIG. 9  and the processing of S 34  of the second dye-transfer suppression agent ejection processing shown in  FIG. 10 , the amount of the dye-transfer suppression agent to be ejected may be increased to an amount larger than a preset value. In this case, the effect of suppressing the dye-transfer sublimation can be improved. Further, the color head  123  is not limited to the four colors of black (K), yellow (Y), cyan (C), and magenta (M). A nozzle configured to eject another color may also be provided. Further, the color head  123  may be three colors of yellow (Y), cyan (C), and magenta (M). Further, the color head  123  may be a head of any one color or a plurality of colors. Further, the heater  4  is not limited to the heat press, and may be an oven, a hot air blower, or the like. Further, instead of ejecting the dye-transfer suppression agent from the dye-transfer suppression agent head  124 , potting, doming, dispenser application or the like may be used. Further, the porous fine particles included in the dye-transfer suppression agent are not limited to activated carbon, zeolite, or MOF, and may be any fine particles having an adsorption property. In addition, the dye-transfer suppression agent may include a plurality of types of porous fine particles. 
     Note that, in the first to third embodiments, the platen  31  is configured to move in the sub-scanning direction, and the carriage  13  on which the printing head  12  is mounted is configured to move in the main scanning direction. However, the present disclosure is not limited thereto. The platen  31  may be configured not to move and the carriage  13  may be configured to move in the main scanning direction and in the sub-scanning direction. Further, the carriage  13  may be configured not to move and the platen  31  may be configured to move in the main scanning direction and in the sub-scanning direction. Further, the carriage  13  and the platen  31  may be configured to move relative to each other. Further, the platen  31  is not necessarily limited to a flat plate. Further, the dye-transfer suppression agent is not necessarily required to include a resin component. The dye-transfer suppression agent is not necessarily to have a color. Transparent fine particle having an adsorption property may also be used. In this case, the area  3 A to which the dye-transfer suppression agent is ejected may be the entire area of the fabric  3 . Further, even when the ink is ejected over the entire area of the fabric  3 , the area  3 A to which the dye-transfer suppression agent is ejected may also be the entire area of the fabric  3 . Further, the CPU  81  may perform the processing of S 21  to S 25  shown in  FIG. 9  and the processing of S 31  to S 35  shown in  FIG. 10  in parallel to change the amount of ejection of the dye-transfer suppression agent. Further, the processing of reducing the amount of ejection of the dye-transfer suppression agent in S 33  may be changed according to a density of the ink ejected by the color head  123 .