JP4954773B2 - Printing method - Google Patents

Description

The present invention relates to a printing method for printing using an electrophotographic printing apparatus, and more specifically, a natural fiber, a synthetic fiber or the like, or a woven fabric, a knitted fabric, a non-woven fabric, or a leather sheet made of these blended fibers. Jo product (hereinafter the present invention, referred to as cloth) and relates textile printing method of using a device for printing by an electrophotographic method, in particular, the more the staining quality drops disturbance of an image due to bleeding at the time of color development, It can be effectively prevented.

Conventionally, textile printing methods include (1) screen printing method, (2) roller printing method, (3) rotary screen printing method, (4) thermal transfer printing method, and (5) inkjet printer printing method. However, these printing methods have the following drawbacks.
(1) The screen printing method has the disadvantages that it takes time to manufacture the screen, takes up space for storing the screen, and the work is an intermittent process, so that the production speed of the printing is slow. On the other hand, (2) the roller printing method has a high production speed, but has a drawback that the process of engraving the pattern on the metal roll is complicated and the roller is heavy, so that the handling is difficult.

(3) The rotary screen printing method has the characteristics of the roller printing method and the screen printing method. This rotary screen is lightweight and can be easily replaced. However, both types of textile printing take time to produce a screen for creating a new pattern, and roller engraving and adjustment of color paste are also necessary.
In addition, after printing, the dye is fixed by coloring by means such as steaming or dry heat treatment, and thereafter, there are various processes such as washing and drying. Therefore, it takes a long time from the design to the printing fabric, and usually it is forced to make predictions and production prospects. In particular, when fashion is diversified or individualized as in recent years, it is impossible to follow from the viewpoint of delivery, and disadvantages such as difficulty in profitability for processing a small variety of products are becoming problematic.

(4) Under the circumstances described above, the thermal transfer printing method was considered as a printing method with improved design of screens after design, roller engraving, adjustment of color paste, cleaning after printing, and drying process. The above-mentioned drawbacks and disadvantages are remarkably improved.
However, a sheet printed with a sublimation dye is brought into close contact with the cloth, heated to sublimate the dye, and dyed onto the cloth. The fiber that can be printed by this method is a pretreatment that can be dyed with polyester fiber or sublimation dye. The design change is limited to the master paper for transfer supplied by the printing manufacturer, suitable for mass production, but inefficient, the transfer paper is uneconomical, and the processing process Has the same problem as above.

(5) The ink-jet printing method is linked to a computer by omitting the engraving plate making process, which is the biggest problem of the above-mentioned printing methods, while the demand for shortening the delivery time is increasing against the background of high-mix low-volume production. For example, Patent Literature 1 (Japanese Patent Laid-Open No. 10-195576) and Patent Literature 2 (Japanese Patent No. 2995135) are representative examples.
According to this ink-jet textile printing technology, engraving rolls and screens are no longer necessary, production is possible immediately after receiving an order, the design and color can be easily changed, and the design can be stored and taken out easily. It has a lot of progress and is more flexible than conventional printing methods. However, this ink-jet printing method has poor technical distribution and sales expansion because it requires specialized skills and knowledge to operate the printing method.

  Various types of textile printing methods as described above are known, but the current situation is that many technical problems remain. Against this background, a textile printing method using electrophotographic technology has attracted attention. The textile printing method applying the electrophotographic technology is a method of drawing a design pattern using an electrostatic copying apparatus. Specifically, a toner containing an original image as an electrostatic latent image on the surface of a photosensitive drum and containing a colorant. In this method, toner is developed by electrostatically landing the toner, the toner development is transferred to a cloth or the like at a transfer portion, and the toner is heat-melted and fixed to the cloth or the like at a fixing portion.

Various studies have been made on the textile printing method using the electrophotographic technology. One example will be described below.
Patent Document 3 (Japanese Patent Application Laid-Open No. 51-56313) discloses a direct development printing method for cloth or the like by electronic printing. In this method, coloring is performed by steaming, and then washing and de-resining are performed using trichlene. Is. Further, Patent Document 4 (Japanese Patent Publication No. 60-009155) has an electrostatic printing method, in which a dye is dyed on a cloth by steam heat fixing, and then a binder resin in the toner is used as a solvent or the like. This is a method of removing by washing.

  In the above-described printing method using the electrophotographic technology, in the conventional technology, the solvent used in the resin removal process is a substance such as trichlene, methyl ethyl ketone, toluene, xylene, acetone, butyl acetate, and these are volatile organics. It corresponds to a compound (VOC (volatile organic compounds)) and is considered to be one of air pollution related to suspended particulate matter and photochemical oxidants, and there is concern about the impact of suspended particulate matter on human health. There were a lot of reports and it was a problem.

  Against this background, in recent years, with regard to textile printing methods that apply electrophotographic technology, consideration has been given to removing the resin with a material that is non-volatile and has little impact on the environment. Various technical disclosures have been made on textile printing methods applying the electrophotographic technology developed from the above.

For example, Patent Document 5 (Japanese Patent Application Laid-Open No. 2005-195636) discloses that in an electrophotographic printing method, an image having a high image density and a high resolution can be obtained. fouling are of no developer and printing method thereof, and further, suppress the fluffing of the fabric, preventing the fiber incorporation into the machine, the printing workability and efficiency, gave on-demand property, provides a textile printing method In a printing method in which toner particles in which a colorant is dispersed in a carrier liquid having a high resistivity and a low dielectric constant of 109 Ω · cm or more are directly printed on a printed fabric by electrophotography, before transferring, A technique for solving the problem by applying or spraying a solvent to a transfer cloth has been disclosed.

On the other hand, in the textile printing method using electrophotographic technology, when a resin containing a colorant such as a dye is transferred to the cloth, it adheres to the fibers on the cloth surface using the electric field or the physical binding force of the resin. Therefore, the transfer cannot be performed unless the surface of the resin carrier and the cloth as the transfer body are in contact or very close to each other.
There are various types of cloth, but basically there are many shapes in which yarns made of fibers are alternately crossed in the vertical and horizontal directions, and the surface has irregularities according to the thickness of the yarn. It is difficult to bring the surface of the resin carrier in contact with the convex portion into contact with the concave portion, and it is difficult to transfer the colored resin into the concave portion.
Ordinary screen printing is easy to dye the entire surface of the cloth because the paste containing a dye called color glue is supplied so as to fill the recesses, but in the printing method using electrophotographic technology, the unevenness of the cloth is It was difficult to supply an amount of colored resin to fill.

Therefore, in the textile printing method using the electrophotographic technique, the amount of colored resin necessary for coloring the entire surface of the cloth on the convex portion of the cloth is locally concentrated and supplied. In this way, when the coloring process is performed in a state where the dye is present only on the convex portion of the cloth, the dye diffuses in the direction of the fiber during the color development, often causing a problem called so-called bleeding. .
FIG. 4 is a schematic diagram showing a toner transfer state in the image area. In this way, the bleed defect is prominently generated in the direction of the fiber where the dye is locally concentrated, and the dye in the warp direction as shown in FIG. Shifts to cause a bleed failure, and the edge portion expands in the warp direction depending on the pattern.
Bleed failure is a technical solution that suppresses this bleed failure because it causes problems such as overlapping and the boundary part becoming an unintended color in designs that have different colors next to each other. Is required. On the other hand, if the correction amount is too large, a gap is generated, and thus a fine adjustment is required for the correction.

Even when paper is used as the transfer body, the paper surface has irregularities, and there is a similar problem that toner does not easily adhere to the concave parts. Improvement was seen by forming the body with an elastic body and deforming it according to the unevenness of the paper surface. In addition, the transfer paper does not spread the colorant in the toner with directionality at the time of fixing, so the above bleed failure is a particular problem when using cloth in a printing method applying electrophotographic technology. there were.
Japanese Patent Laid-Open No. 10-195576 Japanese Patent No. 2995135 JP-A 51-56313 Japanese Patent Publication No. 60-009155 JP 2005-195636 A

The problem to be solved by the present invention based on such a background is that when printing on a fiber such as a cloth by an electrophotographic method, even in a portion that has a convex shape along the direction of the fiber, color development is caused. It is an object of the present invention to provide a textile printing method capable of suppressing bleeding problems in which a dye diffuses in the direction of the fiber and eliminating image disturbance on the fiber.

(1) Means of the Invention of Claim 1 Means for solving the above-mentioned problem is the means of the invention of claim 1, wherein printing is performed on a fabric to be printed by an electrophotographic method using a toner containing a resin and a dye. In the textile printing method using the apparatus , the problems are solved by the following configurations (a) and (b).
(B) the latent image bearing member at least as an image forming unit, a charging unit, an exposing unit for latent image formation, developing means for developing by the toner a latent image, using a printing apparatus comprising a transfer unit to be printed cloth A printing method for printing ,
(B) The main scanning direction or sub-scanning direction of the exposure unit after adjusting the exposure resolution of the exposure unit with respect to the warp direction formed by the convex shape of the surface of the fabric to be printed adjustment resolution of the exposure to match whichever direction has high by printing, by adjustment means of the exposure unit, the exposure amount of the edge portion of the image that intersects the warp direction of the printed fabric, than the other exposed portion Make adjustments to decrease .

(2) Means of Invention of Claim 2 A means of an invention of claim 2 is that, in the textile printing method of claim 1, the exposure means arranges a plurality of light sources in the main scanning direction.

(3) means of the invention means according to claim 3 of the invention of claim 3 is the textile printing method according to claim 1 or claim 2, adjustment means is a benzalkonium adjust the emission time.

( Delete )

( 4) Means of Invention of Claim 4
According to a fourth aspect of the present invention, there is provided the printing method according to any one of the first to third aspects , wherein the thickness of the warp yarn constituting the fabric to be printed is the thickness of the toner layer transferred to the fabric to be printed. a If it is less than of the adjustment means is O to go a perform adjustment of the exposure amount.

( 5) Means of the Invention of Claim 5
According to a fifth aspect of the present invention, in the printing method according to any one of the first to fourth aspects, a liquid developer in which the toner is dispersed in a carrier liquid is used.

( 6) Means of the Invention of Claim 6
According to a sixth aspect of the present invention, in the printing method according to any one of the first to fifth aspects, the transfer means to the cloth or the like is urged by the urging mechanism and applies a high contact pressure. This is due to the transfer roller.

The effects of the present invention are as follows.
(1) Advantages of the Invention of Claim 1 By making the direction in which the exposure amount adjustment resolution is high in the main scanning direction and the sub-scanning direction of the exposure means coincide with the cloth longitudinal direction of the cloth, it is remarkable as compared with the cloth lateral direction. The exposure amount can be adjusted accurately to prevent image distortion due to bleeding in the vertical direction, and the image quality can be improved.
Also, by adjusting the exposure means to reduce the exposure amount of the edge of the image that intersects the warp direction of the fabric to be printed compared to other parts, image distortion due to bleeding in the warp direction is prevented. , Image quality can be improved .

(2) The effect of the invention of claim 2 By using an exposure means such as an LED head in which a plurality of light sources are arranged in the main scanning direction, the direction in which the exposure amount adjustment resolution is high becomes the sub-scanning direction. Therefore, when the longitudinal direction of the cloth is set to the sub-scanning direction, detailed exposure amount correction is possible, and it is possible to continuously transfer to a cloth that is long in the longitudinal direction. It becomes possible to print on the fabric to be printed.

(3) The effect of the invention of claim 3 By adjusting the exposure amount of the exposure means by adjusting the light emission time, more accurate correction can be performed and the image quality can be improved.

( Delete )

( 4) The effect of the invention of claim 4 When the thickness of the warp yarn constituting the fabric to be printed is less than the thickness of the toner layer transferred to the fabric, no adjustment is made, so If the cohesive does not occur, it can be prevented that conversely reduces the quality performing unnecessary correction.

(5) Ri by the the use of a liquid developer in which is dispersed in a carrier liquid to effect toner of the invention of claim 5, to prevent disturbance of the image by the transfer does not occur expulsion due to scattering at the time of transfer, the warp Direction correction can be realized as intended, and image quality can be improved.

( 6) The effect of the invention of claim 6 By using a transfer roller provided with a mechanism capable of applying pressure to the transfer object in the transfer part to the fabric to be printed or the like as the transfer means, Since the adhesion of the toner image can be improved, bleeding due to local adhesion of the toner can be reduced, and the correction amount in correction can be reduced.

Then, using the images forming apparatus using a liquid developer, a specific example of textile printing method of the present invention to carry out the printing on the printed fabric.
First, an outline of the image forming unit around the photosensitive drum will be described with reference to FIG.
In FIG. 1, there is a charging device 36 above the photosensitive drum 1 to charge the surface of the photosensitive drum. The charges other than the image area are erased by the partial lighting of the erase lamp 37. Then, a beam corresponding to the image is formed on the surface of the photosensitive drum by the exposure unit 2. Thereby, an electrostatic latent image is formed on the photosensitive drum.

  The developing means 3 includes two developing rollers, a first developing roller 4 and a second developing roller 5, and a reverse roller 6. The developer tank 7 contains liquid developer 8 and is supplied to the developing means 3 and the cleaning means 15 by the pump 9. The liquid developer supplied to the developing means 3 is poured into two developing rollers, a first developing roller 4 and a second developing roller 5. The two developing rollers are rotated, and the liquid developer 8 is supplied to the electrostatic latent image on the photosensitive drum 1 by this rotation. Therefore, the toner in the liquid developer adheres on the electrostatic latent image on the surface of the photosensitive drum 1 by electrophotographic electrophoresis. Next, the reverse roller 6 in which the gap between the photosensitive drum and the developing roller is narrower removes excess carrier liquid and undeveloped toner from the liquid developer adhering to the surface of the photosensitive drum. Thereafter, the developer image formed on the photosensitive drum 1 is transferred onto the fabric to be printed 21 by the transfer roller 20. The residual liquid developer 8 that has not been transferred is sucked by the foam roller 31 in the cleaning device 30, further squeezed from the foam roller 31 by the squeezing roller 32, and returned to the developer tank 7. Further, the remaining liquid developer 8 is scraped off by a cleaning blade 33 for cleanly cleaning the surface of the photosensitive drum 1, and the scraped liquid developer is also sucked out by the foam roller 31.

  Next, an outline of the entire printer will be described. The fabric to be printed 21 conveyed from the cloth supply device (not shown) passes through the cloth conveyance guide and hits the registration roller 22. Here, a timing is set so that the image on the photosensitive drum 1 is aligned with a predetermined position of the fabric to be printed 21 conveyed to the registration roller 22, and an electromagnetic clutch is driven from a drive source (not shown) for driving the registration roller 22. A printing force is transmitted through (not shown) to rotate the registration roller 22 and convey the fabric to be printed 21. Thereafter, the fabric to be printed 21 that has passed through the registration roller 22 faces the photosensitive drum 1, and when the photosensitive drum 1 and the fabric to be printed 21 move together and reach the position just above the transfer roller 20, the transfer roller 20. With this transfer potential, the developer image formed on the photosensitive drum is transferred as described above. Thereafter, the cloth is separated from the photosensitive drum 1. Thereafter, the separated fabric to be printed 21 is conveyed to the coloring device in FIG. 2 by a conveying device (not shown).

  At this time, since the fabric to be printed 21 has low rigidity and it is difficult to convey the cloth alone, it is adhered to a conveyance support 23 such as a PET film and conveyed. The transport support 23 used for transport can be reused after cleaning if the fabric 21 is peeled off after transfer. Moreover, the form which makes the conveyance support body 23 endless belt shape, affixes the to-be-printed fabric 21, and conveys it may be sufficient.

FIG. 2 shows an outline of the cloth processing process after the pattern transfer. After the liquid developer liquid is removed by the electrophotographic printing apparatus and dried, the steaming process, the resin removing process, and the washing are performed. Processing is performed in the order of the process and the drying process.
First, color development (fixation) is performed after drying in a steaming process. Examples of the coloring method include HT steaming, HP steaming, and thermosoling. HT steaming uses superheated steam obtained by superheating steam, for example, wet heat treatment at about 175 ° C. for 8 minutes, and HP steaming uses steam at high temperature and high pressure. For example, the wet heat treatment is performed at about 130 ° C. for 30 minutes, and the thermosoling is performed, for example, at about 200 ° C. for 90 seconds.
By this coloring device, the toner on the cloth is fixed to the cloth, and the dye in the toner moves to the cloth. At this time, since the dye in the toner moves so as to diffuse along the direction of the attached fibers, it spreads in the direction of the fibers and develops color.

The cloth or the like to which the softening agent is applied is then subjected to a cleaning process. The treatment in this washing process differs slightly depending on the type of fabric. For example, polyester can be used for printing after reduction washing (soaping), hot water washing, water washing, and drying treatment, and softened resin is used in these processes. It is detached from the cloth and removed. The reduction cleaning is, for example, soaked in a mixture of 2 to 38 ml of caustic soda at 70 to 80 ° C., 2 g of hydrosulfite and 1 g / l of a cleaning agent for 1 to 5 minutes, and then 50 to 50 ° C. Washed with hot water at ˜60 ° C., washed with water and dried.
Further, as the final product, for example, a finishing process may be performed in which a finishing agent such as an antistatic agent, a water repellent, or a functional agent is applied.

[Toner]
As the colorant that can be used in the present invention, a direct dye, an acid dye, and a basic dye (cationic dye) reactive dye are used. For example, direct dyes include Direct Fast Yellow R, Direct Fast Yellow GC, Direct Fast Orange, Direct Sky Blue 5B, Direct Splash Red 3B, Coplantin Green G, Direct Fast Black D, etc. Acid Acid Brilliant Scarlet 3R, Acid Violet 5B, Alizarin Direct Blue A2G, Acid Cyanin 6B, Acid Cyanin Green G, Acid First Black VLG, etc., and cationic dyes include Cationic Yellow 3G, Cationic Golden Yellow GL, Cationic Orange R , Cationic Brilliant Red 4G, Cationic Blue 5G, etc., and reactive dyes such as Reactive Orange 2R, Reactive Red 3 , There Reactive Blue 3G, Reactive Brilliant Blue R, is Reactive Black B, etc.. About 80% by weight or more of these dyes are present in the carrier liquid in a dispersed state.

  When these dyes are used, they are excellent in the reflection on the back of the cloth and the fastness to washing. Depending on the material of the printed fabric, it is better to select the dye, and the dyeing property and fastness to washing are better. In the case of acrylic fibers, basic dyes are used. In the case of cellulosic fabrics such as cotton and hemp, reactive dyes and direct dyes are used. Further, in the case of fabrics such as nylon and rayon, direct dyes are used. Acid dyes are desirable for fabrics such as silk and wool.

  Commercially available powder dyes have a dye purity of about 50% and often contain a large amount of salt and sodium sulfate, which adversely affects the resistance and chargeability of the liquid. In this invention, it is desirable that the purity is 80% or more.

The carrier liquid used for the liquid developer in the present invention is preferably a high resistance and low dielectric constant, and is preferably an isoparaffinic hydrocarbon, a silicone oil or the like. Isoparaffinic hydrocarbons include Isopar C, Isopar E, Isopar G, Isopar H, Isopar L, Isopar M, Isopar V (Exxon Chemical), etc., and KF 961-10000 cst (Shin-Etsu Chemical Co., Ltd.) as the silicone oil , SH200, SH344 (Toray Dow Corning Co., Ltd.), TSF451 (GE Toshiba Silicone), and the like. Of these, saturated hydrocarbons having a boiling point of 130 ° C. or higher are preferable in terms of odor and safety. These solvents can be evaporated at the stage of heating and steaming in the subsequent process.

なお、Ｒ ^１ は、ＨまたはＣＨ _３ を、Ｒ ^２ はＣ _１ 〜Ｃ _４ のアルキル基を、ｎは６〜２０の整数を表わす。 Moreover, as the dispersing resin preferably used in combination in the present invention, a vinyl monomer represented by the component (A) of the following general formula (1) and a vinyl monomer represented by the component (B) of the general formula (2), And a copolymer of at least one monomer selected from the group consisting of vinyl pyridine, vinyl pyrrolidone, ethylene glycol dimethacrylate, styrene, divinyl benzene, and vinyl toluene as a third component, and a graft copolymer. .

R ¹ represents H or CH ₃ , R ² represents a C _{1 to} C ₄ alkyl group, and n represents an integer of 6 to 20.

The copolymerization ratio of the component (A) and the component (B) is 60 to 95:40 to 5, preferably 70 to 90:30 to 10, and the third component is 0 to 5 of the component (A). % Is preferred.
These colorant, resin, and carrier liquid are charged into a dispersing machine such as a ball mill, a kitty mill, a disk mill, and a pin mill, dispersed, and kneaded to prepare a concentrated toner, which is dispersed in the supporting liquid of the present invention. Thus, a liquid developer can be obtained.

[Printed fabric]
Any fabric structure can be used as the fabric to be printed, regardless of whether it is a woven fabric, a knitted fabric, a braid, or the like, and a woven fabric is particularly preferable.
The materials that make up the cloth include various polyesters such as polyethylene terephthalate and polybutylene terephthalate, synthetic fibers such as polyethylene, polyurethane, polyvinyl chloride, vinylon, acrylic, nylon and acetate, recycled fibers such as rayon, cotton, hemp There are animal fibers such as cellulosic fibers such as silk and wool. The above-described fiber blend or union may be used.

Here, an example in which the image is directly transferred from the photosensitive member to the cloth has been described. However, the present invention is not limited to this structure, and the structure may be such that transfer to the cloth is performed via an intermediate transfer member in the form of a roller or a belt. . In addition, although an example of a single color is shown here, it is possible to print a color pattern by arranging and transferring them on a cloth, for example, overlapping four colors of yellow, magenta, cyan, and black. Can print color designs. In addition, it is also possible to use a special color electrophotographic unit if necessary in design.
Further, although an example in which a liquid developer is used as an electrophotographic system is shown, there is no problem even in a system using a dry developer.

Embodiments of the invention will be described using more specific examples.
As shown in FIG. 3, the fabric to be printed 21 is composed of warp and weft, and is woven so that the weft x passes between the warps y. In the case of such a fabric 21 to be printed, on the surface of the fabric to be printed, the warp yarn y mainly forms a convex portion and the weft yarn x forms a concave portion.

  In the electrophotographic textile printing apparatus, most of the toner is transferred to the warp yarn y that comes into contact with the toner on the toner carrier in the transfer portion, so that the toner is hardly transferred to the weft yarn x. Further, as shown in FIGS. 4 and 5, when the coloring process by heating is performed, the dye moves in the warp direction to which the toner is adhered and bleeds, so that the edge portion of the image spreads in the warp direction depending on the pattern. It has caused problems.

  To solve this problem, the amount of toner adhering to the edge portion may be reduced, and the development amount can be partially adjusted by adjusting the exposure amount by the exposure means after charging.

  For example, by adjusting the exposure amount in the warp direction y as shown in FIG. 6, a target image can be obtained as shown in FIG. 7. Fine adjustment is required. Since the exposure means has different resolutions for adjusting the exposure amount in the two directions of the main scanning direction and the sub-scanning direction, the cloth is conveyed so that the high resolution direction coincides with the longitudinal direction of the cloth. In this way, the amount of exposure can be finely adjusted in the warp direction by transporting the cloth so that the direction in which the resolution for adjusting the exposure is high and the warp direction coincide with each other. The exposure amount can be accurately adjusted in consideration of bleeding at the time of color development in the direction.

  As an electrophotographic exposure means, an LED head having a laser head and a polygon mirror and an LED head in which light sources are arranged in a line are often used. The former is characterized by high resolution for adjusting the exposure amount in the main scanning direction and the latter in the sub-scanning direction.

  In the laser head method, dots are formed by turning on and off when scanning laser light in the main scanning direction, so the size and position of each dot can be adjusted by shifting the on / off timing. The resolution in the main scanning direction can be set with a high degree of freedom, but the resolution in the sub-scanning direction is determined by the reciprocating timing in the main scanning direction, and is difficult to adjust. For this reason, when the resolution is improved, the resolution in the main scanning direction is increased, for example, 600 dpi in the main scanning direction and 400 dpi in the sub scanning direction.

  On the other hand, in the LED head system, the resolution in the sub-scanning direction is determined by the LED arrangement density, and is generally about 600 dpi to 1200 dpi. On the other hand, the resolution in the main scanning direction can be adjusted by the lighting timing and has a higher degree of freedom than the resolution in the sub-scanning direction, and is generally used at 1200 dpi to 2400 dpi, which is higher than the resolution in the sub-scanning direction. By doing so, the resolution is increased so that a higher resolution image can be obtained.

For example, when a laser head system is used as the optical system, as illustrated in FIG. 8, the warp direction of the cloth 1 conveyed by the conveyance support 23 (see FIG. 1) is aligned with the main scanning direction. The cloth 1 is conveyed. This makes it possible to adjust the exposure amount so as to suppress image disturbance due to bleeding.
Further, when using the LED head in which the light sources like the latter are arranged in a line, as illustrated in FIG. 9, by conveying the fabric so that the warp direction of the fabric matches the sub-scanning direction, Fine adjustments can be made to suppress image disturbance due to bleeding.

As the exposure means used in the image forming unit of the textile printing apparatus used in the textile printing method of the present invention, an LED head in which light sources are arranged in a row is desirable.
The printed fabric is then often processed into clothes and the like, and it is desirable that the fabric can be printed as large as possible. The cloth used for printing is often in the form of a roll having a width of 44 to 60 inches. In order to print on a larger size cloth, the main scanning direction of the exposure means is aligned with the cloth width direction, and the sub-scanning direction is set. It is desirable to transport the fabric. When the fabric is conveyed in such a direction, the warp direction becomes the sub-scanning direction, and in order to finely adjust the exposure amount in this direction, finely adjust the exposure amount in the sub-scanning direction. An exposure means such as an LED head in which light sources capable of being arranged are arranged in a row is desirable.
Moreover, when performing long exposure, it is necessary to arrange and use a plurality of heads. In an optical system consisting of a laser head and a polygon mirror, it is difficult to synchronize at the joint in the main scanning direction. However, the LED head has the advantage that it can be lengthened once adjusted and assembled. is there.

When adjusting the exposure amount, not only ON / OFF in pixel units, but also by adjusting the light emission time as shown in FIG. 10A, in the warp direction as shown in FIG. 10B. The positions of the dots can be shifted, fine adjustment in units of dots or less is possible, and finer adjustment of the exposure amount can be performed. For this reason, the driver of the exposure means in the textile printing apparatus used in the textile printing method of the present invention can adjust the light emission time.
Although it is possible to correct the light intensity as shown in FIG. 10 (a), the dot size is adjusted here. Therefore, in order to correct the bleed as in the printing method of the present invention, the light emission It is preferable to shift the dot position by adjusting the time length and timing.
FIG. 10 (a) corrects the uncorrected pulse p1 to a pulse p2 by time adjustment or a pulse p3 by pulse intensity adjustment, and FIG. 10 (b) shows a dot d1 by the pulse without correction and a dot d2 by the pulse p2. Alternatively, the dot d3 is corrected by the pulse p3.

In the printing apparatus used in the textile printing method of the present invention, the adjusting means of the exposure means 2 performs adjustment to reduce the exposure amount of the edge e of the image intersecting the warp y direction of the fabric to be printed 21 as compared with other portions. A bleed (see FIG. 5), which is a disturbance of an image caused by diffusion of the dye of the toner t that is locally concentrated and adhered to the warp y of the fabric to be printed 21 along the fiber during the color forming process, is a solid image. In the portion, there is an effect of improving the uniformity by improving the connection between the dots, but in the edge portion (see the edge portion of the image in FIG. 4) intersecting the warp y, the accuracy of the edge e of the image is lowered. Will end up. Therefore, in the textile printing method of the present invention, the bleed amount is assumed in advance at the edge portion as shown in FIG. 6, and the exposure amount of the exposure means is adjusted so as to shift the edge position of the image according to the bleed amount. Is set to the desired image (FIG. 7).

Bleed (see FIG. 5) is caused by the fact that the toner is transferred concentrated on the convex portions on the surface of the cloth, and the dye concentration is locally high. For this reason, a grade is improved by transferring uniformly to the whole cloth surface. That is, if the toner can be transferred to the weft yarn x under the warp yarn y, the toner t can be transferred to the entire surface of the fabric to be printed 21, so that the toner can be prevented from being concentrated locally. Therefore, it is not necessary to correct in this case.
Whether the toner t can be transferred to the weft yarn x existing below the warp yarn y varies depending on the unevenness amount of the fabric 21 to be printed, that is, the relationship between the thickness of the yarn constituting the fabric and the thickness of the transferred toner. . Therefore, in the textile printing method of the present invention, as illustrated in FIG. 11, when the thickness t of the transferred toner layer is larger than the thickness s of the warp yarn y constituting the fabric, the exposure amount in the warp direction with respect to the bleed. Do not make corrections. In this way, even when the cloth is changed, the bleed can be corrected properly.
If the weaving method of the fabric is the same, if the yarn is thick, the fabric will be thick, and if it is thin, the fabric will be thin. Therefore, it is possible to determine whether or not to adjust the exposure amount depending on the thickness of the fabric.

The toner used in the textile printing method of the present invention is a liquid developer. A dry electrophotographic toner can also be used, but in this case, since the colored resin moves using air as a medium during transfer, there is a problem of “scattering” in which the colored particles move during transfer. It is difficult to perform correction as intended for correct correction. On the other hand, in a liquid developer in which toner (colored particles) is dispersed in an insulating liquid (carrier liquid), since the toner (colored particles) is present in the liquid, there is a problem in the dry electrophotographic method. Since such “scattering” at the time of transfer does not occur, the use of a liquid developer enables correction with higher accuracy.

  In the transfer step of transferring the colored resin to the cloth, there are a charger 40 (FIG. 12) and a transfer roller as means for forming a transfer electric field. In the former, an electric field is formed between a printed fabric 21 that is a transfer target and a photosensitive drum 1 that is a colored particle carrier through a conveyance support 23 by discharging from a thin wire. In this system, the wire and its case are kept at a certain distance from the photosensitive drum, and have no function of pressing the fabric to be printed 21 against the photosensitive drum 1 at the transfer portion. Although it is possible to apply tension to the transport support 23 that transports the fabric 21 and press the fabric 21 against the photosensitive drum 1 by this tension, there is a limit to increasing the pressing force too much. Therefore, the contact pressure between the fabric to be printed 21 and the photosensitive drum 1 is insufficient, and the fabric is deformed (crushed) by the contact pressure to further improve the contact state between the fabric 21 to be printed and the photosensitive drum 1. It is difficult to adhere.

On the other hand, as shown in FIG. 13, in the case of using the transfer roller 20, the state is pressed between the transfer roller 20 and the photosensitive drum 1 with the fabric to be transferred 21 as the transfer target and the conveyance support 23 sandwiched therebetween. A transfer electric field is formed, and the fabric 21 to be printed is sandwiched between the transfer roller 20 and the photosensitive drum 1 and the transfer roller 20 is urged by a pressurizing mechanism (in this example, a coil spring) 44 to increase the contact pressure. Since the toner can be applied, it is possible to reduce the concentration of the toner locally at the time of transfer.
Therefore, the textile printing apparatus used in the textile printing method of the present invention includes a transfer roller type transfer means so that a sufficient pressure can be applied at the transfer portion.

上記表に示す測定結果から、付勢機構で付勢された転写ローラによる転写方式の方が、有効であることが明らかである。
これに対して露光量の調整により縦糸方向のブリード量の補正を行った結果、縦糸方向においても２％程度までブリード率を軽減できた。よって、本発明の捺染方法においては、ブリードが顕著な縦糸方向にブリード防止のために精度の高い補正を行うことができ、その結果、ブリードによる画像の変形を低減することができる。 With a printing apparatus used in the printing method of the present invention, a 1 mm wide line is transferred to a polyester fabric having a thickness of 150 μm (yarn thickness 50 to 60 μm) with a liquid developer toner layer thickness of about 10 to 15 μm. The bleed rate was measured without correction. The results are shown in the table below. The bleed amount is calculated by measuring the line width after color development, subtracting the original line width of 1.0 mm from this, and dividing by 2 by 1.0 mm.

From the measurement results shown in the above table, it is clear that the transfer method using the transfer roller biased by the biasing mechanism is more effective.
On the other hand, as a result of correcting the bleed amount in the warp direction by adjusting the exposure amount, the bleed rate was reduced to about 2% in the warp direction. Therefore, in the textile printing method of the present invention, high-precision correction can be performed in order to prevent bleeding in the warp direction in which bleeding is significant, and as a result, image deformation due to bleeding can be reduced.

FIG. 3 is a side view of the entire image forming unit in an electrophotographic textile printing apparatus. These are the schematic diagrams which show the outline of the cloth treatment process after pattern transfer. FIG. 4 is a schematic diagram illustrating a transfer state to warp and weft yarns that come into contact with toner on the photosensitive drum in a transfer portion of an electrophotographic textile printing apparatus. FIG. 4 is a schematic diagram illustrating a toner transfer state in an image area. Is a schematic view showing a state in which the dye migrates and bleeds in the warp direction by color development processing by heating, and the edge portion spreads in the warp direction by the pattern. FIG. 5 is a schematic diagram illustrating a toner adhesion state in an image region when an exposure amount in the warp direction is adjusted. FIG. 7 is a schematic diagram showing an image region when the toner of FIG. 6 is heated or colored, and the adhesion state of the toner after coloring. These are the schematic diagrams which show the relationship between the main scanning direction of the exposure apparatus by a laser head and a polygon mirror, the direction of a warp, and the conveyance direction of cloth. These are the schematic diagrams which show the relationship between the arrangement direction of the light source of the exposure apparatus by the LED head which has arranged the light source in a line, the direction of the warp, and the cloth conveyance direction. (A) is a figure which shows an exposure amount control pattern, (b) is a figure which shows the toner shape after color development by the exposure amount control pattern of (a). (A) is a schematic diagram showing the relationship between the warp yarn and the toner layer when the thickness of the toner layer to be transferred is less than the thickness of the warp yarn constituting the fabric, and (b) is the image to be transferred. FIG. 5 is a schematic diagram illustrating a relationship between a warp and a toner layer when the thickness of the toner layer is equal to or greater than the thickness of the warp constituting the fabric. These are the whole side views of the example which uses a charger as a formation means of the transfer electric field of the transfer process which transfers colored resin with respect to cloth. These are the whole side views of the example which uses a transfer roller as a formation means of the transfer electric field of the transfer process which transfers colored resin with respect to cloth.

1: Photosensitive drum 2: Exposure means 3: Developing means 4: First developing roller 5: Second developing roller 6: Reverse roller 7: Developer tank 8: Liquid developer 9: Pump 20: Transfer roller 21: Printing Cloth 22: Registration roller 23: Conveyance support 30: Cleaning device 31: Foam roller 32: Drawing roller 33: Cleaning blade 36: Charging device 37: Erase lamp 40: Charger 44: Pressure mechanism e: Edge of image y: Warp yarn x: Weft t: Toner

Claims (6)

A printing apparatus for printing on a fabric to be printed by an electrophotographic method using a toner containing a resin and a dye , and at least a latent image carrier, a charging device, an exposure means for forming a latent image, and a latent image as the image forming means. In a printing method of performing printing using a developing device that develops with toner and a printing device that includes a transfer device to a fabric to be printed,
The exposure amount in the main scanning direction or sub-scanning direction of the exposure unit is adjusted after adjusting the adjustment resolution of the exposure amount of the exposure unit with respect to the warp direction formed by the convex shape of the surface of the fabric to be printed. and textile printing by matching the adjusted resolution high not better direction by adjustment means of the exposure means, adjusting the exposure amount of the image of the edge portion that intersects the warp direction of the printed fabric, than the other exposed portion reduces printing method and performing. In textile printing method according to claim 1, wherein the exposure means, printing method characterized in that a plurality of light sources is disposed. In textile printing method according to claim 1 or claim 2, wherein the adjusting means, printing wherein the benzalkonium adjust the emission time. The printing method according to any one of claims 1 to 3 , wherein the adjustment is performed when the thickness of the warp yarn constituting the fabric to be printed is less than the thickness of the toner layer transferred to the fabric to be printed. A textile printing method, wherein the means does not adjust the exposure amount . In textile printing method of any one of claims 1 to 4, printing method characterized by using a liquid developer prepared by dispersing the toner in the carrier liquid. It in textile printing method according to any one of claims 1 to 5, wherein the transfer means to be printed cloth, and is biased by the biasing mechanism is due to the transfer roller which is applied a high pressing force A printing method characterized by.

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