Patent Application
20220097413
The present invention relates to making prints on textile fabrics, and more particularly to a garment printing apparatus and a method thereof for improving color fastness and color shadings.
With reference to US Patent Publication No. 20060249039 A1, a conventional digital DTG (Direct-to-Garment) printing system has multiple pallets for garments or cut parts of garments to be placed on and a digital printing apparatus for printing patterns on the garments or the cut parts.
The conventional digital DTG printing system uses inkjet technology to print pixelate patterns on fabric contexture. The fabric contexture of a textile surface is seemingly rugged to the scale of an inkjet droplet. Whereas, the ink droplets could be agglomerated, misaligned, sunk deep into the voids between fabric filaments or absorbed into the fibers by capillary phenomenon, such as that the intentioned print losses its resolution and shading details. Whereas, the textile ink is water-based chemicals that could be incompatible to the surface parity of the textile fiber, such as to fell forming firm bonding between the two.
To overcome the disability of the conventional digital DTG printing system, the present invention provides a garment printing apparatus and a method thereof for improving color fastness and color shadings.
The main objective of the present invention is to provide a garment printing apparatus and a method thereof for improving color fastness and color shadings.
The garment printing apparatus of the present invention comprises a production line, a loading station, an unloading station, a plural number of intermediate stations, and a pallet.
The loading station and the unloading station are respectively disposed on the production line, and the plural number of intermediate stations are disposed between the loading and unloading stations.
The plural number of intermediate stations include a pretreatment station for applying primer coating on a textile-piece, a pattern printing station for printing a desired pattern on the textile-piece, and at least one plasma treatment station. The at least one plasma treatment station is disposed after the loading station and before the pattern printing station, to impose specific plasma efficacy on the textile-piece before pattern printing.
The pallet is mobile on the production line for conveying textile-piece from station to station.
The garment printing method of the present invention comprises a preparation step, a pretreatment step, at least one plasma treatment step, and a pattern printing step.
The preparation step comprises preparing a production line and a textile-piece that could be a garment or a cut parts of a garment. The production line has a mobile pallet, a plasma treatment device, and a digital inkjet-printing unit. The plasma treatment apparatus and the digital inkjet-printing unit are disposed on the production line, respectively. The preparation step further comprises laying the textile-piece on the pallet, and conveying the pallet with the textile-piece from station to station, to complete the remaining steps of the present invention.
The pretreatment step comprises applying a primer coating onto the textile-piece. The at least one plasma treatment step comprises imposing specific plasma efficacy on the textile-piece with a plasma generating device. The pattern printing step is performed following completion of the pretreatment step and the at least one plasma treatment step, and comprises printing a pattern on the textile-piece by the digital inkjet-printing unit.
Other objectives, advantages and novel features of the invention will become more apparent from the following detailed descriptions when taken in conjunction with the accompanying drawings.
Referring to
Moreover, the garment printing apparatus has a plural number of pallets 103 for transferring the textile-pieces along the production line 10 through all of aforementioned stations 101, 20, 30, 40, 50 and 102. That is to say, each one of the textile-pieces is being laid on one of the plural number of pallets 103, and is transferred by the pallet 103 for being treated through the plural number of intermediate stations 20, 30, 40 and 50. Referring to
Further, in reference to
The pretreatment station 20 is mainly used for applying primer coating to the textile-pieces. The primer coating serves as a bonding enhancing agent to improve color fastness on textile fibers and ligaments. The pretreatment station 20 may have a pretreatment unit 21, at least one flash-cure unit 22, and an optional heat-press unit 23. In a preferred embodiment shown in
The pattern printing station 30 is disposed between the pretreatment station 20 and the unloading station 102, and is capable of printing various patterns selected from a storage library of the present invention or via information network. The pattern printing station 30 can switch between patterns and print on the corresponding textile-pieces specified by job orders, without having to setup or change printing stencils. The pattern printing station 30 may be a digital inkjet printer comprising an underlay printing unit 31 and a color-print unit 32.
The underlay printing unit 31 can print a white underlay pattern on the textile-piece, especially for dark-color fabrics. White speckles of textile ink are being laid out by digital inkjet-printing unit in pixelate pattern on top of the primer coating done by station 20. The white underlay pattern may not be necessary if the textile-piece is a white fabrics or light-color fabrics. The underlay printing unit 31 may thus be omitted or removed from the production line, if say in such circumstances.
The color-print unit 32 is placed next to the underlay printing unit 31. The color-print unit 32 can make a photo-like pixelated prints composed by multiple colors of textile ink speckles. A typical embodiment of the color-print unit 32 may comprise multiple colors of inks. A typical embodiment of the color-print unit 32 comprises, for example, CMYK (Cyan, Magenta, Yellow and Black) four-color printing capability. With digital compositions of pixelated four-color prints, the present art of the invention has advantages over traditional stencil printing in such as picture resolutions, levels of color-shadings, and the convenience of altering printing patterns. The digital printing device in the present invention is the same as that of the prior art. However, poor color fastness or dull color shadings resulting from a non-sizing pretreatment may be resolved through the following device provided in the present invention.
The at least one plasma treatment station 40 is disposed on the production line 10 between the loading station 101 and the pattern printing station 30 for imposing specific plasma efficacy on the textile-pieces before patter printing. When the garment printing apparatus has only one said plasma treatment station 40, the plasma treatment station 40 is disposed in between the pretreatment station 20 and the pattern printing station 30. Plasma flow is thereby swept through the textile-piece to condition the surface that has already coated with pretreatment primer.
Furthermore, the ions in the plasma flow impinge on the fabric contexture to create a temporary isotropic surface condition which would prevent the textile ink droplets exerted by the printing station 30, later, from being agglomerated, misaligned, sunk deep into the voids between fabric filaments or absorbed into the fibers by capillary phenomenon. Unlike traditional textile dying, digital DTG printing uses pigment inks, thus eliminating the polluting processes of steaming and desizing. Yet, color pigments in the inks are nanoparticles, that can only be visible if it is being affixed onto the exterior surface of the textile-piece. If, however, the nano-pigments are being absorbed into the deeper core of a fiber filament, then, not only the color becomes dull in appearance, but also promotes a phenomenon call color-crossing. Color-crossing is due to wet ink speckles of different colors diffused into each other before the curing process by the curing station 50 could happen, and the diffused, murky ink speckles destroys the definitions and details of a desired pixelate picture or pattern. Therefore, plasma treatment given by the at least one plasma treatment station 40 improves color chroma and shading details of a print done by the pattern printing station 30. In addition, specific gas plasma, exerted by the at least one plasma treatment station 40, can stimulate or activate ionic bonding among the fabric filaments of the textile-piece, the pretreatment agent, exerted by the pretreatment station 20, and the binder compound in the textile inks, exerted by the pattern printing station 30. After curing by the curing station 50, the adhesion converted into stable crosslinking bonding, hence improves the color fastness.
Referring to
Moreover, in prior art, specific gas plasma is known to be used for conditioning the hydrophobicity or hydrophilicity of a textile. Incidentally, the pretreatment agent and the pigment inks are water-based coatings. Furthermore, the method to generate plasma flow is a prior art, comprises a device known as APPJ (Atmospherically Pressure Plasma Jet), or could also be a corona discharge equipment, whichever is effective in creating an ionic efficacy on the textile-piece.
The curing station 50 is disposed next to the pattern printing station 30, before the unloading station 102. When the desired pattern is finished printing on the textile-piece, the corresponding pallet 103 carries the textile-piece to the next curing station 50 for thermofixation or UV curing on prints. Once the pigment-inks on the print are cured, the pallet 103, then, carries the textile-piece to the unloading station 102 for collection. The curing station 50 may comprise another flash-cure unit, as well as may comprise an UV-lamp unit, depending on the ink chemistry.
Accordingly, in reference to
The preparation step comprises laying a textile-piece on a respective one of said conveying pallets 103, and then transporting the pallet on production line 10, from station to station, to complete the remaining steps of the present invented method.
The pretreatment step comprises deploying a wet primer coating onto the textile-piece, and then drying the coating. The primer is normally water-based compounds that promotes chemical polarity on the surface of the textile-piece, and thus enhances the bonding strength between the textile and the inks to be applied. The drying of the pretreatment primer is to simply remove the excessive water from the textile, and to facilitate the quality of the digital pixelate printing comes later by the printing step.
Referring to
Next to the plasma treatment step is followed by the pattern printing step that comprises a digital inkjet device to make prints of desired patterns on the textile-piece. In case of dark garment fabrics, an optional white underlay can be printed before the color print. whereas, the white underlay can mask the dark fabrics and provide a blank background in contrast for the color inks to be laid on. Hence, the color pigments from the color inks can be shown off more vividly against the white pigments from the white ink. Nonetheless, if the garment fabrics is in light color, the underlay print can be omitted.
However, in case the plasma treatment step of the present invention has been skipped, the white or color ink droplets could be drawn further into the fabric core and away from the textile surface, which would, then, reduce the masking effect to cover the background color of the fabrics itself. In consequence, the color print on garment could become dull in appearance. Furthermore, the plasma treatment of the present invention can excite the valence state of a textile surface, hence promote a stronger bonding between the textile fiber and the primer or the ink molecules. As a result, the color fastness and shadings of the printing on a garment is improved with the present invented method.
The next is curing step after the printing step, before the textile-piece could finally be unloaded in the collection step. The curing step uses a thermofixation process or an UV photo-chemistry process to cause the ink binder to be solidified and fix the ink colorants firmly to the textile-piece. Post-curing step, the garment printing job is completed and the textile-piece is sent to the unloading station for collection or for further assembly.
Referring to
The first plasma treatment step is performed before the pretreatment step, and after the preparation step. In the first plasma treatment step, the plasma flow is swept through the exposed fiber filaments of the textile-piece directly. The bombardment of energetic ions from the plasma flow agitate the valence state on the textile surface, and make the surface be more coherent with the pretreatment prime to be applied. In a typical case, the pretreatment primer is water-base agent. The plasma treatment can condition the textile fibers to be properly hydrophilic to ensure a uniform wetting of primer coating on the textile-piece.
The second plasma treatment step is performed after the pretreatment step and before the pattern printing step. The efficacy of the second plasma treatment step is the same as those described in the context of the first embodiment by the present invention.
With the aforementioned technology characteristics, the present invention, a garment printing apparatus and the method thereof for improving color fastness and shadings, has the following advancement merits:
1. With plasma treatment, the wetting characteristics of primer coating and inkjet printing on textile surface are improved, thus the amount of primer or inks used are much less than the conventional printing method.
2. With plasma treatment, the valence state is agitated on the textile surface, promoting stronger bonding between the textile fibers and the primer coating, as well as the textile inks. Hence, the color fastness is improved.
3. With plasma treatment, the colorants from the textile inks are concentrated to the exterior surface of the textile filaments, thus improves the color shadings of a desired prints and reaches a higher print quality.
Even though numerous characteristics and advantages of the present invention have been set forth in the foregoing descriptions, together with details of the structure and features of the invention, the disclosure is illustrative only. Changes may be made in the details, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
