Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B33—ADDITIVE MANUFACTURING TECHNOLOGY
  • B33Y—ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3-D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3-D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
  • B33Y10/00—Processes of additive manufacturing
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41F—PRINTING MACHINES OR PRESSES
  • B41F15/00—Screen printers
  • B41F15/14—Details
  • B41F15/34—Screens, Frames; Holders therefor
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B33—ADDITIVE MANUFACTURING TECHNOLOGY
  • B33Y—ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3-D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3-D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
  • B33Y30/00—Apparatus for additive manufacturing; Details thereof or accessories therefor
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41C—PROCESSES FOR THE MANUFACTURE OR REPRODUCTION OF PRINTING SURFACES
  • B41C1/00—Forme preparation
  • B41C1/14—Forme preparation for stencil-printing or silk-screen printing
  • B41C1/147—Forme preparation for stencil-printing or silk-screen printing by imagewise deposition of a liquid, e.g. from an ink jet; Chemical perforation by the hardening or solubilizing of the ink impervious coating or sheet
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M1/00—Inking and printing with a printer's forme
  • B41M1/12—Stencil printing; Silk-screen printing
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M7/00—After-treatment of prints, e.g. heating, irradiating, setting of the ink, protection of the printed stock
  • B41M7/0081—After-treatment of prints, e.g. heating, irradiating, setting of the ink, protection of the printed stock using electromagnetic radiation or waves, e.g. ultraviolet radiation, electron beams
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41F—PRINTING MACHINES OR PRESSES
  • B41F15/00—Screen printers
  • B41F15/14—Details
  • B41F15/34—Screens, Frames; Holders therefor
  • B41F15/36—Screens, Frames; Holders therefor flat
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41F—PRINTING MACHINES OR PRESSES
  • B41F15/00—Screen printers
  • B41F15/14—Details
  • B41F15/34—Screens, Frames; Holders therefor
  • B41F15/38—Screens, Frames; Holders therefor curved

Definitions

• Screen printing is a printing technique whereby a mesh is used to transfer ink onto a substrate, except in areas made impermeable to the ink by a screen printing stencil, also called a blocking stencil.
• a blade or squeegee is moved across the screen to fill the open mesh apertures with ink, and a reverse stroke then causes the screen to touch the substrate momentarily along a line of contact. This causes the ink to wet the substrate and be pulled out of the mesh apertures as the screen springs back after the blade has passed.
• the creation of a screen printing stencil is a tedious, labor- intensive job. It is one that requires a number of process steps, chemical products, lots of water, and is largely manual. It is the least automated part of the current screen printing business.
• FIG. 1 illustrates a direct to mesh screen printer, according to an example of the present disclosure.
• FIGS. 2A-2E depict, in cross-sectional view, elements of a process in screen printing, using a direct to mesh screen printer, according to an example of the present disclosure.
• FIGS. 3A-3B schematically illustrate an emulsion on a mesh, providing a comparison between current technology (FIG. 3A) and the teachings herein (FIG. 3B), according to an example of the present disclosure.
• FIG. 4 is a flow chart illustrating a method of screen printing, according to an example of the present disclosure.
• Capillary films These are films that are pre-coated with an emulsion.
• the mesh is oversaturated with water and the film (emulsion side down) is placed against the supersaturated mesh.
• the capillary action draws the emulsion into the mesh. This gives a more precise coating of the emulsion, both in thickness and in cover. Once the emulsion has diffused into the mesh, the film is peeled off.
• the screen mesh is emulsified it must be dried. Once dry, it is ready for the image transfer or making of the stencil. As the emulsion dries, it contracts and conforms to the mesh causing a rough, uneven surface. (This rough surface causes an accelerated aging of the squeegee during the printing process.)
• UV radiation i.e., UV-activated
• the stencils must be protected from any exposure to light (even normal visible light has enough UV to start the curing process).
• UV-activated ultra-violet radiation
• CMYK cyan, magenta, yellow, and black
• spot color is one based on discrete colors, usually that might not be readily achievable with CYMK colors.
• the areas of the stencil where one does not want the inks to go through are blocked by an emulsion that is subsequently cured to form the stencil; all other areas have only mesh. Any opening in the mesh may either be completely blocked or partially blocked by the emulsion to form the stencil.
• Film Positive Ink A totally black, UV absorbent layer is printed onto a clear sheet of plastic. The printing is done normally by laser or inkjet printers with special film positive inks (film positive ink means a high opacity black ink that completely blocks all visible and UV light). The film is then attached to the pre-coated mesh and exposed to UV light. The attachment is usually by a removable tape (such as masking tape). Once exposed, the film is removed and the uncured emulsion is washed off.
• film positive ink means a high opacity black ink that completely blocks all visible and UV light.
• the film is then attached to the pre-coated mesh and exposed to UV light. The attachment is usually by a removable tape (such as masking tape). Once exposed, the film is removed and the uncured emulsion is washed off.
• the mesh is pre-coated with a thermally-activated emulsion.
• the mesh (without a frame) is put into a thermal printer, where the emulsion is directly cured/activated.
• the un-exposed emulsion is washed off, the stencil is mounted on a frame, and printed.
• CtS - Wax This method is a close relative of CtS - Printed, but uses wax to block the UV light. All else is the same.
• CtS - Direct Exposure This technology directly exposes the emulsion using a UV laser.
• the finished stencil must be fine adjusted when placed on the carousel to ensure proper registration.
• a Direct to Mesh (DtM) approach to forming a stencil involves directly applying and activating/exposing an emulsion onto a screen using inkjet technology.
• a DtM screen printer includes:
• a fluid dispenser for dispensing the release fluid onto the platen or mesh; and a printer carriage supporting a print head for printing the jettable emulsion on a side of the pre-stretched mesh opposite the platen.
• FIG. 1 depicts a block diagram of the direct to mesh (DtM) printer 100.
• the DtM printer 100 includes a mesh support system 110 that includes the pre-stretched mesh 112 held in place by the frame 114.
• the frame 114 is in turn held by the fixture 116.
• the fixture 116 securely and firmly holds the frame 114 with the pre-stretched mesh 112 in place during the application of the jettable emulsion.
• the mesh 112 is made of connected strands of textiles, fiber, metal, or other flexible/ductile materials, here, woven in a crisscross pattern.
• the material comprising the mesh may be any of a number of textiles (silks, polyesters); metals, such as stainless steel; or plastic, such as polypropylene, polyethylene, nylon, polyvinyl chloride (PVC) or
• the DtM printer 100 further includes a platen support system 120, including a release fluid 122 held against the underside of the pre-stretched mesh 112 by a platen 124.
• the platen 124 provides a smooth flat surface for the release fluid 122 held firmly against the bottom of the pre-stretched mesh 112.
• the platen 124 is configured to be as smooth as possible, impermeable to fluids, and resistant to dents and cracks.
• the platen 124 may also act to dissipate energy from a UV curing source 208 (not shown in FIG. 1 , but shown in FIG. 2D).
• the release fluid 122 may be applied (sprayed or wiped or brushed, for example) directly on the platen 124 or onto the mesh 112 once it is in position over the platen prior to the application of the jettable emulsion.
• a fluid dispenser 126 for introducing or dispensing the release fluid 122 onto the platen 124 may comprise one or more sprayers 126.
• the sprayer(s) 126 may be ordinary misters or other spraying-type elements.
• the release fluid 122 inhibits dot-gain, which is the effect of a printed fluid spreading into a print medium, by not reacting with the curing emulsion. Dot-gain need only be inhibited for a short period, as the curing occurs very quickly after the emulsion fluid is jetted.
• the DtM printer 100 includes an inkjet printer 130 that includes a print head 132 mounted on a printer carriage 134.
• the print head 132 is configured to print the jettable emulsion on the side of the pre-stretched mesh 112 opposite to that of the platen 124.
• the printer carriage 134 is a high- precision printer carriage, accurate in both the X and Y Cartesian directions to support accurate droplet placement over one or more passes while building up the jettable emulsion.
• the emulsion can be“built up” to accommodate a wide range of mesh gauges, from very fine to super coarse.
• the layering can be used to maintain high resolution as it builds up the emulsion.
• the print head 132 may be an inkjet print head, such as thermal inkjet, piezoelectric inkjet, drop-on-demand inkjet, or other suitable jetting printhead capable of jetting fluids, including the jettable emulsion disclosed herein.
• inkjet print head such as thermal inkjet, piezoelectric inkjet, drop-on-demand inkjet, or other suitable jetting printhead capable of jetting fluids, including the jettable emulsion disclosed herein.
• the screen mesh 112 which may be of any type, even quite expensive or cheap and any gauge, is stretched onto the frame 114.
• the frame 114 is put into the inkjet printer 130 with the release fluid 122 which has been placed on the platen 124.
• the jettable emulsion is then applied by the inkjet printer 130 to the masking areas and substantially simultaneously exposed with high intensity UV lamps or other suitable UV source, such as UV-light emitting diodes (LEDs).
• the wavelength of the UV lamp (or LED) may be tuned to the reaction range of the jettable emulsion for optimal performance.
• the emulsion reacts at a wavelength of 395 nanometers (nm).
• Other jettable emulsions may have other reaction
• coarse mesh the application may be a multi-pass operation in order to build up the necessary emulsion thickness.
• coarse mesh mesh is meant mesh having a loose weave, and thus having larger gaps between the strands than a fine mesh screen.
• 335 mesh count is considered to be fine mesh
• 110 mesh count is considered to be coarse mesh, where mesh count is the number of thread crossings per square inch.
• low viscosity jettable emulsions By“low viscosity” is meant a range from about 4 centipoises (cP) to about 15 cP (about 4 millipascal second to about 15 millipascal second). These new jettable emulsions are used to create an embossing effect with UV printers onto a wide variety of materials. These new jettable emulsions_are also more elastic, so they can be used more readily as a replacement for previous emulsions. Any color can be used for the jettable emulsion, including transparent or clear, although light cyan or light magenta may be used to provide a slight contrast in order to verify the stencil.
• jettable emulsion that may be suitably employed in the process disclosed herein is a UV-activated acrylate monomer with elastomeric qualities after curing.
• the jettable emulsions are specialty embossing“varnish” polymers that quickly cure into both highly durable / resistant layers that quickly build up on the substrate.
• the cured polymer is also durable and flexible/elastic (if it were rigid, it would crack easily under use and render the stencil useless).
• VersaUV (Roland DG) technology is an example of a material that may be useful in the practice of the teachings herein.
• the release fluid 122 is configured to provide a smooth, nonreactive printing surface under the mesh 112. It also serves to limit dot gain of the printed emulsion. Dot gain occurs when a jetted droplet (or dot) expands or spreads out before the UV exposure. This is particularly important when a half tone is employed, i.e., less than the entire space in the mesh is filled with emulsion. However, the dot-gain need only be inhibited for a short period as the UV curing occurs very quickly after the emulsion is jetted.
• the release fluid 122 is a fluid that manages the dot gain and is non-reactive with the curing emulsion so that it does not lift or separate the emulsion from the mesh 112.
• the fluid for the release fluid 122 may be modified or tailored for the jettable emulsion by changing certain characteristics, including, but not limited to, changing the surface tension, ionic mix, polar or non-polar components, or whether the fluid is aqueous or non-aqueous.
• the release fluid 122 may be water-based (e.g., distilled water), either water alone or with at least one emulsifier in a sufficient amount to prevent evaporation of the release fluid.
• emulsifiers along with a class of emulsifiers known as surfactants, include, but are not limited to, polysorbates, glycerins, and glycols, such as butyl cellosolve.
• the emulsifier(s) may be may be present in an amount of at least 3 vol% to 5 vol% to prevent evaporation of the release fluid 122.
• Further examples of the release fluid 122 include water-based varnishes, such as butyl acetate, xylene, xylol, dimethyl benzene, and combinations thereof.
• the release fluid 122 is deposited either directly onto the platen 124 or onto the mesh 112 after the mesh is placed onto the platen 124.
• the emulsion can be quite rough; this is often caused by conformance of the emulsion to the mesh during the drying process. This rough emulsion surface can wear away at the squeegee, requiring resurfacing or replacing of the squeegee blade.
• the release fluid 122 ensures a very smooth surface; see, for example, FIG. 3B and its
• the platen 124 provides a smooth, hard, impermeable surface for the release fluid 122 and gently pushes the mesh 112 taut to ensure a good even, flat surface upon which to apply the emulsion.
• the platen 124 does not absorb the release fluid 122 or interact, chemically or physically, with it and is planar ( ⁇ 0.05mm / meter).
• smooth is meant that the surface of the platen 124 is a regular surface that can either be
• FIGS. 2A-2E are cross-sectional views of the DtM apparatus.
• frame 114 surrounds platen 124.
• the fixture 116 for supporting the frame 114 is omitted in this Figure and in FIGS. 2B-2E.
• the frame fixture 116 is similar to what is currently used in the art.
• One or more elements, or sprayers, 126 spray a layer of release fluid 122 on a top surface 124a of the platen 124.
• the sprayer(s) 126 may be fixed in position or configured to traverse across the platen 124. It will be appreciated that the release fluid can be applied in a number of different ways: e.g. wiping, brushing, and the like, as well as spraying.
• mesh 112 is placed across the top of the frame 114.
• the platen 124 with a thin, even coating of the release fluid 122 supported on surface 124a of the platen.
• the thickness of the release fluid 122 is about 20 micrometers (pm), but in any event less than the gauge of the mesh, and is within ⁇ 0.5 pm planarity.
• the release fluid 122 backs up the mesh 112 to provide good coverage of the jettable emulsion, as it is applied.
• the release fluid 122 is formulated to avoid
• the formulation of the release fluid 122 prevents the emulsion from bonding, reacting, or otherwise sticking to the platen. In some cases, the emulsion may react with the release fluid 122, but that interaction/reaction typically may not allow any adhesion to the platen 124. If the adhesion to the platen 124 is greater than the adhesion to the mesh 112, then the emulsion may de-bond / delaminate from the mesh.
• the platen 124 with the release fluid 122 is moved up to the mesh 112, tightening the mesh and pressing the release fluid against the back of the mesh. This provides a smooth, tensioned, level surface to print on.
• the movement of the platen 124 is indicated by arrows 202.
• the print head 132 which is translatable by the printer carriage 134 (not shown in FIG. 2D, but shown in FIG. 1) prints the blocking image, or stencil, 206 (seen in FIG. 2E) directly onto the mesh 112, where the blocking image is the reverse, or negative, of the actual image that is to be printed, or screened, onto a suitable print medium.
• the print head 132 moves laterally in the direction indicated by arrow 204 to form a screen stencil 206 on the mesh 112.
• the "ink” is the UV-cured jettable emulsion, described above, which is UV-cured essentially as it is applied by means of UV source 208. In an example, the UV source moves laterally in the direction indicated by arrow 210.
• FIG. 2D depicts the print head 132 and UV source 208 moving across the mesh 112.
• the mesh support system including the mesh 112 and frame 114 (and fixture 116), could be translated relative to the print head 132 and UV source 208.
• the UV source 208 can be fitted to both sides of the print head 132 to facilitate bi-directional printing of the mesh 112.
• FIG. 2E the resulting stencil 206 is shown.
• the stencil 206 can be removed from the printer and used immediately without any further preparation or treatment.
• a layer 128 may be placed on the surface 124a of the platen 124 prior to dispensing the release fluid 122 thereon.
• the layer 128 is referred to herein as“Background Type”.
• the platen 124 was kept at a constant height and then the“background” 128 was placed on it.
• Examples of the background type 128 include a 4 mm mirror, 2 mm clear glass, 2X glass (up), polyethylene white, glass (up) / mirror (down), 4 mm glass (up), and 3 mm mirror. So, if a 4 mm mirror, for example, was used, the print surface was 2 mm higher than with the 2 mm clear glass. Sometimes, differing results were obtained with a“two component” background.
• “2X glass” comprised two sheets of clear glass,“Glass (up) / Mirror( down) was a 2 mm piece of glass on a 2 mm / 4 mm mirror. Without subscribing to any particular theory, it is believed that using two plates introduces some light
• FIGS. 3A-3B A comparison of results is shown in FIGS. 3A-3B, according to an example. Both Figures illustrate an emulsion applied to the mesh 112.
• FIG. 3A in the combination 300 of a conventional spreadable emulsion 302 and mesh 112, the emulsion is seen to conformally follow the warp and weft (strands 112a and 112b) of the mesh, including both the top of the mesh and the bottom of the mesh. This conformality occurs as the spreadable emulsion 302 air-dries onto the mesh 112.
• FIG. 3A shows how the emulsion 302 applied in the conventional way shrinks as it dries onto the mesh 112 after being applied either by hand or with an applicator machine. This shrinkage is unavoidable as the water component dries.
• the emulsion 302 is one commonly used in the art.
• the jettable emulsion in the combination 350 of the jettable emulsion 302’ of the present teachings and mesh 112, the jettable emulsion is seen to have a flat bottom surface 302’a, which is provided by the smooth surface 124a of the platen 124 (and the release fluid 122 thereon).
• the top surface 302’b of the jettable emulsion 302’ is seen to be less conformal to the warp and weft of the mesh 112 than the current emulsion 302.
• the bottom surface 302’a is where the screen inks will be applied and pressed through using the squeegee during the actual screen printing process.
• DtM because the mesh 112 has the release fluid 122 supported by the smooth platen 124, the underside 302’a of the emulsion 302’ is more nearly planar or flat. This is also a result of being essentially immediately cured by the UV radiation.
• DtM Direct to Mesh
• FIG. 4 depicts a flow chart of an example DtM process 400, in accordance with the disclosure herein, for preparing a stencil for screen printing.
• the direct to mesh printer 100 is provided 405.
• the DtM printer 100 includes the fixture 116 to hold the frame 114, the frame being configured to hold the pre-stretched mesh 112 in place during application of the jettable emulsion 302’.
• the platen 124 of the DtM printer 100 is to hold the release fluid 122 against one side of the pre-stretched mesh 112.
• the DtM printer 100 includes the printer carriage 134 supporting the print head 132 for printing the jettable emulsion 302’ on the side of the pre-stretched mesh 112 opposite the platen 124.
• the DtM process 400 continues with placing 410 the frame 114 in the fixture 116.
• the fixture 116 is part of the DtM printer 100 and is adapted to receive a wide variety of frame 114 sizes.
• the fixture 116 is configured to accurately fix the frame 114 in place, so that the printer carriage 134 is accurately registered to the mesh 112.
• the DtM process 400 continues with applying 415 the release fluid 122 to the platen 124, either directly or through the mesh 112. Applying the release fluid 122 may be just as effective when applied directly to the mesh 112 as pre-applied to the platen 124. This may be important for very large stencils or very high dot density, such as 5,000 DPI, where the release fluid 122 might have time to evaporate even with a good emulsifier.
• the platen 124 coated with the release fluid 122 is brought into contact with the mesh 112 (or the platen 124 is brought into contact with the mesh 112 and the release fluid 122 is applied to the mesh).
• the platen 124 may be raised about 1 millimeter (mm) to about 2 mm above the level of the mesh to provide a tautness to the mesh 112.
• the DtM process 400 continues with applying 420 the jettable emulsion 302’ to the mesh 112.
• the jettable emulsion 302’ is applied relative to the mesh 112 by means of the inkjet printer 130, in which the inkjet print head 132 is to jet the jettable emulsion.
• the DtM process 400 concludes with curing 425 the jettable emulsion 302’ using UV radiation. Any common UV source may be used to cure the jettable emulsion 302’.
• the stencil 206 is formed and cured and is ready to be used to screen print colors onto an appropriate print surface, such as clothing, for example.
• the jettable emulsion after curing forms the screen stencil, in which openings in the screen stencil are to be used to print an image on the print surface.
• “Mesh Resolution” refers to the number of threads per centimeter (cm).
• the mesh resolution may include a letter to indicate the diameter of the thread, such as S (small diameter), T (medium diameter), or HD (heavy diameter).
• S small diameter
• T medium diameter
• HD high diameter
• “43T” is a mesh having 43 threads per cm, of medium diameter.
• “Frame Type” indicates the type of frame 114 used, and may be a roller frame, aluminum, or a big roller frame.
• The“Aluminum” frame was a fixed square metal aluminum frame where the mesh was glued at a specific tension before starting. A typical value for the tension was about 26 Newtons (N).
• the “Roller Frame” was a retensionable frame, which allowed changing the tension of the mesh after the stencil was stretched. The roller frames are much more expensive than a standard square frame but are much easier to keep the tension correct and to re-stretch.
• the big roller frame was somewhat larger than the roller frame.
• the metal mesh was a stainless steel, nickel-plated mesh. This type of mesh is frequently used for rotary screens or for screens that are exposed to aggressive fluids or long use (many prints/pressings) from the same stencil.
• Unit Resolution is the dot density interweave (DPI) that is being jetted out of the printhead.
• Number of Pulses refers to the number of firing pulses that are sent to an individual nozzle.
• the print head used had 8 nozzle rows.
• Channels refers to how many rows were used to jet fluid. “All” means all 8 rows. The notation“11100111” indicates that the middle two rows were not fired; this gives the effect of a“gap” between the jetting.
• UV % refers to the strength of the UV radiation emitted by the UV LED source 208, which was adjustable.
• the intensity of the UV LED source 208 was modulated with a PMW (Pulse Width Modulator) to control the intensity of the UV light generated.
• the maximum on the UV source 208 employed was 100 W/cm 2 .
• a notation of 60%, for example, means that 60% of the UV light was modulated to 60% of full strength.
• Release Fluid refers to the composition of the release fluid 122 that was applied to the platen 124.
• Background Type refers to what was used on the surface of the platen 124. The platen 124 was kept at a constant height and then the “background” was placed on top of the platen.
• background types include a 4 mm mirror, 2 mm clear glass, 2X glass (two sheets of 2 mm clear glass),“Glass(up)/Mirror(down)” (2 mm clear glass on a 2 mm/4 mm mirror), and“Polyethylene White” (white polyethylene sheet).
• TEM refers to Total Emulsion Measure and is a measure of the emulsion thickness. Often, a figure of EoM (emulsion over mesh) is used, but that is a ratio of emulsion thickness divided by mesh thickness. Here, the number in pm refers to overall thickness, including the thickness of the emulsion plus the thickness of the mesh.
• “Smoothness” refers to the smoothness of the stencil. On the platen side, the surface should be extremely smooth to the touch, with no discernable roughness. On the print side, the surface should be smooth to the touch. Slight roughness (similar to what would be experienced with frosted glass) was considered to be“Acceptable”. In the test results deemed“Not Acceptable”, in general, the surface was like sand paper. [0076] The smoothness results are based on a subjective rating, where 1 is acceptable, 2 is marginally acceptable, 3 is marginally unacceptable, and 4 is unacceptable.
• Results refers to a subjective rating of the overall results of the experiment. The same subjective rating scale described for smoothness is used here as well.
• A4 Print Time refers to the time it took to print a screen having the dimensions of A4 media (21.0 cm x 29.7 cm).
• Example Series 1 Six experiments were run; the details are provided in Tables IA (Test Parameters) and 1 B (Results), below. All experiments used as the jettable emulsion UV Super Flex 100 ink, which is an experimental ink. The mesh color in each case was white.
• the frame type was variously a roller frame, aluminum or a big roller frame, as listed in Table IA.
• the unit resolution in each case was 1440 DPI.
• the printing speed in each case was 300 cm/sec.
• the number of pulses was as noted in Table IA.
• the UV in each case was 60% of full strength.
• the release fluid in all six experiments was 100% distilled water.
• the background type in the first three experiments was a 4 mm mirror, while in the last three experiments was 2 mm clear glass.
• the TQM ranged from 10 pm to 22 pm
• Example Series 2 Twelve experiments were run; the details are provided in Tables IIA (Test Parameters) and IIB (Results), below. All experiments used as the jettable emulsion UV Super Flex 100 ink. The mesh color in each case was yellow. The frame type in each case was aluminum. The unit resolution in each case was 1080 DPI. The printing speed was 375 cm/sec. The number of pulses was as noted in Table II. In all experiments, all eight ink channels were fired. The UV was 60% of full strength for all experiments, except Experiment 11 , where the UV was 40% of full strength.
• the release fluid 122 was as noted in Table IIA.
• the background type was a noted in Table IIA.
• Example Series 3 Five experiments were run; the details are provided in Tables MIA (Test Parameters) and NIB (Results), below. All experiments used as the jettable emulsion UV Super Flex 100 UV ink. The mesh color in each case was yellow. The frame type in each case was aluminum. The unit resolution in each case was either 1080 DPI or 1440 DPI. The printing speed was either 300 cm/sec or 375 cm/sec, as noted in Table IIIA. The number of pulses was as noted in Table IIIA. In all experiments, the middle two nozzle rows of the print head were not fired, leaving a gap (“11100111”).
• the UV was 60% of full strength.
• the release fluid 122 in all six experiments was 100% distilled water.
• the background type in all experiments was a 4 mm mirror.
• Example Series 4 four experiments were run; the details are provided in Tables IVA (Test Parameters) and IVB (Results), below.
• the mesh resolution in all cases was 195 (US Standard). All experiments used as the jettable emulsion UV Super Flex 100 UV ink. The mesh color in each case was grey/metal. The frame type was metal. The unit resolution in each case was 1440 DPI . The printing speed was 300 cm/sec. The number of pulses was 1 for all experiments. In all experiments, the middle two nozzle rows of the print head were not fired, leaving a gap (“11100111”).
• the UV was 60%, 40%, and 30%, respectively, of full strength, while in Experiment 4, the UV was 30% of full strength.
• the release fluid in Experiments 1-3 was distilled water; in Experiment 2, no release fluid was used.
• the background type in both experiments was a 3 mm mirror.
• DtM process 400 includes the complete elimination of both stencil preparation and post-processing as follows:
• Machines such as emulsion applicators, dryers, separate exposure units are not needed.
• All of the processing can be done without having special low UV light rooms. Indeed, the DtM process can be carried out in normal factory/office lighting or daylight. The jettable emulsion is retained inside a UV- protected cartridge or bag when handling. It is only exposed to daylight or UV light when it is jetted onto the mesh 112. [0098] Because the process disclosed herein can use conventional, less expensive mesh 112, it can often be more efficient and cheaper to strip and remesh the frame 114 rather than washing the mesh, which entails water and chemicals and a special cleaning station.
• the raw, unprocessed screen, or mesh, 112 is placed on the DtM printer 100 and a fully prepared, ready to use stencil 206 is removed from the screen that can be placed directly onto a carousel for printing an image onto a print surface.
• each stencil 206 is very accurately registered on the mesh 112 so that it is possible to skip micro-registration when mounting on the carousel.
• the stencil frame typically has registration holes or point affixed to it.
• Each different carousel manufacturer has their own registration system.
• the frame fixture 116 is equipped with the same registration system (or possibly an auxiliary registration system of another design). The frame fixture 116 permits the precise alignment of the stencil frame 114.
• DtM process 400 has significant reductions in either or both process time and complexity, labor, and capital equipment (including specialized lighting facilities), as well as significant reductions of process chemicals and water.
• the DtM process 400 can also be used for rotary screen printing.
• Rotary screen printing is used in labelling and other somewhat narrow but frequently repeated printing processes (wall papers, linear linoleum, etc.).
• Rotary screen printing is extremely fast for these applications, where each of the four colors (and any spot colors) are placed on cylinders and the material passes underneath.
• Rotary screen printing typically uses stainless steel mesh 112 for durability and stability.
• dispensing the release fluid 122 onto the platen 124 or mesh 112 may involve dispensing the release fluid onto the platen and then bringing the platen and mesh together.
• the platen and mesh may be brought together and the release fluid dispensed onto the mesh.
• the“orientation” of the printer bed/table may be changed from horizontal to vertical, due to new high / ultra-high velocity print head

Landscapes

• Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• Mechanical Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Materials Engineering (AREA)
• Physics & Mathematics (AREA)
• General Health & Medical Sciences (AREA)
• Toxicology (AREA)
• Electromagnetism (AREA)
• Health & Medical Sciences (AREA)
• Manufacture Or Reproduction Of Printing Formes (AREA)
• Printing Plates And Materials Therefor (AREA)
• Photosensitive Polymer And Photoresist Processing (AREA)
• Screen Printers (AREA)

Priority Applications (7)

Applications Claiming Priority (1)

Related Parent Applications (1)

Related Child Applications (2)

Publications (1)

Family

ID=62873322

Family Applications (1)

Country Status (5)

Cited By (2)

Citations (4)

Family Cites Families (10)

• 2018
  • 2018-07-04 WO PCT/EP2018/068047 patent/WO2020007457A1/en active Application Filing
  • 2018-07-04 JP JP2020572713A patent/JP7184240B2/ja active Active
  • 2018-07-04 KR KR1020207037342A patent/KR102524451B1/ko active IP Right Grant
  • 2018-07-04 EP EP18739492.9A patent/EP3817922A1/en active Pending
• 2019
  • 2019-07-04 TW TW108123527A patent/TWI754827B/zh active

Patent Citations (4)

Also Published As

Similar Documents

Legal Events