An "O" shaped solvent droplet would penetrate the page surface slightly while wetting it, with a pigment droplet aimed dead-center, to the solvent "O", then as the solvent evaporates, it creates a micro-wicking suction effect around the pigment droplet (and limits droplet wicking spread in the process - think spilled coffee-cup stain ring). Of course, timing has to be precise or the benefit of this effect is lost if the solvent evaporates prior to pigment droplet impact.
An "O" shaped solvent droplet would penetrate the page surface slightly while wetting it, with a pigment droplet aimed dead-center, to the solvent "O", then as the solvent evaporates, it creates a micro-wicking suction effect around the pigment droplet (and limits droplet wicking spread in the process - think spilled coffee-cup stain ring). Of course, timing has to be precise or the benefit of this effect is lost if the solvent evaporates prior to pigment droplet impact.
Ideally you want to think of the ink spray channel much as you would the rifling on a standard gun or an paintball gun. If you can induce a slight spiral motion before the ink droplet leaves the channel, then droplet structure will remain intact longer prior to page impact. Ideally with print-interleaving techniques, you'd want a "O" droplet of solvent to hit the page a microsecond prior to the pigment droplet, so that as the solvent evaporates, it causes the pigment droplet to be sucked in.
Triangle inkjet nozzle drops can be made the same way as the "X" square dots with a slightly different similar design. Another consideration on inkjet micro-channels aside from pressure is the issue or adhesion surface-tension pressures in play on the sidewalls of the channels. Faster spraying of the dots means the dots will adhere to the channel walls and spray wider from rolling-motion surface tension. To prevent this, a small mask ring in the channel can break up the force of the rolling.
Otherwise variations on dot types for ink sprayer output can be created using modulation of the channel shapes (think cookie dough press design). The ink is pressurized prior to entering the sprayer channel, it will expand to regain pressure equalization as it exits. Square dots are possible by making the exit of the channel a rounded "X" shape with a straight up-down feed to the ends of the "X", and a 60 degree slope to the inner points of the "X". As pressure equalizes, it makes a square dot.
The better channel for the ink-wash I suppose would be a "Y" or inverted-"h" channel with a "L |" shape in place of my prior-suggests "+" shape for the air-blow ink-cleaning channel. The "L" being the ink-wash spray part of the channel with the "|" being the suction part of the channel. Although a "V" shape for the wash channels would allow dot placement modulation by varying the air blow/suction cycle pressures on either side of the air blow channels.
The ink-wash channel would not be in usage unless the jet sprayer nozzles are in cleaning mode. Otherwise the logical thing is to switch the dirty ink-wash suction channel and the ink-wash pressure spray channel to just air-spray mode. That way as the ink dots are sprayed onto the page, the ink is not encouraged to creep back into either cleaning channel and clog them up. Bonus is that the air spray can be ionized for superior electrostatic ink adhesion to the application surface.
With a "Y" or inverted-"h" sprayer the channel pressure is still problematic, but not so much that dot deformation occurs. Also the extended height of the channel allows an ink-washing spray to be channeled horizontally through the side of the bottom of the channel. This would allow longer printhead usage without ink-clogging issues. In this, think of a large "+" sign placed at the bottom of the "Y" leg with one side of the "+" feeding in ink-wash and the other side suctioning dirty wash.
One other thing to note, I figure that ROLAND has perfected their ink-sprayer heads, but the basic inject printheads could also use a redesign for superior print longevity. Most printheads use a "V" shaped feed-to-spray design, but that is inferior because as ink reaches the bottom of the "V" it is compressed and then sprays outward to equalize pressure creating large dot sizes and inducing later printhead clogging. A better design would be a "Y" shaped or an upside-down "h" sprayer.
With this technique you can have pressure-infused offset printing qualities for your paper output with the ROLAND vinyl-solvent printing process with the inexpensive properties of plateless printing with the ability to simultaneously duplex pages with two presser rollers. This also allows rapid cleanup with a simple automated routine between jobs with almost zero ink wastage. The direct-to-page MEMJET type sprayer array would allow short print runs with no slowdown for a cut sheet feed press.
With this technique you can have pressure-infused offset printing qualities for your paper output with the ROLAND vinyl-solvent printing process with the inexpensive properties of plateless printing with the ability to simultaneously duplex pages with two presser rollers. This also allows rapid cleanup with a simple automated routine between jobs with almost zero ink wastage. The direct-to-page MEMJET type sprayer array would allow short print runs with no slowdown for a cut sheet feed press.
For individualized printing, you simply use the MEMJET sprayer array direct-to-page spray out individual items onto the page after it leaves the spray-to-roller pressure infusers. For UV clear-coating of the stock the same process is used, direct-to-roller spraying for even coverage at budget prices and direct-to-page dot-spraying for 3D gloss effects with curing lights at each stage as the paper leaves. Using UV coating as the after-printing process.
Afterward when the paper is pressure-printed, you spray the printed sheets as they exit the rollers using direct-to-page MEMJET-type arrays using the ROLAND solvent vinyl inks to individualize your output product per page in the empty space designated in the pre-press setup. No printing plates required. If you want a UV coating process, that can be done with a secondary roller-presser with a direct-to-page dot sprayer. For short-runs, direct-to-page sprayers are used, & big runs roller press.
For mass production printing, I would spray the squishable, abrasion-resistant blanket roller (for edge-to-edge printing options), using a MEMJET-type printhead array to give fast pressure-sublimation printing without requiring an inking plate. For mass-mailing printing using this process, one MEMJET-array (or two for auto-duplex printing) would be set up to spray to the pressure-transfer sublimation roller (which then squishes the ink into the page).
Downside of using a vinyl solvent process on a vulcanized rubber printing roller blanket (for pressure sublimation into the paper), is that the printing blanket would likely be partially dissolved with the vinyl solvents, so it might be better to use a polyurethane or polyester printing blanket instead (both plastics needing composite-formulation tweaking to ensure longer wear abrasion resistance). For shiny surface printing an UV coating 3D relief printing, I would use direct-to-page printing.
The ideal compromise appears to be the ROLAND solvent vinyl printers. They have highly durable vibrant vinyl/acrylic inks which can precoat a substrate for superior output quality. Objectively speaking, the ROLAND solvent process is slow, but could be vastly improved for mass production by getting a decent stacked paper feeder and a MEMJET array of printheads spraying the page. To further improve output speeds, in regards to rapid printing, I would spray the vinyl ink onto a printing blanket.
The ideal compromise appears to be the ROLAND solvent vinyl printers. They have highly durable vibrant vinyl/acrylic inks which can precoat a substrate for superior output quality. Objectively speaking, the ROLAND solvent process is slow, but could be vastly improved for mass production by getting a decent stacked paper feeder and a MEMJET array of printheads spraying the page. To further improve output speeds, in regards to rapid printing, I would spray the vinyl ink onto a printing blanket.
The ideal compromise appears to be the ROLAND solvent vinyl printers. They have highly durable vibrant vinyl/acrylic inks which can precoat a substrate for superior output quality. Objectively speaking, the ROLAND solvent process is slow, but could be vastly improved for mass production by getting a decent stacked paper feeder and a MEMJET array of printheads spraying the page. To further improve output speeds, in regards to rapid printing, I would spray the vinyl ink onto a printing blanket.
The ideal compromise appears to be the ROLAND solvent vinyl printers. They have highly durable vibrant vinyl/acrylic inks which can precoat a substrate for superior output quality. Objectively speaking, the ROLAND solvent process is slow, but could be vastly improved for mass production by getting a decent stacked paper feeder and a MEMJET array of printheads spraying the page. To further improve output speeds, in regards to rapid printing, I would spray the vinyl ink onto a printing blanket.
The ideal compromise appears to be the ROLAND solvent vinyl printers. They have highly durable vibrant vinyl/acrylic inks which can precoat a substrate for superior output quality. Objectively speaking, the ROLAND solvent process is slow, but could be vastly improved for mass production by getting a decent stacked paper feeder and a MEMJET array of printheads spraying the page. To further improve output speeds, in regards to rapid printing, I would spray the vinyl ink onto a printing blanket.
Thank you both.... very informative & interesting. Trying to get started in offset (AB dick) printing w/a friend who has been in printing for over 20 yrs. T.Y. for your time.
Good explanation - i like it.
AlphagraphicsCom 1 month ago
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An "O" shaped solvent droplet would penetrate the page surface slightly while wetting it, with a pigment droplet aimed dead-center, to the solvent "O", then as the solvent evaporates, it creates a micro-wicking suction effect around the pigment droplet (and limits droplet wicking spread in the process - think spilled coffee-cup stain ring). Of course, timing has to be precise or the benefit of this effect is lost if the solvent evaporates prior to pigment droplet impact.
Matrix29bear 5 months ago
An "O" shaped solvent droplet would penetrate the page surface slightly while wetting it, with a pigment droplet aimed dead-center, to the solvent "O", then as the solvent evaporates, it creates a micro-wicking suction effect around the pigment droplet (and limits droplet wicking spread in the process - think spilled coffee-cup stain ring). Of course, timing has to be precise or the benefit of this effect is lost if the solvent evaporates prior to pigment droplet impact.
Matrix29bear 5 months ago
Ideally you want to think of the ink spray channel much as you would the rifling on a standard gun or an paintball gun. If you can induce a slight spiral motion before the ink droplet leaves the channel, then droplet structure will remain intact longer prior to page impact. Ideally with print-interleaving techniques, you'd want a "O" droplet of solvent to hit the page a microsecond prior to the pigment droplet, so that as the solvent evaporates, it causes the pigment droplet to be sucked in.
Matrix29bear 5 months ago
Triangle inkjet nozzle drops can be made the same way as the "X" square dots with a slightly different similar design. Another consideration on inkjet micro-channels aside from pressure is the issue or adhesion surface-tension pressures in play on the sidewalls of the channels. Faster spraying of the dots means the dots will adhere to the channel walls and spray wider from rolling-motion surface tension. To prevent this, a small mask ring in the channel can break up the force of the rolling.
Matrix29bear 5 months ago
Otherwise variations on dot types for ink sprayer output can be created using modulation of the channel shapes (think cookie dough press design). The ink is pressurized prior to entering the sprayer channel, it will expand to regain pressure equalization as it exits. Square dots are possible by making the exit of the channel a rounded "X" shape with a straight up-down feed to the ends of the "X", and a 60 degree slope to the inner points of the "X". As pressure equalizes, it makes a square dot.
Matrix29bear 5 months ago
The better channel for the ink-wash I suppose would be a "Y" or inverted-"h" channel with a "L |" shape in place of my prior-suggests "+" shape for the air-blow ink-cleaning channel. The "L" being the ink-wash spray part of the channel with the "|" being the suction part of the channel. Although a "V" shape for the wash channels would allow dot placement modulation by varying the air blow/suction cycle pressures on either side of the air blow channels.
Matrix29bear 5 months ago
The ink-wash channel would not be in usage unless the jet sprayer nozzles are in cleaning mode. Otherwise the logical thing is to switch the dirty ink-wash suction channel and the ink-wash pressure spray channel to just air-spray mode. That way as the ink dots are sprayed onto the page, the ink is not encouraged to creep back into either cleaning channel and clog them up. Bonus is that the air spray can be ionized for superior electrostatic ink adhesion to the application surface.
Matrix29bear 5 months ago
With a "Y" or inverted-"h" sprayer the channel pressure is still problematic, but not so much that dot deformation occurs. Also the extended height of the channel allows an ink-washing spray to be channeled horizontally through the side of the bottom of the channel. This would allow longer printhead usage without ink-clogging issues. In this, think of a large "+" sign placed at the bottom of the "Y" leg with one side of the "+" feeding in ink-wash and the other side suctioning dirty wash.
Matrix29bear 5 months ago
One other thing to note, I figure that ROLAND has perfected their ink-sprayer heads, but the basic inject printheads could also use a redesign for superior print longevity. Most printheads use a "V" shaped feed-to-spray design, but that is inferior because as ink reaches the bottom of the "V" it is compressed and then sprays outward to equalize pressure creating large dot sizes and inducing later printhead clogging. A better design would be a "Y" shaped or an upside-down "h" sprayer.
Matrix29bear 5 months ago
With this technique you can have pressure-infused offset printing qualities for your paper output with the ROLAND vinyl-solvent printing process with the inexpensive properties of plateless printing with the ability to simultaneously duplex pages with two presser rollers. This also allows rapid cleanup with a simple automated routine between jobs with almost zero ink wastage. The direct-to-page MEMJET type sprayer array would allow short print runs with no slowdown for a cut sheet feed press.
Matrix29bear 5 months ago
With this technique you can have pressure-infused offset printing qualities for your paper output with the ROLAND vinyl-solvent printing process with the inexpensive properties of plateless printing with the ability to simultaneously duplex pages with two presser rollers. This also allows rapid cleanup with a simple automated routine between jobs with almost zero ink wastage. The direct-to-page MEMJET type sprayer array would allow short print runs with no slowdown for a cut sheet feed press.
Matrix29bear 5 months ago
For individualized printing, you simply use the MEMJET sprayer array direct-to-page spray out individual items onto the page after it leaves the spray-to-roller pressure infusers. For UV clear-coating of the stock the same process is used, direct-to-roller spraying for even coverage at budget prices and direct-to-page dot-spraying for 3D gloss effects with curing lights at each stage as the paper leaves. Using UV coating as the after-printing process.
Matrix29bear 5 months ago
Afterward when the paper is pressure-printed, you spray the printed sheets as they exit the rollers using direct-to-page MEMJET-type arrays using the ROLAND solvent vinyl inks to individualize your output product per page in the empty space designated in the pre-press setup. No printing plates required. If you want a UV coating process, that can be done with a secondary roller-presser with a direct-to-page dot sprayer. For short-runs, direct-to-page sprayers are used, & big runs roller press.
Matrix29bear 5 months ago
For mass production printing, I would spray the squishable, abrasion-resistant blanket roller (for edge-to-edge printing options), using a MEMJET-type printhead array to give fast pressure-sublimation printing without requiring an inking plate. For mass-mailing printing using this process, one MEMJET-array (or two for auto-duplex printing) would be set up to spray to the pressure-transfer sublimation roller (which then squishes the ink into the page).
Matrix29bear 5 months ago
Downside of using a vinyl solvent process on a vulcanized rubber printing roller blanket (for pressure sublimation into the paper), is that the printing blanket would likely be partially dissolved with the vinyl solvents, so it might be better to use a polyurethane or polyester printing blanket instead (both plastics needing composite-formulation tweaking to ensure longer wear abrasion resistance). For shiny surface printing an UV coating 3D relief printing, I would use direct-to-page printing.
Matrix29bear 5 months ago
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The ideal compromise appears to be the ROLAND solvent vinyl printers. They have highly durable vibrant vinyl/acrylic inks which can precoat a substrate for superior output quality. Objectively speaking, the ROLAND solvent process is slow, but could be vastly improved for mass production by getting a decent stacked paper feeder and a MEMJET array of printheads spraying the page. To further improve output speeds, in regards to rapid printing, I would spray the vinyl ink onto a printing blanket.
Matrix29bear 5 months ago
This has been flagged as spam show
The ideal compromise appears to be the ROLAND solvent vinyl printers. They have highly durable vibrant vinyl/acrylic inks which can precoat a substrate for superior output quality. Objectively speaking, the ROLAND solvent process is slow, but could be vastly improved for mass production by getting a decent stacked paper feeder and a MEMJET array of printheads spraying the page. To further improve output speeds, in regards to rapid printing, I would spray the vinyl ink onto a printing blanket.
Matrix29bear 5 months ago
This has been flagged as spam show
The ideal compromise appears to be the ROLAND solvent vinyl printers. They have highly durable vibrant vinyl/acrylic inks which can precoat a substrate for superior output quality. Objectively speaking, the ROLAND solvent process is slow, but could be vastly improved for mass production by getting a decent stacked paper feeder and a MEMJET array of printheads spraying the page. To further improve output speeds, in regards to rapid printing, I would spray the vinyl ink onto a printing blanket.
Matrix29bear 5 months ago
The ideal compromise appears to be the ROLAND solvent vinyl printers. They have highly durable vibrant vinyl/acrylic inks which can precoat a substrate for superior output quality. Objectively speaking, the ROLAND solvent process is slow, but could be vastly improved for mass production by getting a decent stacked paper feeder and a MEMJET array of printheads spraying the page. To further improve output speeds, in regards to rapid printing, I would spray the vinyl ink onto a printing blanket.
Matrix29bear 5 months ago
The ideal compromise appears to be the ROLAND solvent vinyl printers. They have highly durable vibrant vinyl/acrylic inks which can precoat a substrate for superior output quality. Objectively speaking, the ROLAND solvent process is slow, but could be vastly improved for mass production by getting a decent stacked paper feeder and a MEMJET array of printheads spraying the page. To further improve output speeds, in regards to rapid printing, I would spray the vinyl ink onto a printing blanket.
Matrix29bear 5 months ago
Thank you both.... very informative & interesting. Trying to get started in offset (AB dick) printing w/a friend who has been in printing for over 20 yrs. T.Y. for your time.
devster65 1 year ago
1. Every page is totally re-written on digital presses be it data or images
2. You can print spot colours on digital presses.
3. Litho is not superior to digital in many/most cases it is equal
Enood 1 year ago