Classifications

• • 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
  • B41M1/06—Lithographic printing
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41F—PRINTING MACHINES OR PRESSES
  • B41F7/00—Rotary lithographic machines
  • B41F7/20—Details
  • B41F7/24—Damping devices
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41F—PRINTING MACHINES OR PRESSES
  • B41F7/00—Rotary lithographic machines
  • B41F7/20—Details
  • B41F7/24—Damping devices
  • B41F7/36—Inking-rollers serving also to apply ink repellants
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41N—PRINTING PLATES OR FOILS; MATERIALS FOR SURFACES USED IN PRINTING MACHINES FOR PRINTING, INKING, DAMPING, OR THE LIKE; PREPARING SUCH SURFACES FOR USE AND CONSERVING THEM
  • B41N10/00—Blankets or like coverings; Coverings for wipers for intaglio printing
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41N—PRINTING PLATES OR FOILS; MATERIALS FOR SURFACES USED IN PRINTING MACHINES FOR PRINTING, INKING, DAMPING, OR THE LIKE; PREPARING SUCH SURFACES FOR USE AND CONSERVING THEM
  • B41N7/00—Shells for rollers of printing machines
  • B41N7/04—Shells for rollers of printing machines for damping rollers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41N—PRINTING PLATES OR FOILS; MATERIALS FOR SURFACES USED IN PRINTING MACHINES FOR PRINTING, INKING, DAMPING, OR THE LIKE; PREPARING SUCH SURFACES FOR USE AND CONSERVING THEM
  • B41N2207/00—Location or type of the layers in shells for rollers of printing machines
  • B41N2207/02—Top layers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41P—INDEXING SCHEME RELATING TO PRINTING, LINING MACHINES, TYPEWRITERS, AND TO STAMPS
  • B41P2231/00—Inking devices; Recovering printing ink
  • B41P2231/20—Recovering printing ink
  • B41P2231/21—Recovering printing ink by using mixtures of ink and water or repellant

Definitions

• TECHNICAL FIELD My invention relates, to planogr ⁇ phic printing and has particular reference to lithography and related processes that depend upon delineation of the printed subject matter by means of hydrophilic and oleophilic areas on a printing surface, the ink being repelled by the water-wetted areas and being retained by the grease or oil-absorbing areas.
• a mixture of ink and water and lithographic concentrate may be applied as a single liquid to lithographic plates and that the mixture ratios may be maintained automatically by means of sensors and controls responsive to the sensor outputs through a microprocessor computer or other means.
• This invention also relates to the applying of ink and water to lithographic printing plates and printing cylinders, including direct printing plate cylinders and plates and plate cylinders for offset printing.
• the invention is useful in lithographic and letter press printing.
• BACKGROUND OP THE PRIOR ART Conventional printing machines for newspapers and other high-production printing presses generally use the lithographic process wherein metal plates are treated to have water-retaining or water-loving areas and greaseretaining or oil-loving areas to define the printed subject matter. This process is based upon use of inks that have an oil base and the ink is repelled by the water-dampened areas and absorbed by the oil-retaining areas.
• Such lithographic inks employ pigments that are not soluble In water so as to avoid any tinting.
• the plates are wrapped around cylinders referred to as plate cylinders.
• Water is applied at one axially parallel line on the surface of the rotating cylinders, and, downstream from the water, ink is applied along another longitudinal line.
• the best quality printing is obtained not by printing directly from the plate cylinder, but by transferring the ink from the plate cylinder to a blanket cylinder coated with a rubberlike surface.
• a third cylinder called an impressioon cylinder presses a strip of paper against the surface of the blanket roller to print the paper.
• three principal cylinders are used, the plate cylinder, the blanket cylinder, and the impression cylinder.
• cluster of cylinders or rollers is used to. transport the water from a trough called a fountain to the plate cylinder, and an even more elaborate set of rollers is used to transport the ink from the ink trough or fountain to the surface of the plate cylinder.
• cluster of cylinders or rollers is used to. transport the water from a trough called a fountain to the plate cylinder, and an even more elaborate set of rollers is used to transport the ink from the ink trough or fountain to the surface of the plate cylinder.
• the inking of lithographic and letter press plates, whether flat or in cylinder form, has always been a difficult problem for high-production printing presses.
• the image to be printed is defined on the printing surface, usually photographically.
• photosensitiv coatings are disposed on the printing surface, and the photographic exposure produces hydrophilic, or waterloving, areas that absorb water. These areas repel the ink, which is oil-based.
• the photographic treatment of the surface may also produce oleophilic, or ink-loving, areas that repel water and positively retain the oilbased ink.
• the subject matter being printed, whether words or pictures, is thus defined by these hydrophilic and oleophilic areas on the plates.
• the usual high-production presses use a cluster of rollers to apply water to the plates, and, downstream in printing motion, a second cluster of rollers applies the oil-based ink.
• a cluster of rollers In order to obtain a uniform distribution of water and ink, there are conventionally clusters of rollers for water and a separate cluster of interengaging rollers for ink. Each cluster may vary from five to sixteen or more in number.
• the last roller in a cluster the roller that applies ink or water to a plate cylinder, is general!y constructed with a rubber surface and is generally known as a form roller .
• the form roller contacts the plate cylinder and generally has the same peripheral speed as the plate cylinder.
• the rollers that apply ink or water to the form roller generally have a metal surface and have a variable speed motor drive so that the peripheral speed may be quite different from the peripheral speed of the form roller in order to spread or thicken the film of oil or water. This relative slippage between these supply rollers and the form roller produces heat, which causes problems.
• the pressure between the supply rollers and the form roller is quite critical and varies with the slippage.
• the adjustment of pressure between these rollers is time-consuming and reduces production time.
• the ink and water may be applied to the plate cylinder together as a mixture. I have discovered that this mixture may be continuously controlled in the proportions while being applied to the plate cylinder. Furthermore, I have found that the mixture results in a superior quality of image better than that obtained by the conventional inking and dampening systems. Further, I have discovered that my ink-water mixture may be applied by a simple set of rollers. For example, three cylinders have been satisfactory, thus avoiding large clusters.
• the mixture of water and ink may be made up of approximately equal quantities of water and ink for newspaper printing while maintaining the usual ratio of lithographic concentrate to the water part of the mixture. I maintain the mixture ratios by continuously sensing .the mixture for viscosity, mixture level, pH, and water proportion.
• the density of the ink is photoelectrically determined by scanning the film of ink on a form roller or printed surface.
• the blending rotors or propellers in the trough or fountain are speeded up or slowed down automatically. If the ink level is too high, the ink and water flow is momentarily reduced by throttling down the ink and water flow valves (preferably electrically controlled) and the valves are opened when the ink mixture level is too low. If the pH is too high or too low, the concentrate flow is reduced or increased with relation to water flow depending upon whether acid or alkaline concentrate is being used. . If the water proportion is too low, the water flow is increased and vice versa if the water proportion is too high. If the scanning of the form roller and/or paper shows that the water-ink film is too dark, the variable-speed fountain roller is decreased in speed; if too light, it is increased in speed, all automatically by the microprocessing computer or other means.
• an ink fountain roller or a water fountain roller or a combined ink and water fountain roller will function more effectively if its surface is divided into minute areas that are hydrophilic and other minute areas that are oleophillic.
• the surface may also contain areas that repel both water and oil by coating with polytetrafluoroethylene, a substance that is sold by one manufacturer under 'the brand name and trademark of "Teflon". This material is generally referred to in the trade as TFE, and sometimes PTFE.
• the fountain rollers may be screened to define intaglio-like patterns or may contain dots of any desired size as in half-tone printing.. The dots may represent the hydrophilic area and the background the oleophillic, or vice versa.
• the surface may have minute lines that are preferably parallel of alternating chromium and copper, preferably in a spiral pattern when placed on a cylinder.
• a chromium or other hydrophilic surface is constructed to have areas of. rubber which is oleophilic.
• the pattern need not be uniform. To. counteract the usual water deficiency at the ends of the roller, the number of water-locing areas may be increased in proportion to the ink-loving areas.
• This new type of roller is useful in my combined ink and water fountain, because it automatically picks up the required percentages of water and ink dependent upon the geometry of the yydrophilic and the oleophilic areas.
• the use of this new roller on the mixed water and ink makes the transfer of water and Ink to the form roller independent (within limits) of the intimacy, or minuteness of dispersion of the ink and water mixture.
• This automatic control of the correct amount of water and ink is further enhanced by having areas of the roller surface coated with TFE or equivalent materials.
• This material may be applied by sputtering or similar techniques that result in dispersed lots of TFE. This material repels both water and ink, and, by regulating the area covered with TFE, the amount of water and ink per revolution of the roller is closely controlled.
• Fig. 1 is a diagrammatic view of my inking apparatus showing the various controls;
• Fig. 2 is a three-dimensional view of the mechanical parts of Fig. 1, but deleting the control circuits.
• Fig. 3 is a set of three related diagrams 3A, 3B and 3C showing different stages of my photo-hardened surface adhered to a resilient rubber base.
• Fig. 4 is a diagram showing the conversion of conventional blanket cylinders in conventional rotary presses to plate cylinders using my water and ink supply mechanism, thereby doubling output.
• Fig. 5 is a diagram of five plate cylinders arranged to print both sides of four newsprint webs to obtain a total of eight printed sides.
• Fig. 6 is a mone detailed schematic drawing of the apparatus of Figure 1, wherein a mixture of water and ink is applied to a plate cylinder from a single fountain
• Fig. 7 is a three-dimensional illustration of either the fountain roller of Fig. 6 or the form roller of Fig. 6 having a surface formed in accordance with the invention.
• Fig. 8 is a schematic diagram of one form of surface for the roller of Fig. 7, wherein one of the areas is in the form of dots and the other is the background.
• Fig. 9 is a schematic diagram of the surface of the rollers of Fig. 7, wherein one of the hydrophilic or oleophilic areas is represented by open circles and the other is the background, but wherein there are also areas of water-repellent and oil-repellent material represented by black circles.
• Fig. 10 is a schematic illustration on an enlarged scale of the use of rectangular areas of either hydrophilic or oleophilic material on the surface of the roller of Fig. 7.
• Fig. 11 is a schematic diagram of still a differ ent surface for the roller of Fig. 7, wherein there are lines of either o leophilic or hydrophilic areas, and the background is composed of the other of these two areas.
• Fig. 12 is a diagram on a greatly enlarged scale of a cross section along the line 12-12 of Figure 11, showing a scoring of the surface of the roller, and wherein a rubber-like material has been disposed in the score marks to form the oleophilic areas.
• Fig. 13 is a schematic diagram of the surface for the roller of Fig. 7, wherein the lines on the surface are cross-hatched for greater density of either the oleophilic or hydrophilic material.
• Figs. 14, 15, 16 and 17 are modified forms of roller combinations using the invention.
• a trough 20 referred to in the industry as a fountain, holds a mixture 21 of ink, water, and fountain concentrate, and this mixture is finely divided or dispersed by a series of agitation propellers 22 driven by motors 23.
• the ink is supplied to the trough 20 by a pipe 24 controlled by an electric valve 26 connected to a source of ink under pressure (not shown).
• the fountain concentrate is supplied to the trough 20 by a pipe 27 connected to a pipe 28 having a check valve 29, and flow of concentrate is controlled by an electric valve 31 connected to a source of concentrate under pressure (not shown).
• Water is supplied by a pipe 32 also connected to the pipe 28, and flow is controlled by an electric valve 33 connected to a source of water such as a domestic or municipal water supply.
• a fountain roller 34 driven by a variable speed motor 36.
• This roller 34 is in rolling contact with a form roller 37 which rotates at a uniform velocity.
• the viscosity of the ink-water mixture on the surface of the fountain roller 34 causes the two rollers 34 and 37 to not actually engage each other, approximately by the distance of the thickness of the ink-water film transferred to the form roller 37.
• a cam 35 is provided to adjust the pressure between the fountain roller 34 and the form roller 37, and this is a manual adjustment for the particular ink-water mixture and, once set, is not changed during printing.
• the form roller 37 is in rolling contact with a plate cylinder 38, on which is disposed a lithographic plate made of metal whose surface is treated to form hydrophilic areas and oleophilic areas that define the printed subject matter.
• the form roller transfers the ink-water mixture in finely dispersed form so that discrete particles of water adhere to the hydrophilic areas and discrete particles of oil base ink adhere to the oleophilic areas.
• the ink is transferred to the paper and the subject matter is printed.
• This roller 39 oscillates back and forth on its fixed axis of rotation to spread evenly the film of inkwater mixture on the surface of form roller 37.
• these three rollers 34, 37 and 39 apply both ink and water to the plate cylinder in contrast to the conventional clusters of several dozens of rollers for the same purpose.
• My assembly of three rollers occupies such a small space in conventional printing machines or presses that .they can be readily inserted into existing presses not only on plate cylinders, but also on blanket and impression cylinders that are converted to plate cylinders.
• Each sensor 41-46 has its output conducted by wires of the same number to controllers 47., 48, 49, 51 and 52, respectively, preferably disposed in a panel 50 and each preferably having a readout, preferably digital.
• the moisture controller 47 has a readout 47a and a dial 47b for setting the controller 47 for the predetermined percentage of water in the mixture . Determining the percentage of water automatically determines the percentage of ink, inasmuch as the percentage of concentrate (pH) is about one percent, sometimes a little more and generally less than one percent.
• a wire 47c connected to the water valve 33, which opens wider or closes down to admit more or less water.
• the pH controller 48 has a readout 48a and a setting dial 48b to fix the pH.
• These concentrates are proprietary products usually compounded to work with a proprietary lithographic ink, or in the case of color with a family of inks. Some concentrates are acidic and others are alkaline, the acids having a pH of 5 or 6 and the alkalines about 9 or 10. The exact percentage of concentrate depends, upon the mineral content of the water supply and varies from city to city. Some printers try to avoid the concentration determination by using distilled water or deionized water. However, the dial setting is placed at the manufacturer's recommended pH, and the controller 48 maintains it by opening up or closing down valve 31 by means of a wire 48c. As mentioned previously, the concentrate percentage is small, usually around one percent or less.
• the ink level (mixture level) in the trough 20 is controlled, because the amount of immersion of fountain roller 34 affects the thickness of the film of mixture on form roller 37. I prefer to keep it below the rotation axis of the fountain roller.
• the level sensor 43 delivers its output to the controller 49 having readout 49a and a setting dial 49b which controls the level. This is accomplished by a wire 49c leading from controller 49 to both the water valve 33 and ink valve 26 so that the flow of both may be increased or decreased in unison.
• the viscosity sensor 44 delivers its output to the controller 51 having readout 51a and dial setting 51b and having a wire 51c leading to the variable speed mixture motor 23.
• Actuation of the motor 23 causes agitation resulting in more mixing of the water and ink into finer particles, to change the viscosity. Viscosity is also changed as the agitators heat up the mixture. Agitation may be effected in any desired manner The viscosity determines the amount of ink-water-concentrate mixture that is picked up by the fountain roller 34. The amount of mixing of ink and water for satisfactory results may vary between wide limits. The mixing breaks up the water into droplets, each of which is surrounded by a film of oily ink. Generally, any mixture having eighty-five droplets or more per linear inch is satisfactory, but 200 or more is preferable.
• the density sensor indicates several things, the color of the ink, the thickness of the film, the reflectivity of the surface of form roller 37, etc. For any given ink being used it forms an effective control for the film thickness on the form roller 37.
• the output of sensor 46 is delivered to controller 52 having a readout 52a and a dial setting 52b. Leading from the controller 52 is a wire 52c connected to the variable speed motor 36. This motor drives the fountain roller 34 faster to obtain a thicker film of mixture and slower to obtain a thinner film.
• controllers 47, 48, 49, 51, and 52 to include microprocessors which are solid state electronic circuits commonly used in computer control circuits. I prefer these over more conventional automatic controls because of the memory aspect that regulates the control electronically for a preselected setting of the dials 47b, 48b, 49b, 51b and 52b.
• the controllers do not necessarily supply the actuating current, but may deliver only control current to speed controls at the motors and variable controls at the valves.
• FIG. 2 the apparatus of Fig. 1 is shown in three dimensions.
• the ink pipe 24 has branches 24a leading to each part of the trough 20 that has agitation propellers 22.
• the water concentrate pipe 28 has a corresponding number of branch pipes 28a.
• the panel 50 is energized and ink, water and concentrate flow into the trough 20 through pipes 24, 27, 32 and 28 until the desired level is reached.
• the level sensor 43 then actuates the valves 26 and 33 to shut off flow, and the pH sensor 42 controls the concentrate flow valve 33.
• the mixing propellers 22 are actuated and remain continuously in motion at greater or lesser speeds under the control of the viscosity sensor 44.
• the printing press is then actuated, causing plate cylinder 38 to rotate as well as fountain roller 34, form roller 37, and oscillating roller 39, and the printing process is in full operation.
• the fountain roller 34 picks up mixture 21 from trough 20, and the excess is squeezed out at the contact line with form roller 37.
• the density sensor 46 delivers its output to the thickness controller 52, which delivers a signal by wire 52c to the motor 36 to speed up roller 34 if the film is too thin and slow up roller 34 if it is too thick.
• the percentage of water (and inversely the percentage of ink) in the mixture is continuously monitored by sensor 4l, and the water flow through valve 33 is automatically increased or decreased to keep the percentage at setting made by dial 47b.
• the percentage of water and ink in my process. is approximately the same as that consumed by the same or similar press using conventional separate water and Ink supply mechanisms.
• a typical mixture is fifty-four percent ink, forty-five percent water, and one percent concentrate.
• the amount or percentage of concentrate is regulated automatically by pH sensor 42 and controller 48, which opens or closes valve 31 to give more or less concentrate.
• the viscosity sensor 44 controls the propellers 22 by delivering its output to controller 51, which in turn delivers a current over wire 51c to motors 23 to control their speed.
• controller 51 which in turn delivers a current over wire 51c to motors 23 to control their speed.
• the desired control setting for each controller is dialed into it by dials 47b, 48b, 49b, 51b and 52b. If microprocessors are used, this setting is stored in its memory.
• the readouts 47a, 48a, 49a, 51a and 52a give a visual check of the correct functioning of the system for the information of the operator.
• ELASTIC SURFACE LITHOGRAPHIC PLATE I have devised an elastic surface for lithographic plates that gives a quality of printing when printed directly to the paper that is equal to the conventional metal surface plate cylinder combined with the usual blanket cylinder to achieve offset printing.
• the elastic surface may be made of any rubber-like material.
• the elastic surface is normally flat and after treatment is attached to a substrate of plastic or metal that may be attached to a plate cylinder of any construction for printing.
• the elastic material mayvbe of any suitable kind that is not only flexible, but elastic and elastically deformable under the pressures normally used in rotary printing presses.
• the elastic material may be of any thickness; .006 inch is a practical minimum, but is not a limitation.
• the outer surface is smooth.
• the image may be projected with a lens or the sheet of subject matter may be laid directly on the coating and light passed through the sheets to form hardened areas in the coating.
• the sheet of treated elastic material is then placed over the surface of a plate cylinder, and water and ink are applied to the treated surface.
• a composite printing surface 60 has an elastic base 61 of rubber or rubber-like material and a light-sensitive coating 62, wherein the light-sensitive surface has been "washed out"; the condition it assumes after an image has been projected upon it and after the coating has been washed to remove the areas which did not receive light.
• the light-hardened areas are the coating portions 62, and the washed-out cavities that reveal the elastic material 61 are indicated at 63.
• Fig. 3B water and ink have been applied to the composite surface 60 either by conventional means or by the apparatus of Fig. 1, as desired.
• the elastic material 6l being oleophilic holds ink 64 in the cavities 63 (Fig. 3A), and the raised hardened surfaces 62 hold water 66.
• a sheet of paper 67 has been pressed against the composite surface with a force sufficient to elastically depress the hardened coating sections into the elastic material.
• the amount of elastic depression is about the thickness of the coating, bringing the inked elastic surface into contact with the paper. Additionally, depressing the hardened sections 62 into the elastic material 61 tends to force outwardly adjacent portions of the elastic material 61, The exact amount of pressure is empirically determined for a particular elastic sheet and paper.
• This pressure shown in Fig. 3C forces the colorless water 66 into the paper, and it may subsequently be removed by evaporation. More importantly, the ink 64 is forced into the paper 67 to effect the printing.
• a photo-sensitive coating 62 that is commonly used in letter press printing that uses the "wash out” to create images.
• the raised coating sections are inked by a roller, and the sections of the smooth base that are exposed by the "wash out” are non-printing.
• the raised portions must reject ink.
• I mix gum arable or synthetic equivalents in the light photopolymer, and the hardened coating sections are then hydrophilic and oleophobic.
• the elastic material 6l may be of any suitable type, natural or synthetic, and therefore may be referred to as rubber-like. I presently prefer silicone rubber.
• FIG. 4 there is illustrated two sets of cylinders of two each, which is a common geometry in most well known newspaper printing machines.
• the two lower cylinders 71 and 72 are normally the plate cylinders indicated by a "P", and the two higher cylinders 73 and 74 are normally the blanket cylinders indicated by a "B".
• the plate cylinders 71 and 72 have a supply mechanism for water and ink indicated by the assembly 75 showing theprincipal mechanical parts of Figs. 1 and 2. Because my mechanism of Figs. 1 and 2 is so compact, it may be installed in space presently available in present newspaper presses to engage the two blanket cylinders 73 and 74 as shown and supply them with ink and water. Sheets of paper 76 and 77 are passed between the two sets of cylinders and printed on both sides simultaneously. This effectively doubles the output of existing presses with the same quality of printing.
• each cylinder may be a high quality plate cylinder.
• Cylinders 81, 82, 83, 84 and 85 are each provided with a printing surface, and each is provided with an.inking and/or ink and water supply (not shown).
• the subject matter being printed is the front and back of a page wherein high volume is desired, as in newspaper printing. This format is indicated by "F” for front and "B” for back at the cylinder and also at the surface of each strip or web of paper.
• Passing between cylinders 81 and 82 is a web of paper 86 from a roll of paper 87. Cylinder 8l prints the front of the page and cylinder 82 prints the back of the page. Passing between cylinders 82 and 83 is a web of paper 88 from a roll 89, and the same "back" subject matter is printed by cylinder 82. Since cylinders 81 and 82 are a web of paper 86 from a roll of paper 87. Cylinder 8l prints the front of the page and cylinder 82 prints the back of the page. Passing between cylinders 82 and 83 is a web of paper 88 from a roll 89, and the same "back" subject matter is printed by cylinder 82. Since cylinder 82 is a web of paper 86 from a roll of paper 87. Cylinder 8l prints the front of the page and cylinder 82 prints the back of the page. Passing between cylinders 82 and 83 is a web of paper 88 from a roll 89
• 83 carries the same subject matter as cylinder 81, the front is also printed. Passing between cylinders 83 and
• Cylinder 84 is a web 91 from a roll 92. Cylinder 84 prints the back image, and again cylinder 83 prints the front image. Passing between cylinders 84 and 85 is a web 93 from a roll 94. Cylinder 85 prints the front, and again cylinder 84 prints the back image.
• a fountain or trough 110 containing a mixture of water and ink 111 in which is partially immersed a fountain roller 112, which carries this water and ink mixture to a form roller 113, which in turn is in contact with a plate cylinder 114.
• oscillating roller 116 is in contact with the form roller 113, and it oscillates back and forth on its axis of rotation to smooth out any water and ink mixture on the form roller.
• the pressure of the fountain roller 112 against the form roller 113 is adjusted by virtue of a stationary shaft 117 on which the fountain roller rotates, which is eccentrically mounted about a center 118 so that the shaft acts as a cam and may be manually rotated by means of a handle 119.
• the mixture of ink and water is blended by blending propellers 121 driven by a motor 122 actuated by a control wire 123.
• Ink from a supply source is controlled by a valve 124
• fountain concentrate is controlled by a valve 128, and a supply of water is controlled by a valve 127.
• Check valves 128 and 129 isolate the water from the fountain concentrate, and the mixture of the two is delivered by a pine 131 to the trough, or fountain, 110.
• the fountain roller 112 is rotated at a variable speed by a motor 132 acting through a drive shaft 133 as shown schematically.
• Ink is supplied by opening the solenoid valve 124 by a suitable automatic control (not shown), and concentrate and water are added to the trough, or fountain, 110 by a suitable operation of the solenoid valves 126 and 127, preferably also by automatic control (not shown).
• the mixture 111 of water and oil is blended initimately by propellers 121 driven by the motor 122 under the control of automatic apparatus (not shown) to which the wire 123 connects the motor.
• the mixture of water and oil is not homogenized,but instead is merely intimately mixed so that there are discrete particles of water and oil present.
• the fountain roller 112 is partially immersed in this mixture of water and ink, which collects on the surface by virtue of the oleophilic areas and the hydrophilic areas shown in more detail in Figs. 8 through 13.
• This water and ink mixture is carried to the form roller 113 by virtue of the contact between the two rollers.
• the amount of pressure between the two rollers is manually adjusted by rotating the lever 119 about the eccentrie axis 118.
• the form roller 113 deposits the water and ink mixture on the plate cylinder 114 by virtue of its contact with that cylinder.
• This mixture will also be in the form of discrete particles of water and ink. If there is any lack of uniformity of dispersion of water and ink particles over the surface of form roller 113, this lack of uniformity is corrected by the oscillating roller 116 which oscillates back and forth on its axis of rotation as it rotates.
• Fig. 7 there is illustrated one of the rollers in the train of rollers from the fountain 110 to the plate cylinder 114.
• the fountain roller 112 formed in accordance with my invention, but the invention is applicable also to the form roller 113.
• Fig. 17 illustrates not only the f ountain roller 112, or equivalent, but the f orm roller
• Fig. 8 Illustrated in Fig. 8 is a schematic diagram of one type of surface on the roller of Fig. 7. This may consist of hydrophilic areas 140 on the surface of the roller, and the background may consist of oleophilic areas. It will be noted that the hydrophilic areas 140 are denser and use up a greater portion of the area toward the end of the cylinder of Fig. 8 as shown by the bracket 142 compared to the area designated by the bracket 143 where there is much less hydrophilic area as compared to the oleophilic background 141.
• This concentration of hydrophilic areas at the end of the roller corrects the usual condition found in fountain rollers and form rollers or other rollers in a cluster for applying ink or water or a mixture of both wherein conventionally there is insufficient amount of water at the ends of the rollers.
• Illustrated in Fig. 9 is a roller having areas 145 which may be hydrophilic or oleophilic. If hydrophilic, then the background 146 is oleophilic, or vice versa. Interspersed among these areas 145 are areas 147 that repel both the water and oil. Accordingly, these areas limit the total amount of water and oil that can be picked up by a cylinder. At present, I prefer to use polytetrafluoroethylene, commonly referred to in the chemical trade as PTFE and sometimes TFE. The brand presently sold under the name of "Teflon" is preferred. Illustrated in Fig. 10 is still another surface for the roller of Fig. 7, wherein the areas are rectangular in shape. Thus, squares or rectangles 151 may be formed on a background 152 to define hydrophilic or oleophilic areas. If the areas 151 are hydrophilic, the background 152 is oleophilic, or vice versa.
• Figs. 11 and 12 Illustrated in Figs. 11 and 12 is still another type of surface for the roller or rollers of Fig. 7, wherein material is. deposited in very fine score marks made on the surface of the roller.
• generally parallel lines 155 may be f ormed of ole ophilic material, and the spaces 156 between the lines may be hydrophilic .
• this may be a chromium surface in which the lines are scored in a very fine pattern, and the score marks are then filled with a rubber-like material, which is then caused to adhere to the surface .
• This construction is illustrated in Fig . 12, wherein a plurality of score marks or grooves 157 are formed in the surface 156 .
• the grooves 157 are filled with a rubber-like material 158.
• Rubber is normally oleophilic, and chromium hydrophilic .
• the areas 158 and 156 will define oleophilic and hydrophilic areas, respectively.
• the spacing and width of the score marks, or grooves, 157 with respect to the spaces 156 between them determine the relative amount of water and ink that is picked up or retained on the surface of the roller .
• Fig . 13 Illustrated in Fig . 13 is another modification similar to that of Fig . 11, but wherein there is a cross hatch of grooves that hold rubber-like material 161 and the areas 162 between the grooves or lines 161 define the hydrophilic areas .
• FIG. 14 there is illustrated apparatus similar to that of Fig . 6, but wherein there is added a squeegee roller to reduce or eliminate the buildup of water-ink mixture at the contact line or nip of the fountain roller and the form roller .
• a fountain trough 165 contains a blended mixture of water and oil-based ink 166 in which is partially immersed a fountain roller 167 having a rolling engagement with a form roller 168, which in turn has a rolling engagement with a plate cylinder 169 .
• an oscillating roller 171 may engage the form roller 168 to evenly distribute the water and ink mixture over the surface of the form roller .
• a squeegee roller 172 which has a line of contact or nip 173 with the fountain roller 167, and this line or nip 173 is just above the normal level 174 of the water-ink mixture .
• the squeegee roller 172 preferably has a surface of rubber-like material, and by adjusting the pressure between rollers 172 and 167 the precise thickness of film of water and ink is achieved. I have found that the greater the pressure the greater is the proportion of ink to water, although the total of both is reduced by greater pressure. This pressure relationship, therefore, constitutes another proportion control between ink and water.
• the fountain roller 167 is a uniform surface roller or a surface having intermixed hydrophilic or oleophilic areas.
• the surface of squeegee roller 172 could be composed of mixed hydrophilic and oleophilic area.
• the fountain roller 167 preferably has intermixed hydrophilic and oleophilic areas
• the form roller 168 may have the standard rubber-like surface of conventional form rollers
• the oscillating roller 171 may have a copper or nylon surface
• the plate cylinder may have a standard lithographic surface. Letterpress or flexograph plates may also be used.
• the hydrophilic areas 140 on the surface of the roller of Fig. 8 are chromium, and the oleophilic background 141 is copper.
• This is preferably constructed by copper-plating a steisl cylinder, polishing it, and then coating with a photo-resist. A photographic negative is then wrapped around the cylinder, and the cylinder is rotated to expose the resist to a strong light. The unexposed areas (areas 141) are then washed off, the remaining resist is hardened, and the cylinder is chromium-plated. The chromium is deposited only on the bare copper and not on the resist.
• the resist is then removed, leaving a pattern of chromium 140 (hydrophilic) and the background 141 of copper (oleophilic).
• the thickness of the chromium is so small, on the order of one thousandth of an inch or less, that the resultant roller is smooth for distribution purposes.
• PTFE to the roller of Fig. 9
• silk-screening liquid PTFE or by flame spraying fine particles to spatter small particles on the surface, either directly or through a mask.
• vacuum deposition may be employed wherein a static charge is placed on the roller, a mask is placed over the roller having holes where the PTFE is desired, and a pot of PTFE is heated to boiling or vaporizing temperature in the vacuum chamber.
• the rectangular areas 151 of Fig. 10 may be formed similarly to areas 140 of Fig. 8.
• the roller of Figs. 11, 12 and 13 may be formed in several ways.
• the grooves 157 may be etched by standard etching procedures such as the one described for Fig. 8.
• a steel roller is copper-plated, polished, and then chrome-plated.
• the chrome is then etched as shown in Fig. 12.
• the roller is next covered with unvulcanized rubber, vulcanized under pressure, and then the roller is ground to remove the excess rubber so that the remaining rubber 158 is flush with the surface of the chrome 156 as shown in Fig. 12.
• the roller is mounted in a lathe for slow rotation while a battery of grinding wheels moves lengthwise on the carriage.
• the number d. grooves per inch, measured transversely to the grooves, should be ten or more per inch.
• the grooves ground in the surface may be filled with a rubber-like material as previously described, or, where the chrome plate is think they merely cut through the chromium to expose the copper, which is oleophilic.
• a chrome and copper surface similar to Figs. 11 and 13 is to coat a resist on a copper-coated roller, wrap a negative with spiral lines, expose to light, and wash off the exposed resist. Chromium may then be placed on the bare copper in a spiral pattern or any other pattern, depending upon the negative.
• the surface of the roller of Fig. 13 may be formed by knurling a chromium or other hydrophilic surface. If this causes raised edges along each groove, the roller may be ground to remove any projections, and the grooves are then filled with rubber as described previously and the excess rubber ground off.
• Another method of forming oleophilic areas is to prick the surface with multiple needle-like tools. The resultant crater edges are then ground off, and the holes in the surface filled with a rubber-like material as described previously.
• FIG. 15 is a schematic drawing of another modification which I have used to convert an existing press to my water and ink mixture.
• a conventional lithographic plate cylinder 180 is contacted or engaged by a conventional form roller 181, which. in turn is engaged by a fountain roller 183, which is partially immersed in a water and ink mixture 184 held in. a trough or fountain 186.
• the middle or intermediate roller is provided with a surface having intermixed hydrophilic and oleophilic areas.
• This intermediate roller substitution of my new roller in one type of conventional press results in minimum cost in converting an existing press.
• all three rollers l ⁇ l, 182, and 183 could have the surfaces of Intermixed hydrophilic and oleophilic areas.
• a roller may also be advantageously used in conventional lithographic presses with separate ink and water-applying systems.
• the intermixed areas provide a means and method of regulating the amount of liquid picked up by a fountain roller and help to maintain the uniformity of film as well as correct water deficiency at the ends of the roller.
• the cluster of rollers is often referred to in the industry as “distribution” rollers, whether for water or ink.
• Anilox roller which uses mechanical means to reduce the amount of ink to be transferred .
• Fig . 16 is a diagram of a modified form of the invention employing two form rollers, the upstream form roller applying more water than ink and the downstream form roller applying more ink. than water. Such a sequence may give higher quality results.
• a trough or fountain 190 contains a blended mixture 191 of water and oil-based ink, and partially immersed in the mixture are form rollers 192 and 193 in rolling engagement so that they squeegee each other .
• the surfaces of these two fountain rollers 192 and 193 are quite different, roller 192 having a surface with a predominance of hydrophilic areas and roller 193 having a predominance of oleophilic areas.
• roller 192 pick up about eighty percent water and twenty percent Ink and transport this to a form roller 194, which in turn is in engagement with a lithographic plate cylinder 196.
• the percentages are illustrative only as this percentage will vary with many factors, including paper finish, ink composition, paper humidity, pressure of the rollers and cylinder, etc.
• the fountain roller 193 intermixed hydrophilic and oleophilic areas, so that It picks up about twenty percent water and eighty percent Ink, although, again, these percentages are Illustrative and will vary according to many factors, including the percentages transported by the fountain roller 192.
• the water and ink are transported to an intermediate idler roller 197, which in turn transfers water and ink to a form roller 198, which then transfers water and the ink to the plate cylinder 196.
• the prior or upstream moistening of the plate cylinder gives more accurate water retention on the hydrophilic non-Image-forming areas formed on the plate cylinder.
• the downstream roller gives more accurate Ink retention on the oleophilic Image areas, because the moistened areas will more accurately repel ink.
• Both form rollers 194 and 198 may have oscillating rollers (not shown) to even the water and ink distribution.
• the fountain rollers 192 and 193 may have a greater concentration of hydrophilic areas at the ends, and, if desired, the form rollers 194 and 198 may have treated surfaces with end concentrations of hydrophilic areas.
• Fig. 17 is a diagram for supplying Ink only to a letterpress plate cylinder wherein the image to be printed is In relief.
• a fountain trough contains ink 102, but no water.
• Partially immersed in this ink is a form roller 104, which is squeegeed by a squeegee roller
• the ink is transferred to a relief itetterpress cylinder 107.
• the amount of ink picked up is regulated by forming the surfaces of the squeegee roller 103 and form roller 104 to provide only a certain percentage of ink-carrying capacity. Intermixed areas of rubber and PTFE or copper and PTFE will regulate the amount of pickup. I presently prefer to make the surface of roller 104 of rubber having PTFE spots. These non-oleophilic surfaces, therefore, regulate the amount of ink transported to the letterpress plate cylinder 107.
• the liquid in fountain 101 could also be a mixture of water and oil-based ink for use on a lithographic plate cylinder.
• the rotating action of rollers partially Immersed in the water and Ink mixture, or inbalance causes the liquid to rise at the region of the nip because of adherence to the surface of such rollers.
• the nip should be close to the static level of the liquid in the fountain so that the dynamic action of the rollers will fill the space between the static level of the liquid surface and the nip.
• the nip may be below the surface of the liquid. If the nip is too far above the static liquid surface, then a squeezed-out bead will be formed along the lower edge of the nip. This bead is frequently uneven, which causes uneven amounts of liquid along the nip line, giving uneven delivery of liquid.
• the volume of liquid mixture transported by the rollers may be regulated by varying the static level of the liquid with respect to the nip line, because there is less adherence for a roller that only slightly dips into the liquid.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Inking, Control Or Cleaning Of Printing Machines (AREA)
• Control Of Amplification And Gain Control (AREA)
• Stabilization Of Oscillater, Synchronisation, Frequency Synthesizers (AREA)

Priority Applications (1)

Applications Claiming Priority (3)

Publications (1)

Family

ID=26716450

Family Applications (1)

Country Status (3)

Cited By (13)

Families Citing this family (2)

Citations (22)

Family Cites Families (2)

• 1979
  • 1979-12-05 JP JP50028579A patent/JPS55501136A/ja active Pending
  • 1979-12-05 WO PCT/US1979/001078 patent/WO1980001151A1/en unknown
  • 1979-12-05 GB GB8025726A patent/GB2048781B/en not_active Expired

Patent Citations (22)

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events