Method and apparatus for printing raised ink images
OwnerGilbert F. Dadowski, Robert J. Mahr +1inventors
InventorsGilbert F. Dadowski, Robert J. Mahr, Stanley P. Drachman
Life of this patent
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Abstract
A method of printing a raised ink image on a substrate for use as a hectographic or spirit duplicating master or the like involving forming a printing plate having a raised image area thereon, the latter having a plurality of regularly spaced, screen-like depressions therein for increasing the amount of the ink carried by the raised image area. The plate is mounted on the plate roll of a rotary press and ink is applied to the plate. The plate and the sustrate are then brought into printing engagement with one another and a raised ink image is transferred to the substrate. Apparatus for carrying out the above-described method and details of the printing plate are also disclosed.
Claims11
The method of printing a raised ink hectographic master, utilizing a printing plate having a photosensitive coating which has a generally plane surface, said method comprising:
- A. photographically exposing the coating on the plate to
- (1) an image of material to be printed, and also
- (2) an image of a screen for forming a pattern of ink cells in intaglio in the coating, the exposure rendering removable those portions of the coating around areas of the coating corresponding to the areas of the material to be printed, and also rendering removable those portions of the coating within said areas corresponding to said pattern of ink cells while enabling retention of the said areas of the coating as raised printing areas on the plate;
- B. processing the exposed plate to remove said removable portions of the coating, including the ink cell portions, thereby forming said raised printing areas in relief on the plate with each of said areas having a generally plane surface constituted by a portion of the original plane surface of the coating and with a multiplicity of ink cells in intaglio in each said area corresponding to said pattern;
- C. applying a non-volatile solvent transferable hectographic ink to said raised printing areas in sufficient amount not only to fill said ink cells but also to cover the said surfaces of said raised printing areas;
- and
- D. bringing the inked plate and a master substrate into engagement with one another for transfer not only of the hectographic ink on the said surfaces of the raised printing areas but also for transfer of at least some of the hectographic ink in the ink cells to the substrate, thereby to form raised hectographic ink images on the substrate.
Apparatus for printing a raised ink hectographic master comprising:
- a frame;
- a cylindric roll journalled in the frame for rotation about its axis, said cylindric roll supporting a printing plate for printing engagement with a hectographic master substrate, said printing plate having raised printing areas in relief thereon raised above non-printing portions of the plate, each said raised printing area having a multiplicity of ink cells in intaglio therein for holding a supply of ink sufficient to print raised hectographic ink images on said substrate;
- an ink reservoir adapted to hold a supply of hot-melt hectographic ink which when heated above a first temperature constituting its melting temperature is a liquid and which when cooled below a second temperature constituting its freezing temperature is a solid;
- means for bringing said substrate and said printing plate mounted on said cyclindric roll into printing engagement with one another thereby to transfer an ink image from said printing plate onto said substrate;
- means for heating the ink in said reservoir above said melting temperature of said ink and for maintaining said ink as a liquid as the ink is transferred from said reservoir to said substrate at which time it substantially instantaneously freezes thereby to form a raised ink image on said substrate;
- an ink transfer roll for transferring ink from said reservoir to said plate, said transfer roll being at least partially immersed in said melted ink in said reservoir and thereby being heated to a temperature sufficient for maintaining said ink as a liquid as the ink is transferred to the plate and the substrate;
- said transfer roll having a pattern of ink cells in intaglio in its surface.
Dependencies are inferred from the claim text.