Device for forming flexographic printing plate

A device for forming a flexographic printing plate, the plate being formed from a sheet of film comprising at least one heat resistant layer with a heat resistant surface, and one layer capable of being at least partially liquified having a heat sensitive surface, comprising:

• a frame comprising a first portion and second portion, the first and second portions capable of movement relative to each other;
• a preheating drum mounted for rotation onto a first portion of the frame for contacting the heat resistant surface of said sheet of film and for preheating the layer capable of being partially liquified through the heat resistant surface;
• a hot roller mounted for rotation on a second portion of the frame for heating an absorbent material and for applying heat to the heat sensitive surface of the film, wherein said hot roller has a resilient outer surface which is capable of pressing the absorbent material into recesses formed in the film;
• pressure means for causing the hot roller and the preheating drum to apply pressure on opposite sides of the film, causing the heat sensitive surface of said film and a surface of the heated absorbent material to come into face to face contact at a temperature and pressure sufficient for at least a portion of the heat sensitive layer to liquify and to be absorbed by the absorbent material;
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• separation means for separating the sheet of film from the absorbent material;
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• a pressure limiting arm mounted onto a rotational shaft of said hot roller for engagement with a surface of the preheating drum for limiting the spacing between an outer surface of the hot roller and an outer surface of the preheating drum.

A device for forming a flexographic printing plate, the plate being formed from a sheet of film comprising at least one heat resistant layer with a heat resistant surface, and one layer capable of being at least partially liquified having a heat sensitive surface, comprising:

• a frame comprising a first portion and second portion, the first and second portions capable of movement relative to each other;
• a preheating drum mounted for rotation onto a first portion of the frame for contacting the heat resistant surface of said sheet of film and for preheating the layer capable of being partially liquified through the heat resistant surface, wherein the preheating drum is formed from a substantially cylindrical wall portion having a cavity defined by an inner surface of the cylindrical wall portion, a hub at each end, and means for attaching the hubs to the cylindrical wall portion to allow for thermal expansion, wherein the means for attaching the hubs to the cylindrical wall portion comprises at least one tie rod extending through the cavity of the cylindrical wall portion, the tie rod being segmented and connected to both hubs,
• a hot roller mounted for rotation on a second portion of the frame for heating an absorbent material and for applying heat to the heat sensitive surface of the film, wherein said hot roller has a resilient outer surface which is capable of pressing the absorbent material into recesses formed in the film;
• pressure means for causing the hot roller and the preheating drum to apply pressure on opposite sides of the film, causing the heat sensitive surface of said film and a surface of the heated absorbent material to come into face to face contact at a temperature and pressure sufficient for at least a portion of the heat sensitive layer to liquify and to be absorbed by the absorbent material;
• separation means for separating the sheet of film from the absorbent material.

A device for forming a flexographic printing plate, the plate being formed from a sheet of film having at least one layer capable of being partially liquified, comprising:

• heating means for applying heat to said sheet of film for an amount of time and at a temperature sufficient to cause a portion of said layer to liquify;
• first delivery means for supplying an absorbent material to a surface of said layer of said sheet of film comprising a hot roller mounted for rotation in a movable portion of a frame, wherein the hot roller has a resilient outer surface capable of causing the absorbent material to contact the liquified portion of the film within recesses in the film,
• second delivery means for delivering the sheet of film to said heating means comprising a preheating drum mounted for rotation in a stationary portion of a frame, wherein the movable portion of said frame is moved to bring a surface of the hot roller close enough to a surface of the preheating drum such that when the film and absorptive material are placed between the hot roller preheating drum, the hot roller and preheating drum press the film and absorptive material into contact, wherein the preheating drum and hot roller rotate in opposite directions, and move at substantially the same tangential speed;
• means for limiting the pressure exerted on the flexible sheet by the hot roller and the preheating drum;
• pressure means for causing a surface of said layer and the absorbent material to come into face to face contact between the preheating drum and the hot roller at a pressure sufficient for at least a portion of the liquified material to be absorbed by the absorbent material;
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• separation means for separating the sheet of film from the absorbent material.