Process for producing polymer-covered flexographic printing sleeves

A process for producing a durable, readily-storable, cylindrically-shaped flexographic printing sleeve having an inner and outer cylindrically-shaped wall and a substantially constant cross-sectional inner and outer diameter, the flexographic printing sleeve being readily axially mountable on and dismountable from a complementary cylindrically-shaped printing cylinder having an outer cylindrically shaped wall, which comprises

• providing a printing sleeve body having an outer circumferential surface;
• placing a mold around the outer circumferential surface of the printing sleeve body, the mold and the outer circumferential surface of the printing sleeve body defining a cavity formed therebetween;
• introducing into the cavity and about the outer circumferential surface of the printing sleeve body a low temperature curable polymeric material;
• curing the low temperature curable polymeric material at a temperature not greater than about 150 degrees F. to form a hardened layer of the polymeric material joined to the outer circumferential surface of the printing sleeve body without damaging or distorting the printing sleeve;
• and
• removing a portion of the hardened layer of the polymeric material to produce said flexographic printing sleeve of predetermined thickness of up to about 0.375" and an impression range comprising an engagement distance of at least about 0.015", without any substantial visible reduction in print performance, said print performance comprising a print dot distortion of not more than about 0.0005" in the machine direction and not more than about 0.0002" in the cross machine direction.

A durable, readily-storable, cylindrically-shaped flexographic printing sleeve having inner and outer cylindrically-shaped wall and a substantially constant cross-sectional inner and outer diameter, the flexographic printing sleeve being readily axially mountable on and dismountable from a complementary cylindrically-shaped printing cylinder having an outer cylindrically shaped wall, the flexographic printing sleeve being produced by a process comprising

• providing a printing sleeve body, the diameter of the printing sleeve body being expandable by the introduction of low pressure fluid between an inner surface of the printing sleeve body and the outer cylindrically-shaped wall of the printing cylinder, the printing sleeve body being contractible by the removal of low pressure fluid;
• applying a layer of a low temperature curable polymeric material to an outer surface of the printing sleeve body;
• curing the layer of the low temperature curable polymeric material at a temperature not greater than about 150 degrees F. to form a hardened layer of polymeric material having a substantially uniform degree of hardness without damaging or distorting the printing sleeve;
• and
• removing a portion of the hardened layer of the polymeric material to produce said flexographic printing sleeve having a thickness of up to about 0.375" and an impression range comprising an engagement distance of at least about 0.015" without any substantial visible reduction in print performance, said print performance comprising a print dot distortion of not more than about 0.0005" in the machine direction and not more than about 0.0002" in the cross machine direction.

A process for printing a printable material onto a substrate in a predetermined pattern, which comprises

• providing a cylindrically-shaped printing cylinder having an outer cylindrically shaped wall;
• providing a printing sleeve body having an inner and an outer substantially cylindrically-shaped wall and a substantially constant cross-sectional inner diameter, the printing sleeve body being expandable by the introduction of pressurized air between the inner wall of the printing sleeve body and the outer wall of the printing cylinder, the printing sleeve body being contractible by the removal of the pressurized air;
• applying a layer of a low temperature curable polymeric material to the outer substantially cylindrically-shaped wall of the printing sleeve body;
• curing the low temperature curable polymeric material at a temperature not greater than about 150 degrees F. to form a hardened layer of the polymeric material;
• removing a portion of the hardened layer of the polymeric material to produce a flexographic printing sleeve having a thickness of up to about 0.375";
• providing printing indicia in a predetermined pattern on the hardened layer of the printing sleeve;
• axially mounting the printing sleeve onto the complementary cylindrically-shaped printing cylinder;
• applying a printing material to the printing indicia;
• and printing the predetermined pattern of the printing material from the printing indicia onto the substrate, the printing sleeve having an impression range comprising an engagement distance of at least about 0.015", without any substantial visible reduction in print performance, said print performance comprising a print dot distortion of not more than about 0.0005" in the machine direction and not more than about 0.0002" in the cross machine direction.