Method of making a photopolymer sleeve blank for flexographic printing
A method of making a photopolymer sleeve blank is provided which includes providing a base sleeve, applying a cushion layer over the base sleeve, and applying a first photopolymer layer over the cushion layer. The exterior-facing surface of the first photopolymer layer is exposed to a curing source, followed by the application of a second, uncured photopolymer layer over the first photopolymer layer. The first photopolymer layer is preferably ground to a predetermined thickness either before or after exposure to the curing source to provide a preferred floor dimension. The resulting photopolymer sleeve blank has a uniform floor which can be readily imaged and processed by conventional equipment used in the flexographic printing industry.
1 . A method of making a photopolymer sleeve blank comprising:
providing a base sleeve having an inner surface and an outer surface;
applying a cushion layer over said outer surface of said base sleeve;
applying a first photopolymer layer over said cushion layer;
exposing an exterior-facing surface of said first photopolymer layer to a curing source; and
applying a second photopolymer layer over said first photopolymer layer.
2 . The method of claim 1 wherein said base sleeve comprises a fiber-reinforced polymeric resin.
3 . The method of claim 1 wherein said base sleeve has a wall thickness of from between about 0.01 and about 6.35 mm.
4 . The method of claim 1 wherein said base sleeve has a wall thickness of from between about 0.60 and about 0.80 mm.
5 . The method of claim 1 wherein said first photopolymer layer comprises a styrenic block copolymer-based material.
6 . The method of claim 1 wherein said second photopolymer layer comprises a styrenic block copolymer-based material.
7 . The method of claim 1 wherein said cushion layer is selected from the group consisting of a closed cell foam, an open cell foam, or a volume displaceable material.
8 . The method of claim 1 wherein said cushion layer has a thickness from between about 0.25 mm and about 3.25 mm.
9 . The method of claim 1 wherein said cushion layer has a thickness between about 1.00 to about 1.50 mm.
10 . The method of claim 1 wherein said cushion layer is applied to said base sleeve as a coating onto the surface of said base sleeve.
11 . The method of claim 1 wherein said cushion layer is applied to said base sleeve as a pre-cured layer which is wrapped around said sleeve.
12 . The method of claim 1 including grinding the surface of said cushion layer to achieve a predetermined thickness after application of said cushion layer.
13 . The method of claim 1 including applying a sealer or adhesive promoting agent to the surface of said cushion layer prior to applying said first photopolymer layer.
14 . The method of claim 13 including laminating said first photopolymer layer to said surface of said cushion layer.
15 . The method of claim 13 including fusing said first photopolymer layer to said surface of said cushion layer by the application of heat.
16 . The method of claim 1 including grinding the surface of said first photopolymer layer to achieve a predetermined thickness prior to exposure to said curing source.
17 . The method of claim 1 including grinding the surface of said first photopolymer layer to achieve a predetermined thickness after exposure to said curing source.
18 . The method of claim 1 wherein said first photopolymer comprises from about 40% to about 80% of the total sleeve thickness.
19 . The method of claim 1 wherein said second photopolymer layer is laminated to said first photopolymer layer.
20 . The method of claim 19 including fusing said second photopolymer layer to said first photopolymer layer by the application of heat.
21 . The method of claim 20 including grinding the surface of said second photopolymer layer to achieve a predetermined thickness.
22 . The method of claim 1 wherein said second photopolymer comprises from about 20% to about 60% of the total sleeve thickness.
23 . The method of claim 1 wherein said curing source comprises radiation.
24 . The method of claim 21 wherein said radiation curing source comprises a UV light source positioned exterior to said base sleeve.
25 . The method of claim 1 including coating said second photopolymer layer with an ablatable coating.
26 . The method of claim 1 including forming an image on said sleeve blank.
27 . A photopolymer sleeve blank having a seamless surface formed by the method of claim 1.