Method of making a photopolymer sleeve blank having an integral cushion layer for flexographic printing
View Patent ↗A method of making a photopolymer sleeve blank for use in flexographic printing is provided which includes providing a base sleeve, applying a cushion layer over the base sleeve, applying an optional barrier layer over the cushion layer, and applying a photopolymer layer over the barrier or cushion layer. The method provides a sleeve blank having an integral cushion layer and eliminates the need for a back exposure step.
1. A method of making a seamless photopolymer sleeve blank for use in flexographic printing comprising:
providing a cylindrical base sleeve including an inner surface and an outer surface;
applying a cushion layer over said outer surface of said base sleeve without back exposing said cushion layer; said cushion layer selected from the group consisting of an open-cell foam, a closed-cell foam, or a soft, volume displaceable material having a Shore hardness of about 30 to 70;
grinding the surface of said cushion layer to a predetermined thickness and to establish a relief depth for a final image to form a floor;
applying a barrier layer over said cushion layer;
applying an adhesive layer over said barrier layer; and
applying a photopolymer layer over said adhesive layer and fusing said photopolymer layer by applying heat to partially melt said photopolymer.
2. The method of claim 1 wherein said base sleeve is selected from the group consisting of a fiber-reinforced polymeric resin, metal, or plastic.
3. The method of claim 1 wherein said base sleeve has a thickness between about 0.01 and about 6.35 mm.
4. The method of claim 1 wherein said base sleeve has a thickness between about 0.60 and about 0.80 mm.
5. The method of claim 1 wherein said cushion layer has a thickness between about 0.25 to about 3.25 mm.
6. The method of claim 1 wherein said cushion layer has a thickness between about 1.0 to about 1.50 mm.
7. The method of claim 1 wherein said cushion layer is applied to said base sleeve by rotary casting, extrusion, blade or knife coating.
8. The method of claim 1 wherein said cushion layer is applied to said base sleeve with an adhesive.
9. The method of claim 1 wherein said photopolymer layer comprises a styrenic block copolymer-based material.
10. The method of claim 1 wherein said photopolymer layer has a thickness between about 1.0 and 1.50 mm.
11. The method of claim 1 including grinding the surface of said photopolymer layer to achieve a predetermined thickness.
12. The method of claim 1 including coating said photopolymer layer with an ablatable coating.
13. The method of claim 1 including forming an image on said photopolymer sleeve blank.
14. The method of claim 1 wherein said barrier layer comprises a film-forming polymer.
15. The method of claim 1 wherein said barrier layer comprises an acrylic resin or polyvinylidene chloride.
16. The method of claim 1 wherein said barrier layer is applied to said cushion layer by coating, spraying, or brushing.
17. The method of claim 1 wherein said barrier layer has a thickness between about 0.015 and 0.050 mm.
18. The method of claim 1 wherein said barrier layer has a thickness of about 0.025 mm.
19. A seamless photopolymer sleeve blank formed by the method of claim 1 .
20. A method of making a seamless photopolymer sleeve blank for use in flexographic printing comprising:
providing a cylindrical base sleeve including an inner surface and an outer surface;
applying a cushion layer over said outer surface of said base sleeve without back exposing said cushion layer; said cushion layer selected from the group consisting of an open-cell foam, a closed-cell foam, or a soft, volume displaceable material having a Shore hardness of about 30 to 70;
applying a barrier layer over said cushion layer such that said barrier layer is integral with said cushion layer and said layers together function as a floor for a relief image;
applying an adhesive layer over said barrier layer; and
applying a photopolymer layer over said adhesive layer.