Apparatus and method for producing retroreflective material having printed patterns thereon

• US 6,120,636 A
• Filed: 10/13/1998
• Issued: 09/19/2000
• Est. Priority Date: 01/26/1998
• Status: Expired due to Term

• Current Assignee: Orafol Americas Inc. (Orafol Europe GmbH)
• Original Assignee: Reflexite
• Inventors: Nilsen, Robert B., Hanrahan, Michael J., Bernard, Gus
• Primary Examiner(s): Crispino, Richard
• Assistant Examiner(s): LORENGO, JERRY A
• Application Number:
  US09/170,014
• Time in Patent Office: 707 Days
• Field of Search: 156/230, 156/231, 156/234, 156/235, 156/237, 156/238, 156/240, 156/247, 156/277, 156/384, 156/287, 264/1.6, 264/1.9, 264/212, 264/214, 359/520, 359/530, 359/400, 428/172, 428/178
• US Class Current: 156/230
• CPC Class Codes: B29C 41/26 by depositing flowable material on a rotating drum
• CPC Class Codes: B29D 11/00605 Production of reflex reflectors
• CPC Class Codes: B42D 25/324 Reliefs
• CPC Class Codes: B42D 25/351 Translucent or partly translucent parts, e.g. windows
• CPC Class Codes: B42D 25/45 Associating two or more layers
• CPC Class Codes: G02B 5/124 plural reflecting elements forming part of a unitary plate or sheet
• CPC Class Codes: Y10T 428/24612 Composite web or sheet

Abstract

A continuous process for producing printed patterns on retroreflective material is disclosed, wherein a partially cured pattern is printed on a roll of film and partially cured cube-corner prisms are bonded to the film over the printed matter thereby encapsulating the printed matter to protect the printed matter from the environment.

Claims

1. A method of producing a patterned sheet of retroreflective material comprising the steps of printing the patterns on a transparent film, applying microprisms onto said patterns, such that the patterns are protected from the environment by being incorporated onto a window side of the microprisms and covered by the film, the microprisms having a base and side facets, wherein the patterns and microprisms are partly solidified as formed and after the microprisms are applied to the patterns and wherein the patterns and microprisms are solidified so that printed patterns are embedded into the base of the microprisms.

2. The method of claim 1 wherein the microprisms are transparent and have a base and at least three side facets and wherein the facets are provided with a reflective backing.

3. The method of claim 2 wherein the film and microprisms are formed of the same material.

4. The method of claim 2 wherein the film and microprisms are formed of different material.

5. The method of claim 1 wherein the film is formed in a continuous roll.

16. The method of claim 1 wherein the patterns are transparent.

17. The method of claim 1 wherein the patterns have a different index of refraction than the microprisms.

6. A method for printing patterns of print material on microstructured optical sheeting by forming a film upon which an array of prisms is formed comprising the steps of:

printing said patterns on selected areas of a first side of said film;

applying a prism forming material to a first mold surface having prismatic recesses therein to at least partly fill the recesses with said material;

transferring the material to the first side of the film to form first areas of arrays of prisms over the patterns leaving second areas of blank spaces on said first side of the film;

applying said prism forming material to a second mold surface having prismatic recesses therein to at least partially fill the recesses in the second mold surface with said material; and

transferring the material in the recesses of the second mold surface onto the areas of blank spaces in the first side of the film in such a manner as to form a continuous film of sheeting on the first side of the film, the prisms having a base and side facets, wherein the patterns and prisms are partly solidified as formed and after the prisms are applied to the patterns and wherein the patterns and prisms are solidified so that printed patterns are embedded into the base of the prisms.

7. The method of claim 6 wherein the prismatic recesses in the first mold surface differ in size from those in the second mold surface.

8. The method of claim 6 wherein the areas of the spaces and areas of arrays on said mold surfaces are substantially equal and are alternately spaced over each of the mold surfaces.

9. The method of claim 6 wherein the selected areas of the printed patterns are located opposite both the first and second areas of arrays of prisms.

10. The method of claim 6 wherein the prism forming material and the pattern material are the same.

11. A method of forming easy-sealable retroreflective sheeting comprising the steps of:

a) providing a mold surface containing contiguous arrays of prismatic recesses;

b) applying prism forming material to the selected areas of the arrays leaving other selected areas devoid of prism forming material;

c) applying a front film to said mold surface and transferring the prism forming material from the mold to the front film leaving certain areas on the front film without prism forming material;

d) solidifying the prism material to form a plurality of prims having a base and side facets;

e) applying a back film over the areas of solidified prisms;

f) sealing the front film to the back film at the said certain areas without prism forming material; and

g) partially curing a printed pattern on the front film prior to transferring the prism forming material from the mold, wherein the patterns and prisms are partly solidified as formed and after the prisms are applied to the patterns and wherein the patterns and prisms are solidified so that printed patterns are embedded into the base of the prisms.

12. The method of claim 11 wherein the mold surface is formed on the periphery of a circular rotary drum.

13. A method for printing patterns of print material on retroreflective sheeting by providing a film upon which an array of prisms is formed comprising the steps of:

printing said patterns on selected areas of a first side of said film;

applying a prism forming material to a first mold surface having prismatic recesses therein to at least partly fill the recesses with said material;

transferring the material to the first side of the film to form first areas of arrays of prisms over the patterns leaving second areas of blank spaces on said first side of said film;

applying said prism forming material to a second mold surface having prismatic recesses therein to at least partially fill the recesses in the second mold surface with said material; and

transferring the material in the recesses of the second mold surface onto some of the areas of blank spaces in the first side of the film in such a manner as to form a continuous film of sheeting on the first side of the film some areas of which have prism material directly attached to the film, and others have prism material covering the patterns and attached to the film and other areas have neither and can be used as sealing areas for attaching a sealing film over the sheeting, the prisms having a base and side facets, wherein the patterns and prisms are partly solidified as formed and after the prisms are applied to the patterns and wherein the patterns and prisms are solidified so that printed patterns are embedded into the base of the prisms.

14. A method for producing a patterned sheet of microstructure optical sheeting comprising the steps of printing the patterns on a first side of a transparent film and applying the microstructures to a second side of said transparent film, the microstructures having a base and side facets, wherein the patterns and microstructures are partly solidified as formed and after the microstructures are applied to the patterns and wherein the patterns and microstructures are solidified so that printed patterns are embedded into the base of the microstructures.

15. A method for producing a patterned sheet of microstructure optical sheeting comprising the steps of printing the patterns on a first side of a transparent film and applying the microstructures to the first side of said transparent film, the microstructures having a base and side facets, wherein the patterns and microstructures are partly solidified as formed and after the microstructures are applied to the patterns and wherein the patterns and microstructures are solidified so that printed patterns are embedded into the base of the microstructures.