Method of making packaging material

• US 20040094267A1
• Filed: 11/06/2003
• Published: 05/20/2004
• Est. Priority Date: 02/07/2001
• Status: Active Grant

• Current Assignee: Sonoco Development Inc (Sonoco Products Company)
• Original Assignee: Sonoco Development Inc (Sonoco Products Company)
• Inventors: Schuetz, Jeffrey M., Huffer, Scott W.
• Granted Patent: US 7,341,643 B2
• Time in Patent Office: Days
• US Class Current: 156/277
• CPC Class Codes: B32B 27/32 comprising polyolefins comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30
• CPC Class Codes: B65D 65/14 with areas coated with adhesive
• CPC Class Codes: Y10T 428/1334 Nonself-supporting tubular film or bag [e.g., pouch, envelope, packet, etc.]
• CPC Class Codes: Y10T 428/1379 Contains vapor or gas barrier, polymer derived from vinyl chloride or vinylidene chloride, or polymer containing a vinyl alcohol unit
• CPC Class Codes: Y10T 428/1383 Vapor or gas barrier, polymer derived from vinyl chloride or vinylidene chloride, or polymer containing a vinyl alcohol unit is sandwiched between layers [continuous layer]
• CPC Class Codes: Y10T 428/1386 Natural or synthetic rubber or rubber-like compound containing
• CPC Class Codes: Y10T 428/14 Layer or component removable to expose adhesive
• CPC Class Codes: Y10T 428/24777 Edge feature
• CPC Class Codes: Y10T 428/24802 Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.]
• CPC Class Codes: Y10T 428/2809 including irradiated or wave energy treated component
• CPC Class Codes: Y10T 428/287 including epoxy group or epoxy polymer
• CPC Class Codes: Y10T 428/2883 including addition polymer of diene monomer [e.g., SBR, SIS, etc.]
• CPC Class Codes: Y10T 428/31511 Of epoxy ether
• CPC Class Codes: Y10T 428/31826 Of natural rubber
• CPC Class Codes: Y10T 428/31837 Including polyene monomers
• CPC Class Codes: Y10T 428/31841 Next to cellulosic
• CPC Class Codes: Y10T 428/31917 Next to polyene polymer

Abstract

A packaging material, a method of making such a material, and a package made from such material, are disclosed. A substrate comprises at least one sheet of plastic material. An energy-curable coating is applied to one side of the substrate, which will be the outside of the eventual package. The energy-curable coating is cured by exposing it to an electron beam or other appropriate energy. A cold-seal cohesive coating is applied to the other side of the substrate. The package is formed by pressing together portions of the inside surface of at least one sheet of the material having the cold-seal cohesive coating on them to form a seal. Preferably, the cold-seal cohesive coating is applied only to those portions of the material that are to form seams in the eventual package.

Claims

1. A method of making a packaging material, comprising the steps of:

providing a substrate comprising at least one sheet of plastic material;

applying an energy-curable coating to one side of the substrate;

curing the energy-curable coating by exposing it to a suitable energy; and

applying a cold-seal cohesive coating to the other side of the substrate.

2. A method according to claim 1, further comprising the step of printing in ink on said at least one sheet of plastic material before applying said energy-curable coating.

3. A method according to claim 2, which comprises applying the energy-curable coating over the ink printing.

4. A method according to claim 1, comprising the steps of:

printing in ink on a sheet of plastic; and

laminating the printed sheet of plastic and another sheet of plastic together with the printing between them to form said substrate;

wherein one of said sheets of plastic forming said substrate is clear; and

applying said energy-curable coating to the exposed side of said clear sheet of plastic.

5. A method according to claim 1, wherein said step of curing comprises exposing said energy-curable coating to an electron beam.

6. A method of making packaging material comprising the steps of:

printing an image on a first side of a substrate;

applying an energy curable coating on the first side of the substrate over the printed image, the coating being formulated to act as a release layer for a cold-seal cohesive material once cured;

curing the energy curable coating with an energy source to form a substantially transparent release layer on the first side of the substrate; and

applying a cold-seal cohesive material to a second side of the substrate.

7. The method of claim 6 wherein the step of applying the cold-seal cohesive material comprises pattern applying the cold-seal cohesive material on areas of the second side of the substrate where seals are to be formed.

8. The method of claim 7 wherein the step of pattern applying comprises applying the cold-seal cohesive material at a thickness of from about 5 microns to about 7 microns.

9. The method of claim 6 further comprising the step of fixing slip additives in the energy curable coating during the curing process, wherein the slip additives do not poison the cold-seal coating material when the substrate is stored in a roll with the cold seal cohesive material in contact with the energy cured release layer.

10. A method of making a package comprising the steps of:

printing an image on a first side of a substrate;

applying an energy curable release coating over the printed image;

curing the energy curable release coating with an energy source to form a cured release layer on the substrate, processing additives within the coating becoming fixed during the curing process;

pattern-applying a cold-seal material to a second side of the substrate to form a sealable packaging material;

storing the packaging material in a roll with the cold-seal material in contact with the release layer, wherein the fixed processing additives in the release layer do not poison the cold seal;

unrolling the packaging material such that the pattern-applied cold-seal material remains attached to the second side of the substrate and does not offset onto the release layer;

forming the packaging material into the shape of a package; and

pressing cold-seal coated portions of the second side of the packaging material together to form a seal.

11. The method of claim 10 wherein the step of pattern applying comprises applying the cold-seal cohesive material at a thickness of from about 5 microns to about 7 microns.

12. The method of claim 10 wherein the curing step comprises the step of exposing the coated substrate to electron beam energy such that the coating absorbs a dosage of from about 2.5 megarads to about 5 megarads.

13. The method of claim 12 wherein the coating absorbs a dosage of from about 3 megarads to about 4 megarads during the curing process.