Novel laminates for paperboard cartons and a process of forming said laminates
AssigneeInternational Paper Company
InventorsCharles E. Gibbons, Allan A. Whillock, Robert L. Lanham, Joe L. Kinsey, Jr.
Life of this patent
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Abstract
The present invention relates to an improved container for citrus juices and other liquids. The container utilizes a paperboard barrier laminate for the containment of essential oils and the prevention of losses of Vitamin C. Also disclosed is a process of making the laminate. The laminate makes use of a layer of a heat-sealable glycol-modified polyethylene terephthalate to enhance the barrier properties of the laminate.
Claims22
A container for liquids containing essential oils and/or flavors, said container constructed from a laminate comprising:
- (a) a paperboard substrate;
- (b) an outer layer of a heat-sealable low density polyethylene polymer coated on said outer surface of said paperboard substrate;
- (c) an inner layer of a heat-sealable low density polyethylene polymer coated on said inner surface of said paperboard substrate;
- and
- (d) a liquid contact layer of a heat-sealable glycol modified polyethylene terephthalate which can heat-seal with the outside layer of low density polyethylene of the laminate on conventional equipment at temperatures ranging from 250.degree. F.-500.degree. F. extrusion coated on said outer surface of said inner layer of said polyethylene polymer, acting as a barrier to the transport of oxygen and essential oils/flavors therethrough.
A container for liquids containing essential oils and/or flavors constructed from a laminate comprising:
- (a) a paperboard substrate;
- (b) an outer layer of a heat-sealable low density polyethylene polymer coated on said outer surface of said paperboard substrate;
- (c) an inner layer of heat-sealable low density polyethylene polymer coated on said inner surface of said paperboard substrate;
- (d) an oxygen barrier material layer coated on said outer surface of said inner layer of said polyethylene polymer;
- and
- (e) a heat-sealable layer of glycol modified polyethylene terephthalate coated on said outer surface of said oxygen barrier material layer.
A process for improving the resistance of paperboard to the migration of essential oils and/or flavorings, said process comprising the steps of:
- (a) extrusion coating an outer layer of a low density polyethylene polymer onto said outer surface of said paperboard;
- (b) corona discharge treating said outer layer of low density polyethylene polymer;
- (c) extrusion coating an inner layer of a low density polyethylene polymer onto said inner surface of said paperboard;
- (d) corona discharge treating said inner layer of low density polyethylene polymer;
- and
- (e) extrusion coating of a layer of a heat-sealable glycol-modified polyethylene terephthalate onto said surface of said inner layer of low density polyethylene polymer.
A process for improving the resistance of paperboard to the migration of essential oils and/or flavorings, said process comprising the steps of:
- (a) extrusion coating an outer layer of a low density polyethylene polymer onto said outer surface of said paperboard;
- (b) flame treating said outer layer of low density polyethylene polymer;
- (c) extrusion coating an inner layer of a low density polyethylene polymer onto said inner surface of said paperboard;
- (d) flame treating said inner layer of low density polyethylene polymer;
- and
- (e) extrusion coating a layer of heat-sealable glycol-modified polyethylene terephthalate onto said surface of said inner layer of low density polyethylene polymer.
Dependencies are inferred from the claim text.