Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
  • B65D65/00—Wrappers or flexible covers; Packaging materials of special type or form
  • B65D65/38—Packaging materials of special type or form
  • B65D65/42—Applications of coated or impregnated materials
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J7/00—Chemical treatment or coating of shaped articles made of macromolecular substances
  • C08J7/04—Coating
  • C08J7/0427—Coating with only one layer of a composition containing a polymer binder
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J7/00—Chemical treatment or coating of shaped articles made of macromolecular substances
  • C08J7/04—Coating
  • C08J7/052—Forming heat-sealable coatings
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2301/00—Characterised by the use of cellulose, modified cellulose or cellulose derivatives
  • C08J2301/02—Cellulose; Modified cellulose
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2491/00—Characterised by the use of oils, fats or waxes; Derivatives thereof
  • C08J2491/06—Waxes
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
  • Y02A40/00—Adaptation technologies in agriculture, forestry, livestock or agroalimentary production
  • Y02A40/90—Adaptation technologies in agriculture, forestry, livestock or agroalimentary production in food processing or handling, e.g. food conservation
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
  • Y02W90/00—Enabling technologies or technologies with a potential or indirect contribution to greenhouse gas [GHG] emissions mitigation
  • Y02W90/10—Bio-packaging, e.g. packing containers made from renewable resources or bio-plastics
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/25—Web or sheet containing structurally defined element or component and including a second component containing structurally defined particles
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/27—Web or sheet containing structurally defined element or component, the element or component having a specified weight per unit area [e.g., gms/sq cm, lbs/sq ft, etc.]
  • Y10T428/273—Web or sheet containing structurally defined element or component, the element or component having a specified weight per unit area [e.g., gms/sq cm, lbs/sq ft, etc.] of coating
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/28—Web or sheet containing structurally defined element or component and having an adhesive outermost layer
  • Y10T428/2813—Heat or solvent activated or sealable
  • Y10T428/2817—Heat sealable
  • Y10T428/2822—Wax containing

Definitions

• Wax coated packaging sheets are well known to the packaging art. Such packaging materials have been used particularly to package food materials, such as cheese, bread, luncheon meats and processed vegetables and fruits.
• a suitable base sheet is selected and is coated with molten wax.
• base sheets is meant various sheet materials, such as paper, foil, and various plastics which have been found suitable in preparing wax-coated sheets.
• wax refers to any of the various waxy materials which have been found suitable in preparing packaging materials. These include paraffin, carnauba and various micro-crystalline waxes.
• Wax coated packaging sheets are generally prepared by means of high speed equipment. A roll of the base sheet is unwound and a melt of the wax is applied to one surface of the base sheet. The wax coated base sheet may then be cooled to set the wax, and the wax-coated base sheet is then rewound upon a take-up roll.
• a major problem in the preparation and use of the wax-coated packaging sheet is their tendency to block, that is, to resist separation by a separating force applied perpendicular to the film, such as by a simple lifting action. Wax-coated packaging sheets also exhibit poor slip, that is, they do not slide readily over each other. The poor blocking and slip behavior of wax-coated packaging sheets results in poor handling characteristics and interferes with their use in automatic processing equipment.
• wax-coated packaging sheet material with improved separating characteristics. It would also be desirable to provide block-resistant waxcoated packaging sheet materials which can be readily sealed.
• the separating characteristics of wax-coated packaging sheet material can be improved and good sealing properties retained by applying to the wax surface of a packaging sheet material a homogeneous mixture of a high molecular weight amide and starch in a particular amount.
• the amide has a molecular weight of at least 200 and preferably has a molecular weight in the range of from about 1,000 to about 50,000.
• the amide comprises a major amount of the mixture and the starch comprises a minor amount of the mixture.
• the mixture may be applied to the surface of the wax coating of the packaging sheet material by various methods known to those skilled in the art.
• the amide of the invention may be an amide of a higher fatty acid.
• the term amide of a higher fatty acid is intended to include amides of saturated and unsaturated, water-insoluble monocarboxylic acids and particularly t-hose higher fatty acids having at least 12 carbon atoms in the chain.
• Such higher amides include the amides of oleic acid, arachidic acid, behenic acid and erucic acid. It is particularly preferred, however, to use amides having molecular weights in excess of about 1,000, which are prepared from the reaction of diamines and polymerized fatty acids which are formed by polymerization at the double bond position in unsaturated higher fatty acids.
• the polymerized acids are desirably di-carboxylic, and the amides formed by the reaction of the dicarboxylic acids and diamines are referred to herein as polyamides.
• Polyamides are readily prepared by heating a mixture of the di-carboxylic polymerized acids and the diamine at a predetermined temperature, and thereafter removing the water of formation. Such polyamides are commercially available in various grades under the trade names Versamid and Milvex, sold by General Mills, Inc. The amide of higher fatty acid may be in a suitable carrier, such as propyl alcohol.
• the starch of the mixture may be any of various plant starches. Preferred starches are those obtained from corn, potato or rice.
• the starch is preferably nongelatinized and is dry.
• the mixture of the invention is usually applied to the wax surface of a wax-coated packaging sheet material from a fluid dispersion of the amide and the starch. Therefore, it is preferred to use a starch that has a particle size sufficiently small that settling of the starch in the dispersion is not a problem. Specifically, it is preferred to use starches which have a particle size of at least less than about 60 mesh.
• the amide is present in the homogeneous mixture in a major amount, and preferably comprises from about 50 to about percent by weight of the mixture.
• the starch preferably comprises from about 10 to about 50 percent of the mixture.
• the mixture is applied to the packaging material at levels suflicient to provide from about 0.1 to about 1.5 pounds of the mixture per 3,000 square feet of the packaging material.
• the mixture tends to provide a coating on the wax and it must not be so thick as to interfere with sealing but must be thick enough to provide the desired separating properties. It has been found that the 3 indicated range provides adequate separating properties while permitting good seals.
• the level of wax may be reduced from that previously used with other particular anti-blocking materials.
• starch is known as an anti-blocking material when used by itself.
• starch when starch is applied to a wax coated packaging sheet material, the level of wax must be substantially above that used when the present composition is used.
• the composition of the present invention provides a coating which is more easily fractured during sealing of a package so that the wax can function to effect a seal.
• starch alone a substantially higher level of starch must be used to provide separating characteristics.
• the starch which covers the wax must be pressed and the wax melted so as to flow through the starch in the region of the seal.
• the amide of higher fatty acid when used alone does not provide adequate anti-blocking properties.
• the composition of the present invention is used at the indicated level on the same material, there is adequate provision of separating properties and effective seals can be achieved.
• composition of the invention may be used with many Wax-coated packaging sheet materials, it is particularly adapted for use with wax coated packaging sheet material regularly used in the packaging of cheese.
• a particularly suitable packaging sheet material is one wherein the base sheet is a polymer coated cellophane to which is applied a micro-crystalline wax fortified with polyisobutylene or comminuted butyl rubber.
• the Wax coating may be in the range of from about 35 to about 50 pounds of wax per 3,000 square feet of packaging sheet material.
• the composition of the invention is provided at a level of from about 0.1 to about 1.5 pounds of the composition per 3,000 square feet of the packaging material.
• the starch When starch alone is used as a coating for such wax coated packaging sheet material, the starch is applied at a level of form about 4 to about 5 pounds per 3,000 square feet of packaging material. Also, when starch alone is used as the coating material, the wax must usually be applied at a level of from about 45 to about 60 pounds per 3,000 square feet of packaging material. Also, the composition of the present invention provides better slip than is provided by the use of the starch alone or a polyamide alone.
• composition of the invention may be applied to the wax coated packaging sheet material by any suitable method.
• a preferred method is to disperse the amide and the starch in a suitable fluid carrier and to spray, dip coat, roll on or otherwise apply the dispersion to the surface of the wax coating of the sheet.
• the carrier is then removed by a subsequent drying step.
• Preferred carriers are organic fluids which are capable of dissolving the amide and are not reactive with the wax coating. Such carriers include, but are not limited to, short chain alcohols, such as ethyl, butyl or propyl alcohol.
• the starch may be moistened prior to adding the carrier. However, for reasons of economy during the drying step, it is preferred that the starch be substantially dry.
• the mixture of amide and starch may be present in the carrier at a level of from about 5 to about 50 percent by weight.
• Example A mixture of 7.7 parts of an amide, 90 parts of n-propyl al oh l and 2.3 parts of y o n sta c is p pa ed
• Th 4 amide used is available commercially under the trade name Milvex 1000, from General Mills, Inc.
• the corn starch is ungelatinized, dry and has a particle size which is less than 60 mesh.
• a rolled sheet of polymer coated cellophane is coated with a molten mixture of micro-crystalline wax and comminuted butyl rubber.
• the cellophane has a size designation of 250, which means 25,000 square inches per pound of cellophane.
• the wax is applied at a level sufficient to provide 40 pounds of wax per 3,000 square feet of the polymer coated cellophane.
• the wax is applied by means of a gravure cylinder which revolves into a bath of the molten wax mixture and deposits a coating of wax onto the surface of the cellophane sheet.
• the polymer coated cellophane sheet containing the coating of wax is then cooled to harden the wax and is passed by means of rolls to a second gravure cylinder.
• the second gravure cylinder revolves through a bath of the amide-starch mixture.
• the amide-starch mixture is applied to the wax surface at a level sufiicient to provide 0.5 pound of the amide-starch mixture on a solid basis per 3,000 square feet of the wax-coated cellophane.
• the alcohol is then removed by passing the sheet through a dryer.
• the sheet of polymer coated cellophane, containing a wax coating and an amide-starch coating is then wound upon a take-up roll.
• the sheet material is used to wrap hot or cold cheese and is readily sealed.
• the sheet material also has good separating properties from cheese when packaged hot.
• An improved wax coated packaging sheet material comprising a base sheet, a wax coating and a coating applied to the wax coating which has separating properties, said separating coating consisting essentially of a mixture of a major amount of an amide of a higher fatty acid and a minor amount of a starch, said amide having a molecular weight of above at least 200, said separating coating being at a level which permits heat sealing of the sheet material.
• starch is selected from corn starch, potato starch or rice starch, said starch having a particle size of less than about 60 mesh.

Landscapes

• Chemical & Material Sciences (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Wrappers (AREA)
• Laminated Bodies (AREA)
• Paper (AREA)
• Compositions Of Macromolecular Compounds (AREA)
• Packging For Living Organisms, Food Or Medicinal Products That Are Sensitive To Environmental Conditiond (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=25098900

Family Applications (1)

Country Status (6)

Cited By (2)

Families Citing this family (6)

Family Cites Families (2)

• 1968
  • 1968-11-05 US US3598634D patent/US3598634A/en not_active Expired - Lifetime
• 1969
  • 1969-10-02 GB GB1257235D patent/GB1257235A/en not_active Expired
  • 1969-10-23 ES ES372804A patent/ES372804A1/es not_active Expired
  • 1969-10-29 FR FR6937103A patent/FR2022584B1/fr not_active Expired
  • 1969-11-05 BE BE741300D patent/BE741300A/xx not_active IP Right Cessation
  • 1969-11-05 DE DE1955711A patent/DE1955711C2/de not_active Expired

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