# US 10,870,264 B2 · Cover film, method of making cover film, and method of using cover film for enclosing compressed material > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,870,264 B2 - Document ID: US10870264B2 - Status: Granted - Kind: B2 - Application number: 16/306,720 - Filed: 2017-05-31 - Published: 2019-05-02 - Granted: 2020-12-22 - Earliest claimed: 2016-06-08 - Assignees: RKW Agri GmbH & Co. KG - Applicants: RKW Agri GmbH & Co. KG - Inventors: Jurgen Piazzi; Jan Philip Eubeler; Thomas Steffen; Benjamin Kuhlmann - Web page: https://patentgrep.com/patent/US10870264B2 ## CPC - B32B 27/32: comprising polyolefins {(comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30)} - A01F 15/0715: {Wrapping the bale in the press chamber before opening said chamber} - B29C 48/0018: {combined with shaping by orienting, stretching or shrinking, e.g. film blowing (B29C48/0017 takes precedence)} - B29C 48/0022: {combined with cutting} - B29C 48/022: {characterised by the choice of material} - B29C 48/10: flexible, e.g. blown foils - B29C 48/21: the layers being joined at their surfaces - B29C 55/005: {characterised by the choice of materials} - B29C 55/28: of blown tubular films, e.g. by inflation {(extrusion moulding of tubular films B29C48/03)} - B32B 1/08: Tubular products - B32B 27/08: of synthetic resin - B32B 27/327: {comprising polyolefins obtained by a metallocene or single-site catalyst} - B65B 11/00: Wrapping, e.g. partially or wholly enclosing, articles or quantities of material, in strips, sheets or blanks, of flexible material (bundling articles by applying narrow strips or bands of flexible material B65B13/00) - B65B 27/125: {and wrapping or bagging} - C08J 5/18: Manufacture of films or sheets - C08L 23/06: Polyethylene - A01F 2015/0745: {Special features of the wrapping material for wrapping the bale} - B29K 2023/06: {PE, i.e. polyethylene} - B29L 2023/001: {Tubular films, sleeves} - B32B 2250/03: 3 layers - B32B 2250/24: All layers being polymeric - B32B 2250/40: Symmetrical or sandwich layers, e.g. ABA, ABCBA, ABCCBA - B32B 2270/00: Resin or rubber layer containing a blend of at least two different polymers - B32B 2274/00: Thermoplastic elastomer material - B32B 2307/514: Oriented - B32B 2307/516: mono-axially - B32B 2410/00: Agriculture-related articles - B65B 2011/002: {Prestretching mechanism in wrapping machines} - C08J 2323/06: Polyethene - C08J 2323/08: Copolymers of ethene (C08J2323/16 takes precedence) - C08J 2423/08: Copolymers of ethene (C08J2423/16 takes precedence) - C08J 2423/20: having four to nine carbon atoms - C08L 2203/16: used for films - C08L 2205/025: containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure - C08L 2207/04: Thermoplastic elastomer - C08L 2207/066: LDPE (radical process) - B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM - A01F: PROCESSING OF HARVESTED PRODUCE; HAY OR STRAW PRESSES; DEVICES FOR STORING AGRICULTURAL OR HORTICULTURAL PRODUCE (devices for topping or skinning onions or flower bulbs A23N15/08) - B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00) - B65B: MACHINES, APPARATUS OR DEVICES FOR, OR METHODS OF, PACKAGING ARTICLES OR MATERIALS; UNPACKING (bundling and pressing devices for cigars A24C1/44; devices for tensioning and securing binders adapted to be supported by the article or articles to be bound B25B25/00; applying closure members to bottles, jars or similar containers B67B1/00-B67B6/00; concurrent cleaning, filling and closing of bottles B67C7/00; emptying bottles, jars, cans, casks, barrels or similar containers B67C9/00) - C08J: WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H (working, e.g. shaping, of plastics B29) - C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06) - B29K: INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR {MOULDS, } REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS - B29L: INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES ## Abstract A cover film for the compressing of bales, characterized in that the cover film has been stretched and comprises an inner layer (1) and outer layers (2), wherein the inner layer (1) of the film comprises a copolymer of an ethylene and an α-olefin, wherein the α-olefin is selected from the group consisting of 1-butene, 1-hexene, 1-heptene, and 1-octene, and is used for copolymerization with the ethylene, wherein the copolymer is present in an amount of more than 5% by weight and less than 50% by weight of the inner layer (1) of the film, wherein the inner layer (1) further comprises a linear polyethylene, and wherein the outer layers (2) of the film fail to comprise any significant proportion of the copolymer. ## Claims ### Claim 1 A cover film for enclosing bales of compressed material, the cover film having been stretched, and the cover film comprising: an inner layer and an outer layer; the inner layer comprises: a copolymer of an ethylene and an α-olefin, wherein the α-olefin is selected from the group consisting of 1-butene, 1-hexene, 1-heptene, and 1-octene, and is used for copolymerization with the ethylene; a proportion of said copolymer is more than 5% by weight and less than 50% by weight of the inner layer; and a linear polyethylene; and the outer layer does not have any significant proportion of said copolymer. ### Claim 2 (depends on 1) The cover film according to claim 1, wherein a proportion of the copolymer is less than 40% by weight of the inner layer. ### Claim 3 (depends on 1) The cover film according to claim 1, wherein the copolymer is a plastomer. ### Claim 4 (depends on 1) The cover film according to claim 1, wherein the copolymer is a thermoplastic elastomer. ### Claim 5 (depends on 1) The cover film according to claim 1, wherein the copolymer is at least one of a copolymer of ethylene with at least one of an (ω-1)-methyl-branched α-olefin or an isomeric linear α-olefin. ### Claim 6 (depends on 1) The cover film according to claim 1, wherein the copolymer is a copolymer of ethene and octene. ### Claim 7 (depends on 1) The cover film according to claim 1, wherein the copolymer is a metallocene-catalyzed copolymer. ### Claim 8 (depends on 1) The cover film according to claim 1, wherein the copolymer is a metallocene polyethylene (mPE-LLD) with a density of 0.886 to 0.935 g/cm3. ### Claim 9 (depends on 1) The cover film according to claim 1, wherein the inner layer of the film comprises a proportion of the copolymer of more than 8% by weight of the inner layer. ### Claim 10 (depends on 9) The cover film according to claim 9, wherein the inner layer comprises a proportion of the copolymer of less than 40% by weight of the inner layer. ### Claim 11 (depends on 1) The cover film according to claim 1, wherein the film (20) is stretched at a temperature of more than 80° C. ### Claim 12 (depends on 11) The cover film according to claim 11, wherein the cover film (20) is stretched at a temperature of less than 150° C. ### Claim 13 (depends on 1) The cover film according to claim 1, wherein the cover film is stretched at a temperature at which the copolymer is in molten form. ### Claim 14 (depends on 13) The cover film according to claim 13, wherein the cover film is stretched at a temperature at which all components other than the copolymer are in non-molten form. ### Claim 15 (depends on 13) The cover film according to claim 13, wherein the cover film is stretched at between 5 and 20° C. below the crystallite melting point of the film. ### Claim 16 (depends on 1) A combination of a bale of compressed material wrapped with the cover film of claim 1, wherein the cover film has restoring forces for further compression of the wrapped bale. ### Claim 17 (depends on 16) The combination according to claim 16, wherein the further compression is at least 0.5% of a diameter of the bale. ### Claim 18 (depends on 1) The cover film according to claim 1, wherein the film comprises at least three layers. ### Claim 19 (depends on 1) The cover film according to claim 1, wherein a thickness of the film is less than 20 μm. ### Claim 20 (depends on 1) A method for enclosing bales of compressed material, comprising the following steps: providing the cover film of claim 1; stretching the cover film; compressing material in a chamber to form a bale of compressed material having a bale diameter; wrapping the cover film around the compressed bale in the chamber; and removing the wrapped bale from the chamber, and the cover film further compressing the bale by at least 0.5% of the diameter of the bale compared to the diameter of the bale on removal from the chamber. ### Claim 21 A method for producing a cover film, comprising the following steps: blow extruding a copolymer and other components to form a film tube; dividing the film tube into film sheets, the film sheets each including an outer layer and an inner layer; the inner layer comprises: said copolymer, and said copolymer comprises an ethylene and an α-olefin, wherein the α-olefin is selected from the group consisting of 1-butene, 1-hexene, 1-heptene, and 1-octene, and is used for copolymerization with the ethylene; a proportion of said copolymer is more than 5% by weight and less than 50% by weight of the inner layer; and a linear polyethylene; and the outer layer does not have any significant proportion of said copolymer, and stretching the film sheets in an MDO unit in a longitudinal direction at a temperature at which the copolymer is in molten form and the remaining components are in non-molten form. ### Claim 22 (depends on 21) The method of claim 21, further comprising installing the cover film as a net replacement for fixing of compressed bulk material in compressing of a bale. ### Claim 23 (depends on 21) A roll of a film produced according to claim 21 adapted for use as a net replacement for fixing material in baling.