EP0141555A1 — Oriented polymeric films, packaging made from suc…

Claim 1

Independent Claim 180 words

An oriented film comprising five polymeric layers including: (a) a first barrier layer having a composition of 0% to 50% nylon or nylon copolymer, and 100% to 50% ethylene vinyl alcohol; (b) second and third adhesive layers each adhered to a respective one of the opposite surfaces of the first layer, the second and third adhesive layers both comprising olefinic polymers or copolymers having carboxyl modifications thereto; and (c) fourth and fifth layers adhered to the second and third layers on the respective surfaces opposite the first layer, the fourth and fifth layers comprising 40% to 100% ethylene vinyl acetate and 60 % to 0 % linear low density polyethylene; the said layers each having been stretched in molecular orientation to substantially the same degree, and the said layers being adhered to each other directly at the respective interfaces without the use of additional adhesive materials; the oriented film being susceptible of being made into a closed and sealed container or bag by means of heat seals formed along terminal edges of adjacent superimposed sheets or portions of the film.

Claim 2

Dependent Claim 180 words

An oriented film comprising five polymeric layers including: (a) a first barrier layer having a composition of 0% to 50% nylon or nylon copolymer, and 100% to 50% ethylene vinyl alcohol; (b) second and third adhesive layers each adhered to a respective one of the opposite surfaces of the first layer, the second and third adhesive layers both comprising olefinic polymers or copolymers having carboxyl modifications thereto; and (c) fourth and fifth layers adhered to the second and third layers on the respective surfaces opposite the first layer, the fourth and fifth layers comprising 40% to 100% ethylene vinyl acetate and 60 % to 0 % linear low density polyethylene; the said layers each having been stretched in molecular orientation to substantially the same degree, and the said layers being adhered to each other directly at the respective interfaces without the use of additional adhesive materials; the oriented film being susceptible of being made into a closed and sealed container or bag by means of heat seals formed along terminal edges of adjacent superimposed sheets or portions of the film.

Claim 3

Dependent Claim 43 words

An oriented film according to claim 1, wherein the first layer is either a blend comprising 30% to 50% nylon and 70% to 50% ethylene vinyl alcohol, for example 40% nylon and 60% ethylene vinyl alcohol, or consists essentially of ethylene vinyl alcohol.

Claim 4

Dependent Claim 45 words

An oriented film according to claim 1 or claim 2, wherein the fourth and fifth layers comprise a blend of 10% to 60%, for example 25% to 40%, linear low density polyethylene and 90% to 40 % for example 75% to 60% ethylene vinyl acetate.

Claim 5

Dependent Claim 28 words

An oriented film according to claim 1 or claim 2, wherein the fourth and fifth layers comprise an ethylene vinyl acetate or a blend of ethylene vinyl acetates.

Claim 6

Dependent Claim 48 words

An oriented film according to any of claims 1 to 4, wherein the compositions of said second and third layers are chosen from modified low density polyethylene, modified linear low density polyethylene, modified medium density polyethylene, modified ethylene vinyl acetate, and blends of the aforesaid polymers and copolymers.

Claim 7

Dependent Claim 60 words

An oriented film according to any preceding claim, wherein the composition of at least one of the said second and third layers includes a fractional amount of polymeric material either identical or very similar to, the materials used in the composition of at least one of the layers adjacent said at least one of the said second and third layers.

Claim 8

Independent Claim 168 words

A method of making a five layer oriented polymeric film, wherein the film includes a first barrier layer having a composition of 0% to 50 % nylon or nylon copolymer, and 100% to 50% ethylene vinyl alcohol; second and third adhesive layers both comprising olefinic polymers or copolymers having carboxyl modifications thereto; and fourth and fifth layers adhered to said second and third layers on their respective surfaces opposite the first layer, the fourth and fifth layers comprising 40% to 100% ethylene vinyl acetate and 60% to 0% linear low density polyethylene; and wherein the method comprises the steps of: (a) coextruding the five layers as a five layer film; (b) cooling the film; (c) reheating the film to molecular orientation temperature; (d) molecularly orienting the film; and (e) cooling the molecularly oriented five layer film; the oriented film being susceptible to being made into a closed and sealed container by means of heat seals formed along terminal edges of adjacent superimposed sheets or portions of the film.

Claim 9

Independent Claim 168 words

A method of making a five layer oriented polymeric film, wherein the film includes a first barrier layer having a composition of 0% to 50 % nylon or nylon copolymer, and 100% to 50% ethylene vinyl alcohol; second and third adhesive layers both comprising olefinic polymers or copolymers having carboxyl modifications thereto; and fourth and fifth layers adhered to said second and third layers on their respective surfaces opposite the first layer, the fourth and fifth layers comprising 40% to 100% ethylene vinyl acetate and 60% to 0% linear low density polyethylene; and wherein the method comprises the steps of: (a) coextruding the five layers as a five layer film; (b) cooling the film; (c) reheating the film to molecular orientation temperature; (d) molecularly orienting the film; and (e) cooling the molecularly oriented five layer film; the oriented film being susceptible to being made into a closed and sealed container by means of heat seals formed along terminal edges of adjacent superimposed sheets or portions of the film.

Claim 10

Independent Claim 158 words

A method of making a five layer oriented polymeric film, wherein the film includes a first barrier layer having a composition of 0 % to 50 % nylon or nylon copolymer, and 100 % to 50 % ethylene vinyl alcohol; second and third adhesive layers adhered to said surfaces of said first layer, said second and third adhesive layers both comprising olefinic polymers or copolymers having carboxyl modifications thereto; and fourth and fifth layers adhered to said second and third layers on their respective surfaces opposite the first layer, the fourth and fifth layers comprising 40% to 100% ethylene vinyl acetate and 60% to 0% linear low density polyethylene and wherein the method comprises the steps of: (a) coextruding the five layers as a five layer film; (b) cooling the film; (c) reheating the film to molecular orientation temperature; (d) molecularly orienting the film; (e) heat setting the molecularly oriented film; and (f) cooling the molecularly oriented film.

Claim 11

Independent Claim 158 words

A method of making a five layer oriented polymeric film, wherein the film includes a first barrier layer having a composition of 0 % to 50 % nylon or nylon copolymer, and 100 % to 50 % ethylene vinyl alcohol; second and third adhesive layers adhered to said surfaces of said first layer, said second and third adhesive layers both comprising olefinic polymers or copolymers having carboxyl modifications thereto; and fourth and fifth layers adhered to said second and third layers on their respective surfaces opposite the first layer, the fourth and fifth layers comprising 40% to 100% ethylene vinyl acetate and 60% to 0% linear low density polyethylene and wherein the method comprises the steps of: (a) coextruding the five layers as a five layer film; (b) cooling the film; (c) reheating the film to molecular orientation temperature; (d) molecularly orienting the film; (e) heat setting the molecularly oriented film; and (f) cooling the molecularly oriented film.

Claim 12

Dependent Claim 70 words

A method according to claim 7 or claim 8, wherein the film is coextruded in the shape of a tube and is oriented by introducing into said tube a pressurized gas and drawing the tube between two nips having a differential rate of drawing speed therebetween, such that the pressure of the gas and the drawing of said nips effect the molecular orientation of the film as an expanded tube.

Claim 13

Dependent Claim 47 words

A method according to claim 7, 8 or 9, wherein the first layer is chosen from a blend of 30 % to 50% nylon and 70% to 50% ethylene vinyl alcohol, for example 40% nylon and 60% ethylene vinyl alcohol, or consists essentially of ethylene vinyl alcohol.

Claim 14

Independent Claim 49 words

A method according to any of claims 7 to 10, wherein the fourth and fifth layers are formed from blends of 10% to 60%, for example 25% to 40 % , linear low density polyethylene and 90% to 40 % , for example 75% to 60% ethylene vinyl acetate.

Claim 15

Independent Claim 73 words

A method according to any of claims 7 to 11, wherein the compositions of said second and third layers are chosen from modified low density polyethylene, modified linear low density polyethylene, modified medium density polyethylene, modified ethylene vinyl acetate, and blends of the aforesaid polymers and copolymers; the compositions of said fourth and fifth layers preferably comprising blends of 25% to 40% linear low density polyethylene and 75% to 60% ethylene vinyl acetate.

Claim 16

Dependent Claim 185 words

A fabricated plastics container or bag having an opening on one edge thereof, the bag having been fabricated from an oriented film comprising five polymeric layers, including: (a) a first barrier layer having a composition of 0% to 50% nylon or nylon copolymer, and 100% to 50% ethylene vinyl alcohol; (b) second and third adhesive layers each adhered to a respective one of the surfaces of the first layer, the second and third adhesive layers both comprising olefinic polymers or copolymers having carboxyl modifications thereto; and (c) fourth and fifth layers adhered to said second and third layers on the respective surfaces opposite said first layer, the fourth and fifth layers comprising 40% to 100% ethylene vinyl acetate and 60% to 0% linear low density polyethylene; the said layers each having been stretched in molecular orientation to substantially the same degree, and the said layers being adhered to each other directly at their interfaces without the use of additional adhesive materials; and the bag being susceptible to being made into a closed and sealed container by means of a heat seal along the said opening.

Claim 17

Dependent Claim 185 words

A fabricated plastics container or bag having an opening on one edge thereof, the bag having been fabricated from an oriented film comprising five polymeric layers, including: (a) a first barrier layer having a composition of 0% to 50% nylon or nylon copolymer, and 100% to 50% ethylene vinyl alcohol; (b) second and third adhesive layers each adhered to a respective one of the surfaces of the first layer, the second and third adhesive layers both comprising olefinic polymers or copolymers having carboxyl modifications thereto; and (c) fourth and fifth layers adhered to said second and third layers on the respective surfaces opposite said first layer, the fourth and fifth layers comprising 40% to 100% ethylene vinyl acetate and 60% to 0% linear low density polyethylene; the said layers each having been stretched in molecular orientation to substantially the same degree, and the said layers being adhered to each other directly at their interfaces without the use of additional adhesive materials; and the bag being susceptible to being made into a closed and sealed container by means of a heat seal along the said opening.

Claim 18

Dependent Claim 53 words

A bag according to claim 13, fabricated from said film which is produced in the form of a tube, the bag being formed by heat sealing a length of said tube along one open end leaving the other end open, the bag being closed along said other end by heat sealing after filling.

Claim 19

Dependent Claim 47 words

A bag according to claim 13, fabricated from two superimposed sheets or portions of said film and appropriately heat sealed peripherally to form a pouch open along one edge to permit filling, the pouch being subsequently heat sealed along the said one edge to close the bag.

Claim 20

Dependent Claim 42 words

A bag according to claim 13, 14 or 15, wherein the first layer is either 30% to 50% nylon and 70% to 50% ethylene vinyl alcohol, for example 40% nylon and 60% ethylene vinyl alcohol, or consists essentially of ethylene vinyl alcohol.

Claim 21

Dependent Claim 45 words

A bag according to claim 13, 14, 15 or 16 wherein the fourth and fifth layers comprise blends of 10% to 60%, for example 25% to 40% linear low density polyethylene and 90% to 40 % , for example 75% to 60% ethylene vinyl acetate.

Claim 22

Dependent Claim 48 words

A bag according to any of claims 13 to 17, wherein the compositions of the second and third adhesive layers are chosen from modified low density polyethylene, modified linear low density polyethylene, modified medium density polyethylene, modified ethylene vinyl acetate, and blends of the aforesaid polymers and copolymers.

Claim 23

Independent Claim 211 words

A method of fabricating a plastic bag having an opening on one edge thereof susceptible of closure by heat sealing, the remainder of the periphery of the bag having been closed as appropriate by one or more heat seals to form an open ended pouch, the said bag being fabricated from an oriented film which includes a first barrier layer having a composition of 0% to 50% nylon or nylon copolymer, and 100% to 50% ethylene vinyl alcohol; second and third adhesive layers adhered to respective surfaces of the first layer, the second and third adhesive layers both comprising olefinic polymers or copolymers having carboxyl modifications thereto; and fourth and fifth layers adhered to the second and third layers on their respective surfaces opposite the first layer, the fourth and fifth layers comprising 40% to 100% ethylene vinyl acetate and 60% to 0% linear low density polyethylene; and the method including the steps of: (a) coextruding the five layers as a five layer film; (b) cooling the film; (c) reheating the film to molecular orientation temperature; (d) molecularly orienting the film; (e) cooling the molecularly oriented five layer film; and (f) forming one or more heat seals as appropriate at the periphery of said bag except along the said one edge.

Claim 24

Independent Claim 211 words

A method of fabricating a plastic bag having an opening on one edge thereof susceptible of closure by heat sealing, the remainder of the periphery of the bag having been closed as appropriate by one or more heat seals to form an open ended pouch, the said bag being fabricated from an oriented film which includes a first barrier layer having a composition of 0% to 50% nylon or nylon copolymer, and 100% to 50% ethylene vinyl alcohol; second and third adhesive layers adhered to respective surfaces of the first layer, the second and third adhesive layers both comprising olefinic polymers or copolymers having carboxyl modifications thereto; and fourth and fifth layers adhered to the second and third layers on their respective surfaces opposite the first layer, the fourth and fifth layers comprising 40% to 100% ethylene vinyl acetate and 60% to 0% linear low density polyethylene; and the method including the steps of: (a) coextruding the five layers as a five layer film; (b) cooling the film; (c) reheating the film to molecular orientation temperature; (d) molecularly orienting the film; (e) cooling the molecularly oriented five layer film; and (f) forming one or more heat seals as appropriate at the periphery of said bag except along the said one edge.

Claim 25

Dependent Claim 43 words

A method according to claim 19 and including, after step (d), and before step (e), the additional step of heat setting the oriented film by holding it at an elevated temperature of 200° to 250°F (93.3° to 121°C) for 2 to 10 seconds.

Claim 26

Dependent Claim 36 words

A method according to claim 19 or claim 20, wherein the first layer either comprises a blend of 30% to 50% nylon and 70% to 50% ethylene vinyl alcohol or consists essentially of ethylene vinyl alcohol.

Claim 27

Dependent Claim 33 words

A method according to claim 19, 20 or 21, wherein the fourth and fifth layers comprise a blend of 25% to 40% linear low density polyethylene and 75% to 60% ethylene vinyl acetate.

Claim 28

Dependent Claim 74 words

A method according to claim 19, 20, or 21, wherein the compositions of the second and third adhesive layers are chosen from modified low density polyethylene, modified linear low density polyethylene, modified medium density polyethylene, modified ethylene vinyl acetate, and blends of the aforesaid polymers and copolymers; and the compositions of the fourth and fifth layers preferably comprise blends of 25% to 40% linear low density polyethylene and 75% to 60% ethylene vinyl acetate.

Oriented polymeric films, packaging made from such films and methods of making the films and packaging

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