Thin film for vertical form fill and seal packaging of flowable materials

• US 20070254119A1
• Filed: 04/27/2007
• Published: 11/01/2007
• Est. Priority Date: 04/28/2006
• Status: Abandoned Application

• Current Assignee: Glopak, Inc.
• Original Assignee: Glopak, Inc.
• Inventors: Lloyd-George, Ian
• Application Number:
  US11/790,728
• Publication Number:
  US 20070254119A1
• Time in Patent Office: Days
• US Class Current: 428/35.200
• CPC Class Codes: B29C 48/0019 combined with shaping by flattening, folding or bending
• CPC Class Codes: B29C 48/10 flexible, e.g. blown foils
• CPC Class Codes: B29C 48/17 the components having different colours
• CPC Class Codes: B29C 48/21 the layers being joined at their surfaces
• CPC Class Codes: B29C 53/48 for articles of indefinite length, i.e. bending a strip progressively
• CPC Class Codes: B29C 65/18 using heated tools
• CPC Class Codes: B29C 65/222 comprising at least a single heated wire
• CPC Class Codes: B29C 65/38 Impulse heating
• CPC Class Codes: B29C 65/7433 the tool being a wire
• CPC Class Codes: B29C 66/1122 Single lap to lap joints, i.e. overlap joints B29C66/45, B29C66/472, B29C66/52272 take precedence
• CPC Class Codes: B29C 66/4312 for making flat seams in tubular or hollow articles, e.g. transversal seams
• CPC Class Codes: B29C 66/4322 by joining a single sheet to itself B29C66/4332 takes precedence
• CPC Class Codes: B29C 66/49 Internally supporting the, e.g. tubular, article during joining B29C66/63 takes precedence
• CPC Class Codes: B29C 66/71 characterised by the composition of the plastics material of the parts to be joined welding bar compositions B29C65/125
• CPC Class Codes: B29C 66/723 being multi-layered B29C66/7292, B29C66/72941 take precedence
• CPC Class Codes: B29C 66/7315 Mechanical properties
• CPC Class Codes: B29C 66/81427 comprising a single ridge, e.g. for making a weakening line; comprising a single tooth
• CPC Class Codes: B29C 66/83221 cooperating reciprocating tools, each tool reciprocating along one axis
• CPC Class Codes: B29C 66/8491 welding through a filled container, e.g. tube or bag
• CPC Class Codes: B29K 2023/06 PE, i.e. polyethylene
• CPC Class Codes: B29K 2023/0625 : LLDPE, i.e. linear low density polyethylene
• CPC Class Codes: B29K 2023/0633 : LDPE, i.e. low density polyethylene
• CPC Class Codes: B29K 2023/08 : Copolymers of ethylene B29K2023/16 takes precedence
• CPC Class Codes: B29K 2023/12 : PP, i.e. polypropylene
• CPC Class Codes: B29K 2023/14 : Copolymers of polypropylene B29K2023/16 takes precedence
• CPC Class Codes: B29K 2105/0085 : Copolymers
• CPC Class Codes: B29K 2105/0088 : Blends of polymers
• CPC Class Codes: B29K 2105/256 : Sheets, plates, blanks or films
• CPC Class Codes: B29K 2995/0089 : Impact strength or toughness
• CPC Class Codes: B29L 2009/00 : Layered products
• CPC Class Codes: B32B 27/32 : comprising polyolefins comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30
• CPC Class Codes: B65B 9/20 : the webs being formed into tubes in situ around the filling nozzles
• CPC Class Codes: Y10T 428/1334 : Nonself-supporting tubular film or bag [e.g., pouch, envelope, packet, etc.]
• CPC Class Codes: Y10T 428/1359 : Three or more layers [continuous layer]

Abstract

A multi-layer film for vertical form, film and seal systems for liquid, powder, granules and/or other flowables packaging, said multi-layer comprising: an inner layer made of polyethylene, a blend of polyethylenes or ethylene copolymers; a core, comprising one or more than one layer, made from a blend of polypropylene, linear low density polyethylene, a polymer compatibilizer or tie-layer resin, and/or low density polyethylene, said core being applied against the inner layer; and an outer layer (same or different from the inner layer or the core layer) is made of a polyethylene or a blend of polyethylenes with or without ethylene copolymers, said outer layer being applied against the core and opposite the inner layer; said multi-layer film having an overall thickness of lower or equal to 2.5 mil and at least one of the properties listed hereinafter: a stiffness (as measured by 1% secant modulus in the film machine direction) varying from 3500 psi to 150000 psi; a tensile strength at yield of from 1700 psi to 3300 psi; (measured in film machine direction) and a tensile strength at break of from 4300 to 7400 psi (measured in film machine direction). A method of forming, sealing and filling a pouch with said film, a pouch formed with said film and use of said film to form a pouch.

Claims

1. A multi-layer film for vertical form, fill and seal systems for liquid, powder, granules and/or other flowables packaging, said multi-layer comprising:

an inner layer made of polyethylene, a blend of one or several polyethylenes and/or one or several ethylene copolymers;

a core, comprising one or more than one layer, made from a blend of;

polypropylene;

linear low density polyethylene;

a polymer compatibilizer or tie-layer resin; and

/or

optionally low density polyethylene;

said core being applied against the inner layer; and

an outer layer (same or different from the inner layer or the core layer) is made of a polyethylene or a blend of one or several polyethylenes with or without one or several ethylene copolymers, said outer layer being applied against the core and opposite the inner layer;

said multi-layer film having an overall thickness of lower or equal to 2.5 mil.

2. A multi-layer film according to claim 1, wherein said film has an overall thickness of 1.75 to 2.5 mil.

3. A multi-layer film according to claim 1, wherein the relative thickness of the inner layer:

core layer;

outer layer vary from 10;

80;

10 to 30;

40;

30.

4. A multi-layer film according to claim 2, wherein the relative thickness of the inner layer:

core layer;

outer layer is 25;

50;

25.

5. A multi-layer film according to claim 3, wherein said film further has at least one of the properties listed hereinafter:

a stiffness (as measured by 1% secant modulus in film machine direction) varying from 3500 psi to 150000 psi; and

a tensile strength at yield of from 1700 psi to 3300 psi (measured in film machine direction); and

.

a tensile strength at break of from 4300 psi to 7400 psi (measured in film machine direction).

6. A multi-layer film according to claim 5, wherein said film at least has a stiffness (as measured by 1% secant modulus) varying from 3500 psi to 150000 psi.

7. A multi-layer film according to claim 1, wherein the blend defining the core layer comprises in weight percent:

10% to 90% of polypropylene or a mixture of polypropylenes;

80% to 0% (lower limit not comprised) of a linear low density polyethylene or a mixture of linear low density polyethylenes and low density polyethylene; and

2% to 10% of at least one polymer compatibilizer.

8. A multi-layer film according to claim 7, wherein the polymer compatibilizer is selected from the group consisting of ethylene methacrylate, ethylene methacrylate copolymer, ethylene butyl acrylate, ethylene vinyl acetate, ethylene propylene diamine rubber, ethylene propylene copolymer;

ethylene styrene copolymer, and/or ethylene thermoplastic elastomers.

9. A multi-layer film according to claim 7, wherein the polypropylene is a random copolymer polypropylene or blend of homo-polymer polypropylene and copolymer polypropylene.

10. A multi-layer film according to claim 9, wherein the polypropylene has a grade of polypropylene or blend of polypropylene allowing to prepare a multi-layer film having a high impact strength, the izod impact strength of the polypropylene being greater than 9 ft.lb_f per inch of notch as per American Society for Testing and Materials (ASTM) D256.

11. A multi-layer film according to claim 8, wherein the ethylene methacrylate copolymer has from 10 to 25% of methacrylate content.

12. A multi-layer film according to claim 8, wherein the linear low density polyethylene for the core layer has a melt index (ASTM D1234, 2.16 kg, 190°

C.) from 0.4 to 2.00 g per 10 minutes and a density of approximately 0.926 g/cc.

14. A method of forming, sealing and filling a pouch with a liquid, powder, granules and/or other flowables at high speed, said method comprising the steps of:

i) providing, in roll form, a multi-layer film as defined in claim 1,

ii) drawing said film, by drawing means, over a pouch former to form a plastic film tube having an overlapped vertical film edge,

iii) sealing said overlapped vertical edge with a vertical sealer to form a vertical seal,

iv) effecting a horizontal seal across said plastic film tube with a horizontal sealing jaw and at a predetermined location below said vertical sealer, and simultaneously severing said tube to form a top horizontal seal for a filled pouch and a bottom horizontal seal for a pouch being filled, said horizontal and vertical seals, and

v) continuously feeding a consumable liquid, powder, granules and/or other flowables within said plastic film tube below said vertical sealing jaw and above said transverse sealing jaw.

15. A method of forming, sealing and filling a pouch with a liquid, powder, granules and/or other flowables at high speed, said method comprising the steps of:

i) providing, in roll form, a multi-layer film as defined in claim 11,

ii) drawing said film, by drawing means, over a pouch former to form a plastic film tube having an overlapped vertical film edge,

iii) sealing said overlapped vertical edge with a vertical sealer to form a vertical seal,

iv) effecting a horizontal seal across said plastic film tube with a horizontal sealing jaw and at a predetermined location below said vertical sealer, and simultaneously severing said tube to form a top horizontal seal for a filled pouch and a bottom horizontal seal for a pouch being filled, said horizontal and vertical seals, and

v) continuously feeding a consumable liquid—

or powder, granules and/or other flowables—

within said plastic film tube below said vertical sealing jaw and above said transverse sealing jaw,

the resulting pouch having walls provided with a thickness varying from 1.75 to 2.5 mil and at least one of the properties listed hereinafter;

a stiffness varying 3500 psi to 150000 psi (as determined by 1% secant modulus in the film'"'"'s machine direction); and

a tensile strength at yield of from 1700 psi to 3300 psi (machine direction); and

tensile strength at break from 4300 to 7400 psi (machine direction).

17. A pouch obtained from a multi-layer film as defined in claim 1 on a forming, sealing and filling system.

19. Use of a multi-layers film as defined in claim 1 for preparing a pouch by processing on a high speed vertical form, film and seal systems.

13. A multi-layer film for vertical form, fill and seal systems for liquid, powder, granules and/or other flowables packaging, said multi-layer comprising:

an inner layer made of an octene-LLDPE (or other LLDPE) blended with low density polyethylene;

a single and/or multi-layer core made from a blend in weight percent of;

10% to 90% of polypropylene;

80% to 0% (lower limit not comprised) of a linear low density polyethylene or low density polyethylene and a polymer compatibilizer of from 2.5 to 12%, said core being applied against the inner layer;

an outer skin layer made of an LLDPE, blended with low density polyethylene.

said multi-layer film having an overall thickness varying between 1.75 to 2.5 mil for the packaging of 0.8 to 1.7 kg of liquid, powder, granules and/or other flowables or flowables a stiffness varying from 3500 psi to 150000 psi (measured in film machine direction) as measured by the 1% secant modulus ; and

a tensile strength at yield of from 1700 psi to 3300 psi (machine direction) and a strength at break of from 4300 to 7400 psi (machine direction).

16. A method of forming, sealing and filling a pouch with a liquid, powder, granules and/or other flowables at high speed, said method comprising the steps of:

i) providing, in roll form, a multi-layer film as defined in claim 13,

ii) drawing said film, by drawing means, over a pouch former to form a plastic film tube having an overlapped vertical film edge,

iii) sealing said overlapped vertical edge with a vertical sealer to form a vertical seal,

iv) effecting a horizontal seal across said plastic film tube with a horizontal sealing jaw and at a predetermined location below said vertical sealer, and simultaneously severing said tube to form a top horizontal seal for a filled pouch and a bottom horizontal seal for a pouch being filled, said horizontal and vertical seals, and

v) continuously feeding a consumable liquid within said plastic film tube below said vertical sealing jaw and above said transverse sealing jaw,

the resulting pouch having walls provided with a thickness varying from 1.75 to 2.5 mil, a stiffness varying 3500 psi to 150000 psi (as determined by 1% secant modulus), a tensile strength at yield of from 1700 psi to 3300 psi (machine direction) and a tensile strength at break from 4300 to 7400 psi (machine direction).

18. A pouch obtained from a multi-layer film as defined in claim 13 on a forming, sealing and filling system.

20. Use of a multi-layers film as defined in claim 13 for preparing a pouch by processing on a high speed vertical form, film and seal systems.