Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/32—Layered products comprising a layer of synthetic resin comprising polyolefins
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/06—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
  • B32B27/08—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material of synthetic resin
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/30—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers
  • B32B27/306—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers comprising vinyl acetate or vinyl alcohol (co)polymers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/32—Layered products comprising a layer of synthetic resin comprising polyolefins
  • B32B27/327—Layered products comprising a layer of synthetic resin comprising polyolefins comprising polyolefins obtained by a metallocene or single-site catalyst
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/36—Layered products comprising a layer of synthetic resin comprising polyesters
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
  • B32B5/02—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by structural features of a fibrous or filamentary layer
  • B32B5/024—Woven fabric
• • 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
  • B65D29/00—Sacks or like containers made of fabrics; Flexible containers of open-work, e.g. net-like construction
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/30—Properties of the layers or laminate having particular thermal properties
  • B32B2307/31—Heat sealable
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/50—Properties of the layers or laminate having particular mechanical properties
  • B32B2307/514—Oriented
  • B32B2307/518—Oriented bi-axially
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2439/00—Containers; Receptacles
  • B32B2439/40—Closed containers
  • B32B2439/46—Bags

Definitions

• the invention generally relates to packaging bags and more particularly to packaging bags made of woven multi-layered tapes flexible substrates.
• Woven substrates such as Woven Polypropylene (WPP) fabrics are widely used as they have high bursting and puncture strength, good chemical and wear resistance, and are light in weight as compared to non-woven substrates.
• WPP Woven Polypropylene
• Woven fabric is made in a tubular form and converted to bags after lamination and printing by flattening the tube.
• an essential step is to make the tube.
• the process of making the tube from a web involves overlapping and sealing together the longitudinal edges of the woven substrate after lamination and printing.
• hot air sealing method is disadvantageous because the method requires very high temperature in the range of 700 deg. C. Further, the sealing achieved is not so good as the material of the woven substrate such as WPP has poor sealing property. The overall speed of the process is slow to achieve proper sealing.
• hot melt adhesive Another method of sealing is using hot melt adhesive.
• the hot melt adhesive has a tendency to overflow and leaves excess material overflowing out of the center seal band.
• the sealing strength is not enough for heavy bags.
• Another method of sealing is by ultrasonic method.
• sealing by ultrasonic method is very sensitive and hermetic sealing is not ensured due to less compatible properties of material of woven fabric for ultrasonic sealing and speed of the sealing operation is also slow.
• a co-extruded multi- layered tape includes a middle polymeric layer coextruded with at least one external layer configured on each side of the middle polymeric layer.
• the external layers are coextruded with a low temperature sealable material, such that the external layers on each side of the middle polymeric layer have same sealing properties.
• a woven substrate includes a plurality of multi- layered tapes woven to form the woven substrate.
• Each of the multi-layered tapes include a middle polymeric layer coextruded with at least one external layer configured on each side of the middle polymeric layer.
• the external layers are coextruded with a low temperature sealable material, such that the external layers on each side of the middle polymeric layer have same sealing properties.
• FIG. 1 is a cross sectional view of a co-extruded multi-layered tape, in accordance with an embodiment of the present invention.
• FIGS. 2A-2C show various embodiments of a woven substrate made up of the co-extruded multilayered tape, in accordance with an embodiment of the present invention.
• FIG. 3 illustrates a pictorial representation of an exemplary method of forming a continuous tube from a web of the woven substrate made up of the co-extruded multilayered tapes, in accordance with an embodiment of the present invention.
• FIG. 4 illustrates an exemplary bag formed from the tube made by overlapping the longitudinal edges of the web, in accordance with an embodiment of the invention.
• a method for manufacturing co-extruded multi-layered tapes and packages / bags made from flexible woven substrate made thereof is disclosed.
• the method includes extruding a multilayered film such that one extruder forms a middle layer (102) of said multilayered film and the separate extruder(s) form external co-extruded layers (104a and 104b) of the multilayered film.
• External layers (104a and 104b) are co-extruded with low temperature sealable material such as pure metallocene PE or a mixture of metallocene PE mixed with EVA or any other polymeric material, on both sides.
• the co-extruded external layers are meant for efficient sealing purpose.
• the low temperature sealable material may be in pure form or in a combination of one or more of Polypropylene copolymer, Polypropylene ter-polymer, elastomers, ethylene- vinyl acetate (EVA), modified Polypropylene or Modified Polyethylene modified to provide suitable sealing properties.
• EVA ethylene- vinyl acetate
• FIG. 1 shows a cross sectional view of the exemplary co-extruded multilayered tape (100) obtained after co-extruding the layers (104a and 104b) with the middle layer (102).
• the middle layer 102
• layer (102) may be a single layer of polyolefins such as polypropylene (PP) or High Density Polyethylene (HDPE) or other suitable polymeric materials.
• PP polypropylene
• HDPE High Density Polyethylene
• the co-extruded multi-layered film is further slit into tapes of predefined dimension such as length, width, thickness, denier etc., on a tape line and stretching and tempering operations are performed inline.
• the final co- extruded multi layered tapes are wound on bobbins for weaving the woven substrate on the looms thereby forming the woven fabric / substrate of co- extruded tapes (100).
• the co-extruded multi-layered tapes typically have a width between 1.5 mm to 7 mm, and a denier between 300 and 2,500. It may be contemplated that the woven substrate is either woven as a tube, flattened by pinching, cut on both sides to get two flat webs on rolls or directly flat web is woven to roll.
• the coextruded multi layered tapes have same sealing layers, so as to have same sealing properties on both sides since it is not possible to ensure that the tapes winding on the bobbins or during weaving on looms have a same layer always on one side of the fabric.
• FIGS. 2A-2C shows various embodiments of woven substrates (200a, 200b, and 200c) of the co-extruded tapes.
• FIG. 2A shows a woven substrate (200a) made up of the multi-layered co-extruded tapes without any additional layer coated or laminated to it.
• FIG. 2B shows another woven substrate (200b) made up of the co- extruded multi-layered tapes is extrusion laminated with a molten layer (202) on its surface extruded through a flat extrusion die (210) and a roller (204), according to an alternate embodiment of the present invention.
• Molten layer (202) fills in the gaps and troughs on the woven fabric surface thereby ensuring a smooth surface. It also makes the woven fabric (200b) hermetic.
• the plain and smooth surface provides a conducive surface for printing.
• the molten layer (202) comprises Polypropylene or Polyethylene or a combination of both.
• FIG. 2C shows yet another woven substrate (200c) of the co-extruded tapes laminated with a film of reverse printed BOPP/PET film (208).
• BOPP/PET film (208) has a reverse printed layer (208a), according to another embodiment of the present invention.
• the reverse printed BOPP/PET film (208) may be laminated with the woven substrate (200c) by extrusion lamination, or adhesive lamination.
• FIGS. 2A-2C show some of the embodiments of the many such possibilities.
• FIG. 3 illustrates a pictorial representation of an exemplary method of forming a continuous tube (312) from a web of woven fabric (314), hereinafter referred to as the web (314) of co-extruded multi-layered tapes.
• overlapping and sealing of two longitudinal edges (L1 and L2) of the web (314) is done to form tube (312).
• sealing of the two longitudinal edges (L1 , L2) is achieved by blowing hot air through a nozzle (310).
• the nozzle (310) is positioned such that as the longitudinal edges (L1 and L2) overlap, hot air from the nozzle (310) is blown between the overlapping longitudinal edges (L1 , L2).
• the hot air nozzle (310) is connected to a hot air generator (311 ). Subsequently, the edges (L1 , L2) are pressed and cooled to form the continuous tube (312).
• the continuous tube (312) may be wound in the form of a roll for further processing or may be slit / perforated inline into cut pieces of required bag length.
• the tube (312) so formed is further processed and finished to make bags / packages of various designs and shapes such as valve bags, gusset bags, pinch bottom bags, stitched bags, standup bags etc.
• the sealing of the two longitudinal edges (L1 and L2) can also be done by hot melt adhesive, ultrasonic sealing method or extrusion lamination method. In all these methods of sealing the two longitudinal edges (L1 and L2) is achieved at lower temperatures by virtue of the low temperature sealable material of the multi-layer tape (100) thereby providing easy and effective sealing.
• FIG. 4 shows a bag (400) which is formed after the formation of the continuous tube (312) with a longitudinal seal (402).
• longitudinal sealing (402) while making tube (312) using such a woven substrate / flat fabric, the sealing obtained is hermetic and the sealing can be performed at much lower temperature and much higher speeds and thus production rate increases in various methods of sealing.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Textile Engineering (AREA)
• Laminated Bodies (AREA)
• Wrappers (AREA)
• Extrusion Moulding Of Plastics Or The Like (AREA)
• Bag Frames (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=54393112

Family Applications (1)

Country Status (2)

Cited By (1)

Family Cites Families (4)

• 2014
  • 2014-05-08 IN IN1238DE2014 patent/IN2014DE01238A/en unknown
• 2015
  • 2015-05-05 WO PCT/IN2015/000194 patent/WO2015170338A2/en active Application Filing

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