AU662184B2 - Bag made from laminate film - Google Patents

Description

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66 184 S F Ref: 227293

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

9a~o 09* S 0 00 o 09t 9 Name and Address of Applicant: Actual Inventor(s): Address for Service: Invention Title: Kabushiki Kaisha Hosokawa Yoko No. 11-5, Niban-cho Chiyoda-ku, Tokyo

JAPAN

Shigeyuki Oshima and Yoshiji Moteki Spruson Ferguson, Patent Attorneys Level 33 St Martins Tower, 31 Market Street Sydney, New South Wales, 2000, Australia Bag Made from Laminate Film 0 The following statement is a full description of this invention, including the best method of performing it known to me/us:- 5845/8 ii I L. r -1 BAG MADE FROM LAMINATE FILM BACKGROUND OF THE INVENTION The present invention relates to a bag made from a laminate film, and more particularly to a pillow-type bag having an roughened surface portion area.

Poor rupture strength and moisture resistant properties of cellophane or paper laminated with polyethylene films limits materials that can be stored in bags made of these materials. The greater rupture strength and moisture resistant properties of plastic laminated films leads to their use as materials for bags. However, the high resistance to tearing of plastic laminated films makes opening bags made of this material difficult. To facilitate easy tearing of bags made of plastic laminated films, V- or I-shaped notches are formed in one or more heat-sealed edges of the bags. Such notches serve to concentrate tearing force thereat and to propagate the force along the tearing direction.

I A three-sides-sealed bag and a pillow-type bag have been known in the art. The three-sides-sealed bag is made by folding a sheet of laminated plastic film in half and heat sealing the resultant three open sides. The pillow-type bag is made from a sheet of laminated plastic film in which two opposite edges have one folded area each. Bending the -L I 7>o K *1i 2 laminated plastic film into a tube so that the two opposite edges of the laminated plastic film touch, heat sealing the two opposite edges together, and heat sealing the open ends of the tube so that the bonded section is on a broad surface of the bag and not on an edge forms a pillow-type bag.

Bag manufacturers often sell to end users incomplete bags in the form of laminated plastic tubes with open ends unsealed or laminated film itself. If bag manufacturers sell incomplete bags in which at least one open end is heat sealed and at least one left unsealed to allow filling bags with material at the factory of an end user, the bag manufacturer can easily provide a notch at the heat sealed portion at the 41 bag manufacture's factory. c~ the other hand, if the bag manufacturer sells simply a rolled laminate film, then the 4,15 end user must form the notch at the end users factory, which is difficult because ordinarily, notches are formed after an open end c' he bag is heat sealed which happens after bags are filled using filling machines.

4 In case of pillow-type bags, the notch may be formed at an upper heat-sealed end portion. For taking material out of the bag, a user first tears the bag at the notch portion *i in a direction toward a lower heat seal portion. If the bag is not full of material so that the bag film is not subjected to high tension, tearing the bag in a direction parallel to the central tab-like heat seal portion, i. from the upper 3 heat-sealed portion to the lower heat-sealed portion is easy. On the other hand, if the bag is full of material so that high tension is imparted on the bag film, instead of the tear running toward the lower heat sealed portion, it may run transversely immediately after the tearing line passes over the upper heat seal portion where the notch is formed making the removal of material from the bag difficult.

SUMMARY OF THE INVENTION It i, 'he object of the present invention to overcome or substantially ameliorate the above disadvantages.

There is disclosed herein a bag for containing therein a material comprising: a bag body formed of a plastic laminate film including an inner first film and an outer second film formed thereon with a plastic material interposed there between, the bag body having a front rectangular section and a rear rectangular section having a shape substantially identical with the front rectangular section, the front and rear rectangular sections defining first, second, third and fourth sides; and 15 a tear-facilitating linear surface roughened area extending between opposing two sides of the four sides for serving as a guide line for tearing, wherein: o ,.oo o the bag body constitutes a pillow-type bag body, the pillow-type bag body having an upper opening to be heat sealed together and defining the first side, a lower opening to be heat sealed together and defining the second side, a first folded side defining the third 20 side, a second folded side defining the fourth side, and a heat sealed portion at the rear rectangular section, the heat sealed portion having a first folded-back portion and a second folded-back portion heat sealed to the first folded-back portion to allow the bag body to have a tubular shape, the tear facilitating linear surface roughened area being provided 2along the first and second folded-back portions and between the upper and lower 25 openings.

The tear-faciliating linear surface roughened area is preferably formed by providing a plurality of indentations and perforations in the outer second film. The indentations and the perforations are filled with the plastic material such as adhesive agent for lamination.

[8LIB 0 [N:\LIBT]00288:BCG:cg Jp BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features and advantages of the invention will become more apparent from reading the following description of the preferred embodiment taken in connection with the accompanying drawings in which: Fig. 1 is a perspective view showing a pillow-type bag with its upper end unsealed according to a preferred embodiment of the present invention; Fig. 2 is a cross-sectional view showing a plastic laminate film which is a material of the bag; Fig. 3 is a cross-sectional view showing a plastic laminate film to which a surface 1 o roughening treatment is carried out with respect to one film of the lamination; Fig. 4 is a perspective view showing a resultant pillow type bag and showing a tearing phase according to the preferred embodiment; and Fig. 5 is a front view showing a three-sides-sealed-type bag.

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DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A bag 1 is made from a laminated plastic film 2 in which two opposite edges each have one folded area 3a along which are formed roughened opening areas 6. The bag 1 shown in Fig. 1 is formed by bending the laminated plastic film 2 into a tube so that the two opposite edges of the laminated plastic film 2 touch and heat sealing the two opposite edges together to form a bonded section or a tab 3. The bonded section 3 extends radially outward from the bag 1.

As shown in Fig. 2, the laminated plastic film 2 is formed by laminating, with a plastic material 10 such as an adhesive agent, a 20 microns thick biaxial polypropylene film 4 and a 40 microns thick polyethylene film 5. Alternatively, -t c-~n i, u r i-

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I i uniaxial polypropylene film is preferable if opening the bag 1 along a straight-line tear is desirable.

Fig. 3 is an enlarged fragmentary section through the laminated plastic film 2 showing structure of one of the roughened opening areas 6. The roughened opening areas 6 are formed only on the polypropylene film 4 side of the laminated plastic film 2 by pressing contact with a processing roller (not shown) having minute protrusions on its outer peripheral surface. When the polypropylene film 4 is pressed against the processing roller, a plurality of indentations 7 and perforations 8 are formed in the polypropylene film 4. The laminate bond 10 used to bond the polypropylene film 4 with the polyethylene film 5 fills the indentations 7 and perforations 8 during the lamination process of the laminated 15 plastic film 2. The polypropylene film 4 is positioned at an outer side of the bag 1.

,I Fig. 4 is a perspective view of a pillow-type bag 1 formed according to the present invention. When such bags 1 i are filled with confectioneries or other solid products, and the ends sealed by conventional heating sealing methods to i form a seal 1l so that the bonded section 3 is on a broad surface of the bag 1 and not on an edge, the solid food product that fills the space in the bag applies tension to the portion of the film that forms the storage space.

To open the filled bag 1 the bonded section 3 is 7 -7grasped near the meeting point of the bonded section 3 and the seal 11, and pulled away from the bag 1 in the direction of arrow A. The roughened opening area 6, being the weakest area because of the indentations 7 and perforations 8, tears with this pulling action so that an opening 12 is formed in the bag 1. Continuing to pull the bonded section 3 in the direction of arrow A will cause the roughened opening area 6 to further tear. The opening 12 can be enlarged in this way to promote removal of the contents of the bag 1. Small children or others not possessing a great deal of strength can open su=h pillow-type bags easily, since the roughened i. area 6 extends between upper and lower seal portions 11 and 11 along the tab or the bonded section 3.

A bag *aeeo4.nnct- H nd m- nt-H =t i-rwon-tW e-on will next be described with reference to Fig. Tl-=seond=enmbonee-t s=taia- \a three-sides-sealed-type I" bag.

The bag 20 is formed of the laminated film described in the first embodiment, and the bag 20 has an upper heat- 20 sealed portion 22, a lower heat-sealed portion 23, a side heat-sealed portion 24 and a folded-side edge 25. A small notch 27 is provided at the side heat-sealed portion 24, and above described linear roughened area 26 is positioned in alignment with the notch 27. That is, the roughened area 26 extends between the side heat-sealed portion 24 and the 1i1 I i I C I- 8 44 0* a 4e 44441 folded-side edge 25 so as to serve as a guide line for facilitating tearing. Of course, the roughened area 26 is provided at both front and rear portions 21a and 21b of the bag As a modification to the second embodiment instead of forming the notch 27 at the side heat-sealed portion 24, a tear-start mark can be printed on the tear facilitating linear surface roughened area 26 and at the folded-side edge so that a user can start tearing at the tear-start mark.

While the invention has been described in detail with reference to/ specific embodiment thereof, it would be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit and scope of the invention.

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Claims (4)

1. A bag for containing therein a material, comprising: a bag body formed of a plastic laminate film including an inner first film and an outer second film formed thereon with a plastic material interposed therebetween, the bag body having a front rectangular section and a rear rectangular section having a shape substantially identical with the front ectangular section, the front and rear rectangular sections defining first, second, third and fourth sides; and a tear-facilitating linear surface roughened area extending between two opposing sides of the four sides for serving as a guide line for tearing, wherein: the bag body constitutes a pillow-type bag body, the pillow-type bag body having an upper opening to be heat sealed together and defining the first side, a lower opening to be heat sealed together and defining the second side, a first folded side defining the third side, a second folded side defining the fourth side, and a heat sealed portion at the rear rectangular section, the heat sealed portion having a first folded-back portion and a second folded-back portion he t sealed to the first folded-back portion to allow the bag body to have a tubular shape, the tear facilitating linear surface roughened area being provided along the first and second folded-back portions and between the upper and lower openings. e i

2. The bag as claimed in claim 1, wherein the tear-facilitating linear surface 20 roughened area is formed by providing a plurality of indentations and perforations in the outer second film, the indentations and the perforations being filled with the plastic Smaterial.

3. The bag as claimed in claim 1 or claim 2, wherein the first or second side is I formed with a notch at a position in alignment with the tear facilitating linear surface 25 roughened area.

4. The bag as claimed in any one of claims 1 to 3, wherein a tear-start mark print is provided on the tear facilitating linear surface roughened area and at a position adjacent the first or second side. A bag substantially as hereinbefore described with reference to Figs 1 to 4. Dated 4 October, 1994 Kabushiki Kaisha Hosokawa Yoko Patent Attorneys for the Applicant/Nominated F'erson SPRUSON FERGUSON 1%' NA:\LIBr]00288;BCG,,cg