ES2266550T3 - EASY OPEN CLOSURE OPENED BAG. - Google Patents

Abstract

A bag (10) comprising a front panel (12) and a rear panel (14) and two side panels (16 and 18) folded inwards, each panel having an upper edge (20) and a lower edge (22), an upper section (24) and a lower section (26) formed by the union of the front and rear panels and wherein the bag (10) comprises a means to re-close the bag (10) after opening (30 and 32) and wherein the repeated closing means (30 and 32) is adjustable, characterized in that the upper part is further defined by a line of weakness (28), said line of weakness (28) comprising one of the front panels ( 12) or later (14) and both side panels (16 and 18).

Description

Easy opening bag with repeated closure.

Field of the Invention

This invention relates to bags for use. in the storage of products such as, but not in a way limiting, detergent powder or granulate, animal feed company, coffee, cereals, etc., where the bag has a line of weakness that allows an easy opening of the bag. Plus especially the bags also comprise an adjustable means of repeated closure

Background of the invention

Flexible bags are used today to package a wide variety of consumer products including granulated detergents. To be useful as packaging these bags must be resistant to opening during transport and handling in the store. The detergent bags currently marketed have several drawbacks. First, current bags are difficult to open without the help of scissors, a knife or other utensil. Often the consumer tries to open the bag by tearing it, which has as a final result that the content spills. In addition, the bag and any text printed on the bag can be deformed by the pushing and stretching forces applied during the
opening.

Second, once opened, the bags of current detergent do not offer an efficient or effective means to repeated closure of the bag. The repeated closing capacity of The bag is desired by many consumers. This is especially true for bulky sized containers. So far the repeated closure methods of these bags have resulted unsatisfactory These methods include zippers and ribbons. adhesives, as well as simple folding mechanisms. The main drawback of the aforementioned methods is that the contamination of the repeated closing means with the content of the bag prevents the medium from forming a reliable seal and reusable In addition, simple folding mechanisms do not Provide protection against product leakage.

Third, as the contents of the bag is gradually reduced, it is desirable to be able to adjust the means of Close so that the bag is more carefully sealed. Current flexible detergent bags offer no means of Adjust for a reliable tight seal.

Therefore there is still a need for have a flexible bag for packaged consumer products that is easy to open, that is, without the help of a knife, scissors or other utensil. There is still an additional need to have a mechanism through which the bag can return to Close securely after being opened by the consumer. The repeated closing mechanism should not be affected by No pollution There is also a need for a repeated closure means that is adjustable to provide a secure and reliable seal as the bag is less full.

WO 96/29256 refers to a package bag with repeated closure provided with elements of hook and loop type coupling to close it so that it adapt to the variable amount of product contained in your inside.

Summary of the invention

The present invention meets the needs above mentioned providing a bag according to the claim 1. In dependent claims 2 to 6, describe other preferred embodiments.

All percentages, ratios and proportions they are expressed herein by weight, unless Specify otherwise.

Brief description of the drawings

Figure 1 is a perspective view horizontal of a first embodiment of a bag of the present invention.

Figure 2 is a vertical perspective view of a first embodiment of a bag of the present invention.

Figure 3 is a vertical perspective view of a first embodiment of a bag of the present invention.

Figure 4 is a perspective view horizontal of a second embodiment of a bag of the present invention.

Figure 5 is a perspective view horizontal of a second embodiment of a bag of the present invention.

Figure 6 is a perspective view horizontal of a third embodiment of a bag of the present invention.

Figure 7 is a vertical perspective view of a third embodiment of a bag of the present invention in The closed position.

Figure 8 is a representation of a graph typical obtained using the ASTM D-882 method to Measure tensile strength.

Figure 9 is a representation of a graph typical obtained using the ASTM D-5733 method to measure the trapezoidal tear resistance in a single sample.

Figure 10 is a perspective view vertical of a fourth embodiment of the present invention.

Figure 11 is a perspective view vertical of a fourth embodiment of the present invention in the closed position

Detailed description of the invention

Next, reference will be made in detail to preferred embodiments of the present invention, examples of which are illustrated in the accompanying figures. How I know will understand, the front and back expressions in the present Memory are used to describe the panels of the bag only for guidance purposes and are otherwise interchangeable. How described in more detail below, the present invention is refers to a flexible bag to contain a granulated detergent, powder or other content, preferably a granulated detergent, equipped with a line of weakness to facilitate opening. A especially preferred bag 10 according to the present invention is illustrated in Figure 1. The illustrated bag 10 has a front panel 12, a rear panel 14 and side panels 16 and 18 each panel having an upper edge 20 and a lower edge 22. The bag 10 also has an upper section 24 and a section bottom 26, which are sealed by joining the front panel 12 with the back panel 14 along the upper edges 20 and the bottom edges 22. The bag 10 is provided with a line of weakness 28, in which at least a part of at least one of the panels 12 or 14 is not weakened by line 28. In a preferred embodiment line 28 encompasses both the panels side 16 and 18 as one of between the front panel 12 or the panel back 14.

Figure 2 illustrates the same bag as Figure 1 where line of weakness 28 has been opened by pulling either side of line 28.

Figure 3 represents the same bag 10 as the of Figure 1 and also comprises repeated closing means 30 (not represented in Figure 3) and 32. The means of repeated closure 30 and 32 can be any mechanical fixing mechanism and preferably they comprise a hook and loop fastening system, where one of the means 30 or 32 is the hook component and the Another is the loop component. It is within the scope of this invention that the two are interchangeable. Figure 4 shows the repeated closing means 30 as a small strip adjacent to the top edge 20 and fixed to front panel 12. It is also inside within the scope of this invention that the repeated closing means is composed of a hook and hook system better than a system of hook and loop.

Figure 5 shows a repeated closing means 32 as a vertical strip attached to the back panel 14. Figure 6 shows another representation of the repeated closing means 30. The Figure 7 is a representation of the bag in position closed.

Another preferred embodiment of the closure system Repeated is illustrated in Figures 10 and 11. A component 30 of the repeated closure system is fixed to the hook or loop part opposite to the panel to which it is attached, or to the front panel 12 or to the back panel 14. A part of component 30 is left unbound. He Bag closure occurs by two consecutive folds of upper section 2 of bag 10. The first fold leaves the unbound part of the repeated closing system protruding, which allows you to attach to the second system component. The second fold is actually coupled to mechanical fasteners. The figure 11 represents this alternative embodiment in the position closed.

Bag materials

The bags of the present invention are formed by elastic materials including non-exclusive polymeric film, woven materials, nonwoven materials, preferably polyethylene film, more preferably monolayers, coextrusions, bilayer laminates, three layer laminates and Metallic laminates, all materials with or without coating of varnish. The bags according to the present invention can be formed by any method known in the art. A method for conformation of flexible bags from a continuous band of material is well known in the art and is described in the patent US 5,054,619, granted to Muckenfuhs.

Weakness line

The easy opening element of the bags according to the present invention is the result of the weakening of the film-shaped material in the desired trajectory of the rupture or separation of the bag.

The line of weakness is such that at less a part of a panel of the bag remains without weakening by the line. This prevents the entire upper section of the bag from separate during opening. After opening, the fin that results when breaking the line of weakness gives the bag a handle or grip area for the consumer to hold while dose the product. This item provides a better bag maneuverability and allows more dosing easy.

The line of weakness will deteriorate the resistance of the film so that it can withstand operations normal filling, packaging and handling, while following being easy to open by the consumer. This behavior is achieved by reducing the resistance to trapezoidal tear of the original movie. Tear resistance reduction trapezoidal is also most likely accompanied by a loss of tensile strength.

The line of weakness is identified by following test methods: a) ASTM standard test method D-882 for sheet tensile properties thin plastics and b) ASTM standard test method D-5733 for tear resistance of fabrics no woven by the trapezoidal procedure. The graphics resulting from these test methods are illustrated in Figures 8 and 9. The samples used to generate Figures 8 and 9 are taken from line of weakness 28 as shown in Figure 1. From conforming to ASTM D-882 and ASTM standards D-5733, line of weakness 28 must be parallel to the shortest side of the sample (that is, the width). The line of Weakness 28 should cover the entire width of the sample and should be centered with respect to the length of the sample. The slot for start cutting the trapezoidal tear sample must be at the top of the weakness line 28.

The line of weakness is characterized by three parameters obtained in the standard tests previously mentioned. The first parameter is the voltage value of creep In Figure 8, this graph is illustrative of the value of the approximate creep stress of a weakened film (shown in Figure 8 as Y2) versus the value of the approximate creep stress of a non-weakened film (shown in Figure 8 as Y_ {1}). The voltage value of weakened film creep in the ASTM tensile test D-882 should not be less than 90% of the value of the film creep tension not weakened. Secondly, the value of the final or breaking effort of the weakened film (shown as R2 in Figure 8) should not be less than 90% of the creep tension value of the non-weakened film Y_ {1}.

Third, the tear force trapezoidal medium according to the ASTM D-5733 test of the Weakened film should be less than 39.2 N (4 kgf). The Figure 9 is illustrative of a typical graph obtained using ASTM D-5733 test to measure resistance to trapezoidal tear in the weakened film of a single sample. As for both Figures 8 and 9, the values indicated in the same force, elongation (Figure 8) and extension (Figure 9) should be considered as merely illustrative and of in no way limiting the present invention.

In addition, the line of weakness may present a Pattern. These patterns can be in the form of a continuous line, a dashed line or a combination thereof. But nevertheless, the most preferred pattern is the dashed line, where the line Discontinuous is composed of a plurality of grooved segments.  The length of each grooved segment varies from approximately 0.12 mm to 4.4 mm, preferably ranges from about 0.3 mm to 2 mm and most preferably it ranges from about 0.6 mm to 1 mm. The distance between adjacent grooved segments varies from about 0.4 mm to 4 mm, preferably varies from approximately 1 mm to 3 mm and most preferably varies from approximately 1.5 mm to 2 mm. The groove depth will vary depending on the thickness of the film.

At some point along the line of Weakness can provide a start notch. Notch Startup provides an area that is easier to tear because The groove is deeper. If the weakness line covers the panel posterior in which there is also a vertical joint, the notch of start provides an easy tear through the multiple Nerves of the vertical joint next to the line of weakness.

Production method of the weakness line

The line of weakness can be produced using methods that include, but are not limited to, grooving, drilling, chemical treatment, preferably grooving with laser, laser drilling, mechanical grooving, drilling mechanics, embossing methods or combinations of these methods The line of weakness is preferably incorporated into the film before it becomes a bag.

A method of manufacturing a line of Weakness in a flexible film uses at least one laser. In first a laser beam is directed towards the film with enough watts to evaporate a part of the material in the form of movie. The use of laser technology allows very good control exact depth or penetration being able to perform from very shallow grooves to complete perforations of the movie. You can use a laser that uses any form of electromagnetic radiation. Lasers suitable for use in the Present invention include those based on CO2 gas.

The speed of the film and the movement of the laser beam depend on the pattern and the desired groove depth as well as the type of film used. Suitable methods for laser film grooving are described in the patents
US-3,626,143, US-3,790,744, US-3,909,582, all of them granted to American Can Company and US-5,158,499 and US-5,229,180, granted to American National Can Company, US-5,001 .325, granted to LPF Verpakkingen BV, US-4,743,123, granted to Wavin BV, Japanese patents 09133018, 07008283 and 06103200, all of them granted to Dainippon Printing Company.

Another suitable method to manufacture the line of Weakness is the use of blades. The blades are installed in a Engraving cylinder mounted directly on the equipment film processing so that the cuts are made before of the formation of the stock market. Different patterns can be used of blades to obtain different patterns in the line of weakness. The pressure applied to the blades also varies during the process to control the dimensions and depth of the cuts to ensure that the bag opens easily.

Embossing is another method alternative for the production of the weakness line. The Embossing technology weakens the film in areas specific by pressure, temperature, time and a profile of deformation. The desired results are achieved by changing the thickness and / or structure of the material in the trajectory of the print. The basic equipment used for embossing it consists of a sealing jaw capable of pressing against a back plate A profile or deformation pattern is fixed to the gag and heats up. The film is compressed between the profile of deformation and back plate. The main variables that are known that affect this process are: heating temperature, cooling temperature, pressure, heating time, cooling time, film tension during stamping embossed, film tension after embossing, back plate material, back plate thickness, back plate temperature, jaw pattern and thickness of the gag. The embossing unit would be installed later of a film unwinding station, preferably would incorporate into the packaging equipment line. Suitable examples Embossing are described in the patent US 5,878,549, granted to American National Can Company

Repeated closure system

The repeated closure system is resistant to contamination by the contents of the bag. His principal object is to protect the granulated products contained in the bags against to spills, moisture and other external factors that may affect Product integrity This repeated closing system it comprises a mechanical fastener, preferably of the hook type and loop or hook and hook type, attached to a flexible bag that allows the consumer to open and close the bags safely as many times as the product in the bag is used.

The system consists of placing the materials of fixing on the opposite panels of the bag. In one embodiment preferred, the panels are on the front and back panel, although Other configurations are contemplated. The fixers can be disposable or industrial materials. You want to use materials disposable to optimize costs. Mechanical fasteners they can be of any shape and size and be in any provision. The particular configuration of the components of the repeated closure system should be such that the bag can be seal throughout the use of the product contained inside. Sealing means that there is no spillage of the product when the bag tilts to the side. In particular, the repeated closing system is characterized by energy necessary to detach a component from the fixative with respect to the other component This energy should not be less than 23.5 N (2.4 kgfmm) for every kg of product contained in the bag.

The repeated closing system is expected to operate with the easy opening element described above that It facilitates the opening of the bag. At least one (1) fixer piece mechanic is placed on a panel of the bag while one piece of the coupling fastener is placed on the opposite panel of the bag. Preferably a piece of mechanical fastener is a strip vertical. The top of the bag (with the small piece of the fixer) is wound on the two fixers to couple and close Tightly the bag as the product is consumed. TO As more product is consumed, the fasteners close towards down vertically, obtaining a tight seal. A Variation of this design is also a button closure. This means that mechanical fasteners can also consist in two individual buttons that act as a seal. In this case, the seal instead of adjustable is fixed.

These mechanical fasteners can adhere to the adhesive bag. The adhesive can be an adhesive of hot melt or a pressure sensitive adhesive. A hot melt adhesive to mechanical fastener just before Apply the piece to the bag. The pressure sensitive adhesive will adheres to the fixative as a piece.

The application of these mechanical fasteners to the Bag can be made in different ways. One way is to adhere These fixers to the film before producing the bag. In this case, the parts of the mechanical fasteners are attached to the film during the preparation of the film roll or when the roll of film is being unwound in the machine. Fixers mechanics can also adhere to the bag after it It has formed.

Claims (6)

1. A bag (10) comprising a front panel (12) and a rear panel (14) and two side panels (16 and 18) folded inwards, each panel having an upper edge (20) and a lower edge (22 ), an upper section (24) and a lower section (26) formed by the union of the front and rear panels and wherein the bag (10) comprises a means to re-close the bag (10) after opening ( 30 and 32) and wherein the repeated closing means (30 and 32) is adjustable, characterized in that the upper part is further defined by a line of weakness (28), said line of weakness covering (28) one of the panels front (12) or rear (14) and both side panels (16 and 18). 2. A bag (10) according to claim 1, in the value of the creep tension of the bag (10) with the line of weakness (28) measured according to the ASTM method D-882 is at least 90% of the voltage value of creep of the bag (10) before adding the weakness line (28). 3. A bag (10) according to any of the previous claims, wherein the value of the final effort or bag rupture (10) measured according to the ASTM method D-882 is at least 90% of the voltage value of creep of the bag (10) before adding the weakness line (28). 4. A bag (10) according to any of the previous claims, wherein the tear strength middle trapezoidal bag (10) measured according to the ASTM method D-5733 is less than 4 kg. 5. A bag (10) according to any of the previous claims, further comprising detergent for laundry 6. A bag (10) according to any of the previous claims, wherein the line of weakness (28) is formed using a method selected from the group consisting of chemical treatment, laser grooving, laser drilling, mechanical grooving, mechanical drilling, stamping methods in relief or combinations thereof.