Method to achieve easy-opening flexible packaging laminates and packaging materials made therefrom

ES 2 187 686 T3

DESCRIPTION

Process for manufacturing laminates for flexible and easy to open packaging, and packaging materials made with these laminates

Background of the invention

This invention relates to the field of polymeric films, and packages made from them, for packaging a variety of products, especially food. More specifically, the invention refers to a method of achieving an easy-open container made of a polymeric film.

In general, polymeric or thermoplastic materials are difficult to tear because the materials are flexible and generally consist of long, randomly dispersed chains of molecules that have relatively strong covalent carbon-to-carbon bonds.

One method of facilitating tearing is generally to stretch or orient the thermoplastic materials when they are emptied or blown. Stretching aligns the molecular chains in the stretched direction so that if tearing occurs in that direction, it takes place via weaker non-carbon to carbon bonds. This method has limited effectiveness because not all polyomers can be easily oriented. Furthermore, only a certain number of molecules can be aligned, and despite stretching, tearing may still not be easy and reliable. Orientation also requires special care and manufacturing efforts.

A most effective method of creating an easy-open tear is to score the hermetic seal on the container to initiate the tear. Notches can be made in the airtight seal during sealing operations through the use of a sealing jaw. Alternatively, notches can be made in the bag, in the hermetic seal or otherwise, through the use of a blade or other sharp device, during manufacture or packaging.

A significant problem with bags or films that have a notch is that the notch is not precisely located or is disturbed during manufacturing, packaging, shipping, or general handling.

Another method of forming a tear line, widely used for single layer films, is to use a star wheel to form a line of intermittent perforations in the films. Perforations are not suitable for multilayer laminates for many reasons. One reason is that perforations in the film allow for changes in the product environment that defy a purpose of using multilayer films, that is, to protect a product contained within by combining gas barrier properties of a material with gas barrier properties. moisture from another.

A third prior art method of imparting an easy tear opening to a laminate structure is the use of a tear tape or cord. The tear tape or cord is undesirable because it can cause the structures to split open when the tear tape or cord is torn or otherwise disturbed during manufacturing, packaging, shipping, or handling.

A fourth prior art method of imparting an easy tear opening to a laminate structure is through the use of laser scoring. However, laser scratching requires the use of specialized equipment, and therefore results in higher manufacturing costs.

An alternative to the previous four methods of producing an easy-to-open effect is to "roughen," "knurl," or "make small cuts in" a designated area of ​​film to create the easy-to-open effect.

"Roughening" or "knurling" the surface of a polymeric film can be done by various methods. Roughness can be formed by rotating a round abrasive such as a metal grinding wheel or brush, or other bristled instrument, and bringing the rotating instrument into contact with the film. Alternatively, a flat instrument having a rough or granular surface, such as for example a grain-containing sheet material, can be contacted with the polymeric film.

The following patents and / or publications, which describe easy-open features of the type discussed above, are cited as references:

United States Patent No. 2,703. 764, to Vogt, describes a thermoplastic tape with a weakened embrittled edge to facilitate tearing along the edge.

US Patent No. 3,608. 815, to Bunch, describes a configuration of pore-shaped holes on a fold line at the edge of a formed container.

US Patent No. 4,543. 279, Kai, describes a film with an easy opening characteristic of a plurality of random cuts or scratches formed along the edges of a film.

US Patent No. 5,141. 795, also to Kai, describes a bag or container with an easy open feature of a multiplicity of through cuts formed at the edge portion of the container, where the through cuts are partially or fully closed with the heat seal layer.

US Patent No. 4,778. 058, from Yamazaki, describes an easy opening feature of a rough surface portion of a film or bag, where the rough surface portion is positioned in and around the folded portion and on an outer surface of the bag.

European Patent Application number 0 596 747 A1 discloses an easy opening feature of a plurality of laterally spaced, linearly extending rows of slits formed parallel to and inwardly adjacent to one side of the film.

It has now been found that an effective and practical method of creating an easily openable container made of polymeric or flexible materials is to roughen or knurl the entire surface of the framework by applying a series of small incisions or general minute cuts substantially over the entire air area of ​​the structure. the outer layer of the structure.

This method creates an effective easy-open container that has lower production costs.

ES 2 187 686 T3 than prior art methods. Since the entire surface area of ​​the container is rough or knurled, it is not necessary to match the easy-open characteristic for the impression, or to the shape or structure of the final container, leading to manufacturing efficiencies. This is in contrast to prior art packages that have easy-open characteristics, in which the easy-open characteristic is fixed at a particular position relative to the print or to the shape or structure of the finished container.

This method also creates a packaging material that does not have notches or tear strips, but is rather a smooth surface. Thus, the laminate and packaging material of the invention avoids the problem of tearing or tearing during manufacturing, packaging, transportation or general handling, which is common in the prior art.

Following a first and a second aspect, the present invention provides a multilayer polymeric packaging material as claimed in claims 1 and 4. The present invention also provides a method of manufacturing a multilayer polymeric packaging material as claimed in claims 9 and 10.

This invention encompasses a method of achieving flexible, easy-open packaging laminates and packaging material suitable for easy-open packages made therefrom.

The method of the invention has advantages over the prior art because it allows to produce an easily openable container that does not have tear strips or other notches that can cause problems during manufacturing, packaging, transportation and general handling.

The method of the invention also has advantages over the prior art in that it is more easily processed than the easy opening characteristics of the prior art. The method of the invention does not require the placement of the easy opening feature at a particular point or position on the surface of a film.

The easy-open packaging material of the invention is obtained by roughening or knurling the entire surface of the packaging material. Surface roughness is achieved by applying a series of tiny incisions or tiny cuts in a film or laminate, which is then used as an outer layer of a container. The incisions or cuts are located substantially over the entire area of ​​the laminated film. These incisions create an easy-open tear feature that does not have to be fixed or located in a particular position on the surface of the laminate or packaging material.

The incisions or cuts may be arranged over substantially the entire area of ​​the film or laminated in a pattern, or alternatively, they may be randomly dispersed. However, the incisions should generally be located substantially over the entire surface area of ​​the film or laminate.

The film or laminate can consist of a variety of polymers or copolymers that are commonly used as base layers in the manufacture of polymeric films. Preferably, the laminates of the invention may include a polymer such as an oriented polypropylene ("OPP"), oriented polyethylene terephthalate ("PET") or polyester, or a biaxially oriented nylon ("BON").

The film or laminate, with an adhesive layer, can then be used as an outer layer in a polymeric film such as a sealant film of a type that is common in packaging art. The polymeric sealant film can be a single layer film or a multilayer film, and it can be a heat sealant film or a cold seal adhesive.

Alternatively, the film or laminate can be used as an outer layer of a package having a three-part structure. In this embodiment, the film or laminate is adhered to a layer of lamina, which in turn is adhered to a polymeric film. The polymeric film to which the film adheres can be a sealant film or coating, such as an extrusion coating. The sealant film or coating can be a single layer film or a multilayer film.

Brief description of the drawings

Figure 1 illustrates a top view of the film.

Figure 2 illustrates one method of imparting the easy open characteristic to the laminate.

Figure 3 illustrates a method of imparting the easy-open characteristic to the laminate.

Figure 4 illustrates a method of making a three-layer laminate.

Figure 5 illustrates a side view of a three-layer laminate.

Figure 6 illustrates a side view of a seven-layer film of the packaging material of the invention.

Figure 7 illustrates a side view of a five layer film of the packaging material of the invention.

Figure 8 illustrates a side view of a nine-layer film of the packaging material of Figure 7.

Figure 9 illustrates a top view of a package made with the packaging material of the invention.

Figure 10 illustrates a top view of a package made with the packaging material of the invention.

And Figure 11 illustrates a top view of a reinforced container made with the packaging material of the invention.

Detailed description of the invention

Figure 1 illustrates a top view of a flat sheet of polymeric material 5 of the laminate of the invention. Sheet 5 may include any of a number of polymeric materials commonly used as base layers in filmmaking techniques. In a preferred embodiment of the laminate, sheet 5 includes an oriented polypropylene ("OPP"), an oriented polyethylene terephthalate ("PET"), or a biaxially oriented nylon ("BON").

Oriented polypropylene or OPP refers to polypropylene, including polypropylene copolymers, that have been stretched or oriented. Examples of OPP films that can be used in

ES 2 the laminate of the invention are T-523 or B-523, manufactured by Hercules Chemical Co.

In orientation, the polymeric material is heated to its orientation temperature range and then cooled to freeze the molecular alignment of the material in the direction of stretching. Orientation temperature ranges for a particular film will vary with the different thermoplastic resinous materials or their mixtures that make up the film. These temperature ranges are generally above room temperature and below the melting point of the thermoplastic material or material mixture. Such ranges are known to those skilled in the art. Uniaxial orientation results from a stretching force applied in one direction. Biaxial orientation results from a stretching force applied in two directions.

Biaxially oriented nylon or BON refers to any of several polyamide or nylon copolymers used topically in the technique of making polymeric films, such as nylon 6, nylon 6,6, nylon 6,10, nylon 11, nylon 12, nylon 6,12, amorphous nylons, partially aromatic polyamides, and nylon copolymers. BON has been oriented in two directions, commonly referred to as the machine and transverse directions.

Polyethylene terephthalate or PET includes copolymers of PET, and also includes oriented PET. Topically, oriented PET has good strength, toughness and clarity properties. Examples of PET films that can be used in films of the inventions are Hostophan 2600 and 2400 films, manufactured by Hoechst Celanese Chemical Co., and LB, LB1 and LB7 resins, manufactured by EI Du Pont & de Nemours, Inc., and SKC-SP65 and SP91, manufactured by Kolon Chemical Company of Korea.

Illustrated on sheet 5 in Figure 1 are a plurality of minute cuts or incisions 7 which are located substantially over the entire surface area of ​​sheet 5 to create the easy opening feature of the invention.

Sheet 5 can be of a range of thicknesses that are common for polymeric base films, for example 32 to 250 gauge. For general packaging applications, a preferred thickness range for base layer 5 is 32 to 100 gauge. For candy or similar product packaging, with a cold seal adhesive, a preferred thickness range for base layer 5 is 125 to 175 gauge.

Sheet 5 may contain any of a variety of additives that are commonly used in polymeric films, such as slip agents, coatings, or coloring agents. Sheet 5 can also be printed prior to creating the easy-open feature of the invention. Printing of the base film lamina 5 can be done by any of the methods commonly used in packaging art to print polymeric films. For example, the printing can be relief printing, lithographic or offset lithographic printing, intaglio printing, which is also called gravure or rotogravure, porous printing, non-impact printing, or flexographic printing.

686 T3 6

Figures 2 to 4 illustrate various steps in the manufacture of the laminates and the additional processing involved in manufacturing the packaging material and containers therefrom.

Figure 2 shows a side view of a method of imparting the easy-open characteristic to a film.

In Figure 2, film 14 is a layer of a polymer such as OPP, PET, BON, or their copolymers. Film 14 was arranged in the manner shown so that surface 14A faces upward.

The film 14 is advanced in the direction along arrows A to B by any of the methods commonly used to advance films during the process, for example by the use of rollers. Film 14 may have previously been printed. At point 31, the surface 14A of the film 14 comes into contact with the contact lines of the roller 32 and the impression roller 35. The roller 32 rotates about its axis in a counterclockwise direction. Roller 35 rotates about its axis in a clockwise direction, and serves to press film 14 against roller 32. Roller 32 has a surface 33 that imparts a roughening or knurling effect to surface 14A of film 14 . Surface 33 may contain a wire structure, brush-like bristles, grinding wheel, granular substance, or other similar structure that roughens surface 14A of film 14 to produce roughened surface 14A '. When the roller 32 rotates and the surface 33 contacts the surface 14A of the film 14, the roller 32 produces a roughness or knurl substantially over the entire area of ​​the surface 14A of the film 14.

Alternatively, a multilayer film can be coextruded consisting of a first layer of a base polymer, such as OPP, PET, or BON, and a second layer of a sealant coating or film. The multilayer film may have a layer of an adhesive disposed between the layer of a base polymer and the layer of a coating or sealant. The outer surface of the base polymer layer may then be subjected to surface roughness of the inventive easy-open feature, as illustrated in Figure 2.

Figure 3 illustrates a side view of the processing of the film as shown in Figure 2. Figure 3 shows the film 14 with surface 14A, advancing in the direction represented by arrows A to B. At point 31, the Roller 32 comes into contact with surface 14A, producing the film of the invention with a rough or knurled surface illustrated as 14A '. The surface 33 of the roll 32 had a structure or construction that roughens the surface 14A of the film.

14.

The film can be further processed by any of several methods common in the art of making multilayer polymeric films to produce the packaging materials of the invention.

The film, after having been roughened or knurled substantially over the entire surface area of ​​the film, can be

ES 2 187 686 T3 is then mined to a sealant single or multilayer polymeric film by using adhesive lamination or extrusion lamination.

Lamination can be accomplished by any of several common laminating methods in the art of making polymeric films, for example by adhesive lamination as shown in Figure 4.

In Figure 4, the film 14, containing the knurled surface 14 'as described in Figures 2 and 3, is turned upward between the contact lines of the roller 40, which rotates on its axis in a clockwise direction, and 41, rotating on its axis in a counterclockwise direction, in the direction of arrows A to B. Roller 41 imparts a layer of an adhesive resin 15 to the side of film 14 opposite the knurled surface 14 '. The adhesive is applied to the film 14 by the rotogravure method. A fine 42 steel blade acted as a brush to remove excess tackifying resin 15 from the film

14. Film 14 is then passed along rollers 43 and 44 and advanced to dryer 45, which acted to dry film 14 and evaporate the solvent from the solvent-based tackifying resin.

15.

After drying, the contact lines 46 and 47 combined pull the film 14, and it advances in the direction of arrows C to D. The sealing film 16 is pulled with the roller 49 in the direction of arrows E to D. F. At point 48, between the contact lines of the roller 46, which rotates in a clockwise direction, and 47, which rotates in a counterclockwise direction, the adhesive resin 15 comes into contact with the sealing film.

16. The sealant film 16 may be a single layer sealant film or a multilayer sealant film. The adhesive acted to adhere the film 14 to the sealant film 16. The finished film

17, having a knurled surface / adhesive / sealant film structure in order, is then wound onto rewind roll 50.

An alternative method of adhesive lamination uses a solvent-free adhesive. With a solvent-free adhesive, the tackifying resin is applied to the film 14 by the multi-roll transfer method. The solvent-free adhesive method does not require the use of a tumble dryer 45.

Alternatively, the film 16 may be a layer of a lamin, such as any of the various lamins used topically in flexible packaging that produces a temporary film, having a knurled film / adhesive / laminate structure. The temporary film is then passed through a second adhesive laminator in place of film 14. An adhesive is added to the temporary film in the lamina, and then a sealant film is adhered to the lamina layer of the temporary film.

In addition to the adhesive laminating method illustrated in Figure 4, the films can be produced by other adhesive laminating methods or by any of the extrusion laminating methods that are common in the art of making polymeric films.

The sealant film can be adhered to the knurled film or the laminate layer, as a coating, such as an extrusion coating. Extrusion coating is a process whereby an extruder passes a molten thermoplastic material through a horizontal slot die onto a moving sheet of material. The speed of application controls the thickness of the deposited film. The molten stream can be extruded in one or more layers.

Figures 5 to 8 illustrate examples of various packaging materials. Figure 6 is a side view of the structure of the first embodiment of the packaging material of the invention. Figure 7 is a side view of the structure of the second embodiment of the packaging material of the invention.

In Figure 5, the film 70 is a laminate. Layer 71 may be any of a number of polyomers or copolymers that are commonly used in the art, and preferably includes OPP, PET, BON, or their copolymers. Layer 71 may have a thickness range of about 32 gauge to about 100 gauge. Surface 71A of layer 71 contains the easy open feature of the invention. Substantially all of the surface area of ​​surface 71A was roughened or knurled by the application of a series of tiny incisions or minute cuts in the laminate.

Layer 72 is a layer of an adhesive, and can include any of a number of polymeric adhesives commonly used in the art, such as solvent-based adhesives and adhesives that do not require a solvent. The adhesive can be a rubber-based adhesive or a hot melt thermoplastic adhesive. Topically, polymeric adhesives in a thickness of approximately 0.00254 mm (0.1 mil) are used for adhesive lamination, 0.01016 to 0.0508 mm (0.4 to 2.0 mil) for extrusion lamination.

In surface-to-surface contact with layer 72 has been disposed film 73, a uonic layer sealant film. Layer 73 can include any of a number of heat sealable polyomers or copolymers that are commonly used in the art. Layer 73 may be within the range of thicknesses from 50 gauge to 0.1016 mm (4 thousandths of an inch), and is preferably from 0.0254 mm to 0.0762 mm (1 to 3 thousandths of an inch).

Heat sealable, as used here, means sealable or bondable by heat obtained in any way, for example, by induction or heating magnetic, ultrasoonic, radio frequency, light, laser, resistance or other sources of energy that cause the materials are bonded, melted or otherwise sealed. Such heat sealable materials are typically film-forming thermoplastic polyomers, are known in the art, and include ethylene polyomers and copolymers, and ethylene copolymers and an ethyloenically unsaturated comonoomer selected from the group consisting of carboxylic and osteric acids, their salts and anhydrides. Layer 73 can include any of several polyomers used in sealant layers, such as LLDPE, including all linear polyethylenes with a density up to about 0.95 gcm.^-3, LDPE, EVA, density polyethylene

ES 2 187 686 T3 medium ("MDPE"), olefins catalyzed by a single site catalyst, EMA, EMAA, an ionomer, or a mixture of any of these polymers, or heat seal coatings.

The invention also contemplates the use of a cold seal adhesive.

Figure 6 illustrates a preferred embodiment of the packaging material of the invention, in which the laminate 70 of Figure 5, with a knurled surface 71A, was adhered to a multilayer sealant film, for example a five-layer coextruded film.

In surface-to-surface contact with layer 72 of laminate 70 has been disposed layer 75 of multilayer sealant film 74. Layer 75 of film 74 can be any of several polyomers that are common in the art for use in strong layers abuse, such as high density polyethylene ("HDPE") or medium density polyethylene ("MDPE").

In contact with layer 75 is a layer 76 of an adhesive. Layer 76 serves to adhere layer 75 to 77, which is an oxygen barrier layer that can include any of several polyomers commonly used in barrier layers, such as for example EVOH. Layer 78 is a second adhesive layer, which was arranged in contact with layer 77. Layer 78 serves to adhere layer77 to layer 79, which is a sealant layer that includes a heat sealable polymer. The multilayer sealant can have a wide range of thicknesses, from 50 gauge to 0.1016 mm (4 thousandths of an inch) and is preferably from 0.0254 mm to 0.0762 mm (1 to 3 thousandths of an inch).

Figure 7 illustrates the laminate in an alternative embodiment of the packaging material of the invention. In this second embodiment, the film contains a layer of aluminum foil.

Multilayer thermoplastic films containing layers of foil, especially aluminum foil, are common in the art. However, prior art films with OPP / foil / sealant structures do not tear easily, and generally require the use of auxiliary cutting devices, such as scissors, to open them. The OPP / laminate / sealant films of the invention, however, having an OPP layer that knurls substantially all of their surface areas, tear easily.

Aluminum foil is a thin laminated sheet of pure or alloyed aluminum, and is known as a versatile material that can be easily laminated to polymeric materials. Aluminum loamine is odorless, and has favorable properties as a barrier to water vapor and as a barrier to gases. Suitable aluminum loamines are those manufactured by the Aluminum Company of America (Alcoa), Alumax, Inc., and Norandol USA, Inc.

In Figure 7, adhesive layer 72 of laminate 70 is arranged in surface-to-surface contact with layer 81, which includes laminate. The loamine can include any of the loamines commonly used in flexible packaging, such as 1100 or 1145 aluminum loamine alloys. The loamine can be used in thicknesses on the order of 0.000635 cm (0.00025 inch) to 0.00254 cm (0.001 inch).

In surface-to-surface contact with layer 81 is adhesive layer 82 disposed. Adhesive layer 82 serves to adhere layer 81 to layer 83. Layer 83 is a uonic layer sealant film that includes a heat sealable polymer. Layer 83 may be of a thickness within the range of 50 gauge to 0.1016 mm (4 thousandths of an inch), and is preferably from 0.0254 mm to 0.0762 mm (1 to 3 thousandths of an inch).

The laminate can alternatively be adhered to a multilayer sealant film having four, five, six or more layers. Figure 8 illustrates the film with a five layer sealant film.

In Figure 8, layer 91 is a layer of a laminate. In surface-to-surface contact with the layer91 is the adhesive layer 97 disposed. The adhesive layer 97 serves to adhere the layer 91 to the five-layer sealant film 98.

The sealant film 98 has a layer 92 that includes any of the commonly used polyomers in abuse resistant layers, such as HDPE or MDPE. In surface-to-surface contact with layer 92 was disposed adhesive layer 93. Adhesive layer 93 serves to adhere layer 92 to layer 94. Layer 94 may include any of several barrier layers commonly used in polymeric films, such as for example EVOH. Layer 95 is a second layer of an adhesive, and serves to adhere layer 94 to layer 96. Layer 96 is a heat sealable polymer that includes any of a number of heat sealable polymers that are commonly used in the art. Layer 96 may be of a thickness within the range of 50 gauge to 0.01016 mm (4 thousandths of an inch), and is preferably from 0.0254 mm to 0.0762 mm (1 to 3 thousandths of an inch).

Figure 9 illustrates a container or a bag 100 made of a multilayer polymeric film or packaging material in which the laminate is used as an outer layer 104. The bag 100 is sealed on its sides 101, 102 and 103 by heat sealing or others. sealing mechanisms commonly used in the art of making polymeric films.

Side 104, which is not sealed as illustrated in Figure 9, can be sealed in an alternative embodiment of the bag. Layer 105 has a plurality of minute incisions or cuts 106 located substantially over the entire surface area of ​​layer 105, including the areas where bag 100 has been sealed.

Figure 10 illustrates a package 110, a further embodiment of a package or bag made from a packaging material of the invention. The container 110 was sealed on the upper side 111 with an upper seal 112 and was also sealed on the lower side 113 with a lower seal 114, and along a line 115a to 115b called the back of the bag, with a rear seal 115. The laminate 116 is used as an outer layer for the package 110. Illustrated in layer 116 are minute cuts or incisions 117 located substantially over the entire surface area of ​​layer 116, including areas where container 110 has been sealed.

ES 2 187 686 T3

A special application of the film is in the production or use of reinforced bags, as illustrated in Figure 11 of the reinforced bag 120. The reinforced sides 121, 122, 123 and 124 are not sealed, but rather are continuous layers. made of polymeric material. At 125 there is illustrated a rear seal or flap seal, or seal in which the sealing layer of the container is folded over on itself.

The outer layer 126 includes a laminate that has been subjected to the minute incisions or cuts described in this application as a method of creating an easy opening feature.

As illustrated in FIG. 11, a consumer wishing to open the reinforced container 120 could easily gain access to the product. Since the method produces minute incisions or cuts located in the laminate 126 used as the outer layer of the bag 120, the consumer will be able to tear the container at any point along the reinforced sides 121, 122, 123 or 124. Examples

The films of the invention were sampled and converted into easy-open bags having a tear-off characteristic as described herein. The samples were converted into reinforced and unreinforced bags.

Comparative Example 1

A pouch was constructed from a film having an OPP / adhesive / sealant film layer structure. The OPP layer, which was T-523 film manufactured by Hercules Chemical Company, was reverse printed with a promotional design. The film was then knurled, that is, subjected to the minute incisions or cuts that are described in this application as a method of creating an easy opening feature. The film was then adhesive laminated to a 0.0508 mm (2 mil) uonic layer sealant film, which was a blend of EVA and LLDPE.

The finished packaging material film was found to have favorable phosphoric properties. For example, the water vapor transmission rate ("WVTR") of the packaging material of the invention was measured and compared with the WVTR of the sealant film itself. In a 24 hour period at 37.8 ° C (100 ° F), the WVTR of the packaging material of the invention was 0.24 g / 645.2 cm² (0.24 g / 100 in.²). The lack of a significant change in the WVTR with the addition of the laminate shows that the roughness or knurling of the entire surface area has little or no negative effect on the barrier properties of the film.

The resulting film was made into bags that were 12.7 cm (5 inches) high and 10.16 cm (four inches) wide. The bags were sealed with a top seal and two side seals. The bags were found to have favorable phosphoric properties, and were easily torn open at any point.

Examples of packages of the films of the invention having a layer of laminated or metallized PET were also produced.

Example 2

Example 2 had a first layer of 75 gauge Hercules T-523 OPP film. The OPP film, which was not printed, was knurled substantially over its entire surface. The OPP layer was then adhesive laminated to a 0.0007239cm (or .000285 inch) laminate layer, and the laminate layer was adhesive laminated in turn to a 0.0254 mm (1 mil) LDPE sealant film. inch).

The resulting film was converted into bags that were 10.16 cm (4 inches) high by

2 1/2 inches (6.35 cm) wide. The bags had favorable phosphoric properties, and were easily opened at any point.

Example 3

Example 3 had a first layer of 48 gauge PET film, American Hoechst Hostaphan 2600. The PET film was adhesive laminated to a 0.0007239 cm (0.000285 inch) sheet layer, and the sheet layer was laminated with adhesive in turn to a 0.0254 mm (1 mil) LDPE sealant film.

The resulting film was converted into bags that were 10.16 cm (4 inches) high by

2 1/2 inches (6.35 cm) wide. The bags had favorable phosphoric properties, and were easily opened at any point.

Examples 2 and 3 are representative of bags that can be made using the laminate of the invention. These examples are not intended to cover unique constructions that can be made, nor are they intended to cover unique structures that can be made, nor are they intended to limit the terms of the invention.