Flexible package for articles

The present invention relates to a package of one or more articles, the package comprising a substrate comprising at least one film layer wherein the substrate forms a plurality of panels and an opening feature, wherein the panels define an interior compartment, and wherein the one or more articles are disposed in the interior compartment, wherein the substrate has a first tearing force in a first direction and a second tearing force in a second direction, the second direction being perpendicular to the first direction, wherein the first tearing force is no greater than about 240 gf as measured according to Tearing Force Test, and wherein a ratio of the second tearing force to the first taring force is no less than about 1.35.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to Chinese PCT Patent Application No. PCT/CN2021/100952, filed on Jun. 18, 2021, which is herein incorporated by reference.

FIELD OF THE INVENTION

The present invention relates to flexible packages for articles which is easy for a consumer to open.

BACKGROUND OF THE INVENTION

Non-fragile consumer products such as hygiene products and cosmetic products are often packaged in a flexible package, such as a package made of film.

One unmet need in flexible package made of film is that it is not easy to open. Many flexible packages are often not easy to control the propagation of the tearing even with assistance with an opening feature, and leave the opened packages with unpleasant appearance or even tear apart the packages completely. Prior opening features such as various configurations of opening perforations have not provided easy facilitation of opening, and in addition or alternatively, tend to promote substantial destruction of the package during opening, rendering it unsatisfactory for use as a storage container.

After opening a package of disposable absorbent articles and removing one or more items needed for immediate use, a consumer may wish to leave the remaining unused supply of product in the package for storage until the next time additional items are needed. In addition, it is often desirable particularly in environments where high humidity and substantial quantities of airborne dust and dirt particles may be present that the package has a recloseability capability that allows the package to be reclosed to an extent suitable to help protect the unused product from airborne contaminants. Moreover, it is desirable that the package retains, to some extent, its shape with a neat appearance, and structural integrity to remain useful as a container for storing unused product following opening.

To date, flexible packages with an opening feature have generally been less than fully satisfactory.

It is an object of the present invention to provide an easy open flexible package which can be easily and reliably opened along a predetermined direction in the package.

It is another object of the present invention to provide a flexible package which can be easily opened with linear, smooth and controlled tearing.

It is still another object of the present invention to provide a flexible package to open easily which can be recloseable.

SUMMARY OF THE INVENTION

The present invention provides a package of one or more articles, the package comprising a substrate comprising at least one film layer, wherein the substrate has a first tearing force in a first direction and a second tearing force in a second direction, the second direction being perpendicular to the first direction, wherein the first tearing force is no greater than about 240 gf as measured according to Tearing Force Test, and wherein a ratio of the second tearing force to the first taring force is no less than about 1.35. The substrate forming a plurality of panels and an opening feature. The panels define an interior compartment, and the one or more articles are disposed in the interior compartment.

For ease of discussion, the invention disclosed herein will be discussed with reference to the numerals referred to in figures. The figures and detailed description should however not be considered limiting the scope of the claims, unless explicitly indicated otherwise, and the invention disclosed herein is suitable to package a wide variety of product.

DETAILED DESCRIPTION OF THE INVENTION

All ranges are inclusive and combinable. The number of significant digits conveys neither limitations on the indicated amounts nor on the accuracy of the measurements. All numerical amounts are understood to be modified by the word “about” unless otherwise specifically indicated.

“Absorbent article” as used herein refers to products that absorb and contain body exudates, and, more specifically, refers to devices that are placed against or in proximity to the body of the wearer to absorb and contain the various exudates discharged from the body. Absorbent articles may include diapers (baby diapers and diapers for adult incontinence), pants (for babies or for adults), absorbent inserts (which are intended to be inserted into an outer cover to form a diaper or pant), feminine care absorbent articles such as sanitary napkins, pantiliners, or tampons, and the like. As used herein, the term “exudates” includes, but is not limited to, urine, blood, vaginal discharges, sweat and fecal matter.

“Film” means a sheet structure having a length, width and thickness (caliper), wherein each of the length and width greatly exceed the thickness, i.e., by a factor of 1,000 or more, the structure having one layer (monolayer) or more respectively adjacent layers (multilayer), each layer being a substantially continuous structure formed of one or more thermoplastic polymer resins (including blends thereof).

“Hygiene products” as used herein refers to products for personal hygienic care, including disposable articles and cleansing products. Typical disposable hygiene products include disposable absorbent articles such as infant diapers, sanitary napkins, panty liners, breast pads, tampons and the like, and cleansing products such as washes, soaps, shampoos, hair conditioners, detergents and the like.

“Package” as used herein refers to a material provided to surround or enclose products such as hygiene products or cosmetic products.

“Machine direction” as used herein refers to the direction of the film production line. “Cross-machine direction” as used herein refers to a direction, which extends perpendicularly to said machine direction.

“Sealed” as used herein refers to a package having an interior that is inaccessible until the package is ruptured.

“Weakness line” as used herein refers to areas in which the package material has a reduced tear resistance compared to regions outside the weakness line. The weakness line can be provided by continuous lines or by a line of weakness points. The weakness line includes perforations, scoring, or a crease line.

Substrates

The substrate to form the package according to the present invention has a first tearing force in a first direction and a second tearing force in a second direction, the second direction being perpendicular to the first direction. The first tearing force is no greater than about 240 gf, or no greater than 210 gf, or no greater than 150 gf, as measured according to Tearing Force Test. When the first tearing force is too high such as greater than about 240 gf, it may require consumers to take more efforts to tear open the package, and thus it is deemed to be not easy opening packages. The first tearing force may be no less than about 20 gf as measured according to Tearing Force Test. When the first tearing force is too low, the package may be too easy to be open or torn and it poses problems in maintaining the integrity of the package before the time of opening, for example, packaging process and/or transportation or storage of packaged products. A ratio of the second tearing force to the first taring force is no less than about 1.35, or no less than about 1.4, or no less than about 1.5. When the ratio of the second tearing force to the first taring force is lower than about 1.35, it may be difficult to control the tearing propagation along the desired direction due to a small tearing force difference between the first and second directions.

In the substrate, the second tearing force may be no less than about 60 gf, or no less than about 100 gf, or no less than about 150 gf. It may be essential for the second tearing force to be sufficiently high to make sure the tear propagation is along the first direction. If the second tearing force is lower than 60 gf, it may be difficult to control the tearing propagation along the desired first direction.

The reduction of the tear force can be achieved by any suitable means known in the art, such as reducing the thickness or strength of the package material by e.g., cutting, punching, mechanical or ultrasonic embossing or by changing the crystalline structure of the package material by e.g., applying heat, a laser beam, high voltage or adding high crystallized material such as HDPE or the like.

The first direction may be a machine direction or a cross-machine direction. The first direction may be a direction forming an acute angle with the machine direction.

A substrate to form the package of the present invention comprises a polymeric film layer.

A polymeric film layer forming or comprised by the substrate according to the present invention may be formed of one or more polyolefins, such as polyethylene (PE) and polypropylene (PP). Polymeric films may also include blown or cast film materials in a blend of low density polyethylene (LDPE), linear low density polyethylene (LLDPE), metallocene PE blends (metPE), ethylene vinyl acetate, Surlyn®, polyethylene terephthalate (PET), mono and biaxially oriented polypropylene (M/BoPP) and nylon.

The film layer may be a single layer (monolayer), or may be formed by at least two layers (multilayer). A multilayer film may have, for example, an outer skin layer formed of a first polymer and an inner skin layer formed of a second polymer. (As used herein, the terms “outer” and “inner” refer to the positioning of the layer relative the inside and the outside of the finished package; thus, the “inner layer” faces the contained product, and the “outer layer” faces outward and has an outer surface that is exposed to view and touch by, e.g., shoppers in a retail store.)

A multilayer film may be co-formed (such as by coextrusion), or in another example, individual layers may be separately formed and then laminated together following their formation, by use of a suitable laminating adhesive. In this latter example, an advantage provided is that one of the layers may be printed on one side before lamination. Following that, the printed side may be faced inward (facing the other layer(s)) during lamination, such that it is protected by the other layer(s) from abrasion and wear in the finished film product, thereby preserving the integrity of the printed images, graphics, verbal content, etc. A suitable multilayer film may be formed of one or more polyolefins, such as polypropylene and polyethylene. In one example, the film may have at least two layers, including a first layer of predominately polyethylene and second layer of predominately polypropylene. In one example, a layer formed of predominately polyethylene having a first relatively higher melting temperature, and a layer of predominately polyethylene having a second relatively lower melting temperature, may be used to form the outer and inner layers, respectively. In another example, an inner layer may be formed predominately of a first type of polyethylene having a relatively lower melting temperature, and an outer layer may be formed predominately of a second type of polyethylene having a relatively higher melting temperature.

In one embodiment, the substrate according to the present invention comprises a multilayer film. A multilayer film may have layers of polymer compositions particularly chosen for the characteristics they impart to the film. For example, one or two outer skin layers may be formed of compositions chosen for, e.g., surface gloss; printability; smooth feel; pliability; low noise generation (upon being handled and manipulated, as by a consumer); relatively lower melt temperature for sealing/weldability; or any combination of these characteristics. One or more intermediate layers may be formed of compositions chosen for, e.g., tensile strength; stiffness; toughness; decorative appearances; suitability for inclusion of blended-in recycled material; environmentally-friendly and/or sustainable material sourceability; relatively higher melt temperature; co-extrusion compatibility with adjacent layers (such that strong bonding between layers occurs upon co-extrusion); or any combination of these characteristics.

The substrate of the present invention may further comprise an additional layer such as a paper layer, a metal layer and a metallization layer. A paper layer herein intends to include a paper layer made from natural fibers, synthetic fibers or any combination thereof. A metal layer herein tends to include foils such as made from aluminum, copper and other suitable metals or alloys. A metallization layer herein intends to include a polymeric film with a thin layer of metals or oxidization of metals via suitable metallization processes, such as vacuum metallization or spattering metallization, etc.

A polymeric film layer forming or comprised by the substrate according to the present invention can be pigmented. The polymeric film layer can be clear or opaque.

Package

A package of the present invention comprises a substrate forming a plurality of panels which define an interior compartment where one or more articles are disposed. The package of the present invention has a longitudinal direction extending from the first side panel (or the first side edge) to the second side panel (or the second side edge), and a transversal direction perpendicular to the longitudinal direction, and comprises an opening feature.

In one embodiment, the package of the present invention is a retail package containing non-fragile, compressible disposable absorbent articles. It may have a hexahedral shape with a top panel, a bottom panel, a first side panel, a second side panel, a front panel, and a back panel. Referring toFIG.1A, in one embodiment, a package100comprises a top panel50, a bottom panel51opposite the top panel50, a first side panel52and a second side panel53opposite the first side panel52, a front panel54and a back panel55opposite the front panel54. The package100has a longitudinal direction L extending from the first side panel52to the second side panel53, and transversal direction T perpendicular to the longitudinal direction L.

The substrate to form the package according to the present invention has a first tearing force in a first direction and a second tearing force in a second direction, the second direction being perpendicular to the first direction. The first direction may be substantially parallel to the transversal direction of the package. The first direction may be substantially parallel to the longitudinal direction of the package. The first direction may be a direction forming an acute angle with the transversal direction of the package.

Referring toFIG.1B, a bag structure47may be formed from a single sheet of film stock that is suitably folded to form bag gussets52b,53band then joined along portions by bonding to form two side seams52a,53aon opposite sides, to form bag structure47with no seam on a top panel50, and open at the other end48(e.g., a gusseted bag structure). Thereafter, the bag structure may be filled by inserting products such as one or more rectangular cuboid shape stack of diapers through the open end48. As may be appreciated fromFIGS.1A and1B, the open end48opposite the top panel50may then be closed by suitably folding to form closing gussets51a, bringing the film edges together, and bonding them together to form end seam51band a bottom panel51. The bag structure47and the stack of products dimensions may be suitably selected and effected through design, folding, stacking, compression and packaging processes such the substrate of the package is taut about the stack to retain individual products in place within the stack, maintain stack compression, and maintain a neat, stable, approximate rectangular cuboid shape for the stack, and as a result, the package100. Because the package100is formed of the flexible substrate disclosed herein, when suitably sized relative the stack dimensions, package100will approximately assume the approximate rectangular cuboid shape and dimensions of the stack, when the package substrate is taut, or otherwise when any loose substrate is pressed against the stack. Still referring toFIG.1A, the package100may have a package length PL, a package width PW, and a package height PH.

In another embodiment, the package is a flexible sachet. Flexible sachets suitable for the present invention may be of any shape, but referring toFIG.2, are most commonly square or rectangular. Square or rectangular sachets are generally preformed by sealing and optionally folding, along two or three edges. The remaining unsealed edge provides an open ended mouth for filling. The preform may consist of two separate polymeric films which are sealed together along three edges. Alternatively, the preform may consist of a single piece of polymeric film which is first folded, the fold forming a top edge, and then sealed along two other edges. In a further alternative embodiment, a length of polymeric film is first folded and sealed along its length to form a tube. The tube is then cut into predetermined lengths and one end of the tube is sealed to form the preform. The preform is then filled with a content to pack, and sealed. Referring toFIG.2, the sachet200comprises a top edge211, a bottom edge212, a first side edge213, a second side edge214, a front panel216and a back panel (not shown inFIG.2) opposite to the front panel, and comprises an opening feature, a notch24in this case. The sachet may have an opening feature on at least one side edge of the sachet.

The package may enclose one or more articles in a hygienically protective manner. In one embodiment, articles are typically arranged in one or more stacks inside the package. The package herein is provided with an opening flap for allowing a user to access and dispense the hygiene articles therethrough.

In one embodiment, the package is designed to provide an opening in the package by tearing a top part of package apart which provides an opening in the package and an opening flap. The opening flap can be reclosed as is, or by use of an adhesive strip which is fixedly joined to the opening flap and which is capable of releasable attachment to the package.

In another embodiment, the package is designed to provide a hood structure when the package is opened. As noted, it may be desired that the package have a recloseability feature. An opening hood structure having three sides each formed of a portion of one of the first side panel52, second side panel53, front panel54or back panel55, and a top formed of a portion of one of the top panel50or bottom panel51, as suggested inFIG.14, can provide an effective, easy to use cover over the supply of unused product, which can help guard against entry of airborne contaminants into the package. In the example depicted inFIG.14, a hood structure has three sides formed of portions of package panels52,54and55, and the top is formed by a portion of panel51. The hood structure is formed when the consumer tears the package film along weakness line302. After opening, the hood structure may be reclosed by returning it to a position similar to the one it occupied with respect to the remainder of the package, prior to opening.

Opening Feature

The package of the present invention further comprises an opening feature.

The opening feature can be various means to indicate a tear initiating point to guide users to initiate tearing the package and/or facilitate to open the package easily.

The opening feature may comprise a feature selected from the group consisting of a weakness line, an adhesive tape, an indicium, a pre-cut, a notch, and combinations thereof.

The opening feature may be located in any appropriate location (panel) in the package considering package shape, opening design and package usage, etc.

The opening feature may comprise a weakness line such as a series of perforations, scoring, or a crease line for easy rapture of the package and propagate the tear. Referring toFIGS.3A and3Bwhere the package has an opening feature30on the top panel50, the weakness line302may have a weakness line length WL in a direction substantially parallel to the second direction perpendicular to the first direction, and/or a weakness line width WW in a direction substantially parallel to the first direction. The width of weakness line parallel to the second direction may determine the width of the opening. The weakness line length WL of the weakness line302may be longer than the weakness line width WW of the weakness line302. In one embodiment, the weakness line width WW of the weakness line302is no greater than 10% of a package length PL.

The present package can be easily and reliably opened without a weakness line or a minimum length of a weakness line if it has which may minimize the chance that tensile forces exerted by the compressed flexible articles will cause premature opening the package before it reaches the end user.

The opening feature may comprise an adhesive tape. Referring toFIGS.4A and4Bwhere the package has an opening feature30on the top panel50, when the opening feature30comprises an adhesive tape304, the adhesive tape304may have a portion305converging from a width to form a generally appeared outline leading to a tear initiating point which can be easily grasped by users' fingers. Referring toFIG.4B, when the opening feature30comprise a weakness line302and an adhesive tape304, the weakness line302may be at least partially covered by an adhesive tape304.

The opening feature may comprise an indicium which can highlight and direct the user's attention to the location of the tear initiating point. Such indicia may include words, graphic indicia, tactilely perceivable indicia, and any combination thereof. Indicia may be provided at an appropriate position of the exterior package, in order to direct the skilled person toward proper opening of the package along the pre-determined tearing direction such as the first direction of the package. The graphic indicia may be an arrow, a line or area of color, or an imprinted path marking or tracing path of a color that visibly contrasts with surrounding package color. The graphic indicia may draw attention to the easy opening property of the package and/or demonstrates how to open the package. For example, the graphic indicia may be an image which may comprise a hand and a perspective view of the package and may demonstrate the movement of the hand relative to the package required to tear the package. The tactilely perceivable indicia may include embossing or other surface texturing of the film, configured to provide raised, tactilely perceivable features that suggest the presence of the location of the tear initiating point and/or tearing direction.

Referring toFIG.5, for example, an opening feature comprising a graphic indicum308, a color line, may exist in a first side seam52a, and/or in a second side seam53a. The opening feature30inFIG.5may further comprise pre-cuts at two longitudinal ends of the graphic indium308. The opening feature30may exist in the first side panel52and/or a second side panel53(not indicated inFIG.5). Referring toFIG.13, the opening feature30may comprising a graphic indicia308and a weakness line302.

The opening feature may comprise a notch or a pre-cut referring toFIG.2.

In some embodiments, an opening feature can primarily exist on a side panel (e.g., one of the left or right panels) or a side edge so that a consumer's eyes are drawn to the graphic indicia to help them to start the package opening process and indicate where the path of tearing direction is. Referring toFIG.2, for example, the opening feature30comprises a notch306or a pre-cut which provides a starting point and indicator for the user to tear the package, the sachet200in this case. The notch306is located on a first side edge213. Without any weakness line in any form, the tear will propagate linearly from the notch24into the nonsealed portion of the sachet200towards a second side edge214. If desired, consumers can tear the entire top off with a linear and smooth edge of the opened bag.

In other embodiments, an opening feature can primarily exist on a top panel referring toFIGS.3A-4B.

In other embodiments, referring toFIG.5, an opening feature may exist in one of the top panel50and bottom panel51, and at least one of the first side panel52, second side panel53, front panel54and back panel55to sandwich a package corner.

Referring toFIGS.13and14, particularly for a larger package100, the package of the present invention may further comprise a carrying handle80. In one example, a carrying handle80may be formed of a strip. In a more particular example, the strip may have its long dimension oriented along the first direction of the substrate forming the package. The strip may be bonded by any suitable mechanism to portions of the package or package film. In another example depicted inFIG.14, a carrying handle80may be formed of an extension of a fin51cextending from the package from an end seam51. The end seam fin51cmay have a handle cutout81made therethrough, providing a carrying handle80. The handle cutout81may have its long dimension oriented along the first direction of the substrate forming the package.

Measurement

1. Tearing Force Test

Tearing force in a machine direction and a cross-machine direction of a substrate is measured according to ASTM D 1922-15. When a substrate specimen is prepared from a package, the substrate is cut from the finished product using a razor blade or scissors to excise the substrate from the package not to include a seam, or a gusset or any bonding. Five replica for each sample are tested and average tearing force of the five replica is reported as tearing force.

2. Tearing Performance Test

Tearing performance of a substrate is conducted in order to test straight linearity tearing in one direction of a sample substrate.

When a substrate specimen is available in a raw material form, a rectangular test specimen with a size of 300 mm×100 mm is cut from the raw material. When a substrate specimen is prepared from a package, the substrate is cut from the finished product using a razor blade or scissors to excise the substrate specimen with a size of 300 mm×100 mm from the package without inclusion of a seam, or a gusset or any bonding area.

Referring toFIG.6A, a substrate specimen10of 300 mm×100 mm is placed on a scale template. An imaginary center line12indicates a center line in a length direction of the specimen10. A 20 mm pre-cut slit14is made from one side end of the specimen10along the center line12. Referring toFIG.6B, each of the two sides of the pre-cut14in the specimen10is held with fingers, and the specimen10is torn along the first direction. Appearance of the torn specimen after tearing is evaluated.

EXAMPLES

Example 1. Film Preparation

Film substrates were prepared as below.

Substrate1: 30 μm mono-axial direction orientation (“MDO”, hereinafter) film layer was prepared. A composite of about 65% polyethylene, about 8% of polypropylene, about 24.5% CaCO3, and about 2.5% polymethyl methacrylate (PMMA) was blended and co-extruded via traditional film blowing process to make a precursor film. The precursor film then passed through a machine direction orientation process in which the film is continuously stretched along the machine direction of the film via a set of several nipper rollers to reduce the film thickness into 30 μm.

Substrate2: Substrate2was prepared by laminating Substrate1and a 70 μm PE film layer using a solvent free adhesive to bond the two film layers together.

Substrate3: Substrate3was prepared by laminating Substrate1and a 30 μm PE film layer using a solvent free adhesive to bond the two film layers together.

Substrate4: 70 μm PE film from package of in market PE film for Pampers (Procter and Gamble, China).

Substrate6: Substrate6was prepared by laminating a 20 μm MDO PE film layer (Huangshan Novel, China) and a 55 μm PE film layer which is blown film with a composition of HDPE, MDPE and LLDPE.

Substrate7: Substrate7was prepared by laminating a 12 μm PE film layer, a 9 μm aluminum layer, a 12 μm PET film layer and a 45 μm PE film layer.

Example 2. Tearing Property of Film Substrates

Tearing forces in a machine direction and in a cross-machine direction of Substrates1-7were tested according to Tearing Force Test disclosed herein. All results are indicated in Table 1 below.

TABLE 1Substrate 1Substrate 2Substrate 3Substrate 4Substrate 5Substrate 6Substrate 7MD Tearing force22.4204.844.8264.4176136876.8(gf)CD Tearing force966.4310.4352>1600*227.2249.683.2(gf)Raito of the second49.701.558.07>61.315.481.13tearing force to thefirst tearing force>1600*: The instrument to test tearing force has an upper measuring limit of 1600 gf. This material exceeded the upper limit

Tearing performance of Substrates1-6were evaluated according to Tearing Performance Test disclosed herein. Images of torn substrates of Substrates1-6in the first direction and the second direction according to the Tearing Performance Test are shown inFIGS.7A-12B.

Each of Substrates1-3shows substantially linear and very neat tearing in the first direction, a machine direction in these cases, while Substrates4-6show failure of linear and neat tearing in either a machine direction or a cross-machine direction.