Home compostable flexible packaging

Abstract

Flexible packaging material for an aqueous product comprising; A barrier layer formed of a bioplastic sheet material compostable under home composting conditions and A structural layer formed of a fibrous sheet material compostable under home composting conditions, the layers being laminated together by a water based adhesive and the entire material is compostable under home composting conditions. The structural layer may be sprayed with a water based protective coating. The bioplastic may be derived from potato starch. A further outer layer also comprising biopolymer compostable under home conditions may be added, this may be the same bioplastic as the barrier layer. The fibrous structural layer may comprise paper. Also included is a flexible packaging made from a single sheet of the flexible packaging material which may further include a spout portion.

Description

FIELD OF THE INVENTION The present technology relates to compostable flexible packaging. In particular, the present technology relates to flexible packaging for aqueous products capable of home composting. BACKGROUND Packaging for aqueous products has conventionally been manufactured from petroleum-based material, for example, plastic bottles or plastic films laminated e.g. to another petroleum-based foil or paper layer. However, the single-use nature of such packages resulted in a significant volume of petroleum-based material being discarded into landfills and into the oceans where these materials can become long-term unusable waste. While some petroleum-based material is capable of being recycled, typically less than 10% currently is due to suitability - for example, packaging in laminated form comprising different petroleum-based and / or paper layers cannot be recycled. Petroleum-based materials can take as many as 400 years to decompose, and even when they eventually do, such materials generally leave behind toxic substances that can be harmful to human and wildlife. It is therefore desirable to provide biodegradable materials suitable for packaging. While various form of paper packaging is biodegradable and can be composted in uncontrolled ("home") composting conditions, it is unsuitable for packaging aqueous products or any products that contain moisture. "Bioplastic", which is made from plant-based materials such as cellulose or starch, has been developed as an alternative to petroleum-based materials. Bioplastics can be either biobased, biodegradable, or both. Biobased bioplastic is a material that is at least partly derived from plants - biomass, such as from e.g. corn or sugarcane. Biodegradable bioplastic is a material that can be converted into natural substances by microorganisms available in the environment such as water, carbon dioxide, and compost without artificial additives. The property of biodegradation does not depend on the raw resources but is instead a result of the chemical structure of the material. Thus, biobased plastics made completely from biomass, for example, may be non-biodegradable. Flexible packaging materials capable of storing aqueous products that is made from bioplastic often incorporates petroleum-based materials to some extent to achieve an extended shelf-life (e.g. over 6 months), and as such would still leave behind toxins in the environment as the packaging material degrades. Moreover, bioplastic flexible packages for aqueous products are typically not biodegradable or compostable under uncontrolled conditions that are generally found in home composting or in nature; these bioplastic packages are only biodegradable in controlled industrial composting facilities that can maintain specifically controlled composting conditions, e.g. controlled temperatures, humidity, aeration, etc. Industrial composting is a process that has a commonly agreed set of requirements concerning temperature and timeframe for biodegradable waste to metabolise to stable, sanitised products (biomass) to be used in agriculture, for example in the form of humus or fertilisers. The criteria for the industrial compostability of packaging are set out in the European standard EN 13432, which requires compostable plastics to disintegrate after 12 weeks and completely biodegrade after six months. However, many places around the world either has no recycling infrastructure or have poor recycling infrastructure, and therefore waste that is only industrially compostable can often end up in landfill and / or contributing to environmental contamination if there is a lack of facility to recycle or compost such waste. There is currently no international standard specifying the conditions for home composting of biodegradable plastics. However, there are a number of national standards, such as the Australian norm AS 5810 "Biodegradable plastics - biodegradable plastics suitable for home composting", and Belgian certifier TUV Austria Belgium had developed the OK compost home certification scheme that requires at least 90% degradation in 12 months at ambient temperature. Currently available flexible packaging materials that are home compostable are only suitable for dry goods and products as these materials are not capable of holding liquid for an extended period of time. In view of the foregoing, the Applicant has recognised that there is scope for providing a flexible packaging material for aqueous products that is home compostable. SUMMARY OF THE INVENTION An aspect of the present technology provides a flexible packaging material for an aqueous product, comprising: a barrier layer to contain the aqueous product, the barrier layer being formed of a bioplastic sheet material compostable under home composting conditions; and a structural layer to provide structural integrity to the flexible packaging material, the structural layer being formed of a fibrous sheet material compostable under home composting conditions, and the structural layer being laminated to the barrier layer by a water-based adhesive, wherein the flexible packaging material is compostable under home composting conditions. According to embodiments of the present technology, the flexible packaging material comprises a bioplastic inner layer and a fibrous structural layer. The bioplastic material is impermeable to liquid, making it suitable for holding liquid while being home compostable. The fibrous layer is naturally compostable under home composting conditions, and provides the packaging material with structural integrity to enable the resulting laminated material to be used as packaging material. The added structural integrity enables a flexible package made from the packaging material to be placed on shelves in a standing (rather than lying down) position, allows a more robust seal to be formed between two halves of the package, and improves the ability of the package to withstand tear. In preferred embodiments, the water-based adhesive is organic and biodegradable / home-compostable. Being water-based ensure safety when the packaging material is used for food products. It should be appreciated that a skilled reader would be able to select an appropriate commercially available water-based adhesive. In some embodiments, the structural layer may be sprayed with a protective coating, e.g. a water-based coating to protect the structural layer from moisture. The protective coating reduces or prevents moisture from reaching the fibrous structural layer and improves the shelf life of the packaging material. Moreover, in embodiments where the structural layer is printed, e.g. with product information and / or logo, etc., the protective coating reduces or minimise damages to the print. In a non-limiting example, the protective coating may be selected from a wide range of water-based coating to ensure compostability, for example Sirane™ Cl Coating, which is an opaque white liquid, or Sunstar™ coatings manufactured by SunChemical Ltd. In a nonlimiting example, the protective coating may be applied to a surface of the structural layer using rods and rollers in a rotogravure process. In another nonlimiting example, the protective coating may be sprayed onto a surface of the structural layer using air or airless spraying systems and then the film coating may be dried using known drying systems using hot air or infrared equipment, in which the drying and curing temperature may for example be 125 °C to sufficiently protect the structural layer from moisture. In some embodiments, the barrier layer may be 30-40 microns thick, and preferably 35 microns thick. The bioplastic barrier layer may have any suitable thickness as desired. The Applicant has found a bioplastic barrier layer thickness between 5 microns to 150 microns to be suitable. However, the Applicant has recognised that 30-40 microns, and preferably 35 microns, offers sufficient liquid impermeability. In some embodiments, the bioplastic sheet material forming the barrier layer may be derived from potato starch. Bioplastic made from plant material is renewable compared to petroleum-based material. However, corn or sugarcane may have undergone genetic modification and the impact of using corn starch or sugarcane products in bioplastic on human health is unknown. Bioplastic material derived from potato starch is therefore considered a safer option. In some embodiments, the flexible packaging material may further comprise an outer layer to protect the flexible packaging material from moisture, the outer layer may be formed of a bioplastic sheet material compostable under home composting conditions and bonded to the structural layer through the water-based adhesive. As an alternative to a protective coating, an external bioplastic layer may be provided over the fibrous structural layer to reduce or minimise damages, such as from moisture or tear, to a flexible package made from the packaging material. In some embodiments, it is also possible to provide a protective coating over the outer bioplastic layer. In some embodiments, the outer layer may be formed of the same bioplastic sheet material as the barrier layer. This results in a simpler manufacturing process. The outer bioplastic layer does not need to be as thick as the inner bioplastic barrier layer as it is not in contact with the aqueous product. In some embodiments, the outer layer may be 10-20 microns thick, and preferably 15 microns thick. In some embodiments, the fibrous sheet material forming the structural layer may be paper of 90 grams per square meter density. Any suitable fibrous sheet material or paper material may be used as desired; however, the Applicant has recognised that paper material of 90 grams per square meter (gsm) offers sufficient support for the resulting packaging material, but paper material of above 90 gsm, for example up to 150 gsm, may be used as desired. In some embodiments, the paper may be made from agricultural waste. Using agricultural waste, it is possible to reduce or avoid the need for trees to be cut down. Another aspect of the present technology provides a home-compostable flexible package for an aqueous product, comprising: a front body portion; a back body portion; and a gusset portion linking the front body portion and the back body portion, wherein the front and back body portions and the gusset portion are formed of a single sheet of flexible packaging material compostable under home composting conditions, the flexible packaging material comprising: a barrier layer to contain the aqueous product, the barrier layer being formed of a bioplastic sheet material compostable under home composting conditions; and a structural layer to provide structural integrity to the flexible packaging material, the structural layer being formed of a fibrous sheet material compostable under home composting conditions, the structural layer being laminated to the barrier layer by a water-based adhesive. According to embodiments of the present technology, the flexible package is made entirely from materials that are compostable in uncontrolled composting conditions, making the flexible package home compostable. In some embodiments, the flexible package may further comprise a spout portion formed of the flexible packaging material and integral to the flexible package. Flexible packages exist which are made partly of compostable materials. However, for liquid products, these packages would often be provided with a petroleum-based plastic spout. Through provision of the structural layer, the packaging material has sufficient structural integrity for a flexible package made using the packaging material to adopt a design with an integrated spout and negates the need for a separate plastic spout. A further aspect of the present technology provides a method of manufacturing a home-compostable flexible package for an aqueous product, comprising: coating a barrier layer with a water-based adhesive, the barrier layer being formed of a bioplastic sheet material for containing the aqueous product and compostable under home composting conditions; passing the coated barrier layer across a hot drum; air-drying the water-based adhesive onto the barrier layer until tacky; overlaying a structural layer onto a coated surface of the barrier layer, the structural layer being formed of a fibrous sheet material to provide structural integrity to the flexible packaging material and compostable under home composting conditions; and passing the overlayed layers between a pair of cooperating rollers to form a laminated sheet packaging material. In some embodiments, the method may further comprise spraying an unlaminated surface of the structural layer with a protective coating, e.g. a water-based protective coating. By spraying a protective coating, it is possible to protect the packaging material with reduced resources. In some embodiments, the method may further comprise, before passing the overlayed layers between a pair of cooperating rollers, coating the structural layer with the water-based adhesive; passing the coated structural layer across a hot drum; air-drying the water-based adhesive onto the structural layer until tacky; and overlaying an outer layer onto a coated surface of the structural layer, the outer layer being formed of a bioplastic sheet material for protecting the flexible packaging material from moisture and compostable under home composting conditions. All three layers of the packaging material can be laminated in a single step; as such, it may improve the efficiency of manufacturing. The additional outer bioplastic layer may provide more effective protection against damages compared to a protective coating in some implementations. In some embodiments, the method may further comprise: segmenting the laminated sheet packaging material into a plurality of package base shapes, each of the plurality of package base shapes comprising a front portion, a back portion and a gusset portion between the front and back portions. The laminated sheet packaging material may be cut into individual package base shapes, where each shape can later be folded and sealed to form a flexible package. In some embodiments, each of the plurality of package base shapes may comprise a spout portion for forming a spout of the flexible package. By integrating a spout portion into the package design, when a package base shape is folded and sealed, a spout is automatically formed. As such, a separate, often plastic, spout is not required. In some embodiments, the method may further comprise heat sealing corresponding sides of the front portion, back portion and gusset portion. In these embodiments, the heat sealing process is facilitated by the bioplastic sheet material forming the barrier layer being a thermoplastic material that becomes pliable under heat and solidifies when cooled, such that, heat sealing is performed effectively to the internal barrier layer. The sealing process therefore does not require the application of an additional coating (e.g. an adhesive) in order to seal the packaging material. Preferably, the packaging material is folded in such a way that two or more sides of the internal barrier layer meet and heat-sealed together. Sealing a package base shape to form a flexible package using heat only simplifies the manufacturing process and ensures that every element of the flexible package is home compostable. Implementations of the present technology each have at least one of the above-mentioned objects and / or aspects, but do not necessarily have all of them. It should be understood that some aspects of the present technology that have resulted from attempting to attain the above-mentioned object may not satisfy this object and / or may satisfy other objects not specifically recited herein. Additional and / or alternative features, aspects and advantages of implementations of the present technology will become apparent from the following description, the accompanying drawings and the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS Embodiments will now be described, with reference to the accompanying drawings, in which: FIG. 1 shows an exemplary flexible packaging material according to an embodiment; FIG. 2 shows an exemplary processing step for manufacturing the flexible packaging material of FIG. 1; FIG. 3 shows an exemplary processing step for manufacturing a flexible package using the flexible packaging material of FIG. 1; FIG. 4 shows an exemplary processing step for manufacturing a flexible package using the flexible packaging material of FIG. 1; FIG. 5 shows an exemplary processing step for manufacturing a flexible package using the flexible packaging material of FIG. 1; FIG. 6 shows an exemplary flexible packaging material according to another embodiment; FIG. 7 shows an exemplary processing step for manufacturing the flexible packaging material of FIG. 6; FIG. 8 schematically illustrate an exemplary product packaging step; and FIG. 9 shows an exemplary flexible package according to an embodiment. DETAILED DESCRIPTION The Applicant has recognised that conventional home compostable packaging in only able to hold dry goods and products, and while some biobased packaging is able to hold liquids, these packaging still often contains petroleumbased material and / or not compostable under home composting conditions, leading to these packaging being likely to end up in landfills. There is therefore scope for providing home compostable packaging material that is capable of holding aqueous products such as (but not limited to) food, personal care and beauty products. According to embodiments of the present technology, the flexible packaging material comprises a bioplastic barrier layer and a fibrous structural layer laminated thereon. The bioplastic material is impermeable to liquid, enabling the packaging material to hold liquid. The fibrous layer provides the packaging material with structural integrity to enable the resulting laminated material to be used as packaging material. The added structural integrity enables a flexible package made from the packaging material to be placed on shelves in a standing (rather than lying down) position, allows a more robust seal to be formed between two halves of the package, and improves the ability of the package to withstand tear. According to embodiments of the present technology, the flexible package is made entirely from materials that are compostable in uncontrolled composting conditions. In particular, bioplastic material that is compostable under uncontrolled composting conditions is used while the structural layer being formed of a fibrous material is naturally compostable under home composting conditions, thus the two layers synergistically combined to give a strong yet home compostable packaging material. FIG. 1 shows an exemplary flexible packaging material 100 according to an embodiment of the present technology. The packaging material 100 comprises a barrier layer 110 formed of a bioplastic sheet material that can be composted under uncontrolled composting (home composting) conditions and a structural layer 120 formed of a fibrous sheet material that is naturally compostable, and the two layers 110, 120 are laminated together by an adhesive. Preferably, the adhesive is a water-based adhesive to ensure product safety and compostability, and may be organic and biodegradable. The packaging material 100 further comprises a protective coating 130 sprayed onto the structural layer 120 to protect the structural layer 120 from e.g. moisture damage. The protective coating may be selected from a wide range of water-based coating to ensure compostability, for example, Sirane™ Cl Coating, which is an opaque white liquid, or Sunstar™ coatings manufactured by SunChemical Ltd. The present technology is particularly relevant to aqueous product packaging; as such, it is an important feature of a flexible packaging material according to the embodiments that, once formed into an enclosed or sealed product package, it provides good barrier properties against moisture. The Applicant has determined that 100% biodegradable and compostable films available from Packtato™ (https: / / www,packtato. b i p / e n) using vegetable starch from 100% organic raw material (mainly potatoes) in Italy and certified by TUV Austria, with OK COMPOST HOME and INDUSTRIAL certificates, is a suitable material for forming the barrier layer 110. The material may be formed with any suitable and desirable thickness, e.g. from 10 microns to 150 microns. A thickness in the range of 30 to 40 microns is considered to provide good moisture barrier properties and capable of blocking the transmission of gases (including oxygen) sufficiently to reduce or prevent product deterioration (e.g. by oxidation). The preferred thickness for the internal barrier layer 110 is approximately 35 microns. Another important feature of a flexible packaging material according to the embodiments is that a package made using the packaging material and containing an aqueous product can preferably be placed on shop shelves in a standing position instead of lying down. This not only ensures filled packages are less likely to burst under pressure, it also enables better visibility of logos and product information provided (e.g. printed) on the packages. A bioplastic sheet material alone is found to provide insufficient structure for packages to stand and, more importantly, to be sealed properly. The Applicant has determined that a structural layer made from a fibrous material can provide packages made from the packaging material with the structural integrity that gives the packages the ability to stand with a gusset seal at the bottom of the package. A paper material made using agricultural waste as raw material available from envoPAP™ (wyzw.enyopapxom) is identified as a sitable material for forming the structural layer 120. The use of fibres extracted from agricultural waste products reduces or altogether avoids the need to cut down trees. A density of 80 to 150 grams per square meter (GSM) for the paper material is considered to provide sufficient structure to the packaging material. The preferred density for the material used for the structural layer is approximately 90 GSM. The resulting packaging material (e.g. packaging material 100) is estimated to degrade in home composting conditions in around 12 months. An exemplary manufacturing process of the flexible packaging material is described with reference to FIG. 2. The bioplastic film used to form the barrier layer 110 is typically provided in a roll, and the barrier layer 110 is unrolled and passed through an adhesive coating apparatus which applies an adhesive coating onto the barrier layer 110. The adhesive-coated barrier layer 110 is then allowed to dry until tacky, either by heat or air dry, or both. The adhesive-coated barrier layer 110 is then overlayed with the structural layer 120, which is simultaneously unrolled from a storage roll, and both are passed through a pair of cooperating rollers 210, 220, where the barrier layer 110 and the structural layer 120 are pinched / compressed together and bonded by the adhesive to form a laminated flexible packaging material. After the barrier layer 110 and the structural layer 120 have been bonded, the laminated flexible packaging material 100 may then be converted into flexible packages for liquids. The first step is shown in FIG. 3, in which the packaging material 100, for example stored as a roll, is secured onto a conveyor belt and passed through a first printing apparatus 310. The first printing apparatus 310 prints onto the packaging material 100 cutting or segmenting guide for cutting or segmenting the packaging material 100 into a plurality of repeating package base shapes 320. Each package base shape 320 comprises a front body portion 321 and a back body portion 322 connected together through a gusset portion 323. The package base shape 320 is further provided with corresponding side spout portions 324 which, when sealed together, form a side spout to facilitate pouring of the liquid product stored within the package. As shown in FIG. 4, the packaging material 100, now printed with a plurality of package base shape 320 cutting / segmenting guide, is passed through a second printing apparatus 410, which prints onto the packaging material 100 artwork for the packages, logos and / or product information. The first printing apparatus 310 and the second printing apparatus 420 may be the same or different printing apparatuses, and in the case of different printing apparatuses, they may be of the same type (e.g. same make, same model, same size, etc.) or different type. The printed packaging material is then sprayed, as shown in FIG. 5, by a spraying apparatus 510, with a protective coating (protective coating 130). The protective coating 130 is preferable impermeable, or at least with limited permeability, to moisture so as to protect the structural layer 120 from damages from air or other sources of moisture. The Applicant has determined that Sirane™ Cl coating or Sunstar™ coatings are suitable substances to form such a protective coating, but other suitable coating material may be used as desired. After spraying, the protective coating 130 is then left to dry, e.g. by heat or air dry, or both. In an alternative implementation of the present technology, shown in FIG. 6, a flexible packaging material 600 comprises a barrier layer 610 that is impermeable, or has limited permeability, to moisture and gases. For example, the same bioplastic sheet material used for the barrier layer 110 can be used for the barrier layer 610. The packaging material 600 further comprises a structural layer 620 to provide additional structural integrity to the packaging material 600. For example, the same fibrous sheet material used for the structural layer 120 can be used for the structural layer 620. The packaging material 600 differs from the packaging material 100 in that, instead of the protective coating 130, the outer layer of the packaging material 600 is formed of an outer layer 630, which provides a similar function to the protective coating 130 that is to protect the structural layer 620 from moisture damage. In an example, the same bioplastic sheet material used for the barrier layer 110 and 610 can be used for the outer layer 630. In this case, as the outer layer 630 is not in direct contact with a liquid, the Applicant has determined that a thickness of 10 to 20 microns, preferably 15 microns, of the bioplastic sheet material is sufficient. Similar to the packaging material 100, the barrier layer 610 and e.g. the outer layer 630 may each be coated with an adhesive coating, as described above with reference to the packaging material 100, and all three layers 610, 620, 630 can be laminated into a single sheet of laminated packaging material by a pair of corresponding rollers 710, 720, as shown in FIG. 7. In the present alternative embodiment, the steps of printing segmenting guide and printing artwork and product information may be performed on the fibrous structural layer 620 prior to lamination, or be performed on the outer bioplastic layer 630 following lamination. While a protective coating is not required for the present alternative embodiment, it is possible, and within the scope of the present technology, to spray the packaging material 600 with a protection coating if desired. The individual coated and printed package base shapes 520 can then be converted into individual flexible packages 820, as shown in FIG. 8. The conversion process may be performed by the same party (e.g. same factory) as the printing and coating, or the packaging material may be transported to a different site and / or different party to form the packaging material into individual packages 820. An exemplary conversion process may include a step of cutting / segmenting individual shape 520, a step of folding the front and back of a shape 520 such as using a plough bar, a step of opening up the middle fold to form a bottom gusset, a step of sealing the bottom gusset using e.g. heat seal bars, a step of forming side seals using e.g. vertical heat seal bars, and optionally a step of cooling the seals or allowing the seals to cool and a step of trimming the package, if necessary. A cross-sectional view of a flexible package 820 formed as described above is shown in FIG. 9. Note that a side spout portion 910 is formed integrally as part of the flexible package 820, which facilitates pouring of a liquid product stored within the package 820. As the side spout portion 910 is formed of the same packaging material 100, 600, the entire flexible package 820 is home compostable. As will be appreciated by a skilled reader, the spout may be provided to any part of the package as desired, such as a top spout, a bottom spout, etc. Once individual flexible packages 820 are formed, they can be transported to a liquid product manufacturer for filling and final sealing. Flexible packages made using the flexible and compostable packaging material 100, 600 according to the embodiments are capable of storing dry or liquid products alike, though they are particularly suited for storing liquid products, such as (but not limited to) food products, personal care products (e.g. shampoo) and beauty products (e.g. moisturiser). The package base shape shown herein is intended to be an example. Other shapes and sizes, such as sachet for beauty product samples or condiments, are possible and have been contemplated. The examples and conditional language recited herein are intended to aid the reader in understanding the principles of the present technology and not to limit its scope to such specifically recited examples and conditions. It will be appreciated that those skilled in the art may devise various arrangements which, although not explicitly described or shown herein, nonetheless embody the principles of the present technology and are included within its scope as defined by the appended claims. Furthermore, as an aid to understanding, the above description may describe relatively simplified implementations of the present technology. As persons skilled in the art would understand, various implementations of the present technology may be of a greater complexity. In some cases, what are believed to be helpful examples of modifications to the present technology may also be set forth. This is done merely as an aid to understanding, and, again, not to limit the scope or set forth the bounds of the present technology. These modifications are not an exhaustive list, and a person skilled in the art may make other modifications while nonetheless remaining within the scope of the present technology. Further, where no examples of modifications have been set forth, it should not be interpreted that no modifications are possible and / or that what is described is the sole manner of implementing that element of the present technology. Moreover, all statements herein reciting principles, aspects, and implementations of the technology, as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof, whether they are currently known or developed in the future. It will be clear to one skilled in the art that many improvements and modifications can be made to the foregoing exemplary embodiments without departing from the scope of the present techniques.

Claims

1. A flexible packaging material for an aqueous product, comprising:a barrier layer to contain the aqueous product, the barrier layer being 5 formed of a bioplastic sheet material compostable under home composting conditions; anda structural layer to provide structural integrity to the flexible packaging material, the structural layer being formed of a fibrous sheet material compostable under home composting conditions, and the structural layer being laminated to 10 the barrier layer by a water-based adhesive, wherein the structural layer is sprayed with a water-based protective coating to protect the structural layer from moisture,wherein the flexible packaging material is compostable under home composting conditions.

152. The flexible packaging material of any preceding claim, wherein the barrier layer is 30-40 microns thick, and preferably 35 microns thick.

3. The flexible packaging material of any preceding claim, wherein the 20 bioplastic sheet material forming the barrier layer is derived from potato starch.

4. The flexible packaging material of any preceding claim, further comprising an outer layer to protect the flexible packaging material from moisture, the outer layer being formed of a bioplastic sheet material compostable under home 25 composting conditions and bonded to the structural layer through the water-based adhesive.

5. The flexible packaging material of claim 4, wherein the outer layer is formed of the same bioplastic sheet material as the barrier layer.

306. The flexible packaging material of claim 4 or 5, wherein the outer layer is 10-20 microns thick, and preferably 15 microns thick.

7. The flexible packaging material of any preceding claim, wherein the fibrous35 sheet material forming the structural layer is paper of 90 grams per square meterdensity.27 03 238. The flexible packaging material of claim 7, wherein the paper is made from agricultural waste.

59. A home-compostable flexible package for an aqueous product, comprising:a front body portion;a back body portion; anda gusset portion linking the front body portion and the back body portion, 10         wherein the front and back body portions and the gusset portion are formedof a single sheet of flexible packaging material compostable under home composting conditions, the flexible packaging material comprising:a barrier layer to contain the aqueous product, the barrier layer being formed of a bioplastic sheet material compostable under home composting 15 conditions; anda structural layer to provide structural integrity to the flexible packaging material, the structural layer being formed of a fibrous sheet material compostable under home composting conditions, the structural layer being laminated to the barrier layer by a water-based adhesive, wherein the structural layer is sprayed 20 with a water-based protective coating to protect the structural layer from moisture.

10. The flexible package of claim 10, further comprising a spout portion formed of the flexible packaging material and integral to the flexible package.25

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