CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to Provisional Application No. 62/891,347, filed on August 24, 2019, which is hereby incorporated by reference in its entirety.

FIELD OF THE DISCLOSURE

[0002] The present invention relates to a method to produce biomass based thin film products containing high percentages of non-hydrolyzed biomass.

BACKGROUND

[0003] Snack bags, approximately 2 mils (48 pm) thick are typically hydrocarbon-based polypropylene. One notable exception is a snack bag for PepsiCo-FritoLay’s SunChips™, which is of 100% NatureWorks Ingeo™ bio-degradable biopolymer resin polylactic acid (PLA). These bio-based resins for thin film snack bags are more expensive than hydrocarbon-based resins. The cost of PLA is driven by producing lactic acid through fermentation of sugar or starch and in converting lactic acid into a monomer, which is then polymerized to form PLA. Knoerzer et al. US 2011/0200796 Al describes a biobased thin film made of PLA, but does not specify non- hydrolyzed biomass as a candidate for his process and product. The PLA film are inherently derived from a chemical process using sugar hydrolyzed from starch to produce a bio-derivative chemical, polylactic acid, or PLA, and lignocellulose.

[0004] Smooth surface thin film containing well-dispersed microfiber-biomass at 40% weight-to-product, with 99% of the microfibers being less than 10 pm, with a 5-6 pm average particle size in 1-2 mil snack bag film was first achieved in prior art using, respectively, polylactic acid, polypropylene and high-density polyethylene combined with bipolar copolymer compatibilizers and other additives in compounding and blown film at 150°C-200°C (Stuart). Elevated temperatures drive decomposition reactions increasing odors from hemicellulose carbohydrates, starch and protein with odors stronger than unheated native biomass odors. The odors, and even pleasant odors, are unacceptable in snack food packaging.

[0005] Practical methods for direct use of biomass in thin film at more than 40% may lower snack bag costs and could be disruptive to snack food and other food packaging markets. Additionally, the need for hydrocarbon-competitive bio-degradable plastic products is persistent. [0006] Films used to manufacture food snack bags require multiple layers to prevent vapors, moisture and odors from passing into the inside of the bag to keep crispy snacks from becoming softened. A method to reduce the level of adhesives for adhering layers, and the number of plastic sheets used to prevent odor and vapor transmission, is highly desirable for lowering cost.

[0007] In existing resin-biomass microparticle compounding, the distances and volume of

“space” between well -dispersed 10-40% biomass-microparticles in resin-based compounding results is in minimal direct contact between bioparticles. Resins and required specialty additives are effectively used in amounts that exceed what is needed for particle-to-resin adhesion. While such high amounts of resins undesirably increase cost, they are generally deemed necessary to achieve appropriate compounding rheology while achieving a marketable surface smoothness. [0008] The need for a lower cost biodegradable snack bag is of intense global interest and research. It is presently impractical to blow or cast film generally less than 20 microns with most substrates.

SUMMARY OF THE DISCLOSURE

[0009] The method of the present disclosure includes, grinding most, or optionally, all components, including biomass, plastic or epoxy resins, adhesives, additives to microscopic levels (e.g., 1 to 500 pm, 5 pm to 100 pm or 5 pm to 20 pm), desirably under 10 microns in maximum dimension (e.g., 1 pm to 10 pm or 1 pm to 5 pm) to be combined in making multi layered film. Pre-blown or pre-cast film may be shaped into outside film layers. The disclosed process includes creating microscopic plastic resin particles which are formed into extremely thin layers, typically less than 10 microns (e.g., 1 pm to 10 pm) and preferably less than 6 microns thick (e.g., 1 mih to 6 mih). These particle layers can be subjected, optionally, to heat from microwave or plasma or any energy to melt the particles to form a layer of biomass or hydrocarbon-based film. Printing is typically applied to the side of film opposite what will become the outside of the film packaging. A fine grinding of the outside layer may be desirable to achieve widespread commercial acceptance of the snack bags made in accordance with this disclosure. In certain embodiments, vaporized aluminum under vacuum is applied on top of the printing. A core adhesive layer comprising a mixture of biomass and adhesive is used to bond to the aluminum with a film that becomes the inside of food packaging. The inside layer of the bag will not typically have any printing.

[0010] The ground microscopic components interact chemically and physically for creating rolls of film which function much like typical film but with outer and inner layers thinner than in typical food packaging. The microscopically thin plastic or epoxy based particle layer design is more cost effective than similar thicker-blown or cast film. The inner core adhesive layer comprising high percentages of biomass microfibers, from 40%-99.9% of the total weight of the adhesive layer, contributes to a lower cost product due to the lower cost of biomass microfibers relative to plastic and other additives used in creating thin film plastics. [0011] The disclosed formulation of biomass-plastic-adhesives-additives based thin film products contains high percentages of native (i.e., not hydrolyzed or otherwise chemically treated) biomass, bound by low concentrations of adhesives, epoxies, lignin or any form of glue or plastic sheets which meet FDA regulations. Optionally, bio-based adhesives such as lignin can be used in combination with other materials including calcium carbonate, silica, aluminum and smaller percentages of any type of biobased fiber, protein, starch, sugar or components derived from these. Adhering products are referenced herein as “adhesive(s) while some of the same products may be used alternately to create thin outer or inner plastic sheets. The biomass- adhesive core film acts as an adhesive construct for attaching directly to an outer plastic film layer, and/or aluminized plastic, such as blown or cast film as printed outer and inner food protection layers for snack bags, or formulation of a core adhesive biomass film in which print is applied directly to the core film and to an aluminized or non-aluminized sheet on the opposite side from the printed side. The formulae reduce the number of plastic and/or epoxy thin film layers, adhesive percentages and adhesive layers compared to traditional plastic resin/adhesive layered thin film. Outside layers can be made of hydrocarbon or biobased plastic or epoxy resin, or resins which become the outside printed layer and inside protective layer of a snack bag. Optionally, “Biochar” is included as an additional or stand-alone odor control to enhance the odor barrier preventative qualities provided by vapor deposited aluminum. Specially formulated adhesives, plastics and/or epoxy help block odors and vapors from entering the inside of the bag and contaminating or softening food products, in particular crispy snacks or pet food, as examples, through water absorption and to prevent biomass smells from leaving the bag through the print film exterior sheet.

[0012] The inside and outside film layers of a snack bag in accordance with this disclosure can comprise a synthetic resin, but are preferably comprised exclusively or primarily of biomass material or materials produced from biomass materials. Biomass-derived film layers can be sprayed on as a mist, or rolled on in thin layers on top an adjacent layer of the overall film including aluminum and composites of the biomaterials described herein. Biomass-derived layers can also be created by grinding material to micro-size dimensions, dispersing the ground material to a uniform thickness on a substrate, melting the dispersed ground material (e.g., using microwave and/or plasma or other heat or heat-generating sources) to cast a film upon the substrate or between other layers of material, including composites of biomass microparticles. The same outer film applied in the outer and inner layer can be cast independent of the primary adhesive-biomass-additive film, and applied as a film after its casting and melting. The biomass composite layers may contain additives that form vapor, moisture and odor barriers. The outer layer can serve to cover print applied to or adjacent a layer, to alternately provide vapor barrier properties and to provide strength. Specialty lignin which has been manufactured to emit little to no odor can be employed within the outer or inner layer as an adhesive to bind together components and to bind the outer layers described above with an inner layer comprising combinations of the various element options described herein. When a clear layer is desired to allow viewing of a printed layer, a non-filler film solution is preferred which may consist of biodegradable or compostable film. Certain products produced using the methods and materials described herein are compostable, or in the case of any aluminum employed as vapor barrier, separated from all other hydrolysable, biodegradable components during decomposition in landfills.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 illustrates a biomass-adhesives mixture along with plastic film on each side of the mixture in one embodiment having outer plastic films with vapor-deposited aluminum. The figure further illustrates that space between the particles have been reduced and virtually eliminated by crushing biomass microparticles together. Mechanical pressure spreads adhesives throughout the biomass matrix and forces a thin layer to the edge of the film for adhering to aluminum-coated film or directly to a printed plastic film layer without aluminum, and optionally directly to the “inner” layer opposite the print film layer which becomes the inside of a snack bag, reducing the need for expensive adhesives.

[0014] Figure 2 illustrates the configuration of a printed film going through a vapor deposition system wherein a thin aluminum layer is deposited upon the inner side of an outer printed sheet directly on the printed side to provide an aluminum face to which adhesives can readily bind to adhere the internal biomass/adhesive core to the outer pre-blown or cast film. The same vapor deposited aluminum can be deposited on the opposite side which becomes the inside sheet of a plastic snack bag or other food packaging. The inner core of biomass microfibers and adhesives can be bound to the aluminum on the inner side of the aluminum opposite the inner plastic film layer or an aluminum layer deposited on the inner plastic film layer.

DETAILED DESCRIPTION

[0015] The present invention relates to a method for producing a multi-layered biomass- based thin film, one version being approximately 2 mils (52 pm) thick consisting of a high percent of biomass microparticles compared to existing products and another size of 4 or more mils thick bag wall thickness, e.g. 35-40 lb. pet food bags. Thin film snack bags typically have no non-hydrolyzed biomass. Bio-based films are manufactured using bio-based chemicals in which carbohydrates are hydrolyzed and converted into PLA resin, then biofilm; Biomass-based film is a different type and degree of difficulty, but at a lower cost compared to bioplastic film based on PLA and should not be confused with each other unless PLA can be used in an outside layer without biomass in this invention when processed as described herein. Any source of target-sized biomass microfibers from industry or processes can be used as described herein. [0016] Other end-product dimensions can be achieved using the same methods disclosed herein. For example, the same formula can be applied to achieve a composite thickness of approximately 4 mils (108 pm) as used in 40 lb. bags of dry pet food, wherein the preferred biomass microfiber maximum dimension is, as one example, <28 pm for large pet food bags. [0017] In another example, biomass microfibers of a maximum size of 16 pm, preferably below 10 pm are blended with a synthetic (hydrocarbon) or biobased adhesive or adhesives. The mass ratio of adhesive(s) to biomass microfibers and additives can be in the range of from 0.0001 to 0.2. Adhesive or adhesives can be any type including melt adhesives, a single liquid or binary, two-part liquid adhesive/epoxy, of low or medium viscosity or any other type of glue or adhesive that binds with aluminum polyolefin film. Optionally, <32 pm sized microparticles can be used for 4 mil thick film. Any size film can be created employing the disclosed method. [0018] Additives include calcium carbonate, biochar, coloring agents, and compatibilizers which can optionally be ground to match the size of the biomass microfibers for optimal blending with biomass microfibers. Grinding melt adhesives below 200, 100, 50 microns or below <10 microns enhances distribution and blending with biomass microfibers while increasing their spreading between and around biomass microparticles. However In the use of Platamid, a melt adhesive, no difference was seen in adhesion characteristics between 20 pm and 100 pm particle size allowing for potentially larger starting adhesive particle size.

[0019] The A-part (believed to be an oligomer or combination of oligomers) of a two- part epoxy resin (binary epoxy) had a viscosity as received from the manufacturer with examples of the viscosity approximately that of Hershey’s liquid chocolate and the B-part (believed to be crosslinkers) had a viscosity of a milk diluted version of Hershey’s chocolate. The epoxy formula generated an exothermic reaction driving curing of the hardening epoxy. Melt adhesives require added heat through chamber heating, heated rollers, or both. Temperatures from ambient to 220°C can be applied depending on brand and type of melt or other adhesive. The present invention benefits from temperatures much lower than 220°C in preventing or reducing odors from heated biomass. Lower temperature and longer curing time in the final roll up is a preferred formula for controlling biomass odors.

[0020] Heating, when required for melt adhesives, before, during, and after, or at all timepoints may be applied.

[0021] Any combination of the above-described mixtures, at ambient or with heat added are fed and spread onto a roller, or a roller and a moving belt or any other conventional high throughput press known to those skilled in the art. The mixture and combined layers are compressed until biomass microfibers are in intimate contact. The mechanical pressure can be from .01 psi to 1,666 psi to achieve a desirable distribution of adhesives between biomass microfiber and additive particles. Simultaneously, compression causes filling surface interstices of the biomass microfibers with adhesives, while space between biomass particles is reduced to where additional pressure weight does not reduce film dimensions significantly (e.g., less than 10 pm). This fixes the lowest ratio of adhesives to the biomass microfibers, while creating strong bonds. Outer plastic film layers supply strength to the finished snack food wrapping product. [0022] Before or during compression of the biomass/adhesive/additive mixture, sheets of pre-blown or pre-cast film, optionally having at least one film with vapor deposited aluminum coating on the side facing the biomass-adhesive layer are applied from rolls which adhere to the adhesive on the surface of the biomass-adhesive layer. Two feeds of blown thin film sheets each from 1-20 pm, preferably from 1-12 pm thick, or 5-9 pm thick, each consisting of one or more each of BOPET, PET, polypropylene, high density polyethylene, Green Dot™ bio-resins, NatureWorks™ polylactic acid, Ecopoxy epoxy resins, and/or any other bio-resins are qualified, are lain upon the moving system of belt, and or rollers, and, or compression rollers, or combinations of each, to adhere to the core biomass-adhesive adhesive layer. The 3 layers are compressed until a final, prescribed target dimension is reached. Resins can be modified to increase friability to facilitate grinding to smaller particle sizes to spread and melt upon the surface of other film components, or created independent of the core laminate to create outside and inside protective layers at much smaller dimensions than possible with conventional epoxy formulae. A conventional "crispy snack" bag has a thickness of approximately 52 pm (2 mils). Thinner and thicker snack bags can be created using the formulae and methods disclosed herein. Formulae can be modified to create more friable adhesives and/or film to facilitate grinding to extremely low particle size or sizes (e.g., below 10 microns maximum dimensions). Microwave or plasma or other heat source can be used to melt plastic or epoxy into film and/or adhesive layers.

[0023] The composite film of the biomass/adhesive/additives/face once fully compressed can be disposed on a combination of one or more of chilled rollers, chilled belt inline, cooling chamber. Controlled cooling can be employed to promote curing of certain adhesives. For certain formulations, curing can occur without cooling, with curing continuing in the final rolled configuration. In certain epoxy resin systems, elevated temperatures can be employed to achieve rapid curing. Cooling can be applied if required after components of a two-part epoxy adhesive are mixed and applied to the product film.

[0024] The composite film is rolled up on a windup roller where curing continues until complete and is ready for use in a snack bag or other food packaging. Cooling may optionally be applied ahead of the windup for epoxy and other adhesives.

[0025] In certain aspects of this disclosure, opposite outer thin film plastic sheet layers can be printed and/or coated with a vapor deposited aluminum layer (e.g., 0.5 nanometer) for preventing vapor reaching crispy snacks, and to control odor. Adhesion of the biomass microfiber-adhesive core layer to the print and internal food protective sheet can be achieved directly with the deposited aluminum on one side, the internal side, of the sheets, if aluminum is applied.

[0026] An adhesive formula that is subjected to ambient or moderate temperature, or temperatures lower than traditional plastic compounding can be employed to bind biomass to adhesive, biomass to biomass and to adhere the biomass-adhesive formula along with any fillers such as CaC03 or biochar, as examples, to outer layers of film including film optionally containing a thin layer of vapor deposited aluminum wherein the biomass-adhesive core layer is adhered to the thin outer layers, or without vapor deposited aluminum wherein the core biomass- adhesive layer is adhered directly to the outer plastic print film or opposite side layer which becomes the inside of a snack bag or other packaging product. [0027] Lower temperature adhesive formulae minimize creation of odors from biomass which result from heat breaking down biomass components into vapor, including sugars, starch, protein, other hemicellulose carbohydrates, and lignin. Formulating exterior plastic sheet resins and adhesives can help reduce and block vapor and moisture transfer through the laminates and prevent moisture vapor contact with dry, crispy snacks within plastic bags made from the laminate formula to augment vapor deposited aluminum or to entirely replace vapor deposited aluminum.

[0028] Adhesives of glue, epoxy of any effective type can serve to bind plastic film components, with or without aluminum deposited on the plastic thin film, with the adhesive- biomass-filler option core laminate, which functions as an adhesive in binding, while greatly reducing the use of plastic resin and adhesive, and can reduce the number of sub-film layer while greatly increasing biomass percentage over any other type of film.

[0029] Adhesives can include lignin derived from biomass, including in particle size less than 10 micron. Lignin may be applied within any configuration herein including a central film layer containing biomass microfibers, calcium carbonate, other additives which when combined becomes an adhesive on its own terms and can be used to bind other layers together to form a composite laminate film. Lignin may comprise from .01% to 99.99% of the mass of the central adhesive film layer. New non-odor lignin enhances effectiveness of other components for controlling odors leaving a snack bag or other packaging to the outside, or preventing odors including biomass odors, natively or increased through heating processes.

[0030] West System 650-8 Gflex Epoxy is an example adhesive solution for binding biomass-to-biomass, with or without fillers such as CaCo3, and for binding the biomass- adhesive-additive laminate to pre-blown or pre-cast thin film of any type. Variations of the Gflex Epoxy or entirely new formulations can be created and applied by West System, including formulae which can be manufactured from biodegradeable elements, specifically tailored to FDA approval for food packaging. 650-8 GFlex is a toughened, versatile, liquid epoxy for permanent waterproof bonding of fiberglass, ceramics, metals, plastics, damp and difficult-to-bond woods. [0031] Vaporized aluminum is achieved by heating aluminum to hundreds of degrees.

When deposited upon a plastic surface, the temperature has been brought down by a chilled roller at -5° F which will minimize or prevent smearing or otherwise damage already-applied ink on the print film, “interior” reverse print side when the vapor deposition system is configured accordingly for use with the methods and materials disclosed herein. The disclosed methods and materials can reduce the number of laminate layers within the final snack bag laminate.

[0032] In certain aspects of this disclosure, an adhesive-based thin film is created by applying an ultrafme mist deposition of epoxy to an aluminum metallized plastic film that has been printed upon. An adhesive-biomass film is adhered on the opposite side of the print face. The aluminum is printed upon without customary reversing of image and lettering. The epoxy mist is applied and is dried rapidly at temperatures from ambient to about 200°C (400°F) depending upon the type of ink employed (laser printer ink being the highest temperature ink). The extremely thin layer applied with thickness between 1-12, or 1-16 microns thick provides a platform for nearly instant drying. Visually clear epoxy provides a clear view of the print.

[0033] The combinations of any and all of the above embodiments are employed to optimize the effectiveness of the core process embodied in the various examples described herein.

[0034] In another embodiment, multiple types of bonding agents can be deployed together, separately and/or in various time points in sequence to achieve a first, fast or instant bonding, e.g. a “superglue” type of glue, followed by another, longer curing but strong glue for additional strength when fully cured, and optionally for added flexibility or stiffness. A bio based, preferably protein-based, or a protein/carbohydrate-based adhesive is preferred and establishes a platform for a complete and cost-effective biobased and biodegradeable film product.

[0035] Water-based adhesive can be applied followed by a fast moisture removal step.

[0036] Use of ball media, including but not limited to chrome steel balls of any dimension, in final milling at low dimensions (e.g., 1.6 mm), is achieved by moving media balls, and biomass microfibers created in ball milling, collectively out of a mill over a shaker sieve of any type in which the holes are small enough to prevent the ball media from flowing through while easily allowing all or virtually all microfiber biomass to pass the sieve holes to achieve separation of product and media. The separated media balls are returned to the mill while the freshly ground microfibers are moved forward into the process for air disagglomeration and classification into product and Overs for further grinding. Single chemical formula resins and epoxies are processed within the scope of the present disclosed formulation to below 10 microns thickness, with a preferred thickness of less than 6 microns.

EXAMPLE

[0037] 40 pm thick biomass-adhesive core adhesive film has been produced combining

10% (by mass) Platamid 100 pm particle size adhesive with 70% (by mass) -10 pm oat hull microfibers and 20% (by mass) CaC03 under pressure in a Carver lab press at 205f for 1.5 minutes (without benefit of pre-heating the mixture) to form an effective adhesion between the core adhesive-based laminate and two 12-micron thick BOPET blown film sheets covered on one side with .5 pm vapor deposited aluminum on each side, glued to the core adhesive-based laminate, resulting in a strong bond between all laminates yielding a strong laminated composite. Other combinations of oat hulls, Platamid adhesive, CaC03, with and without a micro thin spray of 3MSuper77 adhesive, and in one case 1% Fusabond all created strong bonds between laminates. All were pressed and heated as described above and cooled on the lab floor. Many combinations of the formula are possible in creating an optimized series of film products with high percentage of oat hulls.

[0038] The above description is intended to be illustrative, not restrictive. The scope of the invention should be determined with reference to the appended claims along with the full scope of equivalents. It is anticipated and intended that future developments will occur in the art, and that the disclosed devices, kits and methods will be incorporated into such future embodiments. Thus, the invention is capable of modification and variation and is limited only by the following claims.