WO2025069116A1

WO2025069116A1 - Transport pallet made from cellulose fibers and hydrophobic component and process for producing such a pallet

Info

Publication number: WO2025069116A1
Application number: PCT/IS2024/050013
Authority: WO
Inventors: Fridrik R. Jonsson; Johann BJORGVINSSON
Original assignee: Jonsson & Co Ehf
Current assignee: Jonsson & Co Ehf
Priority date: 2023-09-26
Filing date: 2024-09-26
Publication date: 2025-04-03
Anticipated expiration: 2026-03-26
Also published as: IS050577A; IS3059B

Abstract

A composite transport pallet comprises a composite of cellulose fiber material and a hydrophobic component. The composite material is a preferably two-material composite where the matrix comprises in the range of 10-40 wt% hydrophobic component selected from wax and hydrogenated oils and fats and the reinforcement is moulded cellulose fiber pulp. The hydrophobic component can comprise various forms of hydrogenated vegetable oils, hydrogenated fats, waxes like oil-based paraffin waxes and vegetable waxes and optionally also polymers.

Description

TRANSPORT PALLET MADE FROM CELLULOSE FIBERS AND HYDROPHOBIC COMPONENT AND PROCESS FOR PRODUCING SUCH A PALLET

FIELD OF INVENTION

The disclosure is in the field of moulded pulp articles and specifically relates to pulp moulded paper pallets, where a significant increase in strength and hydrophobicity is achieved from producing the paper pallet from a composite material structured from cellulose fiber and a hydrophobic component comprising hydrogenated oils or fats or wax.

BACKGROUND

There is growing awareness and a global concern over increasing cost and pollution from pallets made from wood. The wood pallets put considerable strain on forests and wood supply streams. Wood pallets are durable but heavy, which leads to higher transport costs. Wood pallets do not nest and therefore take up large space during transport. Wood pallets can carry parasites across continents and therefore have to be heat-treated by law if used in crosscontinental transport. This is a costly procedure. Plastic pallets are an alternative solution to wood pallets and have some advantages over wood pallets, for example, plastic pallets have been provided in shapes such that they can be nested when stored (stacked so that one pallet fits into the next) but they add to the ever increasing plastic pollution on land and in oceans. While proper waste management is crucial to plastic recycling, proper and efficient recycling of plastics remains a challenge; much of collected plastic recycling waste ends up as fuel in high-temperature disposal incinerators and huge amounts of plastic are simply left not properly disposed of, much of it ending up in water streams and the oceans. There is therefore a need for biodegradable materials that can be employed in the production of articles currently made of plastic.

Prior art describes pallets made from moulded paper. They are light-weight and fully recyclable, however, they suffer from low strength and from being hydrophilic, which drastically lowers the strength of the paper pallet when exposed to humidity and water.

US 3,611 ,952 discloses a molded pallet made of wood fiber hot-molding, its feet may be dipped in a solution with resin and/or wax in spirits.

CN 201770074U discloses a paper-based pallet comprising a bottom plate with supporting feet and a panel, a middle layer fixed between the bottom plate and the panel; the middle layer is formed by bonding and fixing of one layer or more than one layer of honeycomb-core paper plates; and the honeycomb holes on adjacent honeycomb-core paper plate layers are staggered and bonded. The bottom plate is manufactured by a paper-pulp compression moulding method. The manufacture pallet is wax-impregnated for surface sealing and waterproofing.

US 4,714,026 discloses a pallet with a deck board and legs which are fixed to the under surface of the deck board. The deck board is constituted of laminated corrugated fibreboard, and each of the legs is formed by a square-tubular frame, which is made of a corrugated fibreboard, and in which a pad or pads made of plastic resin is inserted. The deck board, frame materials, bottom plate, and corrugated sheet may be provided with water resistance treatment such as soaking in or application of water-resistant agents represented by paraffin wax.

WO 2005/044679 discloses wooden pallets, which are treated with a thermoplastic material, for instance paraffin, which forms a coating of the subject, so that the wood is not porous, and the pallet can be wet disinfected.

To date, the above prior art disclosures of paper pallets forming methods have not led to widely available applicable solutions in the industry due to low strength issues and the hydrophilic nature of the paper pallets.

SUMMARY OF THE INVENTION

The new production method and product solve the strength and hydrophilicity challenges of prior art paper pulp-based pallets.

By using a composite of natural fiber comprising cellulose and a hydrophobic component selected from wax and hydrogenated oils and fats, the buckle strength of the pallet feet increases by about two-fold and water resistance is substantially increased, from withstanding less than an hour in water to four weeks.

A composite material is made up of two or more materials with different chemical and physical properties. A composite material is used to enhance the properties of its base materials. Composites offer significant benefits in various material performance aspects, exceeding the mono-material alternatives and particularly stand-alone use of the constituent parts like a normal paper pallet material in the case of the present invention. Most man-made composites combine high tensile fibers that are flexible, with a matrix that forms the fibers into a rigid structure that acquires the compressive strength of the matrix material. The result is a combined material that benefits from the tensile strength of the fiber reinforcer, the compressive strength of the matrix, and the bending strength resulting from the combination of the two to make a strong, rigid, stiff, and bend-tolerant resultant material. The composite pallet of the disclosure is light by nature and automatically sterilized in the manufacturing process. The pallet is fully recyclable and can be shredded and returned to a pulp mix, which in turn can be separated into an aqueous phase (with paper pulp) and organic phase (oils/fats or wax). The composite pallet is very suited for airtransport where light weight is mandatory as it only weights approximately 20% to 30% of a same-size wood pallet.

The disclosure provides a moulded pulp pallet comprising a composite material comprising cellulose fiber and a hydrophobic component as described herein. A fiber pulp-based intermediate pallet is moulded in conventional pulp molding machine, dried and subsequently soaked in a heated bath of the hydrophobic component, such as by submerging, to impregnate the cellulose web with the hydrophobic component matrix. This provides the composite material of the disclosure, where the cellulose fiber makes up the reinforcer and the added hydrophobic component functions as a matrix component.

The present disclosure provides a new and improved way to produce pulp-based pallets using fiber pulp and a hydrophobic component selected from wax and hydrogenated oils and fats. The disclosure overcomes problems of the existing prior art technology. The disclosure provides, over prior art pulp-based pallets, an increase of the buckling strength of pallet feet by at least about twofold and water resistance (to breakdown) from one hour to four weeks.

Hydrogenated oils and fats are types of fats created by the process of hydrogenation. This process involves adding hydrogen atoms to unsaturated fat molecules in order to make them more saturated. The primary reason for hydrogenating oils or fats is to change their physical properties, making them more solid at room temperature. Hydrogenated oils and fats offer the convenience over natural hard fats that the presence of unsaturated fats or oils can be substantially eliminated, and thus hydrogenated oils and fats can be used in the present disclosure without leaving any “greasy” effect on the surface if composite articles, as could happen when using natural fats that typically contain some minor amount of unsaturated fatty chains.

The main benefits of using hydrogenated oils and fats in the composite of fibers and oils or fats is besides the water resistance and added strength mentioned above, is recyclability, and in this regard hydrogenated oils and fats are preferred over wax, as the hydrophobic component of the composite pallet of the disclosure. The composite of cellulose fibers and hydrogenated oils and fats breaks down easily in a hydropulper.

Hydrogenated oils are manufactured from many different sources and mixtures such as those mentioned herein. In the present disclosure it is preferred to select a hydrogenated oil with a relatively low melting point, such as but not limited having a melting point in the range 50- 65°C, such as about 55°C, 58°C, 60°C, 62°C or 65°C. This makes recycling of the pallets easier and quicker.

In a first aspect, the disclosure provides a composite transport pallet comprising natural fiber (cellulose fiber) comprising cellulose and a hydrophobic component selected from hydrogenated oils and fats and wax. The new pallet can advantageously be obtained by molding a pallet from cellulose pulp, drying the pallet, and at least partially soaking the pallet with the hydrophobic component, such as preferably in a bath of the selected hydrophobic component, such that the hydrophobic component is introduced into at least part of the pallet as a composite matrix component.

The hydrophobic matrix component thus not only provides a hydrophobic water repellent surface layer on the pallet of the invention but penetrates the pallet to form an internal matrix component and thus forms a composite with the cellulose fiber material. Advantageously and quite surprisingly, the introduction of the hydrogenated fat/oil or wax component substantially increases the strength of the pallet, compared with prior art moulded pulp pallets.

In a further aspect, the disclosure provides a process for producing a water-resistant biodegradable composite transport pallet comprising the steps of:

- preparing a wet pulp pallet from cellulose pulp by forming in molds,

- drying the moulded pallet,

- releasing the dried pallet from a convective dryer,

- soaking the dried pallet in liquid hydrophobic component selected from wax or hydrogenated oils and fat to obtain a composite pallet, and

- allowing the obtained composite pallet to cool and dry.

In one embodiment the drying comprises drying in drying press mould. In this case, the wet pulp pallet is transferred to the drying press and dried by applying heat.

The advantage of using a drying press mould is that the pre-soaked paper pallet can be made very dense thus reducing the air volume inside the fiber web. Dense fiber web will result in less matrix material being absorbed, thus reducing cost.

It is also possible and in accordance with another embodiment of the invention to dry the moulded pallet without using drying press mold but use a heated convection dryer instead, giving similar results.

The novel application of the composite of fiber with the hydrophobic component provides enhanced strength and hydrophobicity of the product. The process of the invention is applicable to various natural cellulose fiber material such as but not limited to wood-based fiber, hemp, bamboo, cotton fiber, sugar cane fiber, coconut fibers, fibers from grains and straw material.

The hydrophobic component material (matrix) can comprise one or more of various forms hydrogenated oils and fats such as but not limited to canola oils, rape seed oils, olive oils, sunflower oils, soybean oils, peanut oils, sesame oils, corn oils, coconut oils, palm oils, flaxseed oils, grapeseed oils, walnut oils, avocado oils, almond oils, hemp seed oils, animals fat such as pig fats, chicken fats, farmed salmon fats, oils from other farmed fish.

In another embodiment the hydrophobic component comprise one or more vaxes such as but not limited to paraffin waxes and vegetable waxes. In some embodiments the wax is selected from but is not limited to one or more of natural waxes including carnauba wax, rice wax, jojoba wax, candelilla wax, beeswax, and any mixture thereof. Paraffin wax (or petroleum wax) is a soft colorless solid derived from petroleum, coal, or oil shale that consists of a mixture of hydrocarbon molecules containing between 20 and 40 carbon atoms. It is solid at room temperature and begins to melt above about 40°C and can typically have a melting point in the range between about 46° and 70°C (depending on the alkane chain length composition). Various polymers can be added to the wax to enhance the strength and/or alter the properties of the composite in other ways. Preferably such added polymer(s) are selected to be biodegradable. Accordingly, in some embodiments the composite comprises one or more polymer component.

The pulp forming steps of the process are preferably substantially similar to those of existing prior art processes for molding articles from pulp. Accordingly, wet pulp is placed in forming molds, typically with a consistency of 0.7% to 1 .5% dry matter. The forming molds provide the shape of the pallet to the pulp, and water is drawn off with vacuum suction and wire mesh screen.

The pallet of the invention can be of various sizes such as but not limited to, from quarter size Europallet size up full size Europallet (800mm x 1200mm) or US standard pallet of 48 inch x 40 inch. Larger or smaller pallets are possible and within the scope of the invention.

Dipping process

The composite material from cellulose fiber and hydrophobic component is preferably achieved by dipping the formed and dry pallet structure into a bath of the hydrophobic component, preferably with the bath having a temperature in the range from 90°C up to 190°C, to avoid flash point of wax or fats/oils. Time in the bath is preferably in the range from a minimum of 1 second and up to 20 seconds, but more preferably at least about 2 seconds. Typically, after about 20 seconds essentially no further buildup of the hydrophobic component is achieved, though this may depend on the temperature and viscosity of the selected component. In some embodiments the time in the bath is in the range from about 1 second or from about 2 seconds or from about 3 seconds or from about 4 seconds or from about 5 seconds, to about 1 minute or to about 40 seconds or to about 30 seconds or to about 20 second or to about 15 seconds or to about 10 seconds.

There are at least two ways to dip the pallet structure, according to the invention. First is to dip the entire pallet structure into the hydrophobic component bath. This results in that the hydrophobic component penetrates the whole pallet and thus the entire pallet being made of composite structure. The hydrophobic component content achieved with this method is approximately 40% of the weight of the dry finalized pallet, the rest, about 60%, being fiber material. Thus, accordingly, in some embodiments the pallet of the invention comprises in the range of 10-40 wt% of said hydrophobic component and preferably in the range of 20-40 wt% of said hydrophobic component, such as about 20 wt%, about 25 wt%, about 30 wt%, about 32 wt%, about 34 wt%, about 36 wt%, about 38 wt% or about 40 wt%. In some embodiments the pallet of the invention comprises in the range from about 10 wt% or from about 12 wt% or from about 15 wt% or from about 16 wt% or from about 18 wt% or from about 20 wt%, to about 40 wt% or to about 36 wt% or to about 32 wt% or to about 20 wt% or to about 28 wt% or to about 25 wt% of said hydrophobic component.

A second dipping method is to only dip the feet and optionally lower side (bottom surface of the main pallet part) of the pallet into the hydrophobic component bath. With this method is achieved strength and hydrophobicity of pallet crucial legs and lower deck of the pallet, saving considerable quantity of the hydrophobic component. With this method of dipping the hydrophobic component is approximately 10% to 25% of the dry pallet weight for a conventionally shaped pallet, this will depend on the size and shape of the pallet.

The present disclosure generally also relates to and provides a composite material comprising a hydrophobic component selected from wax, and/or hydrogenated oils and hydrogenated fats and moulded cellulose fibers. As described herein above for transport pallets, this composition possesses enhanced mechanical, hydrophobic, thermal, and other properties, as compared to conventional moulded cellulose fiber articles, making it suitable for various applications such as but not limited to paper bottles, general food and fresh produce containers, hospital bedpans, urinal paper bottles, transport pallets, moulded furniture, fish containers, meat containers, burial coffins and inserts into laminated furniture.A benefit of using a hydrophobic component selected from wax and hydrogenated oils and fats in the composite of the invention is recyclability. Unlike moulded articles with added polymer barrier (plastic barrier), the composite of cellulose fibers and hydrogenated oils and fats breaks down easily, e.g., in a hydropulper.

A beneficial surprise of the invention is the substantial increase in strength of moulded cellulose fiber articles after they have been made into the composite of the invention. Pallet feet made according to the invention showed in a conventional buckling load test increased buckling load by about 100%.

A composite material (also called a composition material or shortened to composite, which is the common name) is a material which is made up of two or more constituent materials. These constituent materials have notably dissimilar chemical or physical properties and are merged to create a material with properties unlike the individual elements. Useful composite materials enhance the properties of its base materials. Within the finished structure, the individual elements remain separate and distinct, distinguishing composites from mixtures and solid solutions.

Composites offer significant benefits in various material performance aspects, exceeding the mono-material alternatives and particularly stand-alone use of the constituent parts like a normal pulp moulded article in the case of the present invention. The result, in the case of the present invention, is a combined material that benefits from the tensile strength of the fiber reinforcer, the compressive strength of the matrix, and the bending strength of their marriage to make a strong, rigid, stiff, and bend-tolerant resultant material.

The composite material of the invention is light by nature and automatically sterilized in the manufacturing process. The material is fully recyclable, provided the pulping process in the recycling process is at temperatures exceeding the melting temperature of the hydrogenated oils or fats, and can be shredded and returned to a pulp mix, which in turn can be separated into an aqueous phase (with paper pulp) and organic phase (vax or hydrogenated oils or fats).

The matrix provided by the hydrophobic component selected from wax or hydrogenated oils or fats not only provides a hydrophobic water repellent surface layer on the moulded products but penetrates the product to form an internal matrix component. Advantageously and quite surprisingly, the introduction of the hydrophobic component substantially increases the strength of the moulded product, compared with prior art moulded products, as mentioned above.

In a primary aspect the invention provides a composite material, comprising a mixture of a hydrophobic component selected from wax and hydrogenated oils or fats, and cellulose fibers, wherein the cellulose fibers are uniformly distributed within the hydrophobic component. The hydrogenated oils or fats may be selected from but is not limited to hydrogenated canola oils, rape seed oils, olive oils, sunflower oils, soybean oils, peanut oils, sesame oils, corn oils, coconut oils, palm oils, flaxseed oils, grapeseed oils, walnut oils, avocado oils, almond oils, hemp seed oils, animal fat such as pig fats, beef fats, chicken fats, farmed salmon fats, oils from other farmed fish, or combinations thereof.

The wax may be selected from but is not limited to paraffin wax, beeswax, carnauba wax, microcrystalline wax, or combinations thereof.

The cellulose fibers are preferably derived from wood pulp, cotton, hemp, bamboo, sugar cane fiber, flax fiber, fiber from grains, coconuts or other plant-based cellulose fiber source.

Typically and preferably, the composite material of the invention comprises in the range of about 10-50 wt% hydrogenated oils or fats and preferably in the range of about 20-40% hydrogenated oils or fats, such as in the range from about 10% or from about 12% or from about 15%, or from about 20%, to about 50% or to about 45% or to about 40% or to about 35% or to about 30% or to about 35% of hydrogenated oils or fats (wt%).

As is apparent from the present disclosure, the composite material can be obtained by methods described herein, which generally comprise steps of first moulding said cellulose fibers in a pulp moulding process to obtain an intermediate dry moulded pulp article, and subsequently by submerging, fully or partially, said intermediate moulded pulp article in melted hydrogenated oils or fats to allow the hydrogenated oils or fats to impregnate the moulded pulp article, recovering the article and allowing said article to dry, which comprises said composite material.

In some embodiments of the invention spraying the hot hydrogenated oils and fats on to the intermediate moulded pulp article is applied. Spraying the hot hydrogenated oils at temperature in the range from 90°C to 170°C will result in composite formation on moulded pulp surfaces.

The pulp moulding processes applicable in the invention to prepare the intermediate articles are as such known in the art. Thus, the source pulp may be made by a conventional pulping method where virgin fiber or wastepaper or other fiber source is placed into a hydro pulper. Consistency of between 2 to 5% dry matter is typically used during pulping process or up to 18% if using high consistency pulper. The pulp is later diluted down to 0,7% to 1 ,5% in a moulding machine. The moulding process is preferably a conventional vacuum forming method where a mould (tool) is dipped into the pulp mixture, vacuum is applied to the mould comprising a product shape and wire mesh screen. The screen filters out fiber onto the shaped mould. The mould is transferred out from the pulp mixture and dewatering takes place. After about 4 to 30 seconds of dewatering the resulting article has a fiber content of about 27 to 35% fiber and thus about 65% to 73% water. The wet intermediate article is then moved to a drying station. There are multiple types of drying stations known in the art and applicable in the present invention. The most common is a convection oven operating at a temperature of 160°C to 230°C. Another drying method is applying microwaves to dry the product. A third method is to place the wet intermediate article into a heated pressure tool set comprising male and female die parts. The wet intermediate article is placed between the tool parts and heat is transferred into the fiber web drying the intermediate article to 3% to 9% humidity level. After the drying, whichever method is applied, the dry intermediate article is now ready as an intermediate to be further processed into an article of the composite material.

The conditions and specifications of the pulp material and the pulp moulding process can be selected and optimized depending on the type of article being made, for example, the compression force applied in the moulding machine and other factors such as source of pulp material may effect the density and microscopic characteristics of the intermediate object, which in turn will affect how much hydrophobic component (wax or hydrogenated oils or fats) will be absorbed by the object in the step of soaking in the bath of hot hydrophobic component (wax or hydrogenated oils or fats).

The next step is to soak (e.g. by submerging, dousing or spraying) the intermediate article in liquid hydrophobic component, i.e. wax or hydrogenated oils or fats, preferably by dipping (submerging fully or partially) the article into a bath of melted liquid hydrophobic component (wax or hydrogenated oils or fats), where the liquid wax or hydrogenated oils or fats preferably have a temperature in the range from 50°C to 190°C, such as preferably in the range from 110°C to 190°C, such as from about 50°C or from about 60°C or from about 70°C or from about 80°C or from about 90°C or from about 100°C or from about 110°C or from about 120°C or from about 130°C, to about 190°C or to about 180°C or to about 170°C or to about 160°C or to about 150°C. The minimum melting temperature depends i.a. on the melting point of the selected wax or hydrogenated oils or fats, as the temperature must be sufficient to fully melt the wax/oils or fats and preferably is above the melting point by at least 5°C or more preferably by at least 20°C. In some embodiments, however, a substantially higher temperature is used for the bath than the melting temperature, such as but not limited to a temperature which is in the range of 50° to 100°C higher than the melting point of the wax, oils or fats used. A high temperature such as in the mentioned ranges is preferred as this lowers the viscosity of the wax or oils and enhances its penetration into the intermediate article. The hot liquid wax or hydrogenated oils or fats will penetrate the intermediate article, and flow in between the cellulose fibers, creating a matrix of the hydrophobic component (wax or hydrogenated oils or fats) and reinforcement from moulded cellulose (moulded pulp) thus forming a composite material of great strength.

Accordingly, the composite material of the invention generally and preferably exhibits improved mechanical strength, hydrophobic character, thermal stability, or water resistance compared to pure wax or hydrogenated oils or fats and conventional moulded pulp, respectively.

In another aspect of the disclosure , a rigid composite article is provided and encompassed by the invention, comprising composite material according to the invention, such as described and defined herein.

In yet a further aspect, the disclosure provides a method of preparing the composite material of the disclosure or a rigid composite article of the disclosure, comprising the steps of:

- obtaining a hydrophobic component selected from wax, oils or fats; and cellulose fiber;

- hydrogenating oils or fats or providing hydrogenated oils or fats (these can advantageously be obtained as a ready-made ingredient, i.e. hydrogenated intermediate product, from several suppliers);

- moulding fiber into a shape via pulp moulding method;

- drying the moulded pulp shape into an intermediate article, melting the hydrophobic component (wax or hydrogenated oils or fats) and heating to desired temperature;

- dipping or submerging, fully or partially, said intermediate article into the melted hydrophobic component for sufficient time to allow the hydrophobic component to penetrate and impregnate the intermediate article or other wise applying to the intermediate article the hydrophobic component such as e.g. by dousing or spraying, and

- recovering the impregnated article and allowing the obtained article comprising the composite material to cool and solidify.

Preferably the step of drying may be selected from drying in drying press mould, and drying in convection oven, as mentioned above.

In the case of dipping or submerging, the time in the hydrophobic component bath is preferably in the range from a minimum of 1 second and up to 20 seconds but more preferably at least 2 seconds, such as in the range of 2 to 20 seconds. Typically, after about 20 seconds essentially no further hydrogenated oils or fats penetration is achieved, though this may depend on the temperature and viscosity of the selected wax or hydrogenated oils or fats matrix. Accordingly, the dipping or submerging step may in some embodiments take in the range from 1 sec. or 2 sec. or 3 sec. or 5 sec. to about 20 sec or 18 sec or 15 sec. Longer submerging times may as well be applied if desired e.g. for logistic purposes, such as in the range from 20 sec or from 30 sec to about 60 sec.

As mentioned, spraying or dousing the wax or hydrogenated oils or fats is an option. This creates a matrix layer of between 0,5mm up to 2mm deep. Thus, with this embodiment articles can be obtained that comprise the composite of the disclosure as an outer layer extending about 0,5 to 2 mm into the article, and beyond the outer composite layer is non-penetrated moulded cellulose, depending on the overall thickness of the walls of the object. Thus, in some embodiments moulded articles such as bottles, boxes and trays can be moulded and then at least the inside surface of the articles (the surface intended to be in contact with liquid or wet material) can be sprayed with wax, hydrogenated oils or fats, but optionally also the outside.

Another aspect of the disclosure provides and encompasses the use of the composite material of the disclosure, in an application selected from packaging material, furniture or parts thereof such as furniture inserts, construction, and art and crafts, trays, cartons, including paper-based bottles, and burial coffins.

1 . Composition:

Hydrogenated oils or fats: The hydrogenated oils or fats component can comprise any hydrogenated oils or fats including but not limited to canola oils, rape seed oils, olive oils, sunflower oils, soybean oils, peanut oils, sesame oils, corn oils, coconut oils, palm oils, flaxseed oils grapeseed oils, walnut oils, avocado oils, almond oils, hemp seed oils, animals fat such as pig fats, beef fats, chicken fats, farmed salmon fats, farmed fish oils or combinations thereof. The hydrogenated oils or fats material (matrix) can comprise one or more of various forms of hydrogenated oils or fats. Hydrogenated oils or fats are a colorless solid derived from hydrogenating oils or fats that consists of a mixture of hydrocarbon molecules. Hydrogenated oils, which include partially and fully hydrogenated oils, are types of fats used in various food products. The number of carbon atoms in hydrogenated oils can vary widely because these oils are derived from various sources such as vegetable oils such as the above mentioned or animal fats. These oils are composed of triglycerides, which are molecules made up of a glycerol backbone bonded to three fatty acid chains. The fatty acids in these oils, which determine the number of carbon atoms, typically have anywhere from 12 to 22 carbon atoms, depending on the source of the oil and the specific fatty acids it contains. In some embodiments the hydrogenated oils are selected to be relatively homogeneous, e.g. with only one, two or three major fatty acid constituents. In other embodiments the hydrogenated oils may comprise a relatively heterogeneous mixture of fatty acids. The hydrogenated oils or fats material is solid at room temperature and begin to melt at different temperature depending on the fatty acid composition and degree of hydrogenation, but generally at a temperature above about 38°C and can typically have a melting point in the range between about 46° and 90°C. Various polymers can be added to the hydrogenated oils or fats to enhance the strength and/or alter the properties of the composite in other ways. Preferably such added polymer(s) are selected to be biodegradable. Accordingly, in some embodiments of the invention the composite comprises one or more polymer component.

Hydrogenated oils are manufactured from many different sources and mixtures such as those mentioned above. In the present invention it is preferred to select a hydrogenated oil with a relatively low melting point, such as but not limited to having a melting point in the range 50- 70°C or in the range 60-70°C, such as about 55°C, 58°C, 60°C, 62°C or 65°C. The melting point should be such that the materials remain fully solid at any typical temperatures that respective objects made from the composite may withstand during normal use. However, selecting a hydrogenated oils composition with relatively low melting point, such as those mentioned just above makes recycling of the objects of the invention easier and quicker.

Wax: The wax component can be any wax including but not limited to paraffin wax, beeswax, carnauba wax, microcrystalline wax, or combinations thereof. The wax material (matrix) can comprise one or more of various forms of waxes like paraffin waxes and vegetable waxes. In some embodiments the wax is selected from but is not limited to one or more of natural waxes including carnauba wax, rice wax, jojoba wax, candelilla wax, beeswax, and any mixture thereof. Paraffin wax (or petroleum wax) is a soft colorless solid derived from petroleum, coal, or oil shale that consists of a mixture of hydrocarbon molecules containing between 20 and 40 carbon atoms. It is solid at room temperature and begins to melt above about 38°C and can typically have a melting point in the range between about 46° and 70°C (depending on the alkane chain length composition). Various polymers can be added to the wax to enhance the strength and/or alter the properties of the composite in other ways. Preferably such added polymer(s) are selected to be biodegradable. Accordingly, in some embodiments of the invention the composite comprises one or more polymer component.

Cellulose Fibers: The cellulose fibers can be derived from sources such as but not limited to wood pulp, cotton, hemp, or any other plant-based fiber rich sources. The process of the invention is applicable to various natural cellulose fiber material such as but not limited to wood-based fiber, hemp, bamboo, cotton fiber, sugar cane fiber, coconut fibers, fibers from grains and straw material. These fibers can be refined, unrefined, bleached, unbleached, or treated in any other manner. 2. Preparation: a. The hydrogenated oils or fats material is melted, typically and preferably to a temperature in the range from about 90°C up to about 190°C, appropriate for its type. Typically and preferably, the material is heated to at least about 5°C above the melting temperature of the material mixture but in some embodiments to more than that, ad discussed above. b. Cellulose fibers are moulded into a shaped article, through traditional pulping process with vacuum being applied to a mould that filters out fibers from a slurry composed of water and typically in the range 0,7% to 1 ,5% fiber. The moulded wet product is after the vacuum forming preferably composed of in the range of approximately 29% to 34% fiber and in the range of about 71 % to 66% water. The moulded article is then dried, preferably either in a thermoforming tool, a traditional convective air dryer or a microwave dryer. c. The composite is preferably created by dipping the dry moulded article into a bath of melted hydrogenated oils or fats as described above, or alternatively by dousing or spraying the melted hydrogenated oils or fats onto the intermediate article. The hydrogenated oils or fats impregnate the cellulose structure and reinforce the web of intertwined cellulose fibers. Once thoroughly blended, the composite is allowed to cool and solidify.

3. Properties:

The resulting hydrogenated oils or fats-cellulose composite has enhanced properties compared to either solid hydrogenated oils or fats or moulded cellulose alone. These can include: a. Improved mechanical strength due to the reinforcing nature of cellulose fibers and the embedding of the fibers in the hydrogenated oils or fats matrix. b. Enhanced thermal stability because of the heat-resistant nature of cellulose. c. Much improved water resistance.

4. Potential Applications:

The hydrogenated oils or fats -cellulose composite can be used in various applications such as but not limited to: a. Paper bottles that are liquid resistant; b. Packaging: providing water-resistant and biodegradable packaging alternatives; c. Hospital trays like bed pans and urinal bottles; d. Inserts into composite wood structures such as furniture, e.g. bookshelves, cabinets and more; e. Moulded paper burial coffins; f. Construction: as insulation or protective coatings or sheets.

SELECTED EMBODIMENTS

1 . A composite material, comprising a mixture of hydrogenated oils or fats and cellulose fibers, wherein the cellulose fibers are uniformly distributed within the hydrogenated oils or fats matrix.

2. The composite material of claim 1 , wherein the hydrogenated oils or fats comprise oils and/or fats selected from the group consisting of canola oils, rape seed oils, olive oils, sunflower oils, soybean oils, peanut oils, sesame oils, corn oils, coconut oils, palm oils, flaxseed oils grapeseed oils, walnut oils, avocado oils, almond oils, hemp seed oils, animals fat such as pig fats, beef fats, chicken fats, farmed salmon fats, farmed fish oils, and combinations thereof.

3. The composite material of claim 1 or 2, wherein the cellulose fibers are derived from wood pulp, cotton, hemp, bamboo, sugar cane fiber, flax fiber, fiber from grains, or other plant-based source.

4. The composite material of any of the preceding claims comprising in the range of 10-50 wt% of said hydrogenated oils or fats and preferably in the range of 20-40 wt% of said hydrogenated oils or fats.

5. The composite material of any of the preceding claims wherein said hydrogenated oils or fats have a melting point in the range in the range 50-70°C.

5. The composite material of any of the preceding claims, obtainable by first moulding said cellulose fibers in a pulp moulding process to obtain an intermediate moulded pulp article, and subsequently by submerging said intermediate moulded pulp article in full or partially in a bath of melted hydrogenated oils or fats, or by spraying said melted hydrogenated oils or fats on to said intermediate moulded pulp article to allow the hydrogenated oils or fats to impregnate the moulded pulp article, recovering the article and allowing said article to dry, which comprises said composite material. 6. The composite material of claim 5, wherein an intermediate article is obtained by pulp vacuum moulding process and the obtained intermediate article is subjected to impregnation and penetration by said hydrogenated oils or fats.

7. The composite material of any of the preceding claims, exhibiting improved mechanical strength, thermal stability, or water resistance compared to corresponding moulded pulp intermediate article that has not been treated with said hydrogenated oils or fats.

8. A rigid composite article comprising composite material according to any of claims 1 to 7.

9. A method of preparing a composite material of any of claims 1 -7 or the rigid composite article of claim 8, comprising the steps of:

- obtaining hydrogenated oils or fats and cellulose fiber,

- moulding fiber into a shape via pulp moulding method,

- drying the moulded pulp shape into an intermediate article,

- melting said hydrogenated oils or fats,

- submerging fully or partially said intermediate article into the melted hydrogenated oils or fats for sufficient time to allow the hydrogenated oils or fats to impregnate the intermediate article or dousing or spraying the melted hydrogenated oils or fats onto the intermediate article, and

10. The method according to claim 9, wherein said step drying is selected from: a) drying in drying press mould, and b) drying in convection oven or a microwave dryer.

11 . The method according to claim 8 or 9, wherein said melted hydrogenated oils or fats is at a temperature in the range of 50°C to 190°C.

12. The process according to any of claims 8 to 11 , wherein said submerging is maintained for a period of time in the range of 1 to 20 seconds and preferably in the range of 2 to 20 seconds. 13. The use of the composite material of any one of claims 1 to 7, in an application selected from paper-based bottle, cartons, trays, packaging material, furniture, furniture inserts, construction, burial coffins, and art and crafts.

BRIEF DESCRIPTION OF FIGURES

Figure 1 shows a schematic flow of the process for making a pellet according to the disclosure.

DETAILED DESCRIPTION

In the following, exemplary embodiments of the disclosure will be described, referring to the figures. These examples are provided to provide further understanding of the disclosure, without limiting its scope.

Figure 1 depicts a schematic overview of a process for making the pallet of the disclosure:

1) a hydropulper 1 produces a pulp with consistency in the range of 2-18% solids.

2) the pulp is pumped into pulp storage tank 2.

3) Pulp and white water (from preceding steps, stored in white water tank 3) is blended to create a suitable pulp for the forming tank 4.

4) A pulp pallet 6 is vacuum formed in the forming tank 4 by applying vacuum and pallet shaped moulds 5.

5) The obtained wet pulp pallet 6 is dried in a set of thermo dies 7a, 7b (hot pressing molds).

6) The dry pallet 8 is transferred to a bath 9 of hydrogenated oils or fats, impregnating the fiber base to create a composite material.

7) The obtained composite pallet 10 is cooled and ready for use.

An option to step 5) is to transfer the wet pallet into a convection oven before entering the hydrophobic component bath.

The pulp is made by a conventional pulping method where wastepaper or other fiber source is placed into a hydro pulper. Consistency of between 2 to 5% dry matter is typically used during pulping process or up to 18% if using high consistency pulper. The pulp is later diluted down to in the range of 0,7% to 1 ,5% in the moulding machine. The moulding process is preferably a conventional vacuum forming method where a mould (tool) is dipped into the pulp mixture, vacuum is applied to a mould comprising a product shape and wire mesh screen. The screen filters out fiber onto the pallet shaped mould. The mould is transferred out from the pulp mixture and dewatering takes place. After about 10 to 30 seconds of dewatering the resulting pallet has a fiber content of about 27 to 35% fiber and thus about 65% to 73% water. The wet pallet is then moved to a drying station. There are multiple types of drying stations known in the art and applicable in the present disclosure. The most common is a convection oven operating at a temperature of 160°C to 230°C. Another drying method is applying microwaves to dry the pallet. A third method is to place the wet pallet into a heated pressure tool set comprising male and female die parts. The wet pallet is placed between the tool parts and heat is transferred into the fiber web drying the pallet to 3% to 8% humidity level. After the drying, whichever method is applied, the dry cellulose pulp pallet is now ready as an intermediate to be one part of a composite material. The next step is to soak the pallet in the liquid hydrophobic component, preferably by dipping the pallet into a bath of the liquid hydrophobic component, that is, where the hydrophobic component has been heated to or above melting point to be in a liquid state, such as preferably at a temperature in the range from 70°C to 190°C and more preferably at a temperature in the range 120°C to 190°C. The hydrophobic component will penetrate the intermediate dried pulp pallet, and flow in between the cellulose fibers, creating a matrix of the hydrophobic component and reinforcement from moulded cellulose (moulded pulp) thus forming a composite material of great strength.

EXAMPLES

Pallet feet were molded in conventional molding process as described above. After drying, two specimen were dipped in hot wax bath (145°C) with paraffin wax and two specimen left untreated. After cooling and drying, the pallet feet were subjected to conventional buckling load test.

The result is shown in Table 1 and shows that the feet specimen from the pulp-wax composite have on average 100% higher buckling load.

Table 1

This demonstrates that not only does the disclosure provide objects with good water resistance but very substantial increase in strength.

Claims

1. A composite transport pallet comprising a composite of cellulose fiber material comprising cellulose and a hydrophobic component selected from wax and hydrogenated oils and fats, obtainable by moulding a pallet from fiber pulp, drying the pallet, and at least partially soaking the pallet in wax such that the wax is introduced into the pallet as a composite matrix component, said composite transport pallet comprising in the range of 10-40 wt% of said hydrophobic component and preferably in the range of 20-40% of said hydrophobic component.

2. The composite transport pallet according to claim 1 , wherein said cellulose fiber material is selected from one or more of wood derived fiber, hemp, bamboo, cotton fiber, sugar cane fiber, coconut fibers, fibers from grains and fibers from straw material.

3. The composite transport pallet according to claim 1 to 2, wherein said hydrophobic component comprises hydrogenated oils or fats selected from the group consisting of canola oils, rape seed oils, olive oils, sunflower oils, soybean oils, peanut oils, sesame oils, corn oils, coconut oils, palm oils, flax seed oils, grape seed oils, walnut oils, avocado oils, almond oils, hemp seed oils, animals fat such as pig fats, chicken fats, farmed salmon fats, and oils from other farmed fish.

4. The composite transport pallet according to claim 1 to 2, wherein said hydrophobic component comprises one or more wax selected from paraffin wax and natural waxes including carnauba wax, rice wax, jojoba wax, and candelilla wax; and any mixture thereof and waxes treated by or mixed with polymers to enhance strength.

5. The composite transport pallet according to any of the preceding claims further comprising more or more polymer added to the hydrophobic component prior to said soaking.

6. The composite transport pallet according to any of the preceding claims, wherein the complete moulded pallet has been soaked in the hydrophobic component such that the entire pallet comprises said composite.

7. The composite transport pallet according to any of claims 1 to 4, wherein the feet of said moulded pallet are soaked in said hydrophobic component and optionally also the lower surface of the pallet main part.

8. A process for producing a water-resistant biodegradable composite transport pallet, comprising the steps of: preparing a wet pulp pallet from cellulose pulp by forming in forming moulds, removing the wet pulp pallet from forming moulds, transferring the wet pulp pallet for drying, drying the pressed pallet, soaking the dried pallet or part thereof in liquid hydrophobic component selected from wax and hydrogenated oils and fats to obtain a composite pallet wherein the soaked part comprises in the range of 10-40 wt% of said hydrophobic component, and allowing the obtained composite pallet to cool and dry.

9. The process according to claim 8, comprising soaking the dried pallet or part thereof until the soaked part comprises in the range 20-40 wt% of said hydrophobic component.

10. The process according to claim 8, wherein said step drying comprises drying in in a convective dryer.

11 . The process according to claim 8, wherein said step drying comprises drying in drying press mould.

12. The process according to any of claim 8 - 11 , wherein said wet pulp pallet is formed in vacuum forming process.

13. The process according to any of claim 8 to 12, wherein said step of drying comprises transferring the wet pulp pallet to convection oven and drying the pulp pallet in the convection oven.

14. The process according to any of claims 8 - 13, wherein the step of soaking comprises immersing at least part of the pallet and preferably the entire pallet in a hot bath of said hydrophobic component.

15. The process according to any of claims 8 - 14, comprising immersing the feet of the dried pallet in said hydrophobic component and optionally also the lower surface of the pallet main part.

16. The process according to any of claims 8 to 15, wherein said liquid hydrophobic component is at a temperature in the range of 70°C to 190°C.

17. The process according to any of claims 8 to 16, wherein said hydrophobic component comprises hydrogenated oils or fats selected from the group consisting of canola oils, rape seed oils, olive oils, sunflower oils, soybean oils, peanut oils, sesame oils, corn oils, coconut oils, palm oils, flax seed oils, grape seed oils, walnut oils, avocado oils, almond oils, hemp seed oils, animals fat such as pig fats, chicken fats, farmed salmon fats, and oils from other farmed fish.

18. process according to any of claims 8 to 16, wherein said hydrophobic component comprises one or more wax selected from paraffin wax and natural waxes including carnauba wax, rice wax, jojoba wax, and candelilla wax; and any mixture thereof and waxes treated by or mixed with polymers to enhance strength.

19. The process according to any of claims 8 to 18, wherein said composite transport pallet is a composite transport pallet according to any of claims 1 to 7.