BACKGROUND OF THE INVENTION

[001 ] Burial containers such as coffins, caskets and ash urns are made from a variety of materials such as wood or other timber-based products, metal, plastics ,fired clay and in old times also carved stone. Some of these containers include holes in their base bottom, potentially allowing the earth to enter the burial container, and by doing so to fulfil, to a certain extent, the divine decree from the book of Genesis "For you are dust, and to dust you shall return "[Genesis 3:19].

[002] In recent years, as part of the environment awareness and "Green" tendency, burial containers are required to be environmentally friendly. Accordingly, the container itself when buried in the ground must not contain materials that will contaminate the sounding ground and preferably may disintegrate after the burial.

[003] Since in small countries and worldwide metropolis space is at a premium, regulations that have already came into place are monitoring new land allocations for graveyards. In Switzerland for example, graves plots are already being rented (e.g., ground space) for 25 years. After a period of time, the graves are dug up and the site re-used. The above emphasizes the need to have a bio-based burial container that degrades efficiently and allows the body to undergo a biological decomposition process at a defined time frame.

[004] The most suitable materials for this purpose are bio-based/biodegradable/ nontoxic materials or composites of bio-based materials that are earth/soil based. Elements/components of a burial container made from the soil based composites may be combined with other natural, pure materials such as natural plain wood.

SUMMARY OF THE INVENTION

[005] A bio-degradable soil based burial container according to embodiments of the invention may be fully biodegradable, according to European standard EN13432, comprising of natural, nontoxic ingredients/materials thus when buried in the ground, may not contaminate the ground. Furthermore, since a soil based composite material from which at least a portion of the burial container is made, comprises mostly of soil, there is no need to form a hole in the container in order to fulfil the divine decree from Genesis 3:19, as required for example, in Jewish burial. [006] Some embodiments of the invention may be related to a bio-degradable soil based burial container at least partially made of a soil based composite material. The soil based composite material may include soil and a bio-based matrix that includes a bio based polymer at a weight percentage of at most 10 wt. % of the total weight of the soil based composite material mass. The soil based composite material may have a specific gravity of at most 2 g/cm ³ or even below a specific gravity of 0.7 g/cm ³ (floating soil based composite material).

[007] Some embodiments of the invention may further be related to a method of forming a bio-degradable soil based burial container at least partially made of a soil based composite material. The method may include mixing soil and a bio- based matrix to form a soil based composite material, such that the soil based composite material has a specific gravity of at most 2 g/cm ³ or even below a specific gravity of 0.7 g/cm ³ , forming one or more portions of the burial container from the soil based composite material.

BRIEF DESCRIPTION OF THE DRAWINGS

[008] The subject matter regarded as the invention is particularly pointed out and distinctly claimed in the concluding section of the specification. The invention, however, both as to organization and method of operation, together with objects, features, and advantages thereof, may best be understood by reference to the following detailed description when read with the accompanying drawings in which:

[009] Fig. 1 is an illustration of a sectional view of a plate made from soil based composite material according to some embodiments of the invention;

[0010] Figs. 2A, 2B and 2C are illustrations of burial containers according to some embodiments of the invention; and

[001 1 ] Fig. 3 is a flowchart of a method of making a soil based burial container according to some embodiments of the invention.

[0012] It will be appreciated that for simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements. DETAILED DESCRIPTION OF THE PRESENT INVENTION

[0013] In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known methods, procedures, and components have not been described in detail so as not to obscure the present invention.

[0014] Some embodiments of the invention may be directed to burial containers made of soil based composite material and method of making such containers. Burial containers according to embodiments of the invention may include coffins, caskets and ash urns and may be environmentally friendly. In some embodiments, the burial containers may include bio-based materials from natural sources. In order to strengthen the bio-based materials (e.g., bio-based matrix) earth soil from natural sources may be added to form a soil based composite material. A soil based composite material according to embodiments of the invention may include soil and a bio-based matrix and therefore may undergo a complete biodegradation. The soil-based composite material may be used to form panels or walls or covers or any decorative or construction part of the burial container or the entire burial container. Burial container according to embodiments of the invention may be considered as an "environmental friendly'V'green product" that may be fully composted biologically (e.g., decomposed and digested by living organisms) to form soil, C02 and water, leaving no harmful or toxic waste.

[0015] Soil based composite material for the use in burial containers according to some embodiments of the invention may be relatively light-weight in comparison to wooden, metallic, fired clay or stone burial containers. In some embodiments, the specific gravity of the soil based composite material may be, at most, 2 gr/cm ³ or even below a specific gravity of 0.7 g/cm ³

[0016] Some burial containers according to embodiments of the invention may have an inherent water resistant property. This property may be achieved by the soil based composite material itself as describe herein, so there is no need for additional water resistant coating to be implemented, for example, ash urns that are configured to be held for years or decades indoors (e.g., in church/ at home etc.). In some embodiments components (portions) made of soil based composite material for making the burial containers have a sufficient inherent rupture modulus and breaking strength as required for their function. [0017] Reference is made to Fig. 1 which is a schematic sectional view of an exemplary portion (e.g., panel, a plate, a component and/or a portion of a wall) made from the soil based composite material according to some embodiments of the invention. As it may be clear to a person skilled in the art, the scale in which details are presented in Fig. 1 is inaccurate in order to allow better understanding of the structure of the materials from which the plates are made. A soil based composite material platel O may include at least a bio-based matrix 12 and soil 14. Bio based matrix 12 may include at least one bio based polymer.

[0018] As used herein bio-based materials may be defined as materials derived from plants and/or others renewable agricultural materials, marine materials, forestry materials or animals products. These materials are materials intentionally made from substances derived from living (or once-living) organisms. Bio-based materials do not contain anypetroleum derived products or any synthetic components and are non-toxic and non-hazardous to the ground and environment.

[0019] Bio based matrix 12 may form a continuous phase for binding (e.g., holding, gluing, sticking and/or the like) soil 14 (e.g., binding the soil particles) to form the plate or the container. Bio-based matrix 12 may include a bio based polymer at a weight percentage of at most 10 wt. % of the total weight of the soil based composite material. In some embodiments, the bio-based polymer may include at least one of: casein (milk proteins), polysaccharides (such as cationic starch), oils, waxes, resins, proteins, enzymes, natural rubber latex and the like. In some embodiments, bio based matrix 12 may include the bio based polymer at no more than 10 wt. %. In some embodiments, bio based matrix 12 may include the bio based polymer at no more than 8 wt. %, no more than 6 wt. %, no more than 4 wt. %, no more than 3 % or less of the total weight of the soil based composite material.

[0020] In some embodiments, bio based matrix 12 may further include additive material. In some embodiments, the additive material may include material for increasing the cohesive strength of the soil based composite material prior to a draying process (also known as the "green strength" of the pre-dried product). For example, materials for increasing the cohesive strength may include: natural fibers, and natural rubber latex.

[0021 ] In some embodiments, natural fibers may further enhance other properties of platel O. Natural fibers added to the soil based composite material may also: increase the impact resistance, increase the elasticity, improve thermal and acoustic properties, improve post cracking ductility and reduce the density (e.g., the weight) of the product. Exemplary natural fibers that may be added to the soil based composite material may include: cellulose fibers, shredded recycled paper, wood fibers, recyclable wood fiber or sawdust, hemp fibers, jute fibers, sisal fibers, flax fibers or any other plant fibers from natural source. In some embodiments natural fibers may be added to bio-based matrix 12 in a form of prefabricated natural fibers net or mesh.

[0022] In some embodiments, the additive materials may be added to increase the formability of the soil based composite material, for example natural oils such as eucalyptus or tang oil as explained and discussed with respect to Fig. 3.

[0023] In some embodiments, the additive material may include color pigments. These pigments may be either natural bio-based pigments of all sources or soil based pigments.

[0024] In some embodiments, in order to improve the resistance of bio-based matrix 12 and plate 10 to deterioration caused by molds or other micro-organisms, preservatives may be added to the soil based composite material mixture.

[0025] A bio-based matrix 12 according to embodiments of the invention may be prepared, for example, by mixing casein, water, hydrated lime (calcium- carbonates, calcium-oxides and calcium-hydroxides) and/or sodium salts. The hydrated lime may be added as a water resistance increasing additive. In some embodiments, in order to further increase the water resistance of bio based matrix 12 the casein to hydrated lime ratio may be at least 6:1 . In some embodiments, the total amount of hydrated lime is controlled to be less than 1 .5 wt. % of the total earth-soil based composite material final mixture. In this concentration the hydrated lime alone is unable to stabilize soil 14 without the casein. The sodium salt may be, for example, sodium oxalate, sodium tartrate, sodium citrate, sodium salicylate, sodium phosphate, sodium sulfite, sodium fluoride, sodium arsenate, sodium arsenite, sodium stannate or sodium hydroxide.

[0026] In another example, a bio-based matrix12 may include a polysaccharide or a blend of polysaccharides, for example, cationic starch. In some embodiments, bio based matrix 12 that includes cationic starch may have improved mechanical properties, for example, having a rupture modulus of above 30 MPa when loaded at a strain rate of 25 mm/min. In some embodiments, bio based matrix 12 that includes cationic starch (or other polysaccharide) may further include a water resistance increasing additive, for example enzymes, at a weight percentage of at most 0.0010 wt. % of the total weight of the soil based composite material mass, that is configured to increase the water resistance of plate 10 when using a cationic starch in bio based matrix 12.

[0027] In some embodiments, soil 14 may include any soil filling material regardless of its crystalline structure, chemical composition and particle size distribution (PSD). In some embodiments, the binding abilities of bio-based matrix 12 are such that even a plate containing 97 wt.% soil 14 may still be consolidated (e.g., bind, fused, joined etc.) by bio based matrix 12. Soil 14 may include, for example quarry by-products, quarry pond fines, quarry baghouse fines, quarry crushed mineral or rock aggregates, deposits of natural soils, natural soil and loose earth of un-lithified mineral or rock. Soil 14 may have maximal average particle size of 1 mm, 600 μηι, 200 μηι, 100 μηι, 75 m, 60 μηι or less. In some embodiments, soil 14 may be defined according to ASTM D653-97.

[0028] In some embodiments, plate 10 or any other portion of the burial container made from the soil based composite material, may have a specific gravity of at most 2 g/cm ³ , for example, 1 .8 g/cm ³ , 1 .6 g/cm ³ , 1 .4 g/cm ³ ,1 .3 g/cm ³ , 1 .2 g/cm ³ , 1 g/cm ³ , 0.7 g/cm ³ or less. Since the specific gravity of dense soil is approximately 2.7 g/cm ³ , a soil based composite material according to embodiments of the invention may have high porosity levels. For example, a burial container according to some embodiments of the invention may float on water (similarly to some wooden burial containers).

[0029] In some embodiments, plate 10 or any other portion of the burial container made from the soil based composite material, may have an inherent water resistance (not to be achieved by using any additional coating material). The water resistance of the soil based composite material may be measured by immersing in water a sample made from the soil based composite material. The sample may have 100x100x10 mm ³ dimensions. In some embodiments, the sample, may gain no more than 5 weight % of water when immersed in the water for 2 hours at room temperature. For example, in some embodiments, the sample, may gain 4 weight %, 3 weight % 2 weight % or less of water when immersed in the water for 2 hours at room temperature. In some embodiment, the sample, may gain more than 5 weight % of water when immersed in the water for 2 hours at room temperature, for example, more than 6%, 8%, 10% or more.

[0030] In some embodiments, , plate 10, or any other portion of the burial container made from the soil based composite material, may have modulus of rapture of at least 5 MPa, for example, 8 MPa, 10 MPa, 20 MPa, 30 MPa or more. For example, a sample having 100x100x10mm ³ dimensions, made from the soil based composite material, may have a minimal modulus of rupture of at least 5 MPa when loaded at a strain rate of 25 mm/min. The modulus of rapture σ values are calculated according to equation 1 , wherein, F is the breaking load, L is the span between the supporting rods, b is the width of the plate at the broken edge and h is the thickness of the plate

[0031 ] equation 1 : σ = 3FL/(2bh ² )

[0032] In some embodiments, the moduli of rapture values given above can be measured using plates having a thickness of at least 3 mm.

[0033] Reference is made to Figs. 2A, 2B and 2C which are illustrations of burial containers according to some embodiments of the invention. A portion of a burial container according to embodiments of the invention may be defined as any part and/or component of the burial container (e.g., a whole base and a whole cover), a wall of the base or a top of the cover, a portion of the wall or a portion of the top, a construction for holding walls or top, or any other element included in the burial container. Fig. 2A is an illustration of a casket comprising a soil based composite material according to some embodiments of the invention. For example, casket (or coffin) 210 may include a base 212 and a cover 214. Both base 212 and cover 214 may be made by forming soil based composite material into a base mold and a cover mold, forming a "sarcophagus" form. In some embodiments, cover 214 may include two portions 214A and 214B. Each of cover portions 214A and 214B may be formed separately. Cover portions 214A and 214B may each be configured to be opened separately. Cover 214 (or portions 214A and 214B) and base 212 may be made from the soil based composite material of plate 10. It should be appreciated that each of base 212 and cover 214 may include one or more parts, such as portions 214A and 214B, or any other number of parts or portions.

[0034] Fig. 2B is an illustration of a casket comprising a soil based composite material according to some embodiments of the invention. Casket (or coffin) 220 may include a base 222 and a cover 224. Base 222 may include at least one panel 221 , 223 and 226 made from the soil-based composite material of plate 10. In some embodiments, all the panels that form base 222 may be made from the soil- based composite material. As would have being appreciated by a person skilled in the art, side panel 221 , bottom panel 226 and head panel 223 are given as examples only and any other panels of base 222 can be made from the soil-based composite material of plate 10. In some embodiments, base 222 may further include a frame 227 made from a soil based composite material according to embodiments of the invention or from a material other than the soil based composite material, for example, wood and the like, or from a combination of soil based composite material and non-soil based materials such as, for example, wood or the like.= Frame 227 may be configured to hold at least one of panels 221 , 226 and 223. For example, frame 227 may be made from a soil based composite material that includes starch as the bio based polymer and panels 221 and 223 may be made from a soil based composite material that includes casein as the bio based polymer. Plates 221 , 226 and 223 and frame 227 may be formed using any forming method, for example, the forming methods discussed with respect to the flowchart of Fig. 3.

[0035] Cover 224 may include a top 225 and a frame 228. In some embodiments, at least one of top 225 and frame 228 may be made from soil-based composite material of plate 10. In some embodiments, farm 228 may be made from a material other than the soil based composite material, for example, wood and the like. Frame 228 may be configured to hold top 225. Top 225 may be made by forming the soil based composite material into a mold as discussed with respect to Fig. 3. The beams of frames 227 and 228 may be formed using any forming method, for example, the forming methods discussed with respect to the flowchart of Fig. 3.

[0036] Fig. 2C is an illustration of an ash urn according to some embodiments of the invention. Ash urn 240 may include a container 242 and a lid or cover 244. In some embodiments, at least one of container 242 and cover 244 may be made or may include the soil based composite material of plate 10. In some embodiments, only a portion of container 242 and/or cover 244 may include the soil based composite material of plate 10. For example, container 242 and a cover 244 may be formed by casting or pressing the soil based composite material into container and cover molds.

[0037] Reference is made to Fig. 3 which is a flowchart of a method of making a soil based composite material for burial containers according to some embodiments of the invention. In box 32, embodiments may include mixing at least soil (e.g., soil 14) and biobased matrix (e.g., bio based matrix 12) at predefined ratio. The soil and the bio-based matrix may be mixed using any know method. The mixture may include soil and biobased matrix that includes at least one bio based polymer (e.g., casein, cationic starch, etc.) at at most 10 wt.% of the total weight of the soil based composite material mixture. The mixture may further include an additive material at between 0 to 37 wt.% of the total weigh of the soil based composite material mixture. The additive material may be any additive material listed above that may be included in bio based matrix 12 (e.g., waxes, natural fibers and the like).

[0038] In box 34, embodiments may include forming one or more portions of the burial container from the soil based composite material. For example, cold forming the mixture at a temperature in the range of 1 and 100 degrees Celsius, such as, for example at room temperature to shape the mixture. The mixture may be shaped as one or more panels (e.g., panels 221 , 223, 225, and/or 226) to be held by a frame (e.g., farms 227 and/or 228) of a burial container. In some embodiments, the mixture may be shaped as beams for making the frame. Alternatively, the mixture may be shaped as the based (e.g., base 212) and/or the cover (e.g., cover 214) of a burial container, as a top of the cover (e.g., top 225), or as an ash urn (e.g., ash urn 240). The cold forming may include, for example, cold extrusion, slab forming, stamping, pressing, and casting. The cold formed soil based composite material may have a specific gravity of at most 2 g/cm ² , for example, at most 1 .8 g/cm ² , 1 .7 g/cm ² , 1 .5 g/cm ² , 1 .3 g/cm ² , 0.7 g/cm ² , or lower. The cold extrusion may include forming continuous elements in extrusion methods adopted from the clay industry or the food industry. The slab forming may include the continuous formation of plate/panel by means of compression drums. The mixtures suitable for this method may be similar to those used in the extrusion method.

[0039] In box 36, embodiments may include drying the shaped mixture at a temperature not exceeding 120 °C. The drying process may be held at the open air, in room temperature or at any drying cabinet and drying method known in the art. No further drying, curing, sintering or any other consolidation processes may be required to form the shaped soil based composite material.

[0040] In some embodiments, the burial container may be one of: a coffin and a casket (e.g., casket 220) having a base and a cover that include panels. In some embodiments, cold forming the mixture may include forming at least one panel of the base and/or the cover from the soil based composite material and embodiments of the method may further include making a frame (e.g., frames 227 and 228) of the base and/or the cover of the burial container and attaching the at least one panel to the frame. Experimental Results

Modulus of rupture

[0041 ] Tests that were conducted on a 100x100x10 mm ³ plate made from a soil based composite material, according to embodiments of the invention, comprising soil and at most 10 weight % cationic starch. The plates were loaded at a strain rate of 25 mm/min and have a modulus of rupture of 30 MPa. This modulus of rupture enables to build a full burial container (e.g., a sarcophagus) as illustrated in Fig. 2A from the tested soil based composite material.

[0042] Tests that were conducted on a 100x100x10 mm ³ plate made from a soil based composite material, according to embodiments of the invention, comprising soil and at most 10 weight % protein. The plates were loaded at a strain rate of 25 mm/min and have a modulus of rupture of at least 5 MPa. This modulus of rupture enables to form the plats included in the burial container of Fig. 2B and the ash urn of Fig. 2C.

Water resistance

[0043] Both the starch containing and the protein containing soil based composite plates discussed above were tested for water resistance. All the tested plates gained no more than 2 weight % of water when immersed in water for 2 hours at room temperature.

[0044] While certain features of the invention have been illustrated and described herein, many modifications, substitutions, changes, and equivalents will now occur to those of ordinary skill in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.