Method for producing a solid molded article made of non-woody plant material

Abstract

The present invention provides a method for producing a solid molded article comprising non-woody plant material, the method comprising the steps of: (a) providing one or more fresh non-woody plant materials having a moisture content of 20% w / w to 99% w / w; (b) heating the fresh non-woody plant material at a temperature of 40°C to 250°C, in particular at a temperature of 60°C to 140°C and at a pressure of 40 kPa to 750 kPa for at least 0.5 hours, maintaining the moisture content of the material equal to or higher than 20% w / w; (c) molding the heated material obtained in step (b); and (d) drying the molded material obtained in step (c). The present invention also provides a solid molded article obtainable by the method of the present invention.

Description

[0001] This application claims the benefit of European Patent Application EP19382702.9 filed on August 8, 2019. Technical Field

[0002] The present invention belongs to the field of methods for producing solid molded articles from plant sources. In particular, the present invention relates to a method for producing solid molded articles from non-woody plant materials. Background Art

[0003] Increasing pollution on land and in the oceans has prompted extensive research into environmentally friendly materials. Natural fibers have become outstanding candidates for the production of bio-based articles due to their low cost, global availability, low density, mechanical properties, sustainability, and biodegradability.

[0004] The most commonly used natural fibers are wood fibers. However, wood takes a long time to grow to a usable size, its processing requires increased energy, and it usually involves the use of polluting agents such as formaldehyde. In addition, the wood-based industry causes deforestation problems that affect most countries.

[0005] Therefore, in the context of declining raw material supplies and increasing demand for plant-based articles, non-woody lignocellulosic plants are considered a good alternative. In particular, there have been some attempts to manufacture articles from agricultural by-products generated after separating the edible parts of cultivated plants. However, the methods disclosed in the prior art have various drawbacks. First, they generally use dry materials such as wheat straw and require the addition of water for rehydration. In addition, the separation of rehydrated fibers requires highly energy-consuming steps such as mechanical grinding or steam explosion, or even dangerous alkaline solutions. More importantly, the products obtained usually do not have the properties required for their use in industry.

[0006] In fact, in order to improve the properties of such products, natural fibers are usually combined with plastics to form composites. In these materials, the natural fibers act as reinforcements and are embedded in a polymer matrix together with a compatibilizer or coupling agent. However, the non-natural components of these composites make their manufacturing difficult and increase their environmental impact.

[0007] In summary, the complexity of the methods developed to date, as well as the high processing costs and long processing times, have hindered the use of non-woody plant materials in industry. Therefore, there is still a need for an inexpensive and simple method for producing high-quality and environmentally friendly solid molded articles from non-woody plant materials. Summary of the Invention

[0008] The present inventor has developed an effective and simple method for producing solid molded articles from non-woody plant materials. Surprisingly, the inventor has found that when a specific type of plant material is subjected to specific heating conditions, the resulting material can be used to produce high-quality articles by simple molding and drying.

[0009] This is highly unexpected because the prior art indicates that forming articles from plant materials, particularly non-woody plant materials, requires the use of chemical binders or adhesives, or high-energy steps such as compression molding at elevated temperatures.

[0010] Thus, the method of the present invention allows for the production of solid molded articles from inexpensive sources such as agricultural by-products and uses a minimal amount of energy since costly mechanical steps such as grinding are not required. Moreover, since the method uses the water naturally present in fresh plant materials, no additional water needs to be used.

[0011] Notably, the method of the present invention is highly versatile. Without wishing to be bound by theory, the use of fresh plant materials and maintaining a substantial portion of their natural moisture content during heat treatment allows for the degradation of intercellular gums without affecting the overall structure of the cell walls. This results in the formed pulp having a wide variety of physical properties, such as unusual strength, excellent low density, or high insulating properties, after molding and drying.

[0012] The present inventor has also found that articles produced by the method provided herein can be reused multiple times as needed through a simple rehydration, molding, and drying process without losing their original properties. Thus, the recycling / reuse of the material requires no new, unused materials at all, eliminating the need to add unused materials.

[0013] Thus, in a first aspect, the present invention provides a method for producing a solid molded article comprising non-woody plant materials, the method comprising the steps of: (a) providing one or more fresh non-woody plant materials having a moisture content of 20% w / w to 99% w / w relative to the total weight of the plant materials; (b) heating the fresh non-woody plant materials at a temperature of 40°C to 250°C, particularly at a temperature of 60°C to 140°C and a pressure of 40 kPa to 750 kPa, for at least 0.5 hours, maintaining the moisture content of the materials equal to or higher than 20% w / w; (c) molding the heated material obtained in step (b); and (d) drying the molded material obtained in step (c).

[0014] In particular, the non-woody plant materials are all or any part of a non-woody plant, or the non-woody parts of a woody plant.

[0015] In particular, fresh non-woody plant material is non-woody plant material that has not been preserved by drying after harvesting.

[0016] In a second aspect, the present invention provides a solid molded article obtainable by the method as defined in the first aspect. Detailed Description

[0017] All terms used herein in this application, unless otherwise specified, shall be understood in their ordinary meaning as known in the art. Other more specific definitions of certain terms used in this application are set forth below and are intended to be applied uniformly throughout the specification and claims, unless a more general definition is provided by an expressly stated definition.

[0018] As used herein, the indefinite articles "a" and "an" are synonymous with "at least one" or "one or more". Unless otherwise specified, the definite articles such as "the" used herein also include the plural forms of the noun.

[0019] As used herein, "moisture content" refers to the percentage ratio of the weight of free water present in the plant material to the total weight of the plant material. For example, a moisture content of 50% w / w means that 100 grams of plant material contains 50 grams of water. Several techniques are known in the art for measuring the moisture content of plant material, such as oven drying (ISO 638:2008) or an electrical contact hygrometer (e.g., DVM125 type Velleman Contact hygrometer).

[0020] Flexural strength and ultimate tensile strength tests were carried out using samples with dimensions of 5.2 mm × 4 mm, with a spacing of 30 mm between the support points. The loading speed was 1 mm / min.

[0021] As used herein, the term "fresh plant material" refers to plant material that has not been preserved by drying after harvesting, that is, the harvested plant material maintains the same or substantially the same moisture content as it had in its in vivo state. As used herein, "substantially the same" means at least 85%, 90%, 95%, 96%, 97%, 98% or 99%. "Fresh plant material" may also refer to plant material harvested within the past 21 days. In a particular embodiment, the plant material is harvested within the past 14 days, past 10 days, past 7 days or past 3 days.

[0022] "Non-woody plant material" refers to all or any part of a non-woody plant, or the non-woody parts of a woody plant, such as fruits and leaves. "Non-woody plant" refers to a plant that does not have a perennial woody stem. "Woody plant" refers to a plant that has a perennial woody stem.

[0023] Parts of non-woody plants that can be used in the method of the present invention include, but are not limited to, the whole plant (e.g., parsley plant), stems (e.g., Swiss chard), shoots (e.g., tomato plant), leaves (e.g., cabbage), roots (e.g., ginger), and fruits (e.g., pineapple).

[0024] As used herein, the term “% w / w” or “weight percent” of a component refers to the amount of the weight of a single component relative to the total weight of the composition or another component if specifically mentioned.

[0025] As used herein, the term “plant” refers to non-woody (i.e., herbaceous) plants having edible parts that are consumed by humans in raw or cooked form. The edible parts can be, but are not limited to, roots, tubers or storage stems, stems, buds, bulbs, petioles, leaves, immature flowers, seeds, immature fruits or mature fruits.

[0026] The term “agricultural product” refers to parts of cultivated plants intended for human or animal consumption. The term “agricultural by-product” refers to parts of cultivated plants that are not intended or not suitable for human or animal consumption, such as inedible parts.

[0027] “Atmospheric pressure” refers to normal atmospheric pressure, e.g., 760 mm Hg or 101325 Pa at sea level. This term is also intended to cover pressures between approximately +15% and -15%, preferably between approximately +10% and -10%, more preferably between approximately +5% and -5% of atmospheric pressure.

[0028] As described above, the present invention provides a method for producing solid molded articles containing non-woody plant materials, the method comprising the steps of: (a) providing one or more fresh non-woody plant materials having a moisture content of 20% w / w to 99% w / w; (b) heating the fresh non-woody plant materials at a temperature of 40°C to 250°C, particularly at a temperature of 60°C to 140°C and a pressure of 40 KPa to 750 KPa for at least 0.5 hours, maintaining the moisture content of the materials equal to or higher than 20% w / w; (c) molding the heated materials obtained in step (b); and (d) drying the molded materials obtained in step (c).

[0029] In particular, the non-woody plant materials are all or any part of a non-woody plant, or the non-woody parts of a woody plant.

[0030] In particular, the fresh non-woody plant materials are non-woody plant materials that have not been preserved by drying after harvesting.

[0031] The method of the present invention utilizes the natural moisture content of non-woody plant materials to allow the separation of cellulose fibers by wet heating to degrade the intercellular pectin, thereby producing a moldable material that can be further processed into articles by simple shaping and drying.

[0032] As shown in the examples below, the inventors have found that, in order to obtain a product with the desired properties according to the simple method provided herein, the starting plant material must be fresh, i.e. it cannot be plant material that has been dried and rehydrated. Equally importantly, the plant material must be herbaceous (i.e. non-woody), and its natural water content (i.e. the water content at the time of harvest) must be higher than a certain value.

[0033] The inventors have surprisingly found that, in order to obtain solid mouldings with properties suitable for industry, plant material with a minimum natural water content must be used. Importantly, these properties are not obtained when non-woody materials are dried and dehydrated prior to being subjected to heat treatment. However, once they have been subjected to the heat treatment of the present invention, they can be reused or reprocessed an unlimited number of times by means of rehydration, moulding and drying cycles. Maintaining the water content of the material equal to or higher than 20% w / w during the heating step means that, at the end of step (b), the water content of the heated material is equal to or higher than 20% w / w.

[0034] In a particular embodiment, optionally in combination with any of the embodiments provided above or below, the method of the first aspect is for producing a solid moulding comprising non-woody plant material, the method comprising the steps of: (a) providing one or more fresh non-woody plant materials having a water content of from 20% w / w to 99% w / w; (b) heating the fresh non-woody plant material at a temperature of from 40 °C to 250 °C, in particular at a temperature of from 60 °C to 140 °C and at a pressure of from 40 kPa to 750 kPa, in particular for at least 0.5 hour, maintaining the water content of the material equal to or higher than 20% w / w; (c) moulding the heated material obtained in step (b); and (d) drying the moulded material in step (c).

[0035] In a particular embodiment, optionally in combination with any of the embodiments provided above or below, in the method of the first aspect, the porosity of the solid moulding made of non-woody plant material is determined by mercury porosimetry and is in the range of 5% to 90%.

[0036] In a particular embodiment, optionally in combination with any of the embodiments provided above or below, in the method of the first aspect, the density of the solid moulding made of non-woody plant material is determined using a pycnometer and is in the range from 25 kg / m 3 to 2000 kg / m 3 More particularly, from 100 kg / m 3 to 2000 kg / m 3 . Even more particularly, from 250 kg / m 3 to 2000 kg / m3 。

[0037] Density measurements using a pycnometer can be carried out using a 37 cc pycnometer and a high-precision balance (1 mg resolution) to achieve a density resolution of 1 mg / cm 3 . This method is based on the weight difference between 37 cc of distilled water and 37 cc of distilled water impregnated with the sample. Regarding the relationship with porosity, this method works better in samples with low porosity because water occupies more volume in low-density samples than is optimal. This means that the density of these highly porous (low-density) samples will be overestimated. Therefore, in this case, size and weight can be used to measure the density value.

[0038] In a particular embodiment, optionally in combination with any of the embodiments provided above or below, in the method of the first aspect, the strength of the solid molded article made of non-woody plant material is determined using a nanoindenter, in the range of 6 MPa to 250 MPa.

[0039] The nanoindentation experiment measures the mechanical properties of a material by measuring the response of the material to stress generated by a calibrated tip. The material strength can be measured using an Agilent Nano Indenter G200 operating according to ISO 14577, by means of a basic automatic load experiment for measuring hardness and Young's modulus. Measurements can be made at 10 different locations to obtain an overall value and reduce local dependence.

[0040] In a particular embodiment, optionally in combination with any of the embodiments provided above or below, in the method of the first aspect, the elasticity of the solid molded article made of non-woody plant material is determined using a nanoindenter, in the range of 50 MPa to 7 GPa.

[0041] In a particular embodiment, optionally in combination with any of the embodiments provided above or below, the thermal conductivity of the solid molded article determined in a thermal testing machine (such as FOX 600GHP of TA instruments) (ISO8302 / ISO22007) is in the range of 0.01 W / mK to 0.15 W / mK.

[0042] In a particular embodiment, optionally in combination with any of the embodiments provided above or below, the flexural strength of the solid molded article is determined by a three-point bending test, in the range of 10 MPa to 150 MPa.

[0043] In a particular embodiment, optionally in combination with any of the embodiments provided above or below, the ultimate tensile strength of the solid molded article is determined using a tensile strength tester (such as the Mega1500 from Labthink) and is in the range of 10 MPa to 500 MPa.

[0044] In a particular embodiment, optionally in combination with any of the embodiments provided above or below, step (b) is carried out without adding water.

[0045] In a particular embodiment, optionally in combination with any of the embodiments provided above or below, step (b) is carried out in a sealed container.

[0046] In a particular embodiment, optionally in combination with any of the embodiments provided above or below, the non-woody plant material after heating step (b) has one or more of the following:

[0047] i) a moisture content in the range of 20% to 99%,

[0048] ii) a dehydration value determined by the Schopper-Riegler method in the range of 20°SR to 100°SR; and

[0049] iii) a viscosity determined by the Brookfield method in the range of 0.001 Pa·s to 15 Pa·s.

[0050] The Schopper-Riegler method can be carried out in accordance with UNE-EN ISO 5267-1:2001. 2 grams of dry matter were recovered at the end of the experiment.

[0051] In a particular embodiment, optionally in combination with any of the embodiments provided above or below, the moisture content of the fresh non-woody plant material in step (a) is in the following ranges: 25% w / w to 99% w / w, 30% w / w to 99% w / w, 35% w / w to 99% w / w, 40% w / w to 99% w / w, 45% w / w to 99% w / w, 50% w / w to 99% w / w, 55% w / w to 99% w / w, 60% w / w to 99% w / w, 65% w / w to 99% w / w, 70% w / w to 99% w / w, 75% w / w to 99% w / w, or 80% w / w to 99% w / w.

[0052] In a particular embodiment, optionally in combination with any of the embodiments provided above or below, the lignin content of the one or more fresh non-woody plant materials of step (a) is less than or equal to 20% w / w; less than or equal to 18% w / w, less than or equal to 16% w / w, less than or equal to 14% w / w, less than or equal to 12% w / w, or less than or equal to 8% w / w. In a more particular embodiment, the lignin content of the one or more fresh non-woody plant materials of step (a) is less than or equal to 20% w / w.

[0053] In a particular embodiment, optionally in combination with any of the embodiments provided above or below, the fresh non-woody plant materials of step (a) are agricultural products or agricultural by-products. The method of the present invention can preferably be carried out using the usually discarded inedible parts of agricultural products.

[0054] In a particular embodiment, optionally in combination with any of the embodiments provided above or below, the fresh non-woody plant materials of step (a) are from non-woody plants.

[0055] In a particular embodiment, optionally in combination with any of the embodiments provided above or below, the fresh non-woody plant materials of step (a) include the whole plant, stems, branches, leaves, roots, fruits or combinations thereof.

[0056] In a particular embodiment, optionally in combination with any of the embodiments provided above or below, the fresh non-woody plant materials of step (a) are from vegetables. Vegetables, especially their inedible parts, can be particularly used to produce solid molded articles according to the method of the present invention.

[0057] In a particular embodiment, optionally in combination with any of the embodiments provided above or below, the fresh non-woody plant materials of step (a) are from plants belonging to plants selected from bryophytes, angiosperms and non-woody gymnosperms.

[0058] In a particular embodiment, optionally in combination with any of the embodiments provided above or below, the fresh non-woody plant materials are from plants selected from the following: artichoke, alfalfa, garlic, eggplant, broccoli, zucchini, pumpkin, hemp, onion, cauliflower, strawberry, chickpea, pea, kidney bean, green bean, lentil, flax, corn, melon, turnip, potato, cucumber, pepper, radish, beetroot, watermelon, tomato, carrot, chard, artichoke, leek, celery, borage, canons, thistle, cabbage, chicory, asparagus, spinach, turnip greens, lettuce, leek, arugula, soybean, and mixtures thereof. The plant parts used in the method of the present invention will depend on the desired properties of the solid molded article to be produced. For example, compared to processing headless lettuce, whole head lettuce promotes a lower density product.

[0059] In a specific embodiment, optionally in combination with any of the embodiments provided above or below, the fresh non-woody plant material of step (a) is selected from the group consisting of: artichoke flowers, cabbage plants, coconut shells, celery plants, lettuce, apples, pineapples, almonds, apples, apricots, bananas, blackberries, blueberries, cherries, chestnuts, coconuts, dates, grapes, hazelnuts, lemons, limes, mangoes, melons, morello cherries, cherries, oranges, peaches, peanuts, pears, pineapples, plums, raspberries, strawberries, tangerines, watermelons, eggplants, asparagus, beans, beetroots, broccoli, brussels sprouts, cabbage, carrots, cauliflower, corn, courgettes, cucumbers, eggplants, garlic, leeks, lentils, mushrooms, onions, peas, peppers, pickles, potatoes, pumpkins, radishes, rice, rye, spinach, pumpkins, tomatoes, turnips, watercress, chard, garlic, watercress, borage, zucchini, thistles, onions, mushrooms, brussels sprouts, kohlrabi , chicory, asparagus, spinach, green beans, lombarda, palm hearts (palmitos), cucumber, leek, radish, beet, soybean, brune, avocado, apricot, blueberry, cherry, custard, apple, coconut, peach, strawberry, pomegranate, passion fruit, red currant, black currant, soursop, guava, fig, kiwi, lemon, lychee, lulo, tangerine, mango, passion fruit, peach, cantaloupe, quince, blackberry, orange, nectarine, yam, papaya, Paraguayan, pitaya whistle, tamarind, grape, sapodilla, alfalfa, carob, oats, barley, peas, corn, millet, chard, thistle, endive, and mixtures thereof.

[0060] In a specific embodiment, optionally in combination with any of the embodiments provided above or below, step (b) is performed at a temperature of 40°C to 250°C, 50°C to 225°C, 60°C to 200°C, 60°C to 150°C, 70°C to 140°C, 80°C to 130°C, 90°C to 120°C, or 95°C to 110°C. More particularly, step (b) is performed at a temperature of 70°C to 120°C. More particularly, step (b) is performed at a temperature of 60°C to 140°C. And more particularly, step (b) is performed at a temperature of about 100°C.

[0061] As used herein, the term "about" or "approximately" refers to a value range of ±10% of a given value. For example, the expression "about 10" or "approximately 10" includes ±10% of 10, ie, 9 to 11.

[0062] In a particular embodiment, optionally in combination with any of the embodiments provided above or below, the fresh non-woody plant material consists of artichoke flowers having a water content of about 70 - 80% w / w, and the heating step is carried out at a temperature of 80°C to 100°C.

[0063] In a particular embodiment, optionally in combination with any of the embodiments provided above or below, the fresh non-woody plant material consists of a cabbage plant with the roots removed, having a water content of about 85 - 95% w / w, and the heating step is carried out at a temperature of 60°C to 100°C.

[0064] In a particular embodiment, optionally in combination with any of the embodiments provided above or below, the fresh non-woody plant material consists of whole lettuce plants without roots, having a water content of about 85 - 95% w / w, and the heating step is carried out at a temperature of 40°C to 250°C, particularly at a temperature of 60°C to 140°C for at least 0.5 hours.

[0065] In a particular embodiment, optionally in combination with any of the embodiments provided above or below, the fresh non-woody plant material consists of coconut husks, having a water content of about 80 - 90% w / w, and the heating step is carried out at a temperature of 100°C.

[0066] In a particular embodiment, optionally in combination with any of the embodiments provided above or below, the fresh non-woody plant material consists of pineapple leaves, having a water content of about 85 - 95% w / w, and the heating step is carried out at a temperature of 80°C to 100°C.

[0067] In a particular embodiment, optionally in combination with any of the embodiments provided above or below, the fresh non-woody plant material consists of celery plants, having a water content of about 90 - 99% w / w, and the heating step is carried out at a temperature of 60°C to 100°C.

[0068] In a particular embodiment, optionally in combination with any of the embodiments provided above or below, the plant material consists of cauliflower flowers, having a water content of about 90 - 99% w / w, and the heating step is carried out at a temperature of 60°C to 100°C.

[0069] In a particular embodiment, optionally in combination with any of the embodiments provided above or below, the solid molded article made of non-woody plant material has a density determined using a pycnometer in the range of 50 kg / m 3 to 1200 kg / m 3 and the method comprises the steps of:

[0070] (a) providing fresh artichoke flowers having a water content of 20% w / w to 99% w / w;

[0071] (b) Heat the fresh artichoke flowers at a temperature of 70 °C to 150 °C and a pressure of 40 KPa to 750 KPa, maintaining the water content of the artichoke flowers equal to or higher than 20% w / w;

[0072] (c) Mold the heated material obtained in step (b); and

[0073] (d) Dry the molded material of step (c).

[0074] In a specific embodiment, optionally in combination with any of the embodiments provided above or below, the strength of the solid molded article made of non-woody plant material determined using a nanoindentation instrument is in the range of 6 MPa to 250 MPa, and the method includes the following steps:

[0075] (a) Provide fresh rootless cabbage plants with a water content of 30% w / w to 99% w / w;

[0076] (b) Heat the fresh cabbage plants at a temperature of 70 °C to 150 °C and a pressure of 40 KPa to 750 KPa, maintaining the water content of the cabbage plants equal to or higher than 20% w / w;

[0077] (c) Mold the heated material obtained in step (b); and

[0078] (d) Dry the molded material of step (c).

[0079] In a specific embodiment, optionally in combination with any of the embodiments provided above or below, the thermal conductivity of the solid molded article made of non-woody plant material determined in a thermal test device is in the range of 0.01 W / mK to 0.15 W / mK, and the method includes the following steps:

[0080] (a) Provide fresh coconut shells with a water content of 65% w / w to 99% w / w;

[0081] (b) Heat the fresh coconut shells at a temperature of 70 °C to 150 °C and a pressure of 40 KPa to 750 KPa, maintaining the water content of the coconut shells equal to or higher than 20% w / w;

[0082] (c) Mold the heated material obtained in step (b); and

[0083] (d) Dry the molded material of step (c).

[0084] In a particular embodiment, optionally in combination with any embodiment provided above or below, the density of a solid molded article made of non-woody plant material, determined using a pycnometer, is in the range of 50 kg / m 3 to 500 kg / m 3 and the method comprises the steps of:

[0085] (a) providing fresh pineapple leaves having a moisture content of 65% w / w to 99% w / w;

[0086] (b) heating the fresh pineapple leaves at a temperature of 70°C to 110°C and a pressure of 40 kPa to 750 kPa, maintaining the moisture content of the pineapple leaves equal to or higher than 30% w / w;

[0087] (c) molding the heated material obtained in step (b); and

[0088] (d) drying the molded material of step (c).

[0089] In a particular embodiment, optionally in combination with any embodiment provided above or below, the strength of a solid molded article made of non-woody plant material, determined using a nanoindenter, is in the range of 6 MPa to 250 MPa, the flexural strength (measured by a three-point test) is in the range of 10 MPa to 150 MPa, and the method comprises the steps of:

[0090] (a) providing fresh celery plants having a moisture content of 65% w / w to 99% w / w;

[0091] (b) heating the fresh celery plants at a temperature of 70°C to 150°C and a pressure of 40 kPa to 750 kPa, maintaining the moisture content of the celery plants equal to or higher than 30% w / w;

[0092] (c) molding the heated material obtained in step (b); and

[0093] (d) drying the molded material of step (c).

[0094] In a particular embodiment, optionally in combination with any embodiment provided above or below, the strength of a solid molded article made of non-woody plant material, determined using a nanoindenter, is in the range of 70 MPa to 150 MPa, and the method comprises the steps of:

[0095] (a) providing fresh cauliflower having a moisture content of 65% w / w to 99% w / w;

[0096] (b) Heat the fresh cauliflower at a temperature of 70°C to 150°C and a pressure of 40 KPa to 150 KPa, maintaining the moisture content of the cauliflower equal to or higher than 20% w / w;

[0097] (c) Mold the heated material obtained in step (b); and

[0098] (d) Dry the molded material of step (c).

[0099] In a particular embodiment, optionally in combination with any embodiment provided above or below, the elasticity of a solid molded article made of non-woody plant material, as determined using a nanoindenter, is in the range of 500 MPa to 2 GPa, and the method comprises the following steps:

[0100] (a) Provide a fresh lettuce plant with a moisture content of 65% w / w to 99% w / w;

[0101] (b) Heat the fresh lettuce plant at a temperature of 70°C to 150°C and a pressure of 40 KPa to 150 KPa, maintaining the moisture content of the lettuce plant equal to or higher than 30% w / w;

[0102] (c) Mold the heated material obtained in step (b); and

[0103] (d) Dry the molded material of step (c).

[0104] (b) The temperature and time of step (b) must be adjusted according to the characteristics of the fresh non-woody plant material, such as its moisture content, fiber content, gum content, etc. One way to know when the heat treatment has the desired effect on the plant material is to observe the loss of mechanical firmness that occurs when the gum degrades, or the color change that occurs when the chlorophyll degrades, from dark green to dull green. This can be done by visual inspection.

[0105] Thus, in a particular embodiment, optionally in combination with any embodiment provided above or below, the heating step is carried out until the molecular structure of the fresh plant material is significantly altered. In another particular embodiment, the heating step is carried out until the color of the fresh plant material is significantly changed. In a more particular embodiment, the heating step is carried out for a period of 3 min to 7 h. In an even more particular embodiment, a period of 0.5 h to 7 h, 0.5 h to 6 h, 0.5 h to 5 h, 0.5 h to 4 h, or 0.5 h to 3 h is carried out.

[0106] In a more specific embodiment, optionally in combination with any of the embodiments provided above or below, the heating step is carried out for at least 0.5 h, at least 1 h, at least 1.5 h, at least 2 h, or at least 2.5 h.

[0107] In a more specific embodiment, after achieving the thermalization of the fresh plant material, the heating step is carried out for a period of 0.5 h to 7 h, 0.5 h to 6 h, 0.5 h to 5 h, 0.5 h to 4 h, or 1 h to 4 h. This means that the material must be heated for the specified period after all of its mass has reached the target temperature. The thermalization of the fresh plant material refers to the time point when all of its mass reaches the target temperature.

[0108] In a specific embodiment, optionally in combination with any of the embodiments provided above or below, the heating step ends before the thermalization of the fresh plant material is achieved, thereby obtaining a mixture of the transformed material and the raw material. In a more specific embodiment, the heating step is carried out for a period of 3 minutes to 0.5 hours, 5 minutes to 0.5 hours, 10 minutes to 0.5 hours, or 15 minutes to 0.5 hours, such that the heating step ends before the thermalization of the substance occurs.

[0109] The method of the present invention has the advantage that high pressure is not required in the heating step or the molding step. Thus, in a specific embodiment, steps (b), (c), and / or (d) of the method are carried out at atmospheric pressure.

[0110] In a specific embodiment, optionally in combination with any of the embodiments provided above or below, the pressure of the heating step is in the following range: 40 KPa to 750 KPa, 50 KPa to 600 KPa, 60 KPa to 450 KPa, 70 KPa to 300 KPa, 80 KPa to 200 KPa, 90 KPa to 150 KPa, or 95 KPa to 130 KPa.

[0111] Thus, the heating step of the method can also be carried out in a sealed container to avoid drying of the solid molded article.

[0112] In a specific embodiment, optionally in combination with any of the embodiments provided above or below, the heating step is carried out while maintaining the moisture content of the material equal to or higher than 20% w / w, equal to or higher than 25% w / w, equal to or higher than 30% w / w, equal to or higher than 35% w / w, equal to or higher than 40% w / w, equal to or higher than 45% w / w, equal to or higher than 50% w / w, equal to or higher than 55% w / w, equal to or higher than 60% w / w, or equal to or higher than 65% w / w.

[0113] The present inventors have found that depending on the heating method used, additional water can be added to the plant material to avoid drying and increase energy efficiency.

[0114] In a specific embodiment, optionally in combination with any of the embodiments provided above or below, the heating step is carried out by baking, microwaving or boiling (preferably in the presence of water) the plant material.

[0115] In a specific embodiment, optionally in combination with any of the embodiments provided above or below, the molding step is carried out with a heated material having a moisture content equal to or higher than 20% w / w, 30% w / w, 40% w / w, 50% w / w or 60% w / w.

[0116] In a specific embodiment, optionally in combination with any of the embodiments provided above or below, the drying step is carried out until the moisture content of the molded material is reduced to equal to or lower than 25% w / w, 20% w / w, 15% w / w, 10% w / w or 5% w / w. Any drying method can be used to reduce the moisture content of the molded material, such as compression, extrusion, filtration, absorption, vacuum drying, air drying, heating, radiation, flapping, air-blast evaporation and other drying methods, including natural air drying.

[0117] In a specific embodiment, optionally in combination with any of the embodiments provided above or below, the method further comprises a cutting step before the heating step, or after the heating step and before the molding step. Using non-woody fresh materials in the method of the present invention does not require high-energy-demand steps such as mechanical grinding or steam explosion to cut the materials. Furthermore, if the material is cut after step (b), simple manual shredding is sufficient before the material is molded. Thus, in a more specific embodiment, the cutting is selected from chopping, crushing, shredding and combinations thereof. In an even more specific embodiment, the particles produced by cutting the plant material have an average size of 0.025 cm to 5 cm, 0.05 cm to 4 cm, 0.075 cm to 3 cm or 0.1 cm to 2.5 cm.

[0118] By cutting the material, the size of the fibers is reduced. Shorter fibers allow for the production of more compact, rigid and sturdy molded articles. In contrast, longer fibers allow for the production of lighter and more flexible molded articles. Moreover, various fresh non-woody plant materials can be mixed to obtain molded articles with desired properties.

[0119] In a particular embodiment, optionally in combination with any of the embodiments provided above or below, the method further comprises the step of mixing the heated non-woody plant material with the woody plant material after step (b) and before step (c). As shown in the examples below, the inventors have found that mixing the heated non-woody plant material with the woody material allows modification of the final properties of the solid molded article produced. If the method further comprises a cutting step after step (b), the mixing step is carried out after the cutting step.

[0120] In a particular embodiment, optionally in combination with any of the embodiments provided above or below, the method further comprises the step of mixing the heated non-woody plant material with cellulose from woody plant sources after step (b) and before step (c).

[0121] In a particular embodiment, optionally in combination with any of the embodiments provided above or below, the method further comprises a pre-drying step after step (c) and before step (d), wherein the moisture content of the molding material is reduced to a value equal to or lower than 35% w / w, 30% w / w, 25% w / w, 20% w / w, 15% w / w or 10% w / w. This pre-drying step can be carried out using any standard technique known to those skilled in the art, such as centrifugation.

[0122] The material obtained in step (b) of the method of the present invention can be molded into products having a wide variety of shapes, forms and designs. The products can be produced by direct forming methods such as casting, compression molding, injection molding, lamination, matrix molding, 3D printing or extrusion.

[0123] Thus, in a particular embodiment, optionally in combination with any of the embodiments provided above or below, step (c) is carried out by a method selected from casting, molding, extrusion and combinations thereof.

[0124] The solid molded articles produced by the method of the present invention can be further improved by adding specific modifiers and / or additives. For example, the resistance of the product to moisture or water, chemically aggressive environments, microbial (e.g., bacterial, fungal) degradation, wood-eating insects and / or fire can be improved by adding specific additives to the material during the method. By adding specific modifiers, other properties of the product, such as color, odor, electrical conductivity or mechanical properties, can be altered. Those skilled in the art will know which additives should be added according to the properties of the solid molded article to be changed, and at which step of the method they should be added. For example, dyes can be added after the heat treatment but before the molding, and varnishes can be applied after the drying step. Additives that can be used in the method of the present invention include, but are not limited to, ecological gums, compounds (such as calcium chloride, sodium silicate, hydrogen peroxide, etc.) and waxes.

[0125] In a particular embodiment, optionally in combination with any of the embodiments provided above or below, the method further comprises the step of mixing fresh non-woody plant material with one or more additives.

[0126] In a particular embodiment, optionally in combination with any of the embodiments provided above or below, the method further comprises the step of mixing fresh non-woody plant material with a flocculant, a coagulant or a chelating agent to improve the dehydration process.

[0127] Furthermore, the molded articles of the present invention can be further improved by physical or chemical treatment, such as heat treatment. Thus, in a particular embodiment, optionally in combination with any of the embodiments provided above or below, the method further comprises a second heating step at a temperature of 100 °C to 250 °C and under a controlled atmosphere after step (d) to increase water resistance.

[0128] It is desirable to use naturally occurring additives, or additives directly derived from naturally occurring materials, and / or additives that are biodegradable (e.g., degraded to carbon dioxide, water and possibly biomass) in composting or other biological waste management processes.

[0129] In a particular embodiment, optionally in combination with any of the embodiments provided above or below, the method further comprises subjecting the solid molded article comprising non-woody plant material to one or more reprocessing steps after the drying step (d) to obtain a reprocessed solid molded article by a process comprising the following steps:

[0130] (e) rehydrating the solid molded article to obtain a rehydrated material;

[0131] (f) molding the rehydrated material obtained in step (e); and

[0132] (g) drying the molded material of step (f).

[0133] In a particular embodiment, optionally in combination with any of the embodiments provided above or below, the rehydration step (e) is carried out by adding water until the weight of the rehydrated object is three times the weight of the object before rehydration. In other words, the rehydration step comprises adding water in a ratio of higher than or equal to 3:1 (water: dry mass of the object).

[0134] One of the main advantages of the method of the present invention is that the solid molded articles produced can withstand the rehydration-molding-drying cycle an unlimited number of times. Thus, the solid molded articles produced are not only biodegradable but also reusable.

[0135] As described above, in a second aspect, the present invention provides a solid molded article obtainable by the method as defined in the first aspect.

[0136] A solid molded article "obtainable by" the method as defined above is used herein to define a solid molded article by its preparation process and relates to a solid molded article obtainable by a preparation method including steps a), b), c) and d) as described above. For the purposes of the present invention, the expressions "obtainable", "obtained" and equivalent expressions are used interchangeably, and in any case the expression "obtainable" includes the expression "obtained".

[0137] The above-described embodiments of the method of the first aspect are also applicable to the solid molded article obtainable by its preparation process.

[0138] Surprisingly, it has been found that by using the method of the present invention, products with completely different properties can be produced from various non-woody plant materials - for example, materials characterized by high stiffness or materials with high elasticity, even in the absence of conventional synthetic chemical crosslinking agents and / or conventional synthetic chemical plasticizers. Thus, for example, by varying the mixture of raw materials and by introducing different processing steps, different products with different properties can be developed, which exhibit good application performance. Thus, products with different strengths, elasticities and stiffnesses can be manufactured according to the present invention; products with different shapes and / or densities; products with different biodegradabilities or combinabilities; products that exhibit barrier properties to oxygen and other gases, from permeable materials to materials with good barrier properties; products with different barrier properties to heat, including materials with good heat resistance; and products with different tolerances to organic solvents, oils, water, etc.

[0139] The products of the present invention, depending on their final properties, can be used in various industries - of course, they can be used in combination with other materials. For example, they are used in the following aspects:

[0140] - As building materials in the construction industry and in the furniture and cabinet manufacturing industry, for example in the form of particle boards, MDF (medium density fiberboard) or HDF (high density fiberboard);

[0141] - As bulk thermoplastic products, such as disposable products, sheets, foils, nets, laminates and films,

[0142] - For agricultural uses (the expression herein includes horticultural uses);

[0143] - As a backing material for floor coverings, such as carpets or carpet tiles;

[0144] - As roofing materials;

[0145] - As building materials for road construction, etc.

[0146] - As an insulating material, for the purpose of insulating heat, electricity and noise;

[0147] - As a packaging material, such as for bottles, snack packs, crates, containers, etc.;

[0148] - As a cushioning material for protection purposes,

[0149] - As a decorative item, such as for tabletops, veneers, storefront fixtures, wall tiles, etc.;

[0150] - As extruded pellets, used as raw materials in, for example, household materials, toys, etc.; and

[0151] In a specific embodiment of the second aspect, optionally in combination with any of the embodiments provided above or below, the density of the solid molded article determined using a pycnometer is in the range of 25 kg / m 3 to 2000 kg / m 3 range.

[0152] In a specific embodiment of the second aspect, optionally in combination with any of the embodiments provided above or below, the elasticity of the solid molded article determined using a nanoindentation instrument is in the range of 50 MPa to 7 GPa.

[0153] In a specific embodiment of the second aspect, optionally in combination with any of the embodiments provided above or below, the strength of the solid molded article determined using a nanoindentation instrument is in the range of 6 MPa to 250 MPa.

[0154] In a specific embodiment of the second aspect, optionally in combination with any of the embodiments provided above or below, the dehydration value of the solid molded article determined by the Schopper-Riegler method is in the range of 20°SR to 100°SR.

[0155] In a specific embodiment of the second aspect, optionally in combination with any of the embodiments provided above or below, the porosity of the solid molded article determined by mercury intrusion porosimetry is in the range of 5% to 90%.

[0156] In a specific embodiment of the second aspect, optionally in combination with any of the embodiments provided above or below, the thermal conductivity of the solid molded article determined in a thermal testing machine (such as FOX 600GHP of TA instruments) (ISO8302 / ISO22007) is in the range of 0.01 W / mK to 0.15 W / mK.

[0157] In a specific embodiment of the second aspect, optionally in combination with any of the embodiments provided above or below, the flexural strength (measured by a three-point bending test) of the solid molded article is in the range of 10 MPa to 150 MPa.

[0158] In a specific embodiment of the second aspect, optionally in combination with any of the embodiments provided above or below, the ultimate tensile strength of the solid molded article in a tensile strength tester (such as the Mega1500 of Labthink) is in the range of 10 MPa to 500 MPa.

[0159] Throughout the specification and claims, the word "comprising" and variations of that word are not intended to exclude other technical features, additives, components, or steps. Additionally, the word "comprising" encompasses the case of "consisting of". Other objects, advantages, and features of the present invention will become apparent to those skilled in the art upon examination of the specification, or may be learned through practice of the present invention. The following examples and drawings are provided as illustrations and are not intended to limit the present invention. Reference signs in parentheses in the claims and related to the drawings are only for the purpose of attempting to increase the understandability of the claims and should not be construed as limiting the scope of the claims. Furthermore, the present invention covers all possible combinations of the specific and preferred embodiments described herein.

[0160] Examples

[0161] Example 1 - Molded article from artichoke flowers

[0162] Fresh artichoke flowers (waste discarded in food preparation) with a moisture content of approximately 72% w / w were cut into pieces smaller than 1 cm in size, then immersed in water and heated at 100 °C for 90 min using an 800 W resistor. The resulting material was pulverized with a 300 W blender and centrifuged at 1000 rpm to obtain a moldable material. The material was placed in a container with the desired final shape and then dried in the sun for one week. The resulting article was solid and exhibited a moisture content of 17% (measured with a DVM125 type Velleman Contact hygrometer) and a density of 568 kg / m 3 (measured with a pycnometer).

[0163] Example 2 - Molded object from cabbage

[0164] Fresh red cabbage with a moisture content of approximately 93% w / w was heated in a microwave oven at 100 °C for 35 minutes at a power of 900 W. Then, it was pulverized with a 300 W blender and placed in a metal container with the desired final shape. Then it was dried in a convection oven at 100 °C for 6 hours. The resulting article was solid and exhibited a density of 1359 kg / m 3 (measured with a pycnometer).

[0165] Example 3 - Thermal insulation properties of low-density materials produced by the method according to the invention

[0166] Fibers from the covering layer of the edible part of coconut husk, with a moisture content of approximately 80% w / w, are immersed in water and heated at a temperature of 100 °C for 90 minutes using an 800 W resistor. Then they are crushed using a 300 W blender, placed in a porous mold, and pressed to remove excess water. The molded material is dried in the sun until the moisture content reaches a minimum value (∼14%). The resulting article is firm and exhibits a moisture content of 17% w / w (measured with a DVM125 type Velleman Contact hygrometer), a density of 114.8 kg / m 3 (weight / dimension), a heat transfer coefficient of 0.472 W / m 2 K, a thermal resistance of 2.119 m 2 K / W, and a thermal conductivity: 0.019 W / mK.

[0167] Example 4 - Mechanical testing of high-hardness articles produced by the method of the invention

[0168] Fresh celery with a moisture content of approximately 95% is immersed in water and heated at a temperature of 100 °C for 90 minutes using an 800 W resistor, and then crushed using a 300 W blender. Subsequently, the said material is placed in a porous mold with a desired shape and pressurized to remove excess water. The molded material is dried in the sun until its moisture content reaches a minimum value of approximately 11% w / w. The resulting article exhibits a density of 1029 kg / m 3 (pycnometer), a Vickers hardness of 11.6 HV (114 MPa) (measured with a Vickers hardness tester MXT70 Matsuzawa), a Brinell hardness of 20.4 HB (measured with a Rockwell hardness tester), a flexural strength of 76.21 MPa (measured by a three-point test), and an ultimate tensile strength of 29 MPa.

[0169] Example 5 - Physical properties of wet substances and high-hardness articles produced by the method of the invention

[0170] Fresh celery (whole plant) with a moisture content of approximately 95% is immersed in water and heated at a temperature of 100 °C for 90 minutes using an 800 W resistor, and then crushed using a 300 W blender. The resulting material is then centrifuged at 1400 rpm, molded, and dried in a microwave oven. The final molded article is solid and exhibits a moisture content of 10.6% (measured in accordance with the provisions of UNE-EN ISO 638:2009). Subsequently, a wet material portion is prepared (in accordance with the provisions of UNE EN-ISO 5263-1). The wet material exhibits:

[0171] - The dehydration value is 88 ± 1.4 °SR (in accordance with UNE-EN ISO 5267-1:2001) (measured by the Schopper-Riegler dehydration test).

[0172] - Viscosity: 135 ± 5 centipoise (Brookfield test, using an RV2 rotor at 25 °C and 100 rpm)

[0173] - Roughness: 6.231 ± 0.984 μm (Sensofar confocal microscope)

[0174] - Porosity: (mercury intrusion porosimeter)

[0175]

[0176]

[0177] Example 6 – Molded article from bryophyte

[0178] Fresh moss with a moisture content of approximately 96% w / w is heated at 100 °C for 120 minutes, then placed in a metal container with the desired final shape and dried at 50 °C on a dryer for 6 hours. The resulting article is firm and exhibits good solidity and low hardness.

[0179] Example 7 (comparative example) – Molded article from lettuce processed at different temperatures

[0180] Fresh lettuce with a moisture content of 96% w / w is immersed in water using a Klarstein pot (model 10031629) and heated at the specified temperatures [(a) 30 °C, (b) 40 °C, (c) 60 °C, (d) 70 °C, (e) 80 °C, (f) 100 °C] for 1 hour. Then it is crushed using a 500 W Sammic blender (model TR-550BXL) and centrifuged at 1400 rpm for 14 minutes. The resulting substance is manually molded to obtain a disc shape and dried at 50 °C on a dryer for 24 hours. The resulting disc is solid and exhibits a moisture content of 13% (DVM125 type Velleman Contact hygrometer). The elastic modulus, hardness (Agilent nanoindenter G200), and density (pycnometer) obtained at the specified temperatures are shown in the following table:

[0181] Temperature (°C) Elasticity (MPa) Hardness (MPa) <![CDATA[Density (kg / m 3 )]]> (a)30 - - - (b)40 158 10 641 (c)60 102 14 741 (d)70 1723 159 811 (e)80 - - 900 (f)100 4288 145 1072

[0182] The article produced by method (a) at 30 °C does not exhibit the properties suitable for its use in industry.

[0183] Example 8 - Lettuce processed at different temperatures

[0184] Fresh lettuce (whole plant) with a water content of approximately 96% w / w was placed in a sealed container and heated in a commercial convection oven at a temperature of (a) 150 °C or (b) 250 °C for 60 minutes. Then it was ground using a 500 W TR-550BXL type Sammic blender and centrifuged at 1400 rpm, and manually molded to obtain a disc shape. The disc was dried on a dryer at 50 °C for 24 hours. The resulting solid article exhibited a water content of 14% (DVM125 type Velleman Contact hygrometer). The values of the elastic modulus and hardness (G20 type Agilent nanoindenter) and density (pycnometer) of the resulting article are shown in the following table:

[0185] Temperature (°C) Elasticity (MPa) Hardness (MPa) <![CDATA[Density (kg / m 3 )]]> (a)150 1464 110 852 (b)250 1167 124 700

[0186] Example 9 – Molded article from artichoke processed at different temperatures

[0187] Fresh artichokes (whole plant) with a water content of approximately 72% w / w were immersed in water using a Klarstein (model 10031629 pot) and heated at (a) 60 °C or (b) 100 °C for 60 minutes. Then they were ground using a 500 W Sammic blender (TR-550BXL type) and centrifuged at 1400 rpm, and manually molded to obtain a disc shape, and dried on a dryer at 50 °C for 24 hours. The resulting article was solid, exhibited a humidity of 10% (DVM125 type Velleman Contact hygrometer), and the density measured using a pycnometer was as follows:

[0188] Temperature (°C) <![CDATA[Density (kg / m 3 )]]> (a)60 715 (b)100 708

[0189] Example 10 – Molded article from artichoke

[0190] Fresh artichokes (whole plant) with a water content of approximately 72% w / w were immersed in water using a Klarstein (model 10031629 pot) and heated at (a) 60 °C or (b) 100 °C for 60 minutes. Then they were ground using a 500 W Sammic blender (TR-550BXL type) and centrifuged at 1400 rpm, and filtered through a sieve to obtain (a) fibers with a size less than 1 mm, (b) fibers with a size greater than 1 mm, and (c) washed fibers with a size greater than 1 mm. The resulting material was manually molded to obtain a disc shape and dried on a dryer at 50 °C for 24 hours. The resulting article was firm and exhibited a water content of 12% (DVM125 type Velleman Contact hygrometer) and the density (measured using a pycnometer; the density value of Example c in parentheses was measured by weight / dimension) was as follows:

[0191]

[0192]

[0193] Example 11 - Molded article from non-woody (NW) material mixed with woody (W) material additive (cellulose)

[0194] Fresh lettuce with a water content of 96% w / w was heated at 100 °C for 60 minutes and immersed in water using a Klarstein pot (model 10031629). It was then crushed using a 500 W Sammic blender (model TR-550BXL) and centrifuged at 1400 rpm for 14 minutes. Then, cellulose powder (obtained from wood) was added and mixed until a homogeneous substance was obtained. The resulting substance was manually molded to obtain a disc shape and dried in a dryer at 50 °C for 24 hours. The final solid articles produced with a specified ratio of non-wood material (NW) and wood material (W) exhibited a water content of 14% (measured using a DVM125 type Velleman Contact hygrometer), and the density (measured using a pycnometer) and elastic modulus and hardness (measured using a G200 type Agilent nanoindenter) values were as follows:

[0195] Weight % Elasticity (MPa) Hardness (MPa) <![CDATA[Density (kg / m 3 )]]> (a) 100% NW 4288 145 1072 (b) 50% NW / 50% W 1020 81 680 (c) 25% NW / 75% W 180 6 637

[0196] Example 12 – Changing the density of the molded article by a filtration step

[0197] Fresh lettuce stalks with a water content of approximately 96% w / w were immersed in water using a Klarstein pot (model 10031629) and heated at 100 °C for 240 minutes. It was then crushed using a 500 W Sammic blender (model TR-550BXL), centrifuged, and filtered through a sieve to obtain materials: (a) with a size below 1 mm, (b) unfiltered, (c) with a size greater than 1 mm, and (d) with a size greater than 1 mm and thoroughly washed with water. The materials were then manually molded to obtain a disc shape and dried in a dryer at 50 °C for 24 hours. The resulting solid articles exhibited a water content of 14% (measured using a DVM125 type Velleman Contact hygrometer) and the density (measured using a pycnometer) was as follows:

[0198]

[0199]

[0200] Example 13 – Molded article from pineapple leaves

[0201] Fresh pineapple leaves with a water content of approximately 87% w / w were immersed in water using a Klarstein pot (model 10031629) and heated at different temperatures [(a) 80 °C, (b) 100 °C] for 1 hour. Then they were pulverized using a 500 W Sammic blender (model TR-550BXL), centrifuged at 1400 rpm, and manually molded to obtain a disc shape, and dried at 50 °C on a dryer for 24 hours. The resulting articles were firm and exhibited a water content of 13% (DVM125 type Velleman Contact hygrometer) and density (measured using a pycnometer) and elastic modulus and hardness (measured using an Agilent nanoindenter G200) values as follows:

[0202] Temperature (°C) Elasticity (MPa) Hardness (MPa) <![CDATA[Density (kg / m 3 )]]> (a)80 123 14 804 (b)100 439 62 772

[0203] Example 14 – Molded article from a mixture of pumpkin and lettuce

[0204] Fresh pumpkins with a water content of approximately 96% w / w were immersed in water using a Klarstein pot (model 10031629) and heated at 100 °C for 60 minutes. Then they were pulverized using a 500 W Sammic blender (model TR-550BXL), centrifuged at 1400 rpm, and mixed with the lettuce fibers of Example 12(d) in the following ratios: (a) 100% pumpkin, (b) 50% pumpkin / 50% fiber, (c) 30% pumpkin / 70% fiber. The resulting substances were manually molded to obtain a disc shape and dried at 50 °C on a dryer for 24 hours. The resulting articles were firm, with a water content of 12 - 15% (DVM125 type Velleman Contact hygrometer) and density (measured using a pycnometer) as follows:

[0205] Sample <![CDATA[Density (kg / m 3 )]]> (a) 1235 (b) 753 (c) 643

[0206] Example 15 – Molded article from non-woody material of woody plants

[0207] Fresh apples with a water content of approximately 84% were immersed in water using a Klarstein pot (model 10031629) and heated at 100 °C for 1 hour. Then they were pulverized using a 500 W Sammic blender (model TR-550BXL), centrifuged at 1400 rpm, and manually molded to obtain a disc shape, and dried at 50 °C on a dryer for 24 hours. The resulting articles were firm and exhibited a water content of 16% (DVM125 type Velleman Contact hygrometer), and a density of 1018 kg / m 3 (measured using a pycnometer).

[0208] Example 16 – Molded article from non-woody material of woody plants

[0209] Fresh apples with a water content of approximately 84% w / w were immersed in water using a Klarstein pot (model 10031629) and heated at 100 °C for 1 hour. Then they were pulverized using a 500 W Sammic blender (model TR-550BXL), centrifuged at 1400 rpm, mixed with the fibers of Example 10(c), manually molded to obtain a disc shape, and dried in a dryer at 50 °C for 24 hours. The resulting article was firm and had a water content of 11% w / w (measured using a DVM125 type Velleman Contact hygrometer) and a density of 679 kg / m 3 (measured using a pycnometer).

[0210] Example 17 – Molded article made from celery treated at various temperatures

[0211] Fresh celery with a water content of approximately 95% w / w was immersed in water using a Klarstein pot (model 10031629) and heated at the following temperatures during 1 hour: (a) 60 °C, (b) 80 °C, (c) 100 °C. Then, it was pulverized using a 500 W TR-550BXL type Sammic blender, centrifuged at 1400 rpm, manually molded to obtain a disc shape, and dried in a dryer at 50 °C for 24 hours. The resulting article was firm, had a water content of 15% (measured using a DVM125 type Velleman Contact hygrometer), and the density (measured using a pycnometer), elastic modulus, and hardness (measured using a G200 type Agilent nanoindenter) values were as follows:

[0212] Temperature (°C) Elasticity (MPa) Hardness (MPa) <![CDATA[Density (kg / m 3 )]]> (a)60 906 102 950 (b)80 1051 87 1042 (c)100 3853 166 1050

[0213] Example 18 – Molded article from cauliflower

[0214] The white part of fresh cauliflower with a water content of approximately 84% w / w was immersed in water using a Klarstein pot (model 10031629), heated at 100 °C for 1 hour, pulverized using a 500 W Sammic blender (model TR-550BXL), centrifuged at 1400 rpm, manually molded to obtain a disc shape, and dried in a dryer at 50 °C for 24 hours. The resulting article was firm, had a water content of 13% (measured using a DVM125 type Velleman Contact hygrometer), an elastic modulus of 3107 MPa (measured using a G200 type Agilent nanoindenter), a hardness of 123 MPa (measured using a G200 type Agilent nanoindenter), and a density of 1051 kg / m 3 (measured using a pycnometer).

[0215] Example 19 – Molded article from grass

[0216] Fresh grass from horticultural waste with a moisture content of approximately 84% w / w was immersed in water using a Klarstein pot (model 10031629), heated at 100 °C for 1 hour. It was then crushed using a 500 W Sammic blender (model TR-550BXL), centrifuged at 1400 rpm, mixed with the fibers of Example 10(c), manually molded to obtain a disc shape, and dried on a dryer at 50 °C for 24 hours. The resulting article was strong and exhibited good firmness and low density.

[0217] Example 20 (comparative example) – Molded article from straw

[0218] Dry straw with a moisture content of approximately 12% w / w and a lignin content of approximately 21% w / w was immersed in water using a Klarstein pot (model 10031629), heated at 100 °C for 1 hour. It was then crushed using a 500 W Sammic blender (model TR-550BXL), centrifuged at 1400 rpm, manually molded to obtain a disc shape, and dried on a dryer at 50 °C for 24 hours. The resulting article was not strong and firm enough to be suitable for use in industry.

[0219] Example 21 – Reprocessing of the molded article of the invention

[0220] The molded article made from fresh whole lettuce according to the method of Example 7 and using a temperature of 100 °C in the heating step was rehydrated at a ratio of at least 3 parts water: 1 part dry matter, centrifuged at 1400 rpm, manually molded to obtain a disc shape, and dried on a dryer at 50 °C for 24 hours. The final solid article exhibited a moisture content of 13% (DVM125 type Velleman Contact hygrometer), an elastic modulus of 2437 MPa (G200 type Agilent nanoindenter), and a hardness of 153 MPa (G200 type Agilent nanoindenter).

[0221] Example 22 – Characterization of the produced molded article

[0222] - The hardness, elastic modulus, and density of the final product depend on the temperature parameter in step (b).

[0223] Values were taken from Examples 7 and 8.

[0224]

[0225]

[0226] - Hardness range

[0227] Hardness values from different examples describe a continuous range from 6 MPa to 166 MPa.

[0228] Example 11(c) 13(b) 8(a) 17(c) Hardness (MPa) 6 62 110 166

[0229] - Density range

[0230] Density values from different embodiments describe a continuous range from 419 kg / m 3 to 1359 kg / m 3 of the continuous range.

[0231] Example 12(c) 10(b) 19 2 <![CDATA[Density (kg / m 3 )]]> 419 694 1051 1359

[0232] - Elastic modulus range

[0233] Elastic modulus values from different embodiments describe a continuous range from 123 MPa to 4288 MPa.

[0234]

[0235] Clause

[0236] 1. A method for producing a solid molded article comprising non-woody plant material, the method comprising the steps of:

[0237] (a) Providing one or more fresh non-woody plant materials having a moisture content of 20% w / w to 99% w / w;

[0238] (b) Heating the fresh non-woody plant material at a temperature of 40°C to 250°C and a pressure of 40 kPa to 750 kPa, maintaining the moisture content of the material equal to or higher than 20% w / w;

[0239] (c) Molding the heated material obtained in step (b); and

[0240] (d) Drying the molded material obtained in step (c).

[0241] 2. The method according to claim 1, wherein the solid molded article comprising non-woody plant material has one or more of the following:

[0242] i) A density in the range of 100 kg / m 3 to 2000 kg / m 3 determined using a pycnometer;

[0243] ii) A strength in the range of 6 MPa to 250 MPa determined using a nanoindentation instrument; and

[0244] iii) An elasticity in the range of 50 MPa to 7 GPa determined using a nanoindentation instrument.

[0245] 3. The method according to any one of claims 1-2, wherein the lignin content of the one or more fresh non-woody plant materials in step (a) is less than or equal to 20% w / w.

[0246] 4. The method according to any one of claims 1-3, wherein the water content of the fresh non-woody plant materials in step (a) is 40% w / w to 99% w / w.

[0247] 5. The method according to any one of claims 1-4, wherein the fresh non-woody plant materials in step (a) are agricultural products or agricultural by-products.

[0248] 6. The method according to any one of claims 1-5, wherein the fresh non-woody plant materials are from plants belonging to the group consisting of bryophytes, angiosperms, and non-woody gymnosperms.

[0249] 7. The method according to any one of claims 1-6, wherein step (b) is carried out without adding water.

[0250] 8. The method according to any one of claims 1-7, wherein step (b) is carried out at a temperature of 70 °C to 120 °C.

[0251] 9. The method according to any one of claims 1-8, wherein step (b) is carried out for a period of 0.5 hours to 4 hours.

[0252] 10. The method according to any one of claims 1-9, wherein the non-woody plant materials after the heating step (b) have one or more of the following:

[0253] i) a water content in the range of 20% to 99% w / w,

[0254] ii) a dehydration value in the range of 20°SR to 100°SR determined by the Schopper-Riegler method; and

[0255] iii) a viscosity in the range of 0.001 Pa·s to 15 Pa·s determined by the Brookfield method.

[0256] 11. The method according to any one of claims 1-10, further comprising a cutting step after step (a) and before step (b), or after step (b) and before step (c).

[0257] 12. The method according to any one of claims 1-11, further comprising a step of mixing the fresh non-woody plant materials with woody plant materials or with one or more additives after step (b) and before step (c).

[0258] 13. The method according to any one of claims 1 - 12, further comprising a pre - drying step after step (c) and before step (d), wherein the moisture content of the moulding material is reduced to a value equal to or lower than 40% w / w.

[0259] 14. The method according to any one of claims 1 - 13, further comprising subjecting the solid moulding containing non - woody plant material to one or more re - processing steps to obtain a re - processed solid moulding by a process comprising the following steps after step (d):

[0260] (e) re - hydrating the solid moulding and obtaining a re - hydrated material;

[0261] (f) moulding the re - hydrated material obtained in step (e); and

[0262] (g) drying the moulded material of step (f).

[0263] 15. A solid moulding obtainable by a method as defined in any one of claims 1 - 14.

Claims

1. A method for producing a solid molded article comprising non-woody plant material, said non-woody plant material being the whole or any part of a non-woody plant, or the non-woody part of a woody plant, said method comprising the following steps: (a) Providing one or more fresh non-woody plant materials having a moisture content of 20% w / w to 99% w / w relative to the total weight of the plant material, wherein the fresh non-woody plant material is plant material that has not been preserved by drying after harvesting; (b) Heating the fresh non-woody plant material at a temperature of 60°C to 140°C and a pressure of 40 KPa to 750 KPa for at least 0.5 hours, maintaining the moisture content of the material equal to or higher than 20% w / w; (c) Molding the heated material obtained in step (b); and (d) Drying the molded material obtained in step (c).

2. The method according to claim 1, wherein the solid molded article comprising non-woody plant material has one or more of the following: i) Density in the range of 100 kg / m 3 to 2000 kg / m 3 determined using a pycnometer; ii) A strength in the range of 6 MPa to 250 MPa determined using a nanoindenter; and iii) An elasticity in the range of 50 MPa to 7 GPa determined using a nanoindenter.

3. The method according to claim 1, wherein the lignin content of the one or more fresh non-woody plant materials in step (a) is less than or equal to 20% w / w.

4. The method according to claim 1, wherein the moisture content of the fresh non-woody plant material in step (a) is 40% w / w to 99% w / w.

5. The method according to claim 1, wherein the fresh non-woody plant material in step (a) is an agricultural product or a by-product of agricultural products.

6. The method according to claim 1, wherein the fresh non-woody plant material is from a plant belonging to a plant selected from bryophytes, angiosperms, and non-woody gymnosperms.

7. The method according to claim 1, wherein step (b) is carried out without adding water.

8. The method according to claim 1, wherein step (b) is carried out at a temperature of 70°C to 120°C.

9. The method according to claim 1, wherein step (b) is carried out for a period of 0.5 hours to 4 hours.

10. The method according to claim 1, wherein the non-woody plant material after the heating step (b) has one or more of the following: i) A moisture content in the range of 20% to 99% w / w, ii) A dehydration value in the range of 20°SR to 100°SR determined by the Schopper-Riegler method; and iii) A viscosity in the range of 0.001 Pa·s to 15 Pa·s determined by the Brookfield method.

11. The method according to claim 1, further comprising a cutting step after step (a) and before step (b), or after step (b) and before step (c).

12. The method according to claim 1, further comprising, after step (b) and before step (c), a step of mixing the fresh non-woody plant material with a woody plant material or with one or more additives.

13. The method according to claim 1, further comprising a pre-drying step after step (c) and before step (d), wherein the moisture content of the molded material is reduced to a value equal to or lower than 40% w / w.

14. The method according to claim 1, further comprising subjecting the solid molded article comprising the non-woody plant material to one or more reprocessing steps to obtain a reprocessed solid molded article by a process comprising the following steps after step (d): (e) rehydrating the solid molded article and obtaining a rehydrated material; (f) molding the rehydrated material obtained in step (e); and (g) drying the molded material of step (f).

15. The method according to claim 1, wherein the lignin content of the one or more fresh non-woody plant materials in step (a) is lower than or equal to 20% w / w and the moisture content is 40% w / w to 99% w / w.

16. The method according to claim 1, wherein the lignin content of the one or more fresh non-woody plant materials in step (a) is lower than or equal to 20% w / w and the moisture content is 40% w / w to 99% w / w, and wherein step (b) is carried out at a temperature of 70°C to 120°C.

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