Vinasse and cork composite material and preparation method thereof

Abstract

The invention belongs to the technical field of wine making by-product treatment, and relates to a vinasse and cork composite material and a preparation method thereof.The preparation method comprises the following steps that alkali, dialdehyde starch and sodium carboxymethyl cellulose are added into vinasse, heating, stirring and centrifuging are conducted, precipitates are collected, and modified vinasse is obtained; uniformly mixing the modified vinasse with cork particles, adding a plasticizer and a preservative, and uniformly mixing to obtain a cork vinasse mixture; mixing the cork vinasse mixture with an adhesive to obtain a composite material mixture; and carrying out compression molding on the composite material mixture, and demolding to obtain the vinasse cork composite material. Vinasse is treated by alkali, so that functional groups in the vinasse are fully exposed, then protein in the vinasse is stabilized by sodium carboxymethyl cellulose, dialdehyde starch and amino groups of the protein are crosslinked, so that the functional groups in the modified vinasse are more easily subjected to complex reaction with cork particles, and the binding force of the modified vinasse and the cork particles is improved; therefore, the hardness, rebound resilience, wear resistance and other properties of the composite material are enhanced.

Description

Technical Field

[0001] The invention belongs to the technical field of winemaking by-product processing and relates to a wine lees cork composite material and a preparation method thereof. Background Art

[0002] Fresh distiller's grains have a high water content. If not handled in time, they can easily rot and mold, breed mosquitoes and bacteria, cause air and water pollution, and affect ecological health. The traditional method for wineries to process distiller's grains is mainly to make feed, but this method has low added value and is affected by the region. Liquor distiller's grains contain natural macromolecules such as protein, lignin, cellulose, starch, etc., have rich active functional groups, and have the potential to prepare new materials.

[0003] Cork is a good material from natural sources. Its natural honeycomb pore structure gives it good elasticity, heat insulation and sound insulation, but its hardness and durability need to be improved. Generally, cork particles are mixed with other ingredients, such as adhesives, and various cork products can be prepared through high-temperature molding. However, adhesives are often derived from petroleum-based and non-degradable, which not only increases product costs but also damages the environment. Summary of the invention

[0004] The invention aims to provide a preparation method of a wine lees-cork composite material, which comprises the following steps: treating wine lees with an alkali to fully expose functional groups in the wine lees, then stabilizing proteins in the wine lees with sodium carboxymethyl cellulose, and cross-linking dialdehyde starch with amino groups of proteins, so that functional groups in the modified wine lees are more likely to react with cork particles for complexation, thereby improving the binding force between the modified wine lees and the cork particles, thereby enhancing the hardness, resilience and wear resistance of the composite material, and utilizing the wine lees as waste, while reducing the application cost of cork.

[0005] In a first aspect, the present invention provides a method for preparing a wine lees cork composite material, comprising the following steps:

[0006] Step 1, modification of vinasse: adding alkali, dialdehyde starch and sodium carboxymethyl cellulose to the vinasse, mixing, heating, stirring, centrifuging, collecting precipitates, and further treating the precipitates to obtain modified vinasse; the dialdehyde starch content is 0.5-1.5% of the vinasse content, and the sodium carboxymethyl cellulose content is 0.5-1% of the vinasse content;

[0007] Step 2, preparing a cork wine lees mixture: mixing the modified wine lees with cork particles, adding a plasticizer and a preservative, and mixing evenly to obtain a cork wine lees mixture; the weight ratio of the modified wine lees to the cork particles is 3:10-50, the weight ratio of the plasticizer to the modified wine lees is 0.015-0.3:3, and the weight ratio of the preservative to the modified wine lees is 0.003-0.06:3;

[0008] Step 3, preparing a composite material mixture: mixing the cork wine lees mixture with a binder to obtain a composite material mixture; the mass ratio of the binder to the modified wine lees is 0.3-5:3;

[0009] Step 4, compression molding: compression molding the composite material mixture, and demoulding to obtain a wine lees cork composite material.

[0010] In some embodiments, in step 3, the method for preparing a composite mixture further includes adding reinforcing fibers to mix with the cork wine lees mixture and the adhesive to obtain a composite mixture; the mass ratio of the reinforcing fibers to the modified wine lees is 0.3-2:3.

[0011] In some embodiments, the content of dialdehyde starch is 0.8-1.2% of the content of the lees, the content of sodium carboxymethyl cellulose is 0.6-0.8% of the content of the lees; the weight ratio of the modified lees to the cork particles is 3:15-50; the mass ratio of the binder to the modified lees is 0.45-4.8:3; the mass ratio of the reinforcing fiber to the modified lees is 0.45-1.8:3;

[0012] Preferably, the amount of modified wine lees added is 2.8-3.2 kg; the amount of cork particles added is 10-50 kg; the amount of plasticizer added is 0.015-0.3 kg, the amount of preservative added is 0.003-0.02 kg; the amount of adhesive added is 0.45-4.8 kg; and the amount of reinforcing fiber added is 0.45-1.8 kg.

[0013] In some embodiments, the moisture content of the modified distillers grains and the cork particles is less than 12%;

[0014] Preferably, the moisture content of the modified wine grains and the cork particles is less than 10%.

[0015] In some embodiments, the plasticizer is a bio-based plasticizer, including at least one of ricinoleate, epoxidized soybean oil, epoxidized cardanol tungstate, eleostearyl glyceride, polylactic acid ester, and glycidol;

[0016] Preferably, the preservative is a food preservative, including at least one of potassium sorbate, nisin, natamycin, sodium dehydroacetate, methyl paraben, sodium diacetate, calcium propionate, and sodium lactate;

[0017] Preferably, the adhesive is a biomass-based adhesive, selected from at least one of a bio-based polyurethane adhesive, a bio-based acrylic resin adhesive, and a bio-based furan resin adhesive.

[0018] In some embodiments, the reinforcing fiber is selected from at least one of glass fiber, carbon fiber, and natural fiber;

[0019] Preferably, the natural fiber includes at least one of polylactic acid fiber, chitosan fiber, calcium alginate fiber and cellulose acetate fiber.

[0020] In some embodiments, the base is a NaOH solution, and the concentration of the NaOH solution is 0.06-0.2 mol / L;

[0021] Preferably, the volume ratio of the mass of the vinasse to the NaOH solution is 1:10-1:30 g / ml.

[0022] In some embodiments, in the lees modification step, the heating temperature is 35-45° C., and the heating time is 1-2 h;

[0023] Preferably, in the lees modification step, the heating temperature is 38-42° C., and the heating time is 1.1-1.8 h.

[0024] In some embodiments, the specific method of the compression molding is: first gradually pressurize to 8-12 MPa at a speed of 0.1-0.2 MPa / min at 140-150°C, stabilize the pressure to maintain the shape, and then slowly cool to room temperature.

[0025] In a second aspect, the present invention provides a wine lees cork composite material, which is prepared by any one of the preparation methods described above.

[0026] In summary, the present application includes at least one of the following beneficial technical effects:

[0027] The lees are treated with alkali to fully expose the functional groups in the lees, and then sodium carboxymethyl cellulose is used to stabilize the protein in the lees. At the same time, dialdehyde starch is cross-linked with the amino groups of the protein to make it easier for the functional groups in the modified lees to undergo complexation reaction with the cork particles, thereby improving the binding force between the modified lees and the cork particles, thereby enhancing the hardness, resilience and wear resistance of the composite material, making use of the lees as waste, and reducing the application cost of cork. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a coaster image of the biomass-based composite material prepared in Example 1 of the present invention;

[0029] Figure 2 This is a diagram of a stationery tube made of a biomass-based composite material prepared in Example 2 of the present invention;

[0030] Figure 3 It is the lees diagram in the specification of the present invention. DETAILED DESCRIPTION

[0031] The technical solution of the present invention is further described below by specific embodiments, which do not limit the protection scope of the present invention. Some non-essential modifications and adjustments made by others based on the concept of the present invention still fall within the protection scope of the present invention.

[0032] The reagents and equipment in the present invention are all commercially available.

[0033] Example 1

[0034] A method for preparing a wine lees cork composite material comprises the following steps:

[0035] Step 1, modification of vinasse: adding alkali, dialdehyde starch and sodium carboxymethyl cellulose to the vinasse, mixing, heating, stirring, centrifuging, collecting the precipitate, and further treating the precipitate to obtain modified vinasse; the content of dialdehyde starch is 0.5-1.5% of the vinasse content, and the content of sodium carboxymethyl cellulose is 0.5-1% of the vinasse content;

[0036] Step 2, preparing a cork lees mixture: mixing the modified lees with the cork particles, adding a plasticizer and a preservative, and mixing evenly to obtain a cork lees mixture; the weight ratio of the modified lees to the cork particles is 3:10-50, the weight ratio of the plasticizer to the modified lees is 0.015-0.3:3, and the weight ratio of the preservative to the modified lees is 0.003-0.06:3;

[0037] Step 3, preparing a composite material mixture: mixing the cork wine lees mixture with a binder to obtain a composite material mixture; the mass ratio of the binder to the modified wine lees is 0.3-5:3;

[0038] Step 4, compression molding: compression molding the composite material mixture, demoulding, and obtaining the wine lees cork composite material.

[0039] The proteins, lignin, etc. contained in the liquor lees provide abundant reactive functional groups (amino groups, carboxyl groups). In particular, the basic building blocks of lignin are phenolic compounds, which are similar to the phenol structure of phenolic resin adhesives and are a natural binder. Alkali fully exposes the chemical groups in the lees, and dialdehyde starch and sodium carboxymethyl cellulose are used to chemically modify the lees to improve the bonding ability between the lees and cork.

[0040] Cork includes lignin, cellulose, suberin, etc. Suberin is composed of hydroxy fatty acids, which can react with the chemical groups exposed in the modified distiller's grains to form a more stable structure by doping the distiller's grains into the cork, so that the modified distiller's grains have a better bonding effect on the cork. The composite materials prepared from liquor distiller's grains and cork particles show excellent mechanical hardness and structural stability, and liquor distiller's grains achieve high added value recycling of resources. According to statistics, China's liquor distiller's grains production in 2021 was about 25.046 million tons, which can be used in cork products to replace 5-8 million tons of cork resources. In addition, the distiller's grains discarded by the liquor industry are used as raw materials to make cork materials. The process is simple, which reduces raw material consumption and can greatly reduce the cost of cork material utilization.

[0041] The content of dialdehyde starch is 0.5-1.5% of the content of lees, such as 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5% and the like of dialdehyde starch content, and the content of sodium carboxymethyl cellulose is 0.5-1% of the content of lees; such as 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0% and the like of sodium carboxymethyl cellulose content. Dialdehyde starch can cross-link with the amino groups of protein in lees to improve the adhesive properties of lees, and sodium carboxymethyl cellulose has a stabilizing effect on protein, preventing the protein from coagulating and losing its adhesive effect. However, dialdehyde starch cannot be added too much. Since the exposed amino groups in the lees have been fully cross-linked, the improvement of the adhesive effect has reached its limit. The excess dialdehyde starch will reduce the proportion of modified lees, thus affecting the subsequent bonding with cork particles. If too little dialdehyde starch is added, the amino groups in the lees are not fully cross-linked, and the bonding effect with cork is poor. However, if the content of sodium carboxymethyl cellulose is too low, it is not conducive to protein stability. If the amino cross-linking degree is low, and the content of sodium carboxymethyl cellulose is too high, after the modification effect of the lees is maximized, it will not only cause material waste, but also dilute the reaction system, which is not conducive to further improving the performance of the composite material. Therefore, the content of dialdehyde starch is 0.5-1.5% of the lees content, and the content of sodium carboxymethyl cellulose is 0.5-1% of the lees content, and the performance of the obtained composite material is the best.

[0042] The weight ratio of the modified distiller's grains to the cork particles is 3:10-50, such as 3:10, 3:15, 3:20, 3:25, 3:30, 3:35, 3:40, 3:45, 3:48, 3:50, etc. The weight ratio of the plasticizer to the modified distiller's grains is 0.015-0.3:3, such as 0.015:3, 0.01:3, 0.05:3, 0.1:3, 0.15:3, 0.2:3, 0. 3:3, etc., the weight ratio of the preservative to the modified wine lees is 0.003-0.06:3, such as 0.003:3, 0.01:3, 0.05:3, 0.01:3, 0.02:3, 0.05:3, 0.06:3, etc., and the mass ratio of the adhesive to the modified wine lees is 0.3-5:3, such as 0.3:3, 0.5:3, 1:3, 1.5:3, 2:3, 3:3, 4:3, 5:3, etc. The functional groups modified by dialdehyde starch in the modified wine lees react with the cork particles to enhance the hardness and other properties of the composite material. When the ratio of the above components is within the above range, the obtained composite material has better performance.

[0043] In some embodiments, in step 3, the method for preparing a composite mixture further includes adding reinforcing fibers to the cork wine lees mixture and a binder to obtain a composite mixture; the mass ratio of the reinforcing fibers to the modified wine lees is 0.3-2:3.

[0044] For example, the mass ratio of reinforcing fiber to modified wine grains is 0.3:3, 0.5:3, 1:3, 1.3:3, 1.5:3, 1.8:3, 2:3, etc. Adding reinforcing fibers in the above ratios can improve the hardness of the composite material.

[0045] In some embodiments, the content of dialdehyde starch is 0.8-1.2% of the content of the lees, the content of sodium carboxymethyl cellulose is 0.6-0.8% of the content of the lees; the weight ratio of modified lees to cork particles is 3:15-50; the mass ratio of adhesive to modified lees is 0.45-4.8:3; the mass ratio of reinforcing fiber to modified lees is 0.45-1.8:3; when the ratio of each component is within the above range, the obtained composite material has better performance.

[0046] In some embodiments, the amount of modified wine lees added is 2.8-3.2 kg; the amount of cork particles added is 10-50 kg; the amount of plasticizer added is 0.015-0.3 kg, the amount of preservative added is 0.003-0.06 kg; the amount of adhesive added is 0.45-4.8 kg; and the amount of reinforcing fiber added is 0.45-1.8 kg. For example, the amount of modified wine lees added is 2.8kg, 3.0kg, 3.2kg, etc., the amount of cork particles added is 10kg, 20kg, 30kg, 35kg, 4kg, 50kg, etc., the amount of preservatives added is 0.003kg, 0.01kg, 0.02kg, 0.03kg, 0.04kg, 0.05kg, 0.06kg, etc., the amount of adhesive added is 0.45kg, 1kg, 2kg, 3.5kg, 4kg, 4.8kg, etc., the amount of reinforcing fiber added is 0.45kg, 0.8kg, 1kg, 1.5kg, 1.8kg, etc. The amount of each component added is within the above range, the amount of the component is moderate, and the obtained composite material has excellent performance.

[0047] In some embodiments, the moisture content of the modified distillers grains and cork particles is less than 12%;

[0048] Preferably, the moisture content of the modified wine lees and cork particles is less than 10%.

[0049] For example, the moisture content of the modified wine lees and cork particles is 0, 1%, 3%, 5%, 6%, 7%, 9%, etc., and too high a moisture content of the modified wine lees and cork particles increases the water content of the reaction, affecting the performance of the composite material. When the moisture content of the modified wine lees and cork particles is lower than 12%, the performance of the composite material is better, and when the moisture content is lower than 10%, the performance of the composite material is further improved.

[0050] In some embodiments, the plasticizer is a bio-based plasticizer, including at least one of ricinoleate, epoxidized soybean oil, epoxidized cardanol tungstate, eleostearic acid glyceride, polylactic acid ester, and glycidol; for example, the plasticizer is ricinoleate, epoxidized soybean oil, epoxidized cardanol tungstate, eleostearic acid glyceride, polylactic acid ester, and glycidol, or the plasticizer is ricinoleate, epoxidized soybean oil, epoxidized cardanol tungstate, eleostearic acid glyceride, and polylactic acid ester, etc.

[0051] The preservative is a food preservative, including at least one of potassium sorbate, nisin, natamycin, sodium dehydroacetate, methyl parahydroxybenzoate, sodium diacetate, calcium propionate, and sodium lactate; for example, the preservative is potassium sorbate, nisin, natamycin, sodium dehydroacetate, methyl parahydroxybenzoate, sodium diacetate, calcium propionate, or sodium lactate, or the preservative is potassium sorbate, nisin, natamycin, sodium dehydroacetate, methyl parahydroxybenzoate, sodium diacetate, calcium propionate, and sodium lactate, etc.

[0052] The adhesive is a biomass-based adhesive, selected from at least one of a bio-based polyurethane adhesive, a bio-based acrylic resin adhesive, and a bio-based furan resin adhesive. For example, the adhesive is a bio-based polyurethane adhesive, a bio-based acrylic resin adhesive, or a bio-based furan resin adhesive, or the adhesive is a bio-based polyurethane adhesive, a bio-based acrylic resin adhesive, and a bio-based furan resin adhesive.

[0053] In some embodiments, the reinforcing fiber is selected from at least one of glass fiber, carbon fiber, and natural fiber;

[0054] The natural fiber includes at least one of polylactic acid fiber, chitosan fiber, calcium alginate fiber, and cellulose acetate fiber. For example, the reinforcing fiber is glass fiber, carbon fiber, polylactic acid fiber, chitosan fiber, calcium alginate fiber, or cellulose acetate fiber, or the reinforcing fiber is glass fiber, carbon fiber, polylactic acid fiber, chitosan fiber, calcium alginate fiber, and cellulose acetate fiber.

[0055] In some embodiments, the base is NaOH solution, and the concentration of the NaOH solution is 0.06-0.2 mol / L; such as 0.06 mol / L, 0.08 mol / L, 0.1 mol / L, 0.15 mol / L, 0.2 mol / L, etc.

[0056] The volume ratio of the lees mass to the NaOH solution is 1:10-1:30 g / ml, such as 1:10 g / ml, 1:20 g / ml, 1:30 g / ml, etc.

[0057] Sodium hydroxide solution can efficiently adjust the pH value of the reaction system, which is beneficial to the exposure of functional groups in the lees. Compared with other alkaline substances such as potassium hydroxide, lithium hydroxide, and ammonia water, sodium hydroxide has low cost and is easy to store. Too high a concentration of sodium hydroxide is prone to excessive corrosion of the lees, affecting the hardness of the composite material, and is inconvenient to operate. Too low a concentration of sodium hydroxide is not conducive to the exposure of functional groups in the lees. Therefore, when the concentration of sodium hydroxide is within the above range, it can fully expose the functional groups in the lees without damaging the protein, affecting the hardness of the composite material. Too little sodium hydroxide is not conducive to the complete exposure of functional groups in the lees, and too much sodium hydroxide causes waste of materials, and the moisture content is too high, which is also not conducive to the hardness and other properties of the composite material.

[0058] In some embodiments, in the step of modifying the lees, the heating temperature is 35-45° C. and the heating time is 1-2 h;

[0059] Preferably, in the lees modification step, the heating temperature is 38-42°C, and the heating time is 1.1-1.8h, such as the heating temperature is 35°C, 36°C, 38°C, 40°C, 42°C, 45°C, etc., and the heating time is 1h, 1.5h, 2h, etc.

[0060] The heating temperature and time affect the complexation reaction, thus affecting the performance of the composite material. Therefore, when the lees are modified, the heating temperature and time are within the above range, and the composite material has better performance. In the lees modification step, the heating temperature is 38-42°C and the heating time is 1.1-1.8h, which can further improve the performance of the composite material.

[0061] In some embodiments, in the compression molding step, the specific method of compression molding is: first gradually pressurize to about 10 MPa at a speed of 0.1-0.2 MPa / min at 140-150°C, maintain a stable pressure for 10 minutes, and finally slowly cool to room temperature.

[0062] In some embodiments, a wine lees cork composite material prepared by the above method is provided.

[0063] In this embodiment, the specific method of step 1, modification of the lees is: mixing the white wine lees with 0.1 mol / L NaOH solution in a ratio of 1:10 (g / ml), adding 0.5% of dialdehyde starch by mass of the white wine lees and 0.8% of sodium carboxymethyl cellulose by mass of the white wine lees, mixing, heating to 40°C, stirring for 1.5 hours, then collecting the precipitate by centrifugation, washing with water, drying at room temperature, sand grinding, and sieving with a 40-mesh sieve to obtain modified lees.

[0064] Step 2, a specific method for preparing a cork wine lees mixture is as follows: the modified wine lees and the cork particles are dried in a drying oven at 60° C. for 24 hours to make their moisture content less than 10%, and then 3 kg of the modified wine lees and 14.8 kg of the cork particles are added respectively under high-speed stirring at 1500-2000 rpm, stirred for 10 minutes, and 0.015 kg of ricinoleic acid ester as a plasticizer and 0.003 kg of potassium sorbate as a preservative are added, and the cork wine lees mixture is obtained after mixing evenly.

[0065] Step 3: The specific method for preparing the composite material mixture is as follows: 0.6 kg of glass fiber as reinforcing fiber and 1.6 kg of bio-based polyurethane adhesive as adhesive are added to the cork lees mixture in sequence, and stirred at a low speed of 600-800 rpm for 10 minutes to obtain the composite material mixture.

[0066] Step 4: The specific method of compression molding is as follows: add the composite material mixture into a molding machine, squeeze it into a rectangular mold for vulcanization, first gradually pressurize to 10MPa at 0.1-0.2MPa / min at 140-150°C, maintain the pressure for 10 minutes, gradually cool down, then remove the pressure, cool and demold, and obtain the wine lees cork composite material.

[0067] Finally, the pressed wine lees cork composite material is cooled, cut and polished to obtain a coaster of a biomass-based composite material, such as Figure 1 As shown, the diameter is 10cm and the thickness is 1cm.

[0068] Example 2

[0069] A method for preparing a wine lees cork composite material comprises the following steps:

[0070] Step 1, modification of vinasse: mix white wine vinasse with 0.1 mol / L NaOH solution in a ratio of 1:10 (g / ml), add 0.5% of dialdehyde starch by mass of white wine vinasse and 0.8% of sodium carboxymethyl cellulose by mass of white wine vinasse, mix well, heat to 40°C, stir for 1.5h, collect the precipitate by centrifugation, wash with water, dry at room temperature, sand grind, and sieve with a 40-mesh sieve to obtain modified vinasse.

[0071] Step 2, preparing a cork wine lees mixture: drying the modified wine lees and the cork particles in a drying oven at 60° C. for 24 hours to make their moisture content less than 10%, then adding 3 kg of modified wine lees and 14.8 kg of cork particles under high-speed stirring at 1500-2000 rpm, stirring for 10 minutes, adding 0.1 kg of ricinoleic acid ester as a plasticizer and 0.02 kg of potassium sorbate as a preservative, and mixing well to obtain a cork wine lees mixture.

[0072] Step 3, preparing a composite material mixture: adding 0.6 kg of glass fiber as a reinforcing fiber and 1.6 kg of a bio-based polyurethane adhesive as an adhesive to a cork lees mixture in sequence, stirring at a low speed of 600-800 rpm for 10 minutes, to obtain a composite material mixture.

[0073] Step 4, compression molding: Add the composite material mixture into a compression molding machine, squeeze it into a rectangular mold for vulcanization, first gradually pressurize to 10MPa at 0.1-0.2MPa / min at 140-150°C, maintain the pressure for 10 minutes, gradually cool down, then remove the pressure, cool and demould to obtain a wine lees cork composite material.

[0074] Finally, the pressed wine lees cork composite material is cooled, cut and polished to obtain a biomass-based composite material stationery tube, such as Figure 2As shown, the specifications of length, width and height are 5cm×5cm×10cm, and the thickness is 1.5cm.

[0075] Example 3

[0076] A method for preparing a wine lees cork composite material comprises the following steps:

[0077] Step 1, modification of vinasse: mix white wine vinasse with 0.1 mol / L NaOH solution in a ratio of 1:10 (g / ml), add 0.5% of dialdehyde starch by mass of white wine vinasse and 0.8% of sodium carboxymethyl cellulose by mass of white wine vinasse, mix well, heat to 40°C, stir for 1.5h, collect the precipitate by centrifugation, wash with water, dry at room temperature, sand grind, and sieve with a 40-mesh sieve to obtain modified vinasse.

[0078] Step 2, preparing a cork wine lees mixture: drying the modified wine lees and the cork particles in a drying oven at 60° C. for 24 hours to make their moisture content less than 10%, then adding 3 kg of modified wine lees and 50.4 kg of cork particles under high-speed stirring at 1500-2000 rpm, stirring for 10 minutes, adding 0.3 kg of ricinoleic acid ester as a plasticizer and 0.06 kg of potassium sorbate as a preservative, and mixing well to obtain a cork wine lees mixture.

[0079] Step 3, preparing a composite material mixture: sequentially adding 1.8 kg of glass fiber as reinforcing fiber and 4.8 kg of bio-based polyurethane adhesive as adhesive into a cork lees mixture, stirring at a low speed of 600-800 rpm for 10 minutes, to obtain a composite material mixture.

[0080] Step 4, compression molding: Add the composite material mixture into a compression molding machine, squeeze it into a rectangular mold for vulcanization, first gradually pressurize to 10MPa at 0.1-0.2MPa / min at 140-150°C, maintain the pressure for 10 minutes, gradually cool down, then remove the pressure, cool and demould to obtain a wine lees cork composite material.

[0081] Example 4

[0082] A method for preparing a wine lees cork composite material comprises the following steps:

[0083] Step 1, modification of vinasse: mix white wine vinasse with 0.1 mol / L NaOH solution in a ratio of 1:10 (g / ml), add 0.5% of dialdehyde starch by mass of white wine vinasse and 0.8% of sodium carboxymethyl cellulose by mass of white wine vinasse, mix well, heat to 40°C, stir for 1.5h, collect the precipitate by centrifugation, wash with water, dry at room temperature, sand grind, and sieve with a 40-mesh sieve to obtain modified vinasse.

[0084] Step 2, preparing a cork wine lees mixture: drying the modified wine lees and the cork particles in a drying oven at 60° C. for 24 hours to make their moisture content less than 10%, then adding 3 kg of modified wine lees and 11.1 kg of cork particles under high-speed stirring at 1500-2000 rpm, stirring for 10 minutes, adding 0.05 kg of ricinoleic acid ester as a plasticizer and 0.01 kg of potassium sorbate as a preservative, and mixing well to obtain a cork wine lees mixture.

[0085] Step 3, preparing a composite material mixture: adding 0.45 kg of glass fiber as a reinforcing fiber and 0.45 kg of a bio-based polyurethane adhesive as an adhesive to a cork lees mixture in sequence, stirring at a low speed of 600-800 rpm for 10 minutes, to obtain a composite material mixture.

[0086] Step 4, compression molding: Add the composite material mixture into a compression molding machine, squeeze it into a rectangular mold for vulcanization, first gradually pressurize to 10MPa at 0.1-0.2MPa / min at 140-150°C, maintain the pressure for 10 minutes, gradually cool down, then remove the pressure, cool and demould to obtain a wine lees cork composite material.

[0087] Comparative Example 1

[0088] A method for preparing a cork composite material comprises the following steps:

[0089] Step 1, preparing a composite material mixture: drying the cork particles in a drying oven at 60° C. for 24 hours to make its moisture content less than 10%, then adding 14.8 kg of cork particles under high-speed stirring at 1500-2000 rpm, stirring for 10 minutes, adding 0.015 kg of ricinoleic acid ester as a plasticizer and 0.003 kg of potassium sorbate as a preservative, mixing evenly, adding 0.6 kg of glass fiber as a reinforcing fiber and 1.6 kg of a bio-based polyurethane adhesive as an adhesive in turn, stirring at a low speed of 600-800 rpm for 10 minutes, and obtaining a composite material mixture.

[0090] Step 2, compression molding: Add the composite material mixture into a compression molding machine, squeeze it into a rectangular mold for vulcanization, first gradually pressurize to 10MPa at 0.1-0.2MPa / min at 140-150°C, maintain the pressure for 10 minutes, gradually cool down, then remove the pressure, cool and demould to obtain a wine lees cork composite material.

[0091] Comparative Example 2

[0092] A method for preparing a cork composite material comprises the following steps:

[0093] Step 1, preparing a composite material mixture: drying the cork particles in a drying oven at 60° C. for 24 hours to make its moisture content less than 10%, then adding 14.8 kg of cork particles under high-speed stirring at 1500-2000 rpm, stirring for 10 minutes, adding 0.015 kg of ricinoleic acid ester as a plasticizer and 0.003 kg of potassium sorbate as a preservative, mixing evenly, adding 0.6 kg of glass fiber as a reinforcing fiber and 10 kg of a bio-based polyurethane adhesive as an adhesive in turn, stirring at a low speed of 600-800 rpm for 10 minutes, and obtaining a composite material mixture.

[0094] Step 2, compression molding: Add the composite material mixture into a compression molding machine, squeeze it into a rectangular mold for vulcanization, first gradually pressurize to 10MPa at 0.1-0.2MPa / min at 140-150°C, maintain the pressure for 10 minutes, gradually cool down, then remove the pressure, cool and demould to obtain a wine lees cork composite material.

[0095] Comparative Example 3

[0096] A method for preparing a cork composite material comprises the following steps:

[0097] Step 1, modification of vinasse: directly mix the liquor vinasse with 0.5% of dialdehyde starch by mass of the liquor vinasse and 0.8% of sodium carboxymethyl cellulose by mass of the liquor vinasse, heat to 40°C, stir for 1.5h, collect the precipitate by centrifugation, wash it with water, dry it at room temperature, sand grind it, and sieve it with a 40-mesh sieve to obtain modified vinasse.

[0098] Step 2, a specific method for preparing a cork wine lees mixture is as follows: the modified wine lees and the cork particles are dried in a drying oven at 60° C. for 24 hours to make their moisture content less than 10%, and then 3 kg of the modified wine lees and 14.8 kg of the cork particles are added respectively under high-speed stirring at 1500-2000 rpm, stirred for 10 minutes, and 0.015 kg of ricinoleic acid ester as a plasticizer and 0.003 kg of potassium sorbate as a preservative are added, and the cork wine lees mixture is obtained after mixing evenly.

[0099] Step 3: The specific method for preparing the composite material mixture is as follows: 0.6 kg of glass fiber as reinforcing fiber and 1.6 kg of bio-based polyurethane adhesive as adhesive are added to the cork lees mixture in sequence, and stirred at a low speed of 600-800 rpm for 10 minutes to obtain the composite material mixture.

[0100] Step 4: The specific method of compression molding is as follows: add the composite material mixture into a molding machine, squeeze it into a rectangular mold for vulcanization, first gradually pressurize to 10MPa at 0.1-0.2MPa / min at 140-150°C, maintain the pressure for 10 minutes, gradually cool down, then remove the pressure, cool and demold, and obtain the wine lees cork composite material.

[0101] Comparative Example 4

[0102] A method for preparing a cork composite material comprises the following steps:

[0103] Step 1, modification of vinasse: mix white wine vinasse with 0.05 mol / L NaOH solution in a ratio of 1:10 (g / ml), add 0.5% of dialdehyde starch by mass of white wine vinasse and 0.8% of sodium carboxymethyl cellulose by mass of white wine vinasse, mix well, heat to 40°C, stir for 1.5h, collect the precipitate by centrifugation, wash with water, dry at room temperature, sand grind, and sieve with a 40-mesh sieve to obtain modified vinasse.

[0104] Step 2, preparing a cork wine lees mixture: drying the modified wine lees and the cork particles in a drying oven at 60° C. for 24 hours to make their moisture content less than 10%, then adding 3 kg of modified wine lees and 14.8 kg of cork particles under high-speed stirring at 1500-2000 rpm, stirring for 10 minutes, adding 0.015 kg of ricinoleic acid ester as a plasticizer and 0.003 kg of potassium sorbate as a preservative, and mixing well to obtain a cork wine lees mixture.

[0105] Step 3, preparing a composite material mixture: adding 0.6 kg of glass fiber as a reinforcing fiber and 1.6 kg of a bio-based polyurethane adhesive as an adhesive to a cork lees mixture in sequence, stirring at a low speed of 600-800 rpm for 10 minutes, to obtain a composite material mixture.

[0106] Step 4, compression molding: Add the composite material mixture into a compression molding machine, squeeze it into a rectangular mold for vulcanization, first gradually pressurize to 10MPa at 0.1-0.2MPa / min at 140-150°C, maintain the pressure for 10 minutes, gradually cool down, then remove the pressure, cool and demould to obtain a wine lees cork composite material.

[0107] Comparative Example 5

[0108] A method for preparing a cork composite material comprises the following steps:

[0109] Step 1, modification of vinasse: mix white wine vinasse with 0.1 mol / L NaOH solution in a ratio of 1:10 (g / ml), add 0.8% sodium carboxymethyl cellulose by weight of white wine vinasse and mix well, heat to 40°C, stir for 1.5h, collect the precipitate by centrifugation, wash with water, dry at room temperature, sand grind, and sieve with a 40-mesh sieve to obtain modified vinasse.

[0110] Step 2, preparing a cork wine lees mixture: drying the modified wine lees and the cork particles in a drying oven at 60° C. for 24 hours to make their moisture content less than 10%, then adding 3 kg of modified wine lees and 14.8 kg of cork particles under high-speed stirring at 1500-2000 rpm, stirring for 10 minutes, adding 0.015 kg of ricinoleic acid ester as a plasticizer and 0.003 kg of potassium sorbate as a preservative, and mixing well to obtain a cork wine lees mixture.

[0111] Step 3, preparing a composite material mixture: adding 0.6 kg of glass fiber as a reinforcing fiber and 1.6 kg of a bio-based polyurethane adhesive as an adhesive to a cork lees mixture in sequence, stirring at a low speed of 600-800 rpm for 10 minutes, to obtain a composite material mixture.

[0112] Step 4, compression molding: Add the composite material mixture into a compression molding machine, squeeze it into a rectangular mold for vulcanization, first gradually pressurize to 10MPa at 0.1-0.2MPa / min at 140-150°C, maintain the pressure for 10 minutes, gradually cool down, then remove the pressure, cool and demould to obtain a wine lees cork composite material.

[0113] Comparative Example 6

[0114] A method for preparing a cork composite material comprises the following steps:

[0115] Step 1, modification of vinasse: mix white wine vinasse with 0.1 mol / L NaOH solution in a ratio of 1:10 (g / ml), add 2% of dialdehyde starch by mass of white wine vinasse and 0.8% of sodium carboxymethyl cellulose by mass of white wine vinasse, mix well, heat to 40°C, stir for 1.5h, collect the precipitate by centrifugation, wash with water, dry at room temperature, sand grind, and sieve with a 40-mesh sieve to obtain modified vinasse.

[0116] Step 2, preparing a cork wine lees mixture: drying the modified wine lees and the cork particles in a drying oven at 60° C. for 24 hours to make their moisture content less than 10%, then adding 3 kg of modified wine lees and 14.8 kg of cork particles under high-speed stirring at 1500-2000 rpm, stirring for 10 minutes, adding 0.015 kg of ricinoleic acid ester as a plasticizer and 0.003 kg of potassium sorbate as a preservative, and mixing well to obtain a cork wine lees mixture.

[0117] Step 3, preparing a composite material mixture: adding 0.6 kg of glass fiber as a reinforcing fiber and 1.6 kg of a bio-based polyurethane adhesive as an adhesive to a cork lees mixture in sequence, stirring at a low speed of 600-800 rpm for 10 minutes, to obtain a composite material mixture.

[0118] Step 4, compression molding: Add the composite material mixture into a compression molding machine, squeeze it into a rectangular mold for vulcanization, first gradually pressurize to 10MPa at 0.1-0.2MPa / min at 140-150°C, maintain the pressure for 10 minutes, gradually cool down, then remove the pressure, cool and demould to obtain a wine lees cork composite material.

[0119] Comparative Example 7

[0120] A method for preparing a cork composite material comprises the following steps:

[0121] Step 1, modification of vinasse: mix white wine vinasse with 0.1 mol / L NaOH solution in a ratio of 1:10 (g / ml), add 0.5% dialdehyde starch by weight of white wine vinasse and mix well, heat to 40°C, stir for 1.5h, collect the precipitate by centrifugation, wash with water, dry at room temperature, sand grind, and sieve with a 40-mesh sieve to obtain modified vinasse.

[0122] Step 2, preparing a cork wine lees mixture: drying the modified wine lees and the cork particles in a drying oven at 60° C. for 24 hours to make their moisture content less than 10%, then adding 3 kg of modified wine lees and 14.8 kg of cork particles under high-speed stirring at 1500-2000 rpm, stirring for 10 minutes, adding 0.015 kg of ricinoleic acid ester as a plasticizer and 0.003 kg of potassium sorbate as a preservative, and mixing well to obtain a cork wine lees mixture.

[0123] Step 3, preparing a composite material mixture: adding 0.6 kg of glass fiber as a reinforcing fiber and 1.6 kg of a bio-based polyurethane adhesive as an adhesive to a cork lees mixture in sequence, stirring at a low speed of 600-800 rpm for 10 minutes, to obtain a composite material mixture.

[0124] Step 4, compression molding: Add the composite material mixture into a compression molding machine, squeeze it into a rectangular mold for vulcanization, first gradually pressurize to 10MPa at 0.1-0.2MPa / min at 140-150°C, maintain the pressure for 10 minutes, gradually cool down, then remove the pressure, cool and demould to obtain a wine lees cork composite material.

[0125] Comparative Example 8

[0126] A method for preparing a cork composite material comprises the following steps:

[0127] Step 1, modification of vinasse: mix white wine vinasse with 0.1 mol / L NaOH solution in a ratio of 1:10 (g / ml), add 0.5% of dialdehyde starch by mass of white wine vinasse and 0.3% of sodium carboxymethyl cellulose by mass of white wine vinasse, mix well, heat to 40°C, stir for 1.5h, collect the precipitate by centrifugation, wash with water, dry at room temperature, sand grind, and sieve with a 40-mesh sieve to obtain modified vinasse.

[0128] Step 2, preparing a cork wine lees mixture: drying the modified wine lees and the cork particles in a drying oven at 60° C. for 24 hours to make their moisture content less than 10%, then adding 3 kg of modified wine lees and 14.8 kg of cork particles under high-speed stirring at 1500-2000 rpm, stirring for 10 minutes, adding 0.015 kg of ricinoleic acid ester as a plasticizer and 0.003 kg of potassium sorbate as a preservative, and mixing well to obtain a cork wine lees mixture.

[0129] Step 3, preparing a composite material mixture: adding 0.6 kg of glass fiber as a reinforcing fiber and 1.6 kg of a bio-based polyurethane adhesive as an adhesive to a cork lees mixture in sequence, stirring at a low speed of 600-800 rpm for 10 minutes, to obtain a composite material mixture.

[0130] Step 4, compression molding: Add the composite material mixture into a compression molding machine, squeeze it into a rectangular mold for vulcanization, first gradually pressurize to 10MPa at 0.1-0.2MPa / min at 140-150°C, maintain the pressure for 10 minutes, gradually cool down, then remove the pressure, cool and demould to obtain a wine lees cork composite material.

[0131] Performance Testing

[0132] The composite materials prepared in Examples 1-4 and Comparative Examples 1-8 were tested for hardness using the GB / T 531.1-2008 test standard and a Shore hardness tester, tested for resilience using GB / T 1681-2008, and tested for wear resistance using GB / T 42122-2022. The results are shown in the following table:

[0133] Table 1 shows the performance results of various embodiments and comparative examples.

[0134] serial number hardness Rebound rate Wear resistance Example 1 70D 21％ No slag Example 2 70D 20％ No slag Example 3 40D 24％ No slag Example 4 60D 18％ No slag Comparative Example 1 30D 20％ There is slag Comparative Example 2 70D 21％ No slag Comparative Example 3 50D 15％ There is slag Comparative Example 4 60D 18％ There is slag Comparative Example 5 55D 18％ There is slag Comparative Example 6 75D 15％ No slag Comparative Example 7 60D 20％ There is slag Comparative Example 8 70D 21％ There is slag

[0135] In comparative example 1, the hardness of the composite material obtained is greatly reduced relative to Example 1 without adding modified vinasse, and the situation of slag falling occurs. It can be seen that modified vinasse is beneficial to improve the hardness and wear resistance of the composite material. In comparative example 2, no modified vinasse is added relative to Example 1, and the hardness, resilience and wear resistance close to those of Example 1 are achieved by increasing the amount of bio-based polyurethane adhesive, proving that the modified vinasse of the present invention can replace the adhesive for use in combination with cork particles to manufacture composite materials, thereby utilizing the waste of vinasse and saving costs. In comparative example 3, the modified vinasse obtained by mixing directly with dialdehyde starch and sodium carboxymethyl cellulose without alkali treatment, and the hardness and resilience of the composite material prepared further for preparation are greatly reduced relative to Example 1, and the situation of slag falling occurs, which may be due to the fact that the functional groups of the vinasse are not fully exposed without alkali treatment, affecting the combination with dialdehyde starch, and the subsequent complexation reaction with cork particles, which affects the performance of the composite material. In Comparative Example 4, the sodium hydroxide concentration is lower than that in Example 1, which may result in fewer exposed functional groups in the lees, thereby affecting the performance of the obtained composite material. In Comparative Example 5, which is equivalent to Example 1, no dialdehyde starch is added to modify the lees, and the obtained composite material is equivalent to Example 1 in that the hardness, resilience and wear resistance are reduced. In Comparative Example 6, the excessive amount of dialdehyde starch relative to Example 1 affects the resilience of the composite material. In Comparative Example 7, compared with Example 1, sodium carboxymethyl cellulose is not added to protect the protein in the lees, and the wear resistance is reduced in Comparative Example 7. In Comparative Example 8, although sodium carboxymethyl cellulose is added to protect the protein in the lees, the amount of sodium carboxymethyl cellulose is too low, and slag still occurs. It can be seen that when the amount of sodium carboxymethyl cellulose is sufficient, the protein in the lees can be more fully stabilized, thereby better improving the performance of the composite material.

[0136] It is to be understood that the present invention is described by some embodiments, and it is known to those skilled in the art that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the scope of protection of the present invention.

Claims

1. A method for preparing a wine lees cork composite material, characterized in that: The following steps are involved: Step 1, modification of vinasse: adding alkali, dialdehyde starch and sodium carboxymethyl cellulose to the vinasse, mixing, heating, stirring, centrifuging, collecting precipitates, and further treating the precipitates to obtain modified vinasse; the dialdehyde starch content is 0.5-1.5% of the vinasse content, and the sodium carboxymethyl cellulose content is 0.5-1% of the vinasse content; Step 2, preparing a cork wine lees mixture: mixing the modified wine lees with cork particles, adding a plasticizer and a preservative, and mixing evenly to obtain a cork wine lees mixture; the weight ratio of the modified wine lees to the cork particles is 3:10-50, the weight ratio of the plasticizer to the modified wine lees is 0.015-0.3:3, and the weight ratio of the preservative to the modified wine lees is 0.003-0.06:3; Step 3, preparing a composite material mixture: mixing the cork wine lees mixture with a binder to obtain a composite material mixture; the mass ratio of the binder to the modified wine lees is 0.3-5:3; Step 4, compression molding: compression molding the composite material mixture, and demoulding to obtain a wine lees cork composite material.

2. The preparation method according to claim 1, characterized in that In step 3, the method for preparing a composite mixture further includes adding reinforcing fibers to mix with the cork wine lees mixture and the adhesive to obtain a composite mixture; the mass ratio of the reinforcing fibers to the modified wine lees is 0.3-2:

3.

3. The preparation method according to claim 2, characterized in that: The content of dialdehyde starch is 0.8-1.2% of the content of the lees, and the content of sodium carboxymethyl cellulose is 0.6-0.8% of the content of the lees; the weight ratio of the modified lees to the cork particles is 3:15-50; the mass ratio of the adhesive to the modified lees is 0.45-4.8:3; the mass ratio of the reinforcing fiber to the modified lees is 0.45-1.8:3; Preferably, the amount of modified wine lees added is 2.8-3.2 kg; the amount of cork particles added is 10-50 kg; the amount of plasticizer added is 0.015-0.3 kg, the amount of preservative added is 0.003-0.06 kg; the amount of adhesive added is 0.45-4.8 kg; and the amount of reinforcing fiber added is 0.45-1.8 kg.

4. The preparation method according to claim 1, characterized in that: The moisture content of the modified wine lees and the cork particles is less than 12%; Preferably, the moisture content of the modified wine grains and the cork particles is less than 10%.

5. The preparation method according to claim 1, characterized in that: The plasticizer is a bio-based plasticizer, including at least one of ricinoleic acid ester, epoxy soybean oil, epoxidized cardanol tungstate, eleostearic acid glyceride, polylactic acid ester, and glycidol; Preferably, the preservative is a food preservative, including at least one of potassium sorbate, nisin, natamycin, sodium dehydroacetate, methyl paraben, sodium diacetate, calcium propionate, and sodium lactate; Preferably, the adhesive is a biomass-based adhesive, selected from at least one of a bio-based polyurethane adhesive, a bio-based acrylic resin adhesive, and a bio-based furan resin adhesive.

6. The preparation method according to claim 2, characterized in that: The reinforcing fiber is selected from at least one of glass fiber, carbon fiber and natural fiber; Preferably, the natural fiber includes at least one of polylactic acid fiber, chitosan fiber, calcium alginate fiber and cellulose acetate fiber.

7. The preparation method according to claim 1, characterized in that: The alkali is a NaOH solution, and the concentration of the NaOH solution is 0.06-0.2 mol / L; Preferably, the volume ratio of the mass of the vinasse to the NaOH solution is 1:10-1:30 g / ml.

8. The preparation method according to claim 1, characterized in that: In the lees modification step, the heating temperature is 35-45° C. and the heating time is 1-2 h; Preferably, in the lees modification step, the heating temperature is 38-42° C., and the heating time is 1.1-1.8 h.

9. The preparation method according to any one of claims 1 to 8, characterized in that: In the compression molding step, the specific method of the compression molding is: first gradually pressurizing to 8-12 MPa at a speed of 0.1-0.2 MPa / min at 140-150° C., stabilizing the pressure to maintain the shape, and then slowly cooling to room temperature.

10. A wine lees cork composite material, characterized in that: The wine lees cork composite material is prepared by the preparation method according to any one of claims 1 to 9.

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