Preparation method of packaging material

Abstract

A preparation method of a packaging material comprises the following steps: selecting at least one of sawdust, rice husk, corn straw and wheat straw, crushing to obtain raw material powder, then adding a carbon source, a nitrogen source and inorganic salt, and uniformly mixing to obtain a matrix; the prepared matrix is sterilized, and the sterilized matrix is obtained; in a sterile environment, cooling the sterilized substrate, and inoculating an edible fungus strain; putting the matrix inoculated with the edible fungus strain into a constant-temperature and constant-humidity culture room, and culturing for 10-20 days; putting the mycelium obtained by culturing and a substrate into a pre-designed mold together for molding; drying the formed mycelium material in drying equipment at 40-60 DEG C until the water content is reduced to be less than 10%; and carrying out surface treatment on the dried mycelium material. The obtained packaging material is completely biodegradable, harmful substances are not generated in the production process, and the current environmental protection requirement is met.

Description

Technical Field

[0001] The invention relates to a method for preparing a packaging material, in particular to a method for producing a degradable packaging material by utilizing an edible fungus matrix, and belongs to the technical field of green environmentally friendly materials and sustainable packaging. Background Art

[0002] As one of the five major packaging materials, plastic has been widely used in packaging due to its wide range of excellent physical and chemical properties such as light weight and high performance. It has replaced traditional packaging materials in many occasions and become the protagonist of packaging. Plastic packaging accounts for about 30% of the entire packaging, and packaging accounts for about 3% of the global annual total of nearly 100 million tons of plastic. As an important part of modern materials, it can be said that people cannot live without plastic for a day. Many products cannot be launched without plastic. However, plastic packaging belongs to the "short-life" application category of plastic. There are only two ways for plastic packaging after use: becoming plastic garbage thrown away at will, or becoming urban solid waste. Either way, it will harm the environment. In addition, due to the special environmental stability of plastic, it will not decompose or decompose very slowly in the environment for a long time, decades or even hundreds of years, so the harm to the environment is very long-lasting. With the increasing understanding of human beings on environmental pollution and ecological protection, the environmental pollution problem of packaging waste is also increasingly concerned.

[0003] At present, traditional plastic packaging materials have become one of the main sources of environmental pollution due to their difficulty in degradation. With the increasing global attention to environmental issues, it is particularly important to develop a degradable and environmentally friendly alternative material. Mycelium materials have gradually become a potential alternative in the packaging field because of their renewable, degradable and environmentally friendly characteristics. Mycelium can grow rapidly in a suitable environment and combine with the matrix to form a material with a certain strength and structure, which can be used to make packaging products.

[0004] In the prior art, mycelium materials based on edible fungi mostly rely on sawdust, straw, etc. as the matrix, which is relatively expensive and has a long growth cycle. Therefore, it is urgent to develop a production process for edible fungi matrix packaging materials that can fully utilize agricultural waste and can be produced quickly. Summary of the invention

[0005] The present invention aims to provide a method for preparing a packaging material. The process can efficiently utilize the growth characteristics of edible fungi, produce environmentally friendly and degradable packaging materials with good mechanical properties through appropriate matrix formulation and process control, and solve the problems of high material cost and long growth cycle in the prior art.

[0006] To achieve the above-mentioned purpose and other related purposes, the technical solution provided by the present invention is: a method for preparing a packaging material, comprising the following steps: Step 1: Preparation of the matrix: At least one of sawdust, rice husk, corn stalk and wheat straw is selected, crushed to obtain raw material powder, then a carbon source, a nitrogen source and an inorganic salt are added, and mixed evenly to obtain a matrix; Step 2: Substrate pretreatment sterilizing the prepared matrix to obtain a sterilized matrix; Step 3: Inoculate edible fungi In a sterile environment, the sterilized substrate is cooled and then inoculated with edible fungi strains; Step 4: Mycelium Culture The substrate inoculated with edible fungi is placed in a constant temperature and humidity culture room for 10-20 days; Step 5: Forming and processing When the cultured mycelium and the substrate are placed into a pre-designed mold for molding; Step 6: Drying and Curing The formed mycelium material is dried in a drying device at 40°C-60°C until the moisture content drops below 10%; the dried mycelium material is surface treated.

[0007] The preferred technical solution is that the carbon source and the nitrogen source are a mixture of rice bran and soybean meal.

[0008] The preferred technical solution is: the inorganic salt is at least one of potassium sulfate, magnesium sulfate and potassium dihydrogen phosphate.

[0009] The preferred technical solution is: the sterilization process conditions are: temperature of 120°C-130°C, time of 15-30 minutes.

[0010] The preferred technical solution is: the culture medium formula is: the edible fungus species is at least one of oyster mushroom and shiitake mushroom.

[0011] The preferred technical solution is: the culture conditions are: temperature of 22°C-28°C, relative humidity of 60%-80%.

[0012] The preferred technical solution is: the surface treatment is to coat the surface of the material with natural resin or paraffin.

[0013] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art: 1. The present invention utilizes the rapid growth characteristics of edible fungi, combines mycelium with low-cost agricultural waste, and produces environmentally friendly packaging materials, which significantly reduces production costs.

[0014] 2. The packaging material obtained by the present invention is completely biodegradable and does not produce harmful substances during the production process, thus meeting current environmental protection requirements.

[0015] 3. The packaging material of the present invention has good mechanical properties, such as compressive strength and tear resistance, and is suitable for various packaging needs.

[0016] 4. The production process of the present invention is simple and easy to implement, suitable for large-scale production, and the production process has low energy consumption, which meets the requirements of sustainable development. DETAILED DESCRIPTION

[0017] The following specific embodiments illustrate the implementation of the present invention, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in the embodiments. Unless otherwise specified, the experimental materials used in the following embodiments were purchased from conventional biochemical reagent stores.

[0018] Example 1: A method for preparing a packaging material Matrix preparation: Select 70% sawdust, 20% rice husk, and 10% rice bran, mix them, add water to adjust the humidity to 65%, and add 0.5% potassium sulfate, 0.3% potassium dihydrogen phosphate, and 0.2% magnesium sulfate, and stir evenly. The above percentages are mass ratios Matrix sterilization: Place the matrix in a high pressure steam sterilizer at 125°C for 20 minutes and cool to room temperature after sterilization.

[0019] Inoculation: In a sterile environment, inoculate the Pleurotus ostreatus spawn into the cooled substrate, with the inoculation amount being 5% of the substrate weight.

[0020] Cultivation: Place the inoculated substrate in a constant temperature culture room with the temperature controlled at 24°C and the humidity controlled at 70% for 14 days.

[0021] Molding: Place the cultured mycelium matrix mixture into a mold and press it into shape.

[0022] Drying: Dry in a drying equipment at 50°C for 12 hours. The obtained packaging material has good mechanical properties.

[0023] Example 2: A method for preparing a packaging material Matrix preparation: Mix 60% corn straw, 30% rice husk, and 10% soybean meal, and add an appropriate amount of inorganic salt mixture.

[0024] Cultivation and processing: Similar to Example 1, but the inoculation is done with shiitake mushrooms, the cultivation time is 18 days, and the molded material is used to make heavy-duty packaging trays.

[0025] Example 3: A method for preparing a packaging material Matrix selection and preparation: Select low-cost agricultural waste rich in cellulose and lignin as the edible fungus substrate, such as sawdust, rice husks, corn stalks, wheat straw, etc. The appropriate mixing ratio can be selected according to the characteristics of the substrate.

[0026] Add appropriate amounts of carbon and nitrogen sources, such as rice bran, soybean meal, etc., to the substrate to provide sufficient nutrients and promote the growth of mycelium.

[0027] Add inorganic salt mixtures (such as potassium sulfate, magnesium sulfate, potassium dihydrogen phosphate, etc.) as needed to improve the nutritional content of the substrate and enhance the growth vitality of the mycelium.

[0028] Matrix pretreatment: The prepared matrix is ​​pretreated, usually by high temperature sterilization or steam disinfection, to eliminate foreign bacteria and ensure that the strains grow in a pollution-free environment.

[0029] The high temperature sterilization temperature is generally 125°C and the time is 20 minutes to ensure the sterility of the matrix.

[0030] Inoculation of edible fungi: In a sterile environment, the sterilized substrate is cooled to a suitable temperature (usually 25°C) and then inoculated with edible fungi.

[0031] Suitable edible fungi include oyster mushrooms, shiitake mushrooms, etc. These species have strong mycelium growth ability and can quickly occupy the substrate.

[0032] Mycelium culture: The inoculated substrate is placed in a constant temperature and humidity culture room for cultivation. The culture temperature is generally controlled at 25°C and the relative humidity is controlled at 70%.

[0033] During the cultivation process, the mycelium gradually grows in the matrix and eventually forms a mycelium network with a certain structural strength.

[0034] The culture cycle is usually 15 days, and the specific time depends on the growth rate of the strain and the ratio of the substrate.

[0035] Forming and processing: When the mycelium has fully grown in the substrate, it is placed in a pre-designed mold together with the substrate for molding. Through mold molding, packaging materials of different shapes can be prepared according to actual needs, such as packaging boxes, packaging boards, trays, etc.

[0036] The formed material can be further pressurized to increase its density and mechanical strength.

[0037] Drying and curing: The formed mycelium material needs to be dried, usually in a drying equipment at 50°C, until the moisture content drops below 10% to ensure that the material has sufficient strength and stability.

[0038] After drying, a secondary curing process can be optionally performed, such as through a hot or cold press process, to further enhance the durability and waterproof properties of the material.

[0039] Surface treatment and packaging: The dried mycelium material is surface treated and a layer of natural resin or wax may be coated as required to increase the moisture-proof and waterproof properties of the material.

[0040] The final packaged mycelium material can be directly used to replace traditional plastic packaging, and has good mechanical properties and environmental protection.

[0041] Example 4: A method for preparing a packaging material A method for preparing a packaging material comprises the following steps: Step 1: Preparation of the matrix: At least one of sawdust, rice husk, corn stalk and wheat straw is selected, crushed to obtain raw material powder, and then a carbon source, a nitrogen source and an inorganic salt are added, and mixed evenly to obtain a matrix; Step 2: Substrate pretreatment sterilizing the prepared matrix to obtain a sterilized matrix; Step 3: Inoculate edible fungi In a sterile environment, the sterilized substrate is cooled and then inoculated with edible fungi strains; Step 4: Mycelium Culture The substrate inoculated with edible fungi is placed in a constant temperature and humidity culture room for 20 days; Step 5: Forming and processing When the cultured mycelium and the substrate are placed into a pre-designed mold for molding; Step 6: Drying and Curing The formed mycelium material is dried in a drying device at 40°C until the moisture content drops below 10%; the dried mycelium material is surface treated.

[0042] A preferred embodiment is that the carbon source and the nitrogen source are a mixture of rice bran and soybean meal, and the mass ratio between the two is 1:1.

[0043] A preferred embodiment is that the inorganic salt is potassium sulfate.

[0044] The preferred embodiment is as follows: the sterilization process conditions are: temperature of 120°C and time of 30 minutes.

[0045] A preferred embodiment is: the culture medium formula is: the edible fungi species are oyster mushroom and shiitake mushroom.

[0046] The preferred embodiment is that the culture conditions are: temperature of 22° C. and relative humidity of 60%.

[0047] A preferred embodiment is that the surface treatment is coating paraffin on the surface of the material.

[0048] The above description is only used to explain the preferred embodiments of the present invention, and is not intended to limit the present invention in any form. Therefore, any modifications or changes made to the present invention under the same inventive spirit should still be included in the scope of protection intended by the present invention.

Claims

1. A method for preparing a packaging material, characterized in that: The following steps are involved: Step 1: Preparation of the matrix: At least one of sawdust, rice husk, corn stalk and wheat straw is selected, crushed to obtain raw material powder, and then a carbon source, a nitrogen source and an inorganic salt are added, and mixed evenly to obtain a matrix; Step 2: Substrate pretreatment sterilizing the prepared matrix to obtain a sterilized matrix; Step 3: Inoculate edible fungi In a sterile environment, the sterilized substrate is cooled and then inoculated with edible fungi strains; Step 4: Mycelium Culture The substrate inoculated with edible fungi is placed in a constant temperature and humidity culture room for 10-20 days; Step 5: Forming and processing When the cultured mycelium and the substrate are placed into a pre-designed mold for molding; Step 6: Drying and Curing The formed mycelium material is dried in a drying device at 40°C-60°C until the moisture content drops below 10%; the dried mycelium material is surface treated.

2. The method for preparing a packaging material according to claim 1, characterized in that: The carbon and nitrogen sources were a mixture of rice bran and soybean meal.

3. The method for preparing a packaging material according to claim 1, characterized in that: The inorganic salt is at least one of potassium sulfate, magnesium sulfate and potassium dihydrogen phosphate.

4. The method for preparing a packaging material according to claim 1, characterized in that: The sterilization process conditions are: temperature 120℃-130℃, time 15-30 minutes.

5. The method for preparing a packaging material according to claim 1, characterized in that: The culture medium formula is as follows: the edible fungus species is at least one of oyster mushroom and shiitake mushroom.

6. The method for preparing a packaging material according to claim 1, characterized in that: The culture conditions are: temperature 22℃-28℃, relative humidity 60%-80%.

7. The method for preparing a packaging material according to claim 1, characterized in that: Surface treatment is to coat the surface of the material with natural resin or paraffin.