Wood buffer material with imitated coconut shell structure as well as preparation method and application of wood buffer material

Abstract

The invention discloses a coconut shell structure imitating wood buffer material and a preparation method and application thereof.The preparation method comprises the following steps that wood is subjected to delignification treatment and soaked in water, and treated wood is obtained; the end face of the treated wood is subjected to end sealing treatment, and a sodium silicate solution is added for primary dipping treatment; and removing the end sealing material on the end surface of the impregnated wood, adding a polyvinyl alcohol solution, carrying out secondary impregnation treatment, and drying to obtain the wood buffer material with the imitated coconut shell structure. The wood buffer material with the imitated coconut shell structure has the advantages of light weight, high strength, good toughness, excellent buffer performance, excellent flame retardant property, good water resistance and the like, can replace a polystyrene foam material, and is widely applied to the field of product packaging.

Description

Technical Field

[0001] This invention belongs to the field of structural wood preparation technology, specifically relating to a coconut shell-like structural wood cushioning material, its preparation method, and its application. Background Technology

[0002] In modern logistics, refrigerated transport plays a crucial role in safeguarding people's lives and health. Due to the unique characteristics of refrigerated transport, its packaging materials need to possess excellent cold insulation and cushioning properties, while also being lightweight and non-toxic. Currently, refrigerated transport packaging materials mainly consist of foam boxes, but these packaging materials suffer from low density, weak physical strength, and fragility and deformation under external forces. Furthermore, the primary material of foam boxes is polystyrene (EPS), which is not easily degradable, has poor heat resistance, and releases toxic gases when burned, posing a threat to human safety and the environment.

[0003] Wood is a renewable and environmentally friendly biomass material. Plantation timber, with its rapid growth, early maturity, and short rotation period, offers the advantages of both price and lightweight, making it primarily used for packaging and transportation of large machinery, electromechanical products, heavy equipment, and production lines. However, using plantation timber for product packaging presents challenges such as low strength, poor toughness, and poor fire resistance, significantly limiting its practical application. Therefore, overcoming these issues to develop a lightweight, high-strength, tough, highly cushioning, flame-retardant, and water-resistant wood-based cushioning material holds promise for replacing polystyrene packaging materials, thereby reducing reliance on petrochemical products and mitigating environmental pollution. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a lightweight, high-strength, tough, excellent cushioning performance, excellent flame retardant performance, and good water resistance imitation coconut shell structure wood cushioning material, as well as its preparation method and application.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution.

[0006] A method for preparing a coconut shell-like wood-based cushioning material includes the following steps: S1. The wood is subjected to delignification treatment to obtain delignified wood. S2. The delignified wood is placed in water for soaking and then dried to obtain the treated wood. S3. The end faces of the treated wood are sealed by adding sodium silicate solution for a single impregnation treatment to obtain impregnated wood. S4. Remove the end-sealing material from the impregnated wood end face, add polyvinyl alcohol solution, perform a second impregnation treatment, and dry to obtain a coconut shell-structured wood cushioning material.

[0007] For the above preparation method, preferably, in step S3, the mass fraction of the sodium silicate solution is 8% - 10%.

[0008] For the above preparation method, preferably, the mass fraction of the polyvinyl alcohol solution is 6% - 8%.

[0009] For the above preparation method, preferably, in step S1, the delignification treatment is as follows: placing the wood in a sodium chlorite solution, soaking at 70°C - 85°C for 8h - 12h; the mass fraction of the sodium chlorite solution is 1.5% - 2.5%, and the pH value of the sodium chlorite solution is 4.2 - 4.7; the wood is poplar.

[0010] For the above preparation method, preferably, the soaking time is 12h - 24h; the specific drying process is: freeze - drying the soaked wood until the moisture content is 5% - 10%, and the temperature of the freeze - drying is - 55°C - - 40°C.

[0011] For the above preparation method, preferably, in step S3, the end - sealing treatment is: coating epoxy resin within a range of 10 mm from the surface on the end face of the treated wood; the shape of the coating is "hui" - shaped or "mu" - shaped; the time of the first impregnation treatment is 1h - 3h.

[0012] For the above preparation method, preferably, in step S4, the time of the second impregnation treatment is 1h - 2h, the drying temperature is 40°C - 60°C, and the drying is carried out under vacuum conditions.

[0013] For the above preparation method, preferably, the addition amounts of each raw material are calculated by mass parts, 1 part of wood, 25 - 30 parts of sodium chlorite solution, 40 - 50 parts of sodium silicate solution, and 30 - 40 parts of polyvinyl alcohol solution.

[0014] As a general technical concept, the present invention also provides a wood - based buffer material with a coconut - shell - like structure prepared by the above preparation method of the wood - based buffer material with a coconut - shell - like structure.

[0015] As a general technical concept, the present invention also provides an application of the above wood - based buffer material with a coconut - shell - like structure in product packaging.

[0016] Compared with the prior art, the advantages of the present invention are as follows: This invention discloses a method for preparing a coconut shell-like wood-based cushioning material. Through a layered design strategy, a coconut shell-like wood-based cushioning material is obtained. Specifically: First, the wood undergoes delignification treatment, which reduces the wood's density and surface hardness while improving its cushioning performance. It also induces the subsequent mineralization of sodium silicate within the wood's cell walls. Then, a portion of the end-capped wood is impregnated with a sodium silicate solution, allowing the sodium silicate to fill the wood cell walls, further improving the wood's strength and flame-retardant properties. Next, the end-capping material is removed, and a polyvinyl alcohol solution is used for a second impregnation treatment. Through chemical cross-linking of the wood cell walls, the toughness and surface cushioning performance of the wood are further improved. The coconut shell-like wood-based cushioning material prepared by this invention has advantages such as light weight, high strength, good toughness, excellent cushioning performance, excellent flame retardancy, and good water resistance. It can replace polystyrene foam materials and is widely used in product packaging. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the imitation coconut shell wood cushioning material prepared in Example 1 of the present invention.

[0018] Figure 2 The images show the actual product of the imitation coconut shell structure wood cushioning material and unmodified poplar wood prepared in Example 1 of this invention.

[0019] Figure 3 The images show the cushioning performance and surface water resistance of the imitation coconut shell structure wood-based cushioning material and unmodified poplar wood prepared in Example 1 of this invention. Detailed Implementation

[0020] The present invention will be further described below with reference to the accompanying drawings and specific preferred embodiments, but this does not limit the scope of protection of the present invention. All materials and instruments used in the following embodiments are commercially available.

[0021] Example 1: A method for preparing a coconut shell-like wood-based cushioning material according to the present invention includes the following steps: S1. Take 1 part of plantation poplar wood and put it into 25 parts of sodium chlorite solution. The sodium chlorite solution has a mass fraction of 1.5% and a pH value of 4.2. Heat it in a water bath at 75 ℃ for 8 h to carry out delignification treatment and obtain delignified wood.

[0022] S2. Place the wood treated with delignification into ultrapure water and soak for 12 hours. Then, use a freeze dryer to dry it at -55°C until the moisture content is 5% to 10%, thus obtaining the treated wood.

[0023] S3. Use epoxy resin to partially seal the end face of the treated wood, that is, apply a "return" - shaped epoxy resin within a range of 10 mm from the surface on the end face (cross - section) of the wood; then place it in 40 parts of sodium silicate solution (mass fraction is 8%), and the molar ratio of sodium oxide (Na2O) to silicon dioxide (SiO2) in this sodium silicate solution is 3.4, and conduct a primary impregnation treatment for 3 h to obtain impregnated wood.

[0024] S4. Remove the epoxy resin on the end face of the above - mentioned impregnated wood, place it in 30 parts of polyvinyl alcohol solution (mass fraction is 6%), conduct a secondary impregnation treatment for 2 h, and dry it at 45 °C in a vacuum environment to obtain a wood - based buffer material with a coconut - shell - like structure. Among them, the model of polyvinyl alcohol in the polyvinyl alcohol solution is 1299.

[0025] Figure 1 This is a schematic diagram of the structure of the wood - based buffer material with a coconut - shell - like structure prepared in Example 1 of the present invention. From Figure 1 It can be seen that the wood - based buffer material with a coconut - shell - like structure of the present invention presents a layered structure. Its surface is a soft layer, which can provide good buffering effect, while the core material is a hard material modified by inorganic substances and has high strength. The overall structure is highly similar to the coconut - shell structure.

[0026] Example 2: A preparation method of a wood - based buffer material with a coconut - shell - like structure of the present invention includes the following steps: S1. Put 1 part of poplar wood from a plantation into 30 parts of sodium chlorite solution with a mass fraction of 2.5% and a pH value of 4.6, and heat it in a water bath at 75 °C for 12 h for delignification treatment to obtain delignified wood.

[0027] S2. Put the above - mentioned delignified wood into ultrapure water, soak it for 12 h, and then use a freeze - dryer to dry it at - 55 °C until the moisture content is 5% - 10% to obtain treated wood.

[0028] S3. Use epoxy resin to partially seal the end face of the above - mentioned treated wood, that is, apply a "return" - shaped epoxy resin within a range of 10 mm from the surface on the end face (cross - section) of the wood; then place it in 50 parts of sodium silicate solution (mass fraction is 10%), and the molar ratio of sodium oxide (Na2O) to silicon dioxide (SiO2) in this sodium silicate solution is 3.4, and conduct a primary impregnation treatment for 3 h to obtain impregnated wood.

[0029] S4. Remove the epoxy resin on the end face of the above - mentioned impregnated wood, place it in 40 parts of polyvinyl alcohol solution (mass fraction is 8%), conduct a secondary impregnation treatment for 2 h, and dry it at 45 °C in a vacuum environment to obtain a wood - based buffer material with a coconut - shell - like structure.

[0030] Comparative Example 1: S1. Put 1 part of poplar wood from a plantation into 30 parts of sodium chlorite solution with a mass fraction of 2.5% and a pH value of 4.6, and heat it in a water bath at 75 °C for 12 h for delignification treatment to obtain delignified wood.

[0031] S2. Put the delignified wood obtained above into ultrapure water, soak it for 12 h, and then use a freeze dryer to dry it at -55 °C until the moisture content is 5% - 10% to obtain treated wood.

[0032] S3. Use epoxy resin to partially seal the end face of the treated wood above, that is, apply a "hui" - shaped epoxy resin within a range of 10 mm from the surface on the end face (cross - section) of the wood; then place it in 40 parts of polyvinyl alcohol solution (mass fraction of 8%) for a single impregnation treatment for 3 h to obtain impregnated wood.

[0033] S4. Remove the epoxy resin on the end face of the impregnated wood above, place it in 50 parts of sodium silicate solution (mass fraction of 10%) with a molar ratio of sodium oxide (Na2O) to silicon dioxide (SiO2) of 3.4 in the sodium silicate solution for a secondary impregnation treatment for 2 h, and dry it at 45 °C in a vacuum environment to obtain a coconut - shell - structured woody buffer material.

[0034] Test the physical and mechanical properties, impact toughness, heat resistance, water resistance, and mildew resistance of the coconut - shell - structured woody buffer materials prepared in Example 1, Example 2, and Comparative Example 1, and unmodified poplar wood. The results are shown in Table 1, Figure 2 、 Figure 3 as shown. Figure 2 Among them, (a) is the coconut - shell - structured woody buffer material of Example 1, (b) is the packaging box made of the coconut - shell - structured woody buffer material in Example 1, and (c) is the packaging box made of unmodified poplar wood.

[0035] Table 1 Performance comparison of coconut - shell - structured woody buffer materials and unmodified poplar wood in Examples 1 - 2

[0036] As shown in Table 1, compared to the coconut shell-structured wood-based cushioning material prepared in Comparative Example 1, the coconut shell-structured wood-based cushioning material prepared in Example 2 is lighter, has higher compressive strength, and better toughness. It is evident that the preparation method of the coconut shell-structured wood-based cushioning material of the present invention, through the technical strategy of "first impregnation with sodium silicate solution, followed by a second impregnation with polyvinyl alcohol solution," can obtain a lightweight, high-strength, tough, excellent cushioning performance, excellent flame retardant performance, and good water resistance coconut shell-structured wood-based cushioning material. The coconut shell-structured wood-based cushioning material of the present invention exhibits a layered structure at the microscopic level, with a loose and soft outer layer and a dense and hard inner layer, similar to the structure of a natural coconut shell.

[0037] from Figure 2 As can be seen, compared with unmodified poplar, the imitation coconut shell structure wood cushioning material in Example 1 has a very different color and morphology. The imitation coconut shell structure wood cushioning material is white, which is closer to the traditional foam packaging material and can reduce heat absorption; at the same time, it has a better anti-mildew effect during use.

[0038] from Figure 3 It can be seen that the coconut shell-like wooden cushioning material of the present invention has better cushioning properties and its surface is difficult to be damaged when subjected to impact; at the same time, it has good hydrophobic properties, which can reduce problems such as water absorption and mold growth.

[0039] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention using the methods and techniques disclosed above, or modify them into equivalent embodiments with equivalent changes, without departing from the spirit and technical essence of the present invention. Therefore, any simple modifications, equivalent substitutions, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall still fall within the protection scope of the technical solutions of the present invention.

Claims

1. A method for producing a wood-based cushioning material having a coconut shell structure, characterized by, It includes the following steps: S1. Carry out delignification treatment on the wood to obtain delignified wood; S2. Place the delignified wood in water for soaking, and after drying, obtain treated wood; S3. Carry out end-sealing treatment on the end face of the treated wood, add sodium silicate solution, and carry out a first impregnation treatment to obtain impregnated wood; S4. Remove the end-sealing material on the end face of the impregnated wood, add polyvinyl alcohol solution, carry out a second impregnation treatment, and after drying, obtain a coconut shell structure-like wood buffer material.

2. The method of claim 1, wherein the method further comprises the step of: In step S3, the mass fraction of the sodium silicate solution is 8% - 10%.

3. The method of claim 2, wherein the method further comprises the step of: In step S4, the mass fraction of the polyvinyl alcohol solution is 6% - 8%.

4. The process for preparing a wood-based buffer material of a coconut shell structure according to any one of claims 1 to 3, characterized in that, In step S1, the delignification treatment is: place the wood in sodium chlorite solution, soak it at 70°C - 85°C for 8h - 12h; the mass fraction of the sodium chlorite solution is 1.5% - 2.5%, and the pH value of the sodium chlorite solution is 4.2 - 4.7; the wood is poplar.

5. The method of claim 1-3, wherein the method is characterized by, In step S2, the soaking time is 12h - 24h; the specific process of drying is: freeze-dry the soaked wood until the moisture content is 5% - 10%, and the temperature of the freeze-drying is -55°C - -40°C.

6. The method of claim 1-3, wherein the method is characterized by, In step S3, the end-sealing treatment is: coat epoxy resin within the range of 10 mm from the surface on the end face of the treated wood; the shape of the coating is "回" (Chinese character for "return") or "目" (Chinese character for "eye"); the time of the first impregnation treatment is 1h - 3h.

7. The method of claim 1-3, wherein the method is characterized by, In step S4, the time of the second impregnation treatment is 1h - 2h, the drying temperature is 40°C - 60°C, and the drying is carried out under vacuum conditions.

8. The process for preparing a wood-based buffer material of a coconut shell structure according to any one of claims 1 to 3, characterized in that, The addition amount of each raw material is calculated by mass parts. For wood, it is 1 part, for sodium chlorite solution, it is 25 parts - 30 parts, for sodium silicate solution, it is 40 parts - 50 parts, and for polyvinyl alcohol solution, it is 30 parts - 40 parts.

9. A coconut shell structure-like wood buffer material prepared by the preparation method of the coconut shell structure-like wood buffer material according to any one of claims 1 - 8.

10. An application of the coconut shell structure-like wood buffer material according to claim 9 in product packaging.

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