Preparation method of natural latex-plant fiber composite foaming buffer material
Through gradient alkali treatment, dynamic crosslinking adhesives, biological enzyme collaborative foaming and freeze-drying technology, natural latex-plant fiber composite foaming buffer materials were prepared, which solved the problems of uneven foaming, insufficient toughness and water resistance, poor environmental friendliness and uncontrollable pore structure in the prior art, and achieved green and environmentally friendly materials, excellent mechanical properties and durability.
Patent Information
- Application Number
- CN202510254292.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-05
- Publication Date
- 2025-05-23
AI Technical Summary
In the prior art, plant fiber foaming materials have problems such as inadequate fiber surface treatment leading to uneven foaming, single adhesive performance leading to insufficient material toughness and water resistance, foaming agents rely on chemical reagents to lead to poor environmental friendliness, and simple drying process leading to uncontrollable pore structure of the material.
Through gradient alkali treatment, dynamic crosslinking adhesives, biological enzyme collaborative foaming and freeze-drying technology, natural latex-plant fiber composite foaming buffer material was prepared. Specific steps include plant fiber gradient alkali treatment, dynamic crosslinking adhesive preparation, biological enzyme synergistic foaming and freeze-drying.
It realizes a composite foam buffer material with green environmental protection, excellent mechanical properties and durability, solves the problems of toughness, water resistance and pore structure control of the material, and has a simple and efficient process, which meets the requirements of green and sustainable development.
Smart Images
Figure CN120025584A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the field of active foaming materials, and specifically relates to a method for preparing a natural latex-plant fiber composite foaming cushioning material, and particularly to the application of gradient alkali treatment, dynamic cross-linking adhesive, bio-enzyme synergistic foaming and freeze-drying technology. Background Art
[0002] With the booming development of the e-commerce industry, logistics and transportation have also risen. In addition to the important responsibilities of containing, protecting products, and being beautiful, packaging also plays a vital role in warehousing and logistics. For cushioning packaging, the main types of packaging on the market are corrugated cardboard, pulp molding, and honeycomb cardboard. However, the moisture-proof performance of corrugated cardboard is poor. If it rains or the air is humid, its cushioning performance may not meet the expected effect. At the same time, the cost is relatively high and the cushioning effect cannot meet the expected effect. The process of pulp molding is complicated and is more suitable for small-scale packaging. Based on this, plant fiber foaming materials have attracted widespread attention due to their environmentally friendly and degradable characteristics. However, the following problems still exist in the prior art: (1) Insufficient fiber surface treatment leads to uneven foaming; (2) The adhesive has a single performance, and the material toughness and water resistance are insufficient; (3) The foaming agent relies on chemical reagents and has poor environmental friendliness; (4) The drying process is simple and the material pore structure is uncontrollable. The present invention solves the above problems through gradient alkali treatment, dynamic cross-linking adhesive, bio-enzyme synergistic foaming and freeze-drying technology, and provides a green and environmentally friendly composite foaming cushioning material with excellent mechanical properties. Summary of the invention
[0003] An object of the present invention is to solve at least the above problems and / or disadvantages and to provide at least the advantages which will be described hereinafter.
[0004] The purpose of the present invention is to provide a method for preparing a natural latex-plant fiber composite foaming cushioning material, and to prepare an environmentally friendly and degradable cushioning material with excellent mechanical properties and durability through gradient alkali treatment, dynamic cross-linking adhesive, bio-enzyme synergistic foaming and freeze-drying technology.
[0005] In order to achieve these purposes and other advantages according to the present invention, a method for preparing a natural latex-plant fiber composite foaming cushioning material is provided, comprising the following steps:
[0006] Step 1, subjecting plant fibers to a gradient alkali treatment to prepare a plant fiber dispersion;
[0007] Step 2, using citric acid as a cross-linking agent to prepare a dynamic cross-linking adhesive;
[0008] Step 3, adding the adhesive solution, the bio-enzyme synergistic active agent solution and the plasticizer into the plant fiber dispersion, and performing active foaming by mechanical stirring with a high-speed shearing machine;
[0009] Step 4, pouring the foamed fiber mixture prepared in step 3 into a mold with a filter screen at the bottom for water filtering, standing for 24 hours and then demolding to obtain a formed plant fiber composite foam material;
[0010] Step 5: placing the formed plant fiber composite foam material in a -55°C environment for gradient cooling, and vacuum freeze-drying for 48 hours to obtain the final composite foam cushioning material.
[0011] Preferably, the fiber raw material of the plant fiber dispersion in step 1 is one or more plant fibers selected from the group consisting of hardwood fiber, softwood fiber, bamboo fiber and cotton fiber.
[0012] Preferably, the process of preparing the plant fiber dispersion by gradient alkali treatment in step one is: soak the plant fiber pulp board in water for 5 hours, beat for 20 minutes, and obtain a plant fiber pulp with a beating degree of 20-50SR° and a water content of 70-80%; treat the plant fiber pulp with a gradient alkali of 3% NaOH solution (treated at 60°C for 1 hour) and 1% KOH solution (treated at room temperature for 1 hour); then use microwave-assisted activation (500W, 2min), rinse to neutral, and obtain a pretreated plant fiber dispersion.
[0013] Preferably, the method for preparing the dynamic cross-linked adhesive in step 2 is: add 2.5 parts of polyvinyl alcohol and 97.5 parts of deionized water into a beaker according to weight parts and stir at 90°C for 25 minutes until the polyvinyl alcohol is dissolved, after cooling to room temperature, pour 5 parts of natural latex and 0.5 parts of nanocellulose suspension into the polyvinyl alcohol solution and stir at 40°C for 5 minutes, then add 0.1 parts of citric acid as a cross-linking agent, and ultrasonically treat at 60°C for 10 minutes to form a dynamic cross-linked network to obtain a composite adhesive.
[0014] Preferably, the active agent polyether in step three is specifically polyether F68, polyether F77, polyether F87, polyether F88, polyether F108, polyether F127, etc., and the amount of the active agent added is 2% of the total mass concentration.
[0015] Preferably, the biological enzyme in step three is derived from Aspergillus niger, and the amount of the biological enzyme added is 0.1% of the total mass concentration.
[0016] Preferably, the plasticizer in step three is glycerol, and the amount of the plasticizer added is fixed at 1.5 mL.
[0017] Preferably, the method for preparing the active agent solution in step three is: add 10 parts of active agent and 90 parts of deionized water by weight into a beaker, stir at 40° C. for 15 minutes until the active agent is fully dissolved, and cool to room temperature for later use.
[0018] Preferably, the method for preparing the bio-enzyme solution in step three is: add 1 part of bio-enzyme and 99 parts of deionized water into a beaker according to weight, stir at room temperature for 10 minutes until the bio-enzyme is completely dispersed, and set aside at room temperature.
[0019] Preferably, in step 3, the mechanical speed of the high-speed shearing machine is 5000 rad / min, and the foaming time is 10 min.
[0020] The present invention includes at least the following beneficial effects: the natural latex-plant fiber composite foaming cushioning material prepared by the present invention is green and environmentally friendly, has excellent mechanical properties and durability, and has a simple and efficient preparation process, conforms to green and sustainable development, and has broad application potential in the fields of packaging, shock absorption, heat preservation, and thermal insulation.
[0021] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Figure 1 These are photos of the natural latex-plant fiber composite foaming cushioning materials of Examples 1, 2, 3 and 4 of the present invention;
[0023] Figure 2 This is an internal SEM electron microscope scanning image of the natural latex-plant fiber composite foaming cushioning material prepared in Example 1 of the present invention;
[0024] Figure 3 This is a stress-strain curve of the natural latex-plant fiber composite foaming cushioning material prepared in Example 1 of the present invention;
[0025] Figure 4 This is a stress-strain curve of the natural latex-plant fiber composite foamed cushioning material prepared in Example 1 of the present invention after 10 consecutive cycles of compression at 50% strain. DETAILED DESCRIPTION
[0026] The present invention is further described in detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.
[0027] It should be understood that the terms such as “having”, “including” and “comprising” used herein do not exclude the existence or addition of one or more other elements or combinations thereof.
[0028] Example 1
[0029] Step 1, prepare plant fiber dispersion: soak the hardwood fiber pulp board in water for 5 hours, then beat for 20 minutes to obtain hardwood fiber pulp with a beating degree of 20SR° and a moisture content of 75%, then perform 3% NaOH and 1% KOH gradient pretreatment on it, then use microwave-assisted activation, and after completion, rinse to neutral so that its moisture content is still maintained at 75%, to obtain a plant fiber dispersion.
[0030] Step 2: Add 2.5 parts of polyvinyl alcohol and 97.5 parts of deionized water into a beaker according to weight, and stir at 90°C for 25 minutes until the polyvinyl alcohol is dissolved. After cooling to room temperature, pour 5 parts of natural latex and 0.5 parts of nanocellulose suspension into the polyvinyl alcohol solution and stir at 40°C for 5 minutes. Then add 0.1 parts of citric acid as a cross-linking agent, and ultrasonically treat at 60°C for 10 minutes to form a dynamic cross-linking network to obtain a composite adhesive.
[0031] Step three, prepare polyether F127 solution: add 10 parts of polyether F127 and 90 parts of deionized water into a beaker according to weight, stir for 15 minutes at 40°C until the active agent is fully dissolved, and obtain F127 solution. Prepare bio-enzyme solution: add 1 part of bio-enzyme and 99 parts of deionized water into a beaker according to weight, stir for 10 minutes at room temperature until the bio-enzyme is completely dispersed, and obtain bio-enzyme solution. Add 2% of polyether F127, 0.1% of bio-enzyme, 8% of adhesive and 1.5 ml of glycerol to the plant fiber dispersion, and foam it at a high speed of 5000rad / min for 10 minutes to obtain an amorphous natural latex-plant fiber foaming mixture.
[0032] Step 4: Pour the natural latex-plant fiber foaming mixture prepared in step 3 into a mold with a 100-mesh filter screen at the bottom for water filtering, let it stand for 24 hours and then demold to obtain a formed natural latex-plant fiber composite foaming material.
[0033] Step 5: Place the formed natural latex-plant fiber composite foam material in a -55°C environment for gradient cooling, and vacuum freeze-dry for 48 hours to obtain the final composite foam cushioning material.
[0034] The density of the natural latex-plant fiber composite foaming cushioning material prepared in this example is 0.124 g / cm 3 The compressive strength under 80% strain is 1.10 MPa, and it can recover to 76% of the initial shape; the rebound rate can reach 85% after 10 cycles of compression under 50% strain, which proves that the composite foam material prepared in this embodiment has good mechanical properties and durability.
[0035] Example 2
[0036] Step 1, prepare plant fiber dispersion: soak the coniferous fiber pulp board in water for 5 hours, then beat for 20 minutes to obtain coniferous fiber pulp with a beating degree of 20SR° and a water content of 75%, and then perform 3% NaOH and 1% KOH gradient pretreatment on it, and then activate it with microwave assisted. After completion, rinse it to neutral so that its water content is still maintained at 75%, and obtain a plant fiber dispersion.
[0037] Step 2: Add 2.5 parts of polyvinyl alcohol and 97.5 parts of deionized water into a beaker according to weight, stir at 90°C for 25 minutes until the polyvinyl alcohol is dissolved. After cooling to room temperature, pour 5 parts of natural latex and 0.5 parts of nanocellulose suspension into the polyvinyl alcohol solution and stir at 40°C for 5 minutes. Then add 0.1 parts of citric acid as a cross-linking agent, and ultrasonically treat at 60°C for 10 minutes to form a dynamic cross-linking network to obtain a composite adhesive.
[0038] Step three, prepare polyether F127 solution: add 10 parts of polyether F127 and 90 parts of deionized water into a beaker according to weight, stir for 15 minutes at 40°C until the active agent is fully dissolved, and obtain F127 solution. Prepare bio-enzyme solution: add 1 part of bio-enzyme and 99 parts of deionized water into a beaker according to weight, stir for 10 minutes at room temperature until the bio-enzyme is completely dispersed, and obtain bio-enzyme solution. Add 2% of polyether F127, 0.1% of bio-enzyme, 8% of adhesive and 1.5 ml of glycerol to the plant fiber dispersion, and foam it at a high speed of 5000rad / min for 10 minutes to obtain an amorphous natural latex-plant fiber foaming mixture.
[0039] Step 4: Pour the natural latex-plant fiber foaming mixture prepared in step 3 into a mold with a 100-mesh filter screen at the bottom for water filtering, let it stand for 24 hours and then demold to obtain a formed natural latex-plant fiber composite foaming material.
[0040] Step 5: Place the formed natural latex-plant fiber composite foam material in a -55°C environment for gradient cooling, and vacuum freeze-dry for 48 hours to obtain the final composite foam cushioning material.
[0041] The density of the natural latex-plant fiber composite foaming cushioning material prepared in this example is 0.125 g / cm 3 The compressive strength under 80% strain is 0.74 MPa, which can recover to 72% of the initial shape; the rebound rate can reach 80% after 10 cycles of compression under 50% strain, which proves that the composite foam material prepared in this embodiment has good mechanical properties and durability.
[0042] Example 3
[0043] Step 1, preparing plant fiber dispersion: soak the bamboo fiber pulp board in water for 5 hours, then beat for 20 minutes to obtain a bamboo fiber pulp with a beating degree of 20SR° and a water content of 75%, and then perform 3% NaOH and 1% KOH gradient pretreatment on it, and then use microwave assisted activation. After completion, rinse to neutral so that its water content is still maintained at 75%, and obtain a plant fiber dispersion.
[0044] Step 2: Add 2.5 parts of polyvinyl alcohol and 97.5 parts of deionized water into a beaker according to weight, stir at 90°C for 25 minutes until the polyvinyl alcohol is dissolved. After cooling to room temperature, pour 5 parts of natural latex and 0.5 parts of nanocellulose suspension into the polyvinyl alcohol solution and stir at 40°C for 5 minutes. Then add 0.1 parts of citric acid as a cross-linking agent, and ultrasonically treat at 60°C for 10 minutes to form a dynamic cross-linking network to obtain a composite adhesive.
[0045] Step three, prepare polyether F127 solution: add 10 parts of polyether F127 and 90 parts of deionized water into a beaker according to weight, stir for 15 minutes at 40°C until the active agent is fully dissolved, and obtain F127 solution. Prepare bio-enzyme solution: add 1 part of bio-enzyme and 99 parts of deionized water into a beaker according to weight, stir for 10 minutes at room temperature until the bio-enzyme is completely dispersed, and obtain bio-enzyme solution. Add 2% of polyether F127, 0.1% of bio-enzyme, 8% of adhesive and 1.5 ml of glycerol to the plant fiber dispersion, and foam it at a high speed of 5000rad / min for 10 minutes to obtain an amorphous natural latex-plant fiber foaming mixture.
[0046] Step 4: Pour the natural latex-plant fiber foaming mixture prepared in step 3 into a mold with a 100-mesh filter screen at the bottom for water filtering, let it stand for 24 hours and then demold to obtain a formed natural latex-plant fiber composite foaming material.
[0047] Step 5: Place the formed natural latex-plant fiber composite foam material in a -55°C environment for gradient cooling, and vacuum freeze-dry for 48 hours to obtain the final composite foam cushioning material.
[0048] The density of the natural latex-plant fiber composite foaming cushioning material prepared in this example is 0.130 g / cm 3 The compressive strength under 80% strain is 0.42 MPa, and it can recover to 75% of the initial shape; the rebound rate can reach 82% after 10 cycles of compression under 50% strain, which proves that the composite foam material prepared in this embodiment has good mechanical properties and durability.
[0049] Example 4
[0050] Step 1, prepare plant fiber dispersion: soak the cotton fiber pulp board in water for 5 hours, then beat for 20 minutes to obtain a cotton fiber pulp with a beating degree of 20SR° and a water content of 75%, and then perform 3% NaOH and 1% KOH gradient pretreatment on it, and then activate it with microwave assisted. After completion, rinse it to neutral so that its water content is still maintained at 75%, and obtain a plant fiber dispersion.
[0051] Step 2: Add 2.5 parts of polyvinyl alcohol and 97.5 parts of deionized water into a beaker according to weight, and stir at 90°C for 25 minutes until the polyvinyl alcohol is dissolved. After cooling to room temperature, pour 5 parts of natural latex and 0.5 parts of nanocellulose suspension into the polyvinyl alcohol solution and stir at 40°C for 5 minutes. Then add 0.1 parts of citric acid as a cross-linking agent, and ultrasonically treat at 60°C for 10 minutes to form a dynamic cross-linking network to obtain a composite adhesive.
[0052] Step three, prepare polyether F127 solution: add 10 parts of polyether F127 and 90 parts of deionized water into a beaker according to weight, stir for 15 minutes at 40°C until the active agent is fully dissolved, and obtain F127 solution. Prepare bio-enzyme solution: add 1 part of bio-enzyme and 99 parts of deionized water into a beaker according to weight, stir for 10 minutes at room temperature until the bio-enzyme is completely dispersed, and obtain bio-enzyme solution. Add 2% of polyether F127, 0.1% of bio-enzyme, 8% of adhesive and 1.5 ml of glycerol to the plant fiber dispersion, and foam it at a high speed of 5000rad / min for 10 minutes to obtain an amorphous natural latex-plant fiber foaming mixture.
[0053] Step 4: Pour the natural latex-plant fiber foaming mixture prepared in step 3 into a mold with a 100-mesh filter screen at the bottom for water filtering, let it stand for 24 hours and then demold to obtain a formed natural latex-plant fiber composite foaming material.
[0054] Step 5: Place the formed natural latex-plant fiber composite foam material in a -55°C environment for gradient cooling, and vacuum freeze-dry for 48 hours to obtain the final composite foam cushioning material.
[0055] The density of the natural latex-plant fiber composite foaming cushioning material prepared in this example is 0.219 g / cm 3 The compressive strength under 80% strain is 1.99 MPa, and it can recover to 76% of the initial shape; the rebound rate can reach 87% after 10 cycles of compression under 50% strain, which proves that the composite foam material prepared in this embodiment has good mechanical properties and durability.
[0056] The number of devices and processing scales described here are used to simplify the description of the present invention. Applications, modifications and variations of the present invention will be obvious to those skilled in the art.
[0057] As described above, the natural latex-plant fiber composite foaming cushioning material prepared by the present invention is green and environmentally friendly, has excellent mechanical properties and durability, and has a simple and efficient preparation process, which conforms to green and sustainable development and has broad application potential in the fields of packaging, shock absorption, heat preservation, and thermal insulation.
[0058] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and the embodiments. It can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily realized. Therefore, without departing from the general concept defined by the claims and equivalent scope, the present invention is not limited to the specific details and the illustrations shown and described here.
Claims
1. A method for preparing a natural latex-plant fiber composite foaming cushioning material, characterized in that: The following steps are involved: Step 1, subjecting plant fibers to a gradient alkali treatment to prepare a plant fiber dispersion; Step 2, using citric acid as a cross-linking agent to prepare a dynamic cross-linking adhesive; Step 3, adding the adhesive solution, the bio-enzyme synergistic active agent solution and the plasticizer into the plant fiber dispersion, and performing active foaming by mechanical stirring with a high-speed shearing machine; Step 4, pouring the foamed fiber mixture prepared in step 3 into a mold with a filter screen at the bottom for water filtering, standing for 24 hours and then demolding to obtain a formed plant fiber composite foam material; Step 5: placing the formed plant fiber composite foam material in a -55°C environment for gradient cooling, and vacuum freeze-drying for 48 hours to obtain the final composite foam cushioning material.
2. The method for preparing a natural latex-plant fiber composite foaming cushioning material according to claim 1, characterized in that: The fiber raw material of the plant fiber dispersion in step 1 is one or more plant fibers selected from the group consisting of hardwood fiber, softwood fiber, bamboo fiber, and cotton fiber.
3. The method for preparing a natural latex-plant fiber composite foaming cushioning material according to claim 1, characterized in that: The process of preparing the plant fiber dispersion by gradient alkali treatment in step 1 is as follows: soaking the plant fiber pulp board in water for 5 hours, beating for 20 minutes, and obtaining a plant fiber pulp with a beating degree of 20-50SR° and a water content of 70-80%; treating the plant fiber pulp with a gradient alkali of 3% NaOH solution (treated at 60°C for 1 hour) and 1% KOH solution (treated at room temperature for 1 hour); Then, the mixture was activated with microwave assistance (500 W, 2 min) and rinsed to neutrality to obtain a pretreated plant fiber dispersion.
4. The method for preparing a natural latex-plant fiber composite foaming cushioning material according to claim 1, characterized in that: The method for preparing the dynamic cross-linked adhesive in step 2 is as follows: 2.5 parts of polyvinyl alcohol and 97.5 parts of deionized water are added to a beaker according to weight, and stirred at 90°C for 25 minutes until the polyvinyl alcohol is dissolved. After cooling to room temperature, 5 parts of natural latex and 0.5 parts of nanocellulose suspension are poured into the polyvinyl alcohol solution and stirred at 40°C for 5 minutes, followed by adding 0.1 parts of citric acid as a cross-linking agent, and ultrasonically treated at 60°C for 10 minutes to form a dynamic cross-linked network to obtain a composite adhesive.
5. The method for preparing a natural latex-plant fiber composite foaming cushioning material according to claim 1, characterized in that: The active agent polyether in step 3 is specifically polyether F68, polyether F77, polyether F87, polyether F88, polyether F108, polyether F127, etc., and the amount of the active agent added is 2% of the total mass concentration.
6. The method for preparing a natural latex-plant fiber composite foaming cushioning material according to claim 1, characterized in that: The biological enzyme in step three is derived from Aspergillus niger, and the added amount of the biological enzyme is 0.1% of the total mass concentration.
7. The method for preparing a natural latex-plant fiber composite foaming cushioning material according to claim 1, characterized in that: The plasticizer in step three is glycerol, and the amount of the plasticizer added is fixed at 1.5 mL.
8. The method for preparing a natural latex-plant fiber composite foaming cushioning material according to claim 1, characterized in that: The method for preparing the active agent solution in step 3 is: add 10 parts of the active agent and 90 parts of deionized water into a beaker according to weight, stir at 40° C. for 15 minutes until the active agent is fully dissolved, and cool to room temperature for later use.
9. The method for preparing a natural latex-plant fiber composite foaming cushioning material according to claim 1, characterized in that: The method for preparing the bio-enzyme solution in step three is: add 1 part of bio-enzyme and 99 parts of deionized water into a beaker according to weight, stir at room temperature for 10 minutes until the bio-enzyme is completely dispersed, and set aside at room temperature.
10. The method for preparing a natural latex-plant fiber composite foaming cushioning material according to claim 1, characterized in that: In the step 3, the mechanical speed of the high-speed shearing machine is 5000 rad / min, and the foaming time is 10 min.