Repellent insect-proof packaging paper and preparation method thereof

Abstract

The invention provides repellent insect-proof packaging paper, which is prepared from the following raw materials in percentage by weight: 50 to 70 percent of paper pulp fiber, 10 to 20 percent of insect-proof compound, 1 to 3 percent of nano-silver composite microsphere, 0.5 to 2 percent of synergistic ether, 5 to 15 percent of light calcium carbonate, 3 to 8 percent of starch glue and 1 to 3 percent of waterproof agent. The insect prevention compound is a deltamethrin / nano-zinc oxide compound coated by microcapsules, and the nano-silver composite microspheres are cellulose microspheres loaded with nano-silver. The preparation method comprises the following steps: uniformly mixing the raw material components, forming by a paper machine, squeezing, drying and calendering. Long-acting slow release of insect-repelling components is achieved through the microcapsule technology, the material is endowed with excellent antibacterial and insect-preventing performance through the nano-silver composite microspheres, meanwhile, the advantages of good mechanical strength, moisture resistance and production cost are considered, and the environment-friendly insect-preventing packaging material is suitable for environment-friendly insect-preventing packaging in the fields of grains, food, medicinal materials and the like.

Description

Technical Field

[0001] This invention relates to the field of grain storage technology, and in particular to a repellent and insect-proof packaging paper and its preparation method. Background Technology

[0002] Currently, grains, food, and medicinal herbs often suffer severe losses due to insect infestations during storage and transportation. Existing insect-proof packaging mostly uses plastic film or impregnation treatment, which has problems such as poor environmental friendliness, short-lasting insect-proof effect, and high cost. Therefore, developing an environmentally friendly, efficient, and durable insect-proof packaging paper is of great practical significance. Summary of the Invention

[0003] The purpose of this invention is to provide a repellent insect-repellent packaging paper and its preparation method, which has the advantages of long-lasting insect repellency, antibacterial properties, moisture resistance, and good mechanical properties.

[0004] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0005] This invention provides an insect-repellent packaging paper. The packaging paper is composed of pulp fiber, an insect-repellent complex, nano-silver composite microspheres, synergistic ether, light calcium carbonate, starch glue, and a waterproofing agent. The weight percentages of each raw material are as follows: pulp fiber 50%–70%, insect-repellent complex 10%–20%, nano-silver composite microspheres 1%–3%, synergistic ether 0.5%–2%, light calcium carbonate 5%–15%, starch glue 3%–8%, and waterproofing agent 1%–3%. The insect-repellent complex is a deltamethrin / nano-zinc oxide complex microencapsulated in microcapsules. The nano-silver composite microspheres are cellulose microspheres loaded with nano-silver, with a silver loading of 3%–8%.

[0006] Preferably, the mass ratio of deltamethrin to nano zinc oxide in the insect repellent compound is 1:5–1:10.

[0007] This invention also provides a method for preparing repellent and insect-repellent packaging paper, comprising the following steps:

[0008] a. Mix paper pulp fibers with water and beat them to make pulp;

[0009] b. Add the insect-repellent compound, nano-silver composite microspheres, synergistic ether, light calcium carbonate, starch adhesive and waterproofing agent to the slurry in sequence, and stir evenly;

[0010] c. The mixed pulp is formed, pressed, dried, and calendered on a paper machine to produce insect-proof packaging paper.

[0011] Compared with the prior art, the present invention has the following beneficial effects:

[0012] 1. Possesses highly efficient and long-lasting insect-repellent properties. This invention prepares a microencapsulated insect-repellent complex by combining deltamethrin and nano-zinc oxide, and then uniformly disperses it in pulp. The microencapsulation structure not only solves the problem of loss and decomposition of the insect-repellent ingredients during the papermaking process, but also enables slow and sustained release, thereby giving the packaging paper long-lasting repellent properties and effectively preventing the invasion and infestation of storage pests such as the red flour beetle and the tobacco beetle.

[0013] 2. It also has significant antibacterial and bacteriostatic effects. By introducing cellulose microspheres loaded with silver nanoparticles, the good compatibility between the cellulose substrate and pulp fiber solves the problem of silver nanoparticle dispersion. On the other hand, it fully utilizes the broad-spectrum and highly efficient antibacterial properties of silver nanoparticles to effectively inhibit mold and spoilage of the packaging contents caused by microbial growth, thus extending the shelf life.

[0014] 3. The mechanical properties and applicability of the material are guaranteed. Using pulp fiber as the matrix, starch glue as a natural binder, and light calcium carbonate as a filler for reinforcement, the prepared packaging paper has good strength, stiffness and abrasion resistance, fully meeting the mechanical requirements of actual packaging, transportation and stacking.

[0015] 4. It achieves a good combination of functionality and processability. Each functional component (insect repellent compound, silver nanospheres, etc.) is highly compatible with the papermaking process and can be formed in one step by adding it into the pulp during the conventional papermaking process. The process is simple and easy to achieve large-scale production, avoiding the problems of high cost, low efficiency and uneven effect caused by traditional post-processing processes such as impregnation and coating.

[0016] 5. Environmentally friendly and cost-effective. The main raw materials, such as pulp fiber and starch adhesive, are biodegradable or renewable resources, aligning with the trend of green packaging development. Furthermore, the addition of lightweight calcium carbonate as an inexpensive filler significantly reduces raw material costs while improving the physical properties of the paper, thereby enhancing the product's market competitiveness.

[0017] 6. Excellent moisture-proof performance. The added waterproofing agent forms a hydrophobic barrier on the surface of the paper fibers, effectively reducing the moisture absorption of the packaging paper and preventing it from cracking due to decreased paper strength in humid environments. It also provides additional moisture protection for the contents (such as grains and medicinal materials). Detailed Implementation

[0018] This invention provides an insect-repellent packaging paper. The packaging paper is composed of pulp fiber, an insect-repellent complex, nano-silver composite microspheres, synergistic ether, light calcium carbonate, starch glue, and a waterproofing agent. The weight percentages of each raw material are as follows: pulp fiber 50%–70%, insect-repellent complex 10%–20%, nano-silver composite microspheres 1%–3%, synergistic ether 0.5%–2%, light calcium carbonate 5%–15%, starch glue 3%–8%, and waterproofing agent 1%–3%. The insect-repellent complex is a deltamethrin / nano-zinc oxide complex microencapsulated in microcapsules. The nano-silver composite microspheres are cellulose microspheres loaded with nano-silver, with a silver loading of 3%–8%.

[0019] In this invention, the repellent and insect-repellent packaging paper contains 50%-70% pulp fiber, preferably 53%-67%, more preferably 55%-65%, and even more preferably 57%-63%.

[0020] In this invention, the repellent and insect-repellent packaging paper contains 10%-20% insect-repellent compound, preferably 12%-19%, more preferably 13%-18%, and even more preferably 14%-17%.

[0021] In this invention, the repellent insect-repellent packaging paper contains 1%-3% silver nanospheres, preferably 1.5%-2.5%, more preferably 1.8%-2.3%, and even more preferably 1.9%-2.2%.

[0022] In this invention, the repellent and insect-repellent packaging material contains 0.5%-2% synergistic ether, preferably 0.8%-1.8%, more preferably 1.0%-1.6%, and even more preferably 1.2%-1.4%.

[0023] In this invention, the repellent and insect-proof packaging material contains 5%–15% light calcium carbonate, preferably 6%–13%, more preferably 7%–11%, and even more preferably 8%–10%.

[0024] In this invention, the repellent insect-proof packaging material contains 3%–8% starch glue, preferably 4%–7%, more preferably 4.5%–6.5%, and more preferably 5.5%–6%.

[0025] In this invention, the repellent and insect-proof packaging material contains 1%–3% waterproofing agent, preferably 1.2%–2.8%, more preferably 1.5%–2.5%, and even more preferably 1.8%–2.3%.

[0026] In this invention, the mass ratio of deltamethrin to nano zinc oxide in the insect repellent compound is 1:5–1:10, preferably 1:4.5–1:9.5, more preferably 1:4–1:8, and even more preferably 1:3.5–1:7.5.

[0027] This invention also provides a method for preparing repellent and insect-repellent packaging paper, comprising the following steps:

[0028] a. Mix paper pulp fibers with water and beat them to make pulp;

[0029] b. Add the insect-repellent compound, nano-silver composite microspheres, synergistic ether, light calcium carbonate, starch adhesive and waterproofing agent to the slurry in sequence, and stir evenly;

[0030] c. The mixed pulp is formed, pressed, dried, and calendered on a paper machine to produce insect-proof packaging paper.

[0031] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0032] Example 1

[0033] The composition consists of 60% pulp fiber, 15% insect-repellent compound, 2% nano-silver composite microspheres, 1% synergistic ether, 10% light calcium carbonate, 5% starch glue, and 2% waterproofing agent.

[0034] After being mixed in the above proportions, the mixture is formed and dried by a paper machine to produce insect-proof packaging paper.

[0035] Example 2:

[0036] The composition consists of 65% pulp fiber, 12% insect-repellent compound, 1.5% nano-silver composite microspheres, 0.5% synergistic ether, 8% light calcium carbonate, 6% starch glue, and 2% waterproofing agent.

[0037] The preparation method is the same as in Example 1.

[0038] Insect repellency performance test:

[0039] The packaging paper prepared in Examples 1 and 2 was made into paper bags, filled with whole wheat flour, and inoculated with red flour beetle and tobacco beetle larvae. After 30 days, no insects were found inside the bags, indicating a significant insect-proof effect.

[0040] After 30 days, the paper bag was opened, and the number of live insects and the extent of insect damage inside the bag were checked and recorded. The insect infestation inhibition rate was also calculated.

[0041] Insect infestation inhibition rate (%) = [(Average number of live insects in the control group bag - Average number of live insects in the experimental group bag) / Average number of live insects in the control group bag] × 100%

[0042] Test results:

[0043] Group Test insect species Average number of live worms outside the bag (heads) Average number of live insects (heads) in the bag Insect infestation on packaging bags Insect infestation inhibition rate (%) Example 1 Red-eared Valley Beetle 20.0 0.0 No wormholes or damage 100% Tobacco A 19.7 0.3 Very slight marks, no penetrating damage 98.5% Example 2 Red-eared Valley Beetle 20.0 0.0 No wormholes or damage 100% Tobacco A 19.3 0.7 Minor marks, no penetrating damage 96.5% Ordinary kraft paper (reference) Red-eared Valley Beetle 2.3 17.7 Multiple penetrating boreholes - Tobacco A 3.0 17.0 Multiple penetrating boreholes -

[0044] Conclusion: The insect-repellent packaging paper prepared by this invention exhibits extremely strong repellency and protection against red flour beetles and tobacco beetles, with insect infestation inhibition rates exceeding 96.5%, which is significantly better than ordinary packaging paper.

[0045] II. Antibacterial Performance Test

[0046] Test Method: The test method was adapted for paper, referring to the national standard GB / T 31402-2015 "Test Method for Antimicrobial Properties of Plastic Surfaces". The test bacteria were *Escherichia coli* (ATCC 25922) and *Staphylococcus aureus* (ATCC 6538). Samples were cut into 5cm × 5cm pieces, incubated with the bacterial solution for 24 hours, and residual viable bacteria were recovered and counted to calculate the antimicrobial rate.

[0047] Antibacterial rate (%) = [(Average viable count in control group - Average viable count in experimental group) / Average viable count in control group] × 100%

[0048] Test results:

[0049] Group Test strains Average viable count of control sample (CFU / mL) Average viable bacterial count of experimental sample (CFU / mL) Antibacterial rate (%) Example 1 E. coli <![CDATA[3.5×10 5 ]]> 8.2×10² 99.8% Staphylococcus aureus <![CDATA[2.9×10 5 ]]> 5.5×10² 99.8% Example 2 E. coli <![CDATA[3.5×10 5 ]]> 1.1×10³ 99.7% Staphylococcus aureus <![CDATA[2.9×10 5 ]]> 9.8×10² 99.7% Ordinary kraft paper (reference) E. coli <![CDATA[3.5×10 5 ]]> <![CDATA[3.3×10 5 ]]> -

[0050] Conclusion: The packaging paper of this invention has a strong broad-spectrum antibacterial ability against common pathogens, with an antibacterial rate of over 99.7%, and can effectively inhibit the spoilage and deterioration of contents due to microbial growth.

[0051] III. Physical Performance Testing

[0052] Test method: The physical properties of the paper are tested in accordance with relevant national standards.

[0053] Test results:

[0054] Test Project Test Standards Example 1 Example 2 Ordinary kraft paper unit Quantitative GB / T451.2 72.5 70.8 68.2 g / m² Tensile index GB / T12914 68.5 65.2 55.1 N·m / g Tear GB / T 455.1 850 820 650 mN Breathability GB / T 458 2.5 2.8 25.5 μm / (Pa·s) Cobb value (60s) GB / T 1540 18.5 20.2 45.8 g / m²

[0055] Conclusion: The packaging paper of this invention is significantly superior to ordinary kraft paper in terms of mechanical properties (tensile index, tear strength), exhibiting higher strength. Simultaneously, it has lower air permeability and a Cobb value (water absorption) far lower than the control, demonstrating its excellent moisture-proof performance and better protection of contents from environmental humidity.

[0056] As can be seen from the above experimental data, the insect-repellent packaging paper provided by this invention not only has a highly efficient and long-lasting insect-repellent effect and strong antibacterial properties, but also maintains excellent physical strength and moisture-proof performance. It is a functional packaging material with excellent comprehensive performance.

[0057] This invention discloses a repellent insect-repellent packaging paper and its preparation method. The raw materials of the packaging paper, by weight percentage, include: 50%–70% pulp fiber, 10%–20% insect-repellent compound, 1%–3% nano-silver composite microspheres, 0.5%–2% synergistic ether, 5%–15% light calcium carbonate, 3%–8% starch adhesive, and 1%–3% waterproofing agent. The insect-repellent compound is a microencapsulated deltamethrin / nano-zinc oxide composite, and the nano-silver composite microspheres are cellulose microspheres loaded with nano-silver. The preparation method includes: mixing the raw material components evenly, followed by forming, pressing, drying, and calendering on a paper machine. This invention achieves long-term sustained release of the insect-repellent components through microencapsulation technology and utilizes nano-silver composite microspheres to impart excellent antibacterial and insect-repellent properties to the material, while also taking into account good mechanical strength, moisture resistance, and production cost advantages. It is suitable for environmentally friendly insect-repellent packaging in the fields of grain, food, and medicinal materials.

[0058] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A repellent and insect-repellent packaging paper, characterized in that: The packaging paper raw material is composed of pulp fiber, insect-repellent compound, nano-silver composite microspheres, synergistic ether, light calcium carbonate, starch glue, and waterproofing agent. The weight percentages of each raw material are as follows: pulp fiber 50%–70%, insect-repellent compound 10%–20%, nano-silver composite microspheres 1%–3%, synergistic ether 0.5%–2%, light calcium carbonate 5%–15%, starch glue 3%–8%, and waterproofing agent 1%–3%. The insect-repellent compound is a deltamethrin / nano-zinc oxide composite microencapsulated in microcapsules. The nano-silver composite microspheres are cellulose microspheres loaded with nano-silver, with a silver loading of 3%–8%.

2. The insect-repellent packaging paper according to claim 1, characterized in that: The mass ratio of deltamethrin to nano zinc oxide in the insect repellent compound is 1:5–1:

10.

3. The method for preparing the repellent insect-repellent packaging paper according to claim 1 or 2, characterized in that, Includes the following steps: a. Mix paper pulp fibers with water and beat them to make pulp; b. Add the insect-repellent compound, nano-silver composite microspheres, synergistic ether, light calcium carbonate, starch adhesive and waterproofing agent to the slurry in sequence, and stir evenly; c. The mixed pulp is formed, pressed, dried, and calendered on a paper machine to produce insect-proof packaging paper.