Double anti-mite fruit cultivating bag paper and preparation method thereof

Abstract

The invention relates to the technical field of agricultural paper, in particular to double anti-mite fruit cultivating bag paper and a preparation method thereof. The preparation method comprises the following steps: pulping: respectively pulping natural-color bamboo pulp and natural-color softwood pulp, then mixing, adding water, and uniformly mixing to obtain pulp; papermaking: sequentially adding iron oxide yellow, aluminum sulfate, rosin size and a wet strength agent into the pulp, adding water for dilution, and drying after papermaking to obtain fruit cultivating bag body paper; sizing: taking oxidized cassava starch, adding water, preparing starch slurry, heating, continuously stirring until the starch is completely gelatinized, taking starch gelatinized liquid, adding neem oil, putting into a high-speed homogenizing emulsifying machine, emulsifying to obtain neem oil anti-mite emulsion, uniformly mixing the neem oil anti-mite emulsion with wax emulsion to obtain anti-mite glue liquid, immersing the fruit cultivating bag body paper into the anti-mite glue liquid, and drying to obtain the fruit cultivating bag. And taking out and drying to obtain the double anti-mite fruit cultivating bag paper. The composite material has physical barrier and long-acting anti-mite functions, and the risk of insect attack invasion is greatly reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of agricultural paper, in particular to a double mite-proof fruit bag paper and a preparation method thereof. BACKGROUND

[0002] China is the largest fruit producer and consumer in the world, and the fruit industry has become the third largest agricultural planting industry after food and vegetables. With the upgrading of consumption, the market demand for high-quality, non-polluted fruits has surged, and the lack of disease and pest control and high dependence on chemical pesticides in traditional planting modes have seriously hindered the upgrading of the industry.

[0003] Among the many diseases and pests, mite pests have become one of the main factors threatening fruit quality and yield. Citrus, apple, pear, peach, grape and other economic crops are commonly damaged by mites. For example, grape eriophyid mites not only damage grape leaves, causing yellow-brown spots and even leaf yellowing and falling, but also damage grape shoots and young fruits, making the fruit surface appear rusty and rough. In addition, grape eriophyid mites can also damage citrus, pomegranate, walnut, pistachio and other fruit trees.

[0004] Traditional fruit bag paper mainly relies on physical barrier principle to achieve the functions of preventing pests and diseases through paper structure. However, such fruit bags can only resist the invasion of external mites and cannot remove the eggs or mites that already exist on the fruit before bagging. At the same time, the closed microenvironment inside the bag actually creates favorable conditions for the reproduction of mites.

[0005] Patent CN116285509A discloses a fruit bag coating solution formula, in which cyclodextrin is heated and stirred with plant essential oil for 2 hours, and then a dispersing agent, high acyl konjac gum and a bonding glue, polyvinyl alcohol, are added and uniformly mixed after the solution is cooled. Although the coating can be used as a carrier for plant essential oil to prevent pests from harming fruits. However, the preparation process is relatively complex, the cost of cyclodextrin inclusion technology is high, and it is not suitable for paper machine site with high-speed production. Moreover, the cyclodextrin inclusion solution does not have good bonding effect and still needs other bonding glue to load the inclusion onto the paper.

[0006] Patent CN114657815A discloses a preparation method of a fruit bag bioactive coating green degradable antibacterial paper, in which a nano-TiO2 / starch solution and a natural eutectic solvent modified chitosan solution are used as the antibacterial inner coating of the fruit bag paper, and a shellac solution is used as the waterproof outer coating liquid of the fruit bag paper. It only considers the factor that fruits are infected by fungi, and does not consider the realistic situation that eggs on fruits before bagging can also cause fruits to be infected. Nano-TiO2 and chitosan do not have a direct mite-killing or mite-proof effect, and cannot eliminate the eggs on fruits before bagging.

[0007] The existing conventional fruit bag paper only relies on physical barrier method, which is difficult to effectively deal with the mite eggs or larvae existing on the surface of the fruit before bagging, and the closed microenvironment formed by the fruit bag may even exacerbate the reproduction and harm of the mites in the bag, further restricting the improvement of fruit quality. In view of this technical bottleneck, the industry urgently needs to develop a new type of fruit bag material with physical barrier and active mite killing functions to realize the whole cycle control of mites and break through the limitations of disease and pest control under the existing planting mode. SUMMARY

[0008] In view of the deficiencies of the prior art, the purpose of the present application is to provide a double mite prevention fruit bag paper which has physical barrier and long-term mite prevention functions, greatly reducing the risk of pest invasion.

[0009] The present application also provides a preparation method, which improves the physical barrier effect of the fruit bag on mites by mixing bamboo pulp and wood pulp to paper, reduces the risk of pest invasion, and prolongs the mite prevention period by using a composite natural mite prevention agent slow-release technology, thereby reducing the frequency of fruit pesticide use. While taking into account environmental friendliness and safety, the fruit quality is improved, and the fruit industry is transformed towards green and sustainable direction.

[0010] Bamboo pulp, as a natural plant fiber, has good physical properties and environmental protection characteristics, and its source is extensive and renewable, which meets the trend of green papermaking and sustainable development. At the same time, the natural antibacterial properties of bamboo pulp fiber help to improve the mite prevention performance of paper, providing a natural basis for the realization of the mite prevention function in the present application.

[0011] The preparation method of the double mite prevention fruit bag paper according to the present application is prepared by the following steps: (1) Beating The natural color bamboo pulp and the natural color coniferous wood pulp are beaten respectively, then mixed, water is added and mixed uniformly to obtain a slurry; (2) Papermaking 2 Iron oxide yellow, aluminum sulfate, rosin glue and wet strength agent are added into the slurry in sequence, diluted with water, dried after papermaking to obtain fruit bag base paper with a basis weight of 40±1 g / m (3) Sizing Take the oxidized tapioca starch, add water, prepare the starch slurry, heat and stir until the starch is completely gelatinized, take the starch gelatinization liquid, add neem oil, and place it in a high-speed homogenizing emulsifier to emulsify and obtain neem oil mite prevention emulsion. Mix the neem oil mite prevention emulsion and wax emulsion uniformly to obtain mite prevention glue solution. The fruit bag base paper is immersed in the mite prevention glue solution, taken out and dried to obtain the double mite prevention fruit bag paper.

[0012] The beating degree of the natural color bamboo pulp and the natural color coniferous wood pulp after beating in step (1) is 50-60°SR.

[0013] ​The mixing mass ratio of the raw bamboo pulp and the raw coniferous wood pulp in step (1) is (60-80):(20-40).

[0014] The pulp mass concentration in step (1) is 2-5%.

[0015] The toner paper addition amount of the iron oxide yellow, aluminum sulfate, rosin glue and wet strength agent in step (2) is 15-30 kg, 15-30 kg, 15-30 kg and 180-250 kg respectively.

[0016] The water dilution in step (2) is diluted to a pulp mass concentration of 0.2-0.5%.

[0017] The mixing mass ratio of the neem oil anti-mite emulsion and the wax emulsion in step (3) is (1-2):(1-2).

[0018] The mass concentration of the starch slurry in step (3) is 7-12%.

[0019] The addition amount of the neem oil in step (3) is 2.5%-10% of the absolute dry weight of the oxidized cassava starch.

[0020] The drying temperature in step (3) is 85-120 DEG C.

[0021] Compared with the prior art, the present application has the following advantages: 1) The fruit bag paper prepared by taking bamboo pulp as the main material in the present application has significant advantages in environmental protection and resource sustainability, and the natural antibacterial property of the bamboo pulp fiber helps to improve the anti-mite performance of the paper, which provides a natural basis for the realization of the anti-mite function in the present application, and is suitable for the application of fruit bag paper which needs environmental protection and high performance.

[0022] 2) The neem oil anti-mite emulsion prepared by the simple and easy method in the present application has good stability, which can be used as a coating liquid to be coated on the fruit bag base paper by surface immersion, and the fruit bag paper with anti-mite performance can be obtained after drying, which can prevent the approach of mites and kill the eggs or mites on the fruit by the physical barrier structure and the continuous release of neem oil in the coating.

[0023] 3) The double anti-mite fruit bag paper prepared in the present application can kill grape short mites or significantly inhibit the activity of grape short mites. In the anti-mite test, compared with the fruit bag paper without anti-mite emulsion coating, the egg laying number of grape short mites decreases by more than 80%, and the 24h mortality rate of grape short mites is up to 80%.

[0024] 4) The double anti-mite fruit bag paper prepared by the present application can achieve 24h half lethal effect on grape short mite when the amount of neem oil is 5%, and still has insecticidal effect after being hung outdoors for thirty days.

[0025] 5) The double anti-mite fruit bag paper prepared by the present application has simple preparation process and mild reaction conditions, and different anti-mite fruit bag papers with different effects can be prepared by adjusting the preparation conditions of the emulsion to adapt to fruits with different bagging periods.

[0026] 6) In the present application, the wax emulsion commonly used in fruit bag paper and the self-prepared starch-based anti-mite emulsion are mixed, and after surface sizing and drying, the wax particles will melt to form a continuous wax film, and the starch molecules will dry and form a layer of brittle polysaccharide film, which will interweave with each other to form a composite film. The starch network and the wax film together constitute a barrier, which greatly slows down the path and speed of the anti-mite molecules diffusing to the outside. This avoids the rapid volatilization of the anti-mite molecules and prolongs the action time. If the anti-mite molecules are directly added, it is easy to destroy the stability of the wax emulsion. Pre-encapsulating the anti-mite molecules into an emulsion makes it change from "oil phase" to "water phase dispersion", which greatly reduces the risk of emulsion breaking caused by the direct fusion of the anti-mite molecules with the wax emulsion oil phase, making the mixing process more controllable and stable. At the same time, starch is an excellent thickening agent and water phase gelling agent, and the addition of the anti-mite emulsion will increase the viscosity of the composite system, even form a gel-like network structure, which will wrap part of the wax particles and essential oil droplets together, which is beneficial to inhibit particle sedimentation and emulsion separation, and improve the physical stability. The fruit bag paper coated with the composite emulsion has certain water resistance and anti-mite function, realizing the dual effects of physical barrier and chemical mite killing. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 Scanning electron microscope images of the anti-mite emulsions prepared in Examples 1-4; Figure 2 Statistical diagram of the number of eggs laid by grape short mite on the surface of the double anti-mite fruit bag paper of Examples 1-4 and Comparative Examples 1-2 for 24h; Figure 3 Grape short mite living body and egg state diagram of Comparative Example 1 and grape short mite state diagram on the double anti-mite fruit bag paper of Example 2; The left graph is the grape short mite living body and egg state diagram on the fruit bag paper of Comparative Example 1, and the right graph is the grape short mite state diagram on the double anti-mite fruit bag paper of Example 2.

[0028] Figure 4 Statistical diagram of the long-acting insecticidal effect (24h) of the double anti-mite fruit bag paper in Example 2 on grape short mite. DETAILED DESCRIPTION

[0029] The present application will be further described below in conjunction with examples.

[0030] All raw materials used in the examples are commercially available, unless otherwise specified.

[0031] Bamboo pulp: Taisheng (Guizhou) Bamboo Resource Development Co., Ltd., natural sulfate bamboo pulp; Softwood pulp: Sulfite softwood pulp (grade B), Saya, Russia; Iron oxide yellow: Hunan Sanhuan Pigment Co., Ltd. G313; Aluminum sulfate: Sanfeng Environmental Group; Rosin size: CEM-1735B cationic rosin size produced by Hangzhou Hanghua Halima Chemical Co., Ltd.; Wet strength agent: MF wet strength agent, Weifang Tianfang Shenghong Chemical Co., Ltd.

[0032] Wax emulsion: non-ionic paraffin wax emulsion, solid content 33±1%, viscosity ≤300 mPa·s (25℃, rotary viscometer NDJ-1), pH value 7-10, Weifang Huapu Chemical Co., Ltd.; Oxidized tapioca starch: FS-608 produced by Jiangxi Lihe Chemical Industry Co., Ltd.; Neem oil: Jiangxi Jinyuan Natural Spice Co., Ltd.

[0033] Example 1 The preparation method of the double-mite-proof fruit bag paper is prepared by the following steps: (1) Beating The natural bamboo pulp and natural softwood pulp were beaten to 55°SR using a PFI mill, then mixed in a mass ratio of 70:30, tap water was added to adjust the slurry concentration to 3%, and mixed uniformly to obtain the pulp; (2) Papermaking Iron oxide yellow, aluminum sulfate, rosin size, and wet strength agent were added to the pulp in turn, with a ton of paper adding amount of 20 kg, 20 kg, 20 kg, and 230 kg respectively, and water was added to dilute the pulp concentration to 0.5%. The paper was made by a paper sheet former with a fixed amount of 40 g / m 2 , dried at 100℃, 0.08kPa for 3min to obtain the fruit bag base paper; (3) Sizing Take an appropriate amount of oxidized cassava starch, add distilled water, and prepare a starch slurry with a mass concentration of 10%. Stir continuously for 30 minutes in a 95℃ water bath until the starch is completely gelatinized. Take an appropriate amount of starch gelatinized liquid, add 2.5% neem oil based on the dry weight of the starch, place it in a high-speed homogenizing emulsifier, set the speed to 10000 rpm, and emulsify for 15 minutes to obtain a neem oil anti-mite emulsion. Mix the neem oil anti-mite emulsion and wax emulsion evenly at a mass ratio of 1:2 to obtain an anti-mite adhesive. Immerse the base paper of the fruit cultivation bag in the anti-mite adhesive, remove it after 2 minutes, and dry it in an oven at 105℃ to obtain a double-anti-mite fruit cultivation bag paper.

[0034] Example 2 The preparation method of the aforementioned double-mite-proof fruit-growing bag paper comprises the following steps: (1) Pulping Natural bamboo pulp and natural softwood pulp were separately pulped to 55°SR using a PFI mill. Then, they were mixed in a mass ratio of 70:30, tap water was added, the pulp concentration was adjusted to 3%, and the mixture was stirred evenly to obtain the pulp. (2) Papermaking Iron oxide yellow, aluminum sulfate, rosin gum, and wet strength agent were added to the pulp in sequence, with the addition amounts of each component per ton of paper being 20 kg, 20 kg, 20 kg, and 230 kg, respectively. The pulp was diluted with water to a consistency of 0.5%, and the sheet forming machine was used to achieve a sheet weight of 40 g / m². 2 The paper was dried at 100℃ and 0.08kPa for 3 minutes to obtain the base paper for the fruit growing bags. (3) Apply adhesive Take an appropriate amount of oxidized cassava starch, add distilled water, and prepare a starch slurry with a mass concentration of 10%. Stir continuously for 30 minutes in a 95℃ water bath until the starch is completely gelatinized. Take an appropriate amount of starch gelatinized liquid, add 5% neem oil based on the dry weight of the starch, place it in a high-speed homogenizer emulsifier, set the speed to 10000 rpm, and emulsify for 15 minutes to obtain a neem oil anti-mite emulsion. Mix the neem oil anti-mite emulsion and wax emulsion evenly at a mass ratio of 1:2 to obtain an anti-mite adhesive. Immerse the base paper of the fruit-growing bag in the anti-mite adhesive, remove it after 2 minutes, and dry it in an oven at 105℃ to obtain a double-anti-mite fruit-growing bag paper.

[0035] Example 3 The preparation method of the aforementioned double-mite-proof fruit-growing bag paper comprises the following steps: (1) Pulping Natural bamboo pulp and natural softwood pulp were separately pulped to 55°SR using a PFI mill. Then, they were mixed in a mass ratio of 70:30, tap water was added, the pulp concentration was adjusted to 3%, and the mixture was stirred evenly to obtain the pulp. (2) Papermaking Iron oxide yellow, aluminum sulfate, rosin gum, and wet strength agent were added to the pulp in sequence, with the addition amounts of each component per ton of paper being 20 kg, 20 kg, 20 kg, and 230 kg, respectively. The pulp was diluted with water to a consistency of 0.5%, and the sheet forming machine was used to achieve a sheet weight of 40 g / m². 2 The paper was dried at 100℃ and 0.08kPa for 3 minutes to obtain the base paper for the fruit growing bags. (3) Apply adhesive Take an appropriate amount of oxidized cassava starch, add distilled water, and prepare a starch slurry with a mass concentration of 10%. Stir continuously for 30 minutes in a 95℃ water bath until the starch is completely gelatinized. Take an appropriate amount of starch gelatinized liquid, add 7% neem oil based on the dry weight of the starch, place it in a high-speed homogenizer emulsifier, set the speed to 10000 rpm, and emulsify for 15 minutes to obtain a neem oil anti-mite emulsion. Mix the neem oil anti-mite emulsion and wax emulsion evenly at a mass ratio of 1:2 to obtain an anti-mite adhesive. Immerse the base paper of the fruit-growing bag in the anti-mite adhesive, remove it after 2 minutes, and dry it in an oven at 105℃ to obtain a double-anti-mite fruit-growing bag paper.

[0036] Example 4 The preparation method of the aforementioned double-mite-proof fruit-growing bag paper comprises the following steps: (1) Pulping Natural bamboo pulp and natural softwood pulp were separately pulped to 55°SR using a PFI mill. Then, they were mixed in a mass ratio of 70:30, tap water was added, the pulp concentration was adjusted to 3%, and the mixture was stirred evenly to obtain the pulp. (2) Papermaking Iron oxide yellow, aluminum sulfate, rosin gum, and wet strength agent were added to the pulp in sequence, with the addition amounts of each component per ton of paper being 20 kg, 20 kg, 20 kg, and 230 kg, respectively. The pulp was diluted with water to a consistency of 0.5%, and the sheet forming machine was used to achieve a sheet weight of 40 g / m². 2 The paper was dried at 100℃ and 0.08kPa for 3 minutes to obtain the base paper for the fruit growing bags. (3) Apply adhesive Take an appropriate amount of oxidized cassava starch, add distilled water, and prepare a starch slurry with a mass concentration of 10%. Stir continuously for 30 minutes in a 95℃ water bath until the starch is completely gelatinized. Take an appropriate amount of starch gelatinized liquid, add 10% neem oil based on the dry weight of the starch, place it in a high-speed homogenizing emulsifier, set the speed to 10000 rpm, and emulsify for 15 minutes to obtain a neem oil anti-mite emulsion. Mix the neem oil anti-mite emulsion and wax emulsion evenly at a mass ratio of 1:2 to obtain an anti-mite adhesive. Immerse the base paper of the fruit-growing bag in the anti-mite adhesive, remove it after 2 minutes, and dry it in an oven at 105℃ to obtain a double-anti-mite fruit-growing bag paper.

[0037] Comparative Example 1 The preparation method of the anti-mite fruit bag paper comprises the following steps: (1) Beating The original color bamboo pulp and the original color coniferous wood pulp are beaten to 55°SR respectively by using a PFI mill, then mixed in a mass ratio of 70:30 of the original color bamboo pulp and the original color coniferous wood pulp, tap water is added to adjust the pulp concentration to 3%, and the mixture is uniformly mixed to obtain pulp; (2) Papermaking Iron oxide yellow, aluminum sulfate, rosin glue and wet strength agent are added into the pulp in sequence, and the ton paper addition amount of each component is 20 kg, 20 kg, 20 kg and 230 kg respectively, water is added to dilute the pulp concentration to 0.5%, and a paper sheet former is used to make a paper sheet with a dosage of 40 g / m 2 , dried at 100 DEG C and 0.08 kPa for 3 min to obtain the fruit bag base paper.

[0038] Comparative Example 2 The wax emulsion is not used, and water is used instead of the wax emulsion, and the rest is the same as in Example 2.

[0039] The microstate of the anti-mite emulsion prepared in Examples 1-4 is shown in Figure 1 The neem oil can form a relatively uniform spherical droplet with the oxidized tapioca starch. This may be because the starch is composed of hydrophilic glucose units connected by α-1,4 and α-1,6 glycosidic bonds, which can theoretically provide steric hindrance to stabilize the droplets in the oil-in-water emulsion. The content of amylopectin in tapioca starch is higher, and it is easier to form a flexible molecular chain network after oxidation. Meanwhile, the carboxyl group of oxidized tapioca starch is negatively charged, and the electrostatic repulsion and steric hindrance effect may jointly enhance the stability of the emulsion.

[0040] According to the evaluation of the anti-mite performance of textiles in GB / T 24253-2009, the insecticidal efficacy of the fruit bag paper in Examples 1-4, Comparative Example 1 and Comparative Example 2 on grape short mite and the number of eggs are tested, the test results of the insecticidal efficacy of the double anti-mite fruit bag paper on grape short mite (24h) are shown in Table 1, and the statistical results of the number of eggs of grape short mite on the surface of the double anti-mite fruit bag paper after 24h are shown in Figure 2 ; Table 1 Insecticidal efficacy of double anti-mite fruit bag paper on grape short mite (24h)

[0041] During the test, it can be observed that the grape short mite on the fruit bag paper without anti-mite glue solution has stretched limbs, moves quickly, and there are eggs in the activity area, while the grape short mite on the fruit bag paper coated with anti-mite glue solution shows a phenomenon of curling and death, and has no reaction when touched with a dissecting needle, and the number of eggs is greatly reduced, as shown in Figure 3As shown, the left graph is the grape short trichome mite on the bag paper of the grape short trichome mite and the right graph is the grape short trichome mite on the bag paper of the grape short trichome mite of the double mite-proof bag paper of Example 2.

[0042] When the bag paper can achieve 24h median lethal effect on the grape short trichome mite, it is considered to have good mite-proof effect. Considering the economy and environmental protection, the double mite-proof bag paper in Example 2 is used to simulate bagging outdoors. The long-term insecticidal efficiency (24h) test statistical graph of the double mite-proof bag paper in Example 2 on the grape short trichome mite is shown in Figure 4 As shown, it still has a certain insecticidal effect after hanging for thirty days.

Claims

1. A method for preparing a double-mite-proof fruit-growing bag paper, characterized in that, It is prepared by the following steps: (1) Pulping Natural bamboo pulp and natural coniferous wood pulp are pulped separately, then mixed together, and water is added and mixed evenly to obtain the pulp. (2) Papermaking Iron oxide yellow, aluminum sulfate, rosin gum, and wet strength agent are added to the pulp in sequence, diluted with water, and dried after papermaking to obtain the base paper for fruit bags. (3) Apply adhesive Take oxidized cassava starch, add water to prepare starch slurry, heat and stir continuously until the starch is completely gelatinized. Take the starch gelatinized liquid, add neem oil, place it in a high-speed homogenizing emulsifier, and emulsify to obtain neem oil anti-mite emulsion. Mix the neem oil anti-mite emulsion with wax emulsion evenly to obtain anti-mite adhesive. Immerse the fruit-growing bag base paper in the anti-mite adhesive, take it out and dry it to obtain double anti-mite fruit-growing bag paper.

2. The method for preparing the double-mite-proof fruit-growing bag paper according to claim 1, characterized in that, The beating degree of the unbleached bamboo pulp and unbleached softwood pulp in step (1) is 50-60°SR.

3. The method for preparing the double-mite-proof fruit-growing bag paper according to claim 1, characterized in that, The mixing mass ratio of unbleached bamboo pulp and unbleached softwood pulp in step (1) is (60-80): (20-40).

4. The method for preparing the double-mite-proof fruit-growing bag paper according to claim 1, characterized in that, The slurry concentration in step (1) is 2-5%, and the dilution with water in step (2) is to dilute the slurry to a concentration of 0.2-0.5%.

5. The method for preparing the double-mite-proof fruit-growing bag paper according to claim 1, characterized in that, The amounts of iron oxide yellow, aluminum sulfate, rosin gum, and wet strength agent added per ton of paper in step (2) are 15-30 kg, 15-30 kg, 15-30 kg, and 180-250 kg, respectively.

6. The method for preparing the double-mite-proof fruit-growing bag paper according to claim 1, characterized in that, The mixing mass ratio of the neem oil anti-mite emulsion and the wax emulsion in step (3) is (1-2):(1-2).

7. The method for preparing the double-mite-proof fruit-growing bag paper according to claim 1, characterized in that, The mass concentration of the starch slurry in step (3) is 7-12%.

8. The method for preparing the double-mite-proof fruit-growing bag paper according to claim 1, characterized in that, The amount of neem oil added in step (3) is 2.5%-10% of the oven-dry weight of oxidized cassava starch.

9. The method for preparing the double-mite-proof fruit-growing bag paper according to claim 1, characterized in that, The drying temperature in step (3) is 85-120℃.

10. A double-mite-proof fruit-growing bag paper, characterized in that, It is prepared by any one of the preparation methods described in claims 1-9.

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