阅读说明：本技术 一种防潮编织袋的制备方法 (Preparation method of moisture-proof woven bag ) 是由 申乾成 申辉 黄振 于 2019-10-24 设计创作，主要内容包括：本发明涉及编织袋技术领域,具体涉及一种防潮编织袋的制备方法,包括编织袋制备、编织袋表面处理、疏水喷洒液制备、编织袋疏水处理和编织袋清洗烘干五大步骤；本发明的编织袋通过以聚丙烯、低密度聚乙烯和聚氨酯为原料共混熔融后,并加入纳米无机粉末和各种功能添加剂,使得编织袋具有优异的力学性,另外通过在编织袋表面枝接一层超疏水表面层,能够极大提高编织袋的防潮性能,而且其表面层无任何毒副作用,可用作粮食保证,极大延长了粮食保证的储存时间。(The invention relates to the technical field of woven bags, in particular to a preparation method of a moisture-proof woven bag, which comprises five steps of woven bag preparation, woven bag surface treatment, hydrophobic spraying liquid preparation, woven bag hydrophobic treatment and woven bag cleaning and drying; the woven bag has excellent mechanical property by taking polypropylene, low-density polyethylene and polyurethane as raw materials, blending and melting the raw materials, and adding nano inorganic powder and various functional additives, and in addition, the moisture resistance of the woven bag can be greatly improved by grafting a super-hydrophobic surface layer on the surface of the woven bag, and the surface layer has no toxic or side effect, can be used for ensuring grains, and greatly prolongs the storage time of the grain.)

1. The preparation method of the moisture-proof woven bag is characterized by comprising the following steps of:

1) preparing a woven bag:

a. preparing the following raw materials in parts by weight: 80-90 parts of polypropylene particles, 15-20 parts of low-density polyethylene particles, 8-12 parts of polyurethane particles, 3-5 parts of nano inorganic powder, 3-6 parts of reinforcing agent, 3-5 parts of coupling agent and 2-3 parts of dispersing agent for later use;

b. putting the raw materials into an internal mixer, uniformly stirring and mixing, heating to 175-180 ℃ for melting, then fully stirring and mixing the melted raw materials, putting into an extruder, extruding into a plastic film at the temperature of 180-190 ℃, and finally cooling and solidifying in water at the temperature of 18-25 ℃ to obtain the plastic film;

c. cutting the film into filaments by using a blade, stretching the filaments into flat filaments by using an oven, drawing the filaments by using a drawing roller for heat setting, continuing drawing and winding the filaments, finally sending the wound flat filaments into a circular weaving machine to weave into woven bag blanks, and obtaining woven bags after edge cutting and sewing;

2) and (3) woven bag surface treatment: paving the woven bags prepared in the step 1) orderly, and then carrying out corona treatment on the upper surface and the lower surface of each woven bag by using a corona machine, wherein the voltage of the corona treatment is 10-20 KV, the power is 500-800W, and the electrode gap is 5-8 mm;

3) preparing a hydrophobic spraying liquid: 60-80 parts by weight of hexamethyldisiloxane is taken, and 14-18 parts of nano SiO is added into the hexamethyldisiloxane₂Fully stirring at the rotating speed of 1200-2000 r/min for 30min, then adding 22-26 parts of hexafluoroisopropanol into hexamethyldisiloxane, and finally carrying out ultrasonic treatment on the mixed solution for 1-2 h to obtain hydrophobic spraying liquid;

4) carrying out hydrophobic treatment on the woven bag: extracting the hydrophobic spraying liquid prepared in the step 3) by using a high-pressure water pump, and uniformly spraying the hydrophobic spraying liquid on the surface of the woven bag treated in the step 2) by using a high-pressure nozzle, wherein the spraying amount is 10-15 g/m²Then, radiating the surface of the woven bag for 20-30 min by using a high-energy electron beam, wherein the energy of the electron beam is 2.0Mev, and the dose is 80-160 kGy;

5) and (3) cleaning and drying woven bags: and (3) putting the woven bag treated in the step 4) into clear water, repeatedly washing for 2-3 times, and drying to obtain the moisture-proof woven bag.

2. The method for preparing the moisture-proof woven bag according to claim 1, wherein the method comprises the following steps: 86 parts of raw material polypropylene particles, 18 parts of low-density polyethylene particles, 10 parts of polyurethane particles, 4 parts of nano inorganic powder, 5 parts of reinforcing agent, 3 parts of coupling agent and 2 parts of dispersing agent in the step 1).

3. The method for preparing the moisture-proof woven bag according to claim 1, wherein the method comprises the following steps: the nano inorganic powder in the step 1) is one or more of nano bentonite, nano kaolin, modified nano alumina or modified nano zirconia.

4. The method for preparing the moisture-proof woven bag according to claim 1, wherein the method comprises the following steps: the temperature in the oven in the step 1) is 95-110 ℃, and the traction speed of the traction roller is 15-20 m/min.

5. The method for preparing the moisture-proof woven bag according to claim 1, wherein the method comprises the following steps: the frequency of ultrasonic treatment in the step 3) is 40-80 kHz.

6. The method for preparing the moisture-proof woven bag according to claim 1, wherein the method comprises the following steps: the drying in the step 5) is hot air drying at 40-60 ℃.

Technical Field

The invention relates to the technical field of woven bags, in particular to a preparation method of a moisture-proof woven bag.

Background

The plastic woven bag is also called snake leather bag, and is a product obtained by extruding polypropylene or polyethylene and other raw materials into a film, cutting, unidirectionally stretching into flat filaments and weaving the flat filaments by warps and wefts. At present, most of packaging bags in the grain industry are plastic woven bags, although the strength and the wear resistance of the packaging bags meet the packaging requirements, the moisture resistance of the existing plastic woven bags is limited, and if grains such as rice, wheat and flour are packaged by the woven bags and stored in a humid environment for a long time, the grains are easy to mildew and the like to influence the grain quality, so that the storage period of the grains is shortened.

The invention with the patent number of CN105885237A discloses a moisture-proof plastic woven bag, which is prepared by 100 parts of polypropylene, 50 parts of polytetrafluoroethylene, 6-10 parts of clay, 1-4 parts of limestone, 2-4 parts of epoxy resin, 0.5-1 part of decabromodiphenyl ether, 15-25 parts of modified additive, 5-9 parts of additive and 4-8 parts of additive master batch through the working procedures of mixing, drying, stirring, melting and extrusion film forming; although the moisture resistance of the plastic woven bag prepared by the invention is improved compared with the common woven bag, the moisture resistance is not obviously improved, and the safety of the plastic woven bag used as a packaging bag in the field of food is not yet determined because the additive contains anhydrous copper sulfate. Therefore, aiming at the defect of the moisture resistance of the existing plastic woven bag, the invention provides the woven bag which can obviously improve the moisture resistance and has higher food safety for grain packaging, which is a technical problem to be solved.

Disclosure of Invention

The invention aims to solve the technical problem of designing a preparation method of a moisture-proof woven bag so as to solve the defects that the existing plastic woven bag is poor in moisture-proof performance and easy to mildew when used for packaging grains.

The invention is realized by the following technical scheme:

a preparation method of a moisture-proof woven bag comprises the following steps:

1) preparing a woven bag:

a. preparing the following raw materials in parts by weight: 80-90 parts of polypropylene particles, 15-20 parts of low-density polyethylene particles, 8-12 parts of polyurethane particles, 3-5 parts of nano inorganic powder, 3-6 parts of reinforcing agent, 3-5 parts of coupling agent and 2-3 parts of dispersing agent for later use;

b. putting the raw materials into an internal mixer, uniformly stirring and mixing, heating to 175-180 ℃ for melting, then fully stirring and mixing the melted raw materials, putting into an extruder, extruding into a plastic film at the temperature of 180-190 ℃, and finally cooling and solidifying in water at the temperature of 18-25 ℃ to obtain the plastic film;

c. cutting the film into filaments by using a blade, stretching the filaments into flat filaments by using an oven, drawing the filaments by using a drawing roller for heat setting, continuing drawing and winding the filaments, finally sending the wound flat filaments into a circular weaving machine to weave into woven bag blanks, and obtaining woven bags after edge cutting and sewing;

2) and (3) woven bag surface treatment: paving the woven bags prepared in the step 1) orderly, and then carrying out corona treatment on the upper surface and the lower surface of each woven bag by using a corona machine, wherein the voltage of the corona treatment is 10-20 KV, the power is 500-800W, and the electrode gap is 5-8 mm;

3) preparing a hydrophobic spraying liquid: 60-80 parts by weight of hexamethyldisiloxane is taken, and 14-18 parts of nano SiO is added into the hexamethyldisiloxane₂Fully stirring at the rotating speed of 1200-2000 r/min for 30min, then adding 22-26 parts of hexafluoroisopropanol into hexamethyldisiloxane, and finally carrying out ultrasonic treatment on the mixed solution for 1-2 h to obtain hydrophobic spraying liquid;

4) carrying out hydrophobic treatment on the woven bag: extracting the hydrophobic spraying liquid prepared in the step 3) by using a high-pressure water pump, and uniformly spraying the hydrophobic spraying liquid on the surface of the woven bag treated in the step 2) by using a high-pressure nozzle, wherein the spraying amount is 10-15 g/m²Then, radiating the surface of the woven bag for 20-30 min by using a high-energy electron beam, wherein the energy of the electron beam is 2.0Mev, and the dose is 80-160 kGy;

5) and (3) cleaning and drying woven bags: and (3) putting the woven bag treated in the step 4) into clear water, repeatedly washing for 2-3 times, and drying to obtain the moisture-proof woven bag.

Preferably, in the step 1), 86 parts of raw polypropylene particles, 18 parts of low-density polyethylene particles, 10 parts of polyurethane particles, 4 parts of nano inorganic powder, 5 parts of reinforcing agent, 3 parts of coupling agent and 2 parts of dispersing agent are adopted.

Preferably, the nano inorganic powder in step 1) is one or more of nano bentonite, nano kaolin, modified nano alumina or modified nano zirconia.

Preferably, the temperature in the oven in the step 1) is 95-110 ℃, and the traction speed of the traction roller is 15-20 m/min.

Preferably, the frequency of the ultrasonic treatment in the step 3) is 40-80 kHz.

Preferably, the drying in the step 5) is hot air drying at 40-60 ℃.

Has the advantages that: according to the invention, after polypropylene, low-density polyethylene and polyurethane are used as raw materials and are blended and melted, the polyurethane can be uniformly dispersed in a matrix of the polypropylene and the low-density polyethylene in a dispersion phase, and a continuous grid is formed in the matrix, so that the toughness and the elongation at break of the woven bag are enhanced, and the strength and the wear resistance of the woven bag can be enhanced by adding the nano inorganic powder, the reinforcing agent and the dispersing agent, so that the woven bag has good mechanical properties and is not easy to break when being used for grain packaging.

Then the surface of the woven bag is subjected to corona treatment to generate a large amount of active groups on the surface, and then hexamethyldisiloxane and nano SiO are added₂The hydrophobic spraying liquid prepared from hexafluoroisopropanol is uniformly sprayed on the surface of the woven bag, and active groups on the surface of the woven bag, hexamethyldisiloxane and nano SiO can be subjected to high-energy electron beam radiation treatment₂Crosslinking with hexafluoroisopropanol to form hexamethyldisiloxane/nano SiO with super hydrophobicity₂The surface layer of the hexafluoroisopropanol three-dimensional space, and the combination of the surface layer and the surface of the woven bag has strong stability, so that the woven bag has stronger moisture resistance compared with the existing woven bag. In addition, the components in the surface layer have no toxic or side effect, can be safely used in the field of grain packaging, can prevent the defect that grains are easy to mildew in humid air, and can greatly prolong the storage time of the grains.

Detailed Description

The following further describes the embodiments of the present invention. It should be noted that the description of the embodiments is provided to help understanding of the present invention, but the present invention is not limited thereto. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

The specific types of various additives used in the examples and comparative examples of the present invention are as follows:

reinforcing agent: PP plastic reinforcer DH-1 (supplied by Jiangsu Taicang Dahao plastics Co., Ltd.);

coupling agent: KBM-903 (available from Soumann trade, Inc., Guangzhou);

dispersing agent: dispersant EBS (available from John Dow trade, Inc., of Changshan City).