CN110725062A

CN110725062A - Method for preparing netting by compounding multi-strand antifouling net wire

Info

Publication number: CN110725062A
Application number: CN201910871340.4A
Authority: CN
Inventors: 张海龙; 张挥球; 莫流业
Original assignee: Zhejiang Ocean University ZJOU
Current assignee: Zhejiang Ocean University ZJOU
Priority date: 2019-09-16
Filing date: 2019-09-16
Publication date: 2020-01-24

Abstract

The invention relates to a preparation method of netting, aiming at the problems of heavy task and uneven coating of antifouling paint coated netting, the invention provides a method for preparing netting by compounding a plurality of strands of antifouling netting, which comprises the steps of firstly mixing polyethylene raw materials and an antifouling agent uniformly, adding the mixture into an extruder to plasticize the mixture into a melt, extruding the melt, simultaneously enabling an inner core with high toughness to pass through a head of the extruder to enable the extruded melt to be coated on the outer surface of the inner core, and cooling and drafting to obtain a PE antifouling monofilament netting; and preparing UHMWPE monofilament net yarns by using the ultrahigh molecular weight polyethylene, blending the PE antifouling monofilament net yarns and the UHMWPE monofilament net yarns into a plurality of net yarns, and weaving the net yarns into the netting. The invention retains the advantages of broad-spectrum fouling resistance, high strength and light weight of UHMWPE by blending, also overcomes the problem that the UHMWPE is easy to age and become brittle, and the multi-strand net wires are soft and are not easy to break; compounding the antifouling paint and the polyethylene raw material for preparing the net twine saves later-stage painting work, and the antifouling paint is more uniformly distributed and is less prone to entering water to cause pollution.

Description

Method for preparing netting by compounding multi-strand antifouling net wire

Technical Field

The invention relates to a preparation method of a netting, in particular to a method for preparing the netting by using a composite multi-strand antifouling net wire.

Background

The netting is woven into a net shape by net wires and is used for aquaculture. China is a big aquaculture country and has great demand on netting. For example, the invention of Chinese patent publication No. CN106637494A, entitled fishing net thread, relates to the technical field of fishing net manufacturing, and the fishing net thread consists of the following components in parts by weight: 55-60 parts of nylon, 15-20 parts of polyethylene, 6-10 parts of titanium dioxide, 6-10 parts of graphite, 4-6 parts of acetic acid, 4-4 parts of an anti-aging agent RD2, 15-20 parts of light calcium carbonate, 5-7 parts of quintozene and 10-15 parts of a composite auxiliary agent. The invention solves the problem of aging of the fishing net, provides the fishing net with high strength and good wear resistance, and the fishing net is made by materials and processes, thereby obviously prolonging the service life of the fishing net and saving the cost. However, the fishing net does not take into account the problem of fouling resistance. According to the report, the fishing net is only soaked in seawater for 1-2 weeks, so that some fouling organisms visible to the naked eyes can be attached to the fishing net, and the attachment of the fouling organisms to the net cage of the netting can bring a series of hazards, such as reduction of the net volume, reduction of the net permeability, increase of the net load, blockage of water flow, oxygen and nutrient exchange, disease nourishing, even death of cultured organisms and the like. At present, the aquaculture industry of net cages depends on antifouling paint to prevent fouling of net cages and net wires, the work task of coating the net wires is heavy, the frequently coated coating is not uniform, and meanwhile, the VOC emission exceeding standard caused by a large amount of organic solvents can cause serious pollution to the environment. Therefore, in order to improve the breeding yield, enlarge the breeding scale, and vigorously develop efficient, embracing and eco-friendly breeding fishery, improvement on the preparation of the net is needed.

Disclosure of Invention

The invention provides a method for preparing netting by compounding multistrand antifouling netting wires in order to overcome the problems of heavy task, uneven coating and the like of coating netting wires with antifouling paint. The net cage prepared in this way can avoid extra burden brought by the antifouling coating treatment carried out in the future and extra pollution to the environment caused by the construction of the protective coating.

In order to achieve the purpose, the invention adopts the following technical scheme:

a method for preparing netting by compounding a plurality of strands of antifouling net wires comprises the following steps:

(1) preparing a PE antifouling monofilament net wire: uniformly mixing a polyethylene raw material and an antifouling agent, adding the mixture into an extruder, plasticizing the mixture into a uniform solution, extruding the solution, simultaneously enabling an inner core to pass through a head of the extruder to enable the extruded solution to be coated on the outer surface of the inner core, and then cooling and drawing the mixture to obtain a PE antifouling monofilament net thread;

(2) preparing UHMWPE monofilament net yarns by using ultrahigh molecular weight polyethylene, and blending the PE antifouling monofilament net yarns and the UHMWPE monofilament net yarns into a multi-strand net yarns according to the proportion of (1-3) to 1;

(3) and weaving a plurality of strands of net wires into the netting.

The UHMWPE monofilament netting product has broad-spectrum antifouling technology, can inhibit the growth of fouling organisms, has high strength and light weight, but is easy to age and become brittle. The antifouling paint is directly compounded with the polyethylene raw material for preparing the mesh wire, and is extruded and molded by an extruder. Compared with the later-stage antifouling paint coating on the surface of the net wire, the net wire prepared in the way reduces the later-stage painting workload and has more uniform antifouling paint distribution. In addition, the antifouling paint is compounded with the polyethylene raw material, and is less prone to separating from the net wire and entering water to pollute the water body compared with the antifouling paint only coated on the surface of the net wire. In order to improve the strength of the PE antifouling monofilament line, a high-toughness inner core is arranged in the PE antifouling monofilament line. In conclusion, the PE antifouling monofilament net thread and the UHMWPE monofilament net thread are blended into the multi-strand net thread, the advantages of the PE antifouling net thread and the UHMWPE monofilament net thread are combined, and the strength and the antifouling performance of the net are improved.

Preferably, the polyethylene raw material in the step (1) comprises the following components in parts by weight: 40-60 parts of polyethylene, 3-10 parts of plasticizer and 1-5 parts of glass fiber. The plasticizer is distributed among molecular chains of the polyethylene, so that intermolecular force can be reduced, the viscosity of the polyethylene is reduced, and the flexibility of the polyethylene is enhanced. The aging mechanism of polyethylene mainly comprises thermal-oxidative aging, photo-oxidative aging and stress aging, and in order to cope with the photo-oxidative aging, glass fiber is added into the raw materials. The glass fiber has good ultraviolet aging resistance, slows down the further expansion of the surface cracks of the net twine, ensures that the surface aging cracks of the net twine are shallow, and the glass fiber layer exposed on the surface can slow down the further erosion of the external environment to the net twine, thereby prolonging the service life of the net twine.

Preferably, the antifouling agent consists of the following components in parts by weight: 5-15 parts of pyrithione salt, 3-10 parts of modified nano zinc oxide and 10-20 parts of pure acrylic emulsion. The pyrithione salt has good prevention and control effect on marine organisms, particularly has excellent algae prevention performance, is stable in property, is insoluble in water, can be stored for a long time, and plays a long-acting antifouling function. But the pyrithione salt has no viscosity, is easy to flush when being put into water, not only influences the water quality, but also is easy to lose efficacy, and after the pure acrylic emulsion is added, the antifouling medicine has thixotropy, the viscosity is greatly improved, and the combination with the polyethylene raw material is firmer. Under the irradiation of ultraviolet light, the nano zinc oxide can automatically decompose free moving negatively charged electrons in water and air, and simultaneously leave positively charged holes. The cavity can activate oxygen and hydroxyl, so that water and air adsorbed on the cavity become active oxygen and hydroxyl, which have strong redox effect, and cause damage to cell membrane to kill bacteria. However, the inorganic nano material has extremely large specific surface area and higher specific surface energy due to the own polarity and the fine particle, so that the inorganic nano material is easy to agglomerate, is not easy to disperse in an organic medium, has poor compatibility with a polymer, and directly influences the actual efficacy of the nano zinc oxide. In order to reduce the surface polarity of the nano material, improve the dispersing capacity and affinity of the nano particles in an organic medium, expand the application range of the nano material and carry out surface modification on the nano zinc oxide.

Preferably, the preparation method of the modified nano zinc oxide comprises the following steps: dispersing nano zinc oxide in water, adding sodium dodecyl benzene sulfonate solution, ultrasonic dispersing, stoving and crushing to obtain modified zinc oxide, wherein the amount of sodium dodecyl benzene sulfonate is 10-20 wt% of nano zinc oxide. The sodium dodecyl benzene sulfonate is an anionic surfactant, is ionized in water, and the negatively charged polar end of the sodium dodecyl benzene sulfonate can be mutually attracted and adsorbed with the positive charges of the nano zinc oxide particles by means of coulomb force.

Preferably, the surface of the inner core in the step (1) is coated with an antifouling coating, and the antifouling coating is formed by uniformly dispersing pyrethroid and isothiazolinone as antifouling agents in polyurethane resin. In order to further increase the antifouling performance of the netting, an antifouling coating is also arranged on the inner core of the PE antifouling monofilament net thread. Isothiazolinones are biocidal by breaking bonds between bacterial and algal proteins. After the isothiazolinone contacts with the microorganism, the growth of the isothiazolinone can be quickly and irreversibly inhibited, so that microbial cells are killed, and the isothiazolinone has strong inhibiting and killing effects on common bacteria, fungi, algae and the like. The biocide has the characteristics of high biocidal efficiency, good degradability, no residue, safe operation, good compatibility, strong stability, low use cost and the like. The pyrethroid is a broad-spectrum pesticide which can prevent and control various pests, has the effects of sterilization and bacteriostasis, and has the defect of high toxicity to fish. However, experiments have found that the addition of a small amount of pyrethroid to isothiazolinone increases the killing of the fouling organisms without affecting fish survival. In addition, the pyrethroid is coated on the inner core of the net wire, so that the toxicity to fishes can be further reduced. The PE antifouling monofilament line is provided with double antifouling layers, and the antifouling coating of the inner core can continue to play a role after the outer antifouling agent loses efficacy, so that the antifouling time is prolonged.

Preferably, the inner core in the step (1) includes a rubber elastic thread and a breakage preventing thread, and the breakage preventing thread is tightly wound on the outer side of the rubber elastic thread by turns. The rubber elastic thread enables the inner core to have toughness, and the winding of the fracture line is prevented.

Preferably, the inner core is made of one or more of a high-strength polypropylene fiber material, a high-strength polyamide fiber material and a high-strength polyester fiber material.

Preferably, the net in the step (3) is a knotted net. The basic structure of the netting is a hollow geometric polygon formed by netting twines, the vertexes of the polygon are called nodes, when the netting with the nodes is under the action of external force, the shape of the polygon can be changed, but the distance between the nodes can be kept stable, and the netting stability is good.

Therefore, the invention has the following beneficial effects: (1) according to the invention, the UHMWPE monofilament net thread and the PE antifouling monofilament net thread are blended, and the prepared netting antifouling technology reserves the advantages of inhibition of growth of fouling organisms by UHMWPE, high strength and light weight, and also overcomes the problem that netting prepared by the UHMWPE monofilament net thread alone is easy to age and become brittle, and the multi-strand net thread is softer and not easy to break compared with the monofilament net thread; (2) the antifouling paint is directly compounded with the polyethylene raw material for preparing the mesh wire, and is extruded and molded by an extruder. Compared with the method that the antifouling paint is coated on the surface of the net wire in the later period, the net wire prepared in the method reduces the workload of later-period coating, and the antifouling paint is more uniformly distributed; (3) the inner core of the PE antifouling monofilament net wire is also provided with an antifouling coating, and the antifouling coating of the inner core can continuously play a role after the outer antifouling agent loses efficacy, so that the antifouling time is prolonged; (4) in order to improve the strength of the PE antifouling monofilament line, a high-toughness inner core is arranged in the PE antifouling monofilament line.

Detailed Description

The technical solution of the present invention is further illustrated by the following specific examples.

In the present invention, unless otherwise specified, all the raw materials and equipment used are commercially available or commonly used in the art, and the methods in the examples are conventional in the art unless otherwise specified.

The preparation method of the modified nano zinc oxide comprises the following steps: adding water into the nano zinc oxide to ensure that the concentration of the zinc oxide is 50 g/L, dispersing, pulping, uniformly stirring, placing in an ultrasonic dispersion instrument for ultrasonic dispersion, adjusting the pH to 6 by using HCl, adding 0.04 mol/L sodium dodecyl benzene sulfonate (analytically pure) solution, wherein the mass of the sodium dodecyl benzene sulfonate is 10 percent of the mass of the nano zinc oxide, performing ultrasonic dispersion for 1 hour at 40 ℃, filtering, washing, drying and grinding to obtain the modified nano zinc oxide.

Example 1

(1) Preparing an inner core: winding the anti-breaking thread made of high-strength polypropylene fiber material on the outer side of the rubber elastic thread tightly circle by circle, mixing pyrethroid and isothiazolinone according to the mass ratio of 1:3, uniformly dispersing the mixture in polyurethane resin as an anti-fouling agent to form a film, coating the film on the outer side of the anti-breaking thread, and drying the film to form an anti-fouling coating;

(2) preparing a PE antifouling monofilament net wire: uniformly mixing a polyethylene raw material consisting of 50 parts by weight of polyethylene, 5 parts by weight of dibutyl phthalate plasticizer and 3 parts by weight of glass fiber with an antifouling agent consisting of 10 parts by weight of copper pyrithione, 3 parts by weight of modified nano zinc oxide and 20 parts by weight of pure acrylic emulsion, adding the mixture into an extruder, plasticizing the mixture into a uniform solution, extruding the uniform solution, passing an inner core through a head of the extruder to coat the extruded solution on the outer surface of the inner core, and cooling and drawing the mixture to obtain a PE antifouling monofilament net wire;

(3) preparing UHMWPE monofilament net yarns by using ultrahigh molecular weight polyethylene, blending the PE antifouling monofilament net yarns and the UHMWPE monofilament net yarns into 40 strands of multi-strand net yarns according to the proportion of 3:1, wherein the diameter of the multi-strand net yarns is 3 mm, and weaving the multi-strand net yarns into the knotted netting.

Example 2

(1) Preparing an inner core: winding the anti-breaking line made of the high-strength polyamide fiber material on the outer side of the rubber elastic line tightly circle by circle, uniformly dispersing isothiazolinone serving as an anti-fouling agent in polyurethane resin to form a film, coating the film on the outer side of the anti-breaking line, and drying the film to form an anti-fouling coating;

(2) preparing a PE antifouling monofilament net wire: uniformly mixing a polyethylene raw material consisting of 40 parts by weight of polyethylene, 3 parts by weight of chlorinated paraffin plasticizer and 5 parts by weight of glass fiber with an antifouling agent consisting of 15 parts by weight of magnesium pyrithione, 10 parts by weight of modified nano zinc oxide and 15 parts by weight of pure acrylic emulsion, adding the mixture into an extruder, plasticizing the mixture into a uniform solution, extruding the uniform solution, passing an inner core through a head of the extruder to coat the outer surface of the inner core with the extruded solution, and cooling and drawing the mixture to obtain a PE antifouling monofilament net wire;

(3) preparing UHMWPE monofilament net yarns by using ultrahigh molecular weight polyethylene, blending the PE antifouling monofilament net yarns and the UHMWPE monofilament net yarns into 40 strands of multi-strand net yarns according to the proportion of 1:1, wherein the diameter of the multi-strand net yarns is 3 mm, and weaving the multi-strand net yarns into the knotless netting.

Example 3

(1) Preparing an inner core: winding the anti-breaking thread made of high-strength polyester fiber material on the outer side of the rubber elastic thread tightly circle by circle, mixing pyrethroid and isothiazolinone according to the mass ratio of 1:4, uniformly dispersing the mixture in polyurethane resin as an anti-fouling agent to form a film, coating the film on the outer side of the anti-breaking thread, and drying the film to form the anti-fouling coating.

(2) Preparing a PE antifouling monofilament net wire: uniformly mixing a polyethylene raw material consisting of 60 parts by weight of polyethylene, 10 parts by weight of tricresyl phosphate plasticizer and 1 part by weight of glass fiber with an antifouling agent consisting of 5 parts by weight of zinc pyrithione, 5 parts by weight of modified nano zinc oxide and 10 parts by weight of pure acrylic emulsion, adding the mixture into an extruder, plasticizing the mixture into a uniform solution, extruding the uniform solution, passing an inner core through the head of the extruder to coat the extruded solution on the outer surface of the inner core, and cooling and drawing the solution to obtain a PE antifouling monofilament network wire;

(3) preparing UHMWPE monofilament net yarns by using ultrahigh molecular weight polyethylene, blending the PE antifouling monofilament net yarns and the UHMWPE monofilament net yarns into 30 strands of multi-strand net yarns according to the proportion of 2:1, wherein the diameter of the multi-strand net yarns is 2 mm, and weaving the multi-strand net yarns into the knotted netting.

Example 4

(1) Preparing an inner core: mixing pyrethroid and isothiazolinone according to the mass ratio of 1:3, uniformly dispersing the mixture serving as an antifouling agent in polyurethane resin to form a film, coating the film on the outer side of a rubber elastic thread, and drying the film to form an antifouling coating;

(2) preparing a PE antifouling monofilament net wire: uniformly mixing a polyethylene raw material consisting of 50 parts by weight of polyethylene, 5 parts by weight of dibutyl phthalate plasticizer and 3 parts by weight of glass fiber with an antifouling agent consisting of 10 parts by weight of copper pyrithione, 5 parts by weight of bromopyridine nitrile, 3 parts by weight of dithiocyano-methane and 20 parts by weight of pure acrylic emulsion, adding the mixture into an extruder, plasticizing the mixture into a uniform solution, extruding the uniform solution, passing an inner core through a head of the extruder to coat the outer surface of the inner core with the extruded solution, and cooling and drawing the mixture to obtain a PE antifouling monofilament net wire;

Example 5

(1) Preparing an inner core: taking a rubber elastic thread as an inner core;

Example 6

(1) Preparing an inner core: winding the anti-breaking thread made of high-strength polypropylene fiber material on the outer side of the rubber elastic thread tightly circle by circle, mixing pyrethroid and isothiazolinone according to the mass ratio of 1:3, uniformly dispersing the mixture in emulsified asphalt as an anti-fouling agent to form a film, coating the film on the outer side of the anti-breaking thread, and drying the film to form an anti-fouling coating;

(2) preparing a PE antifouling monofilament net wire: uniformly mixing a polyethylene raw material consisting of 50 parts by weight of polyethylene, 5 parts by weight of dibutyl phthalate plasticizer, 3 parts by weight of glass fiber, 1 part by weight of antioxidant 1010 and 0.5 part by weight of vaseline with an antifouling agent consisting of 10 parts by weight of copper pyrithione, 3 parts by weight of modified nano zinc oxide and 20 parts by weight of chlorine partial emulsion, adding the mixture into an extruder, plasticizing the mixture into a uniform solution, extruding the uniform solution, passing an inner core through the head of the extruder to coat the outer surface of the inner core with the extruded solution, and cooling and drawing the solution to obtain a PE antifouling monofilament net wire;

Comparative example 1

(1) Preparing an inner core: winding the breakage-proof thread made of high-strength polypropylene fiber material on the outer side of the rubber elastic thread tightly circle by circle;

(2) preparing a PE antifouling monofilament net wire: uniformly mixing polyethylene raw materials consisting of 50 parts by weight of polyethylene, 5 parts by weight of dibutyl phthalate plasticizer and 3 parts by weight of glass fiber, adding the mixture into an extruder to be plasticized into uniform solution, extruding the solution, passing an inner core through a head of the extruder to coat the outer surface of the inner core with the extruded solution, and then cooling and drawing to obtain a PE antifouling monofilament net thread;

And (3) antifouling performance test: carrying out a net hanging experiment according to the national standard GB/T5370-2007, wherein the soaking depth of the fishing net is as follows: 1.5m, soaking time is 30 days, and the biological attachment rate on the surface is detected. The specific detection conditions of the antifouling fishing net are as follows:

as can be seen from the above table, the examples have significant antifouling performance compared to the comparative examples, and example 5 has a slightly higher rate of bioadhesion than the other examples because the antifouling coating is not applied on the inner core.

Although the present invention has been described with reference to a preferred embodiment, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. A method for preparing netting by compounding a plurality of strands of antifouling net wires is characterized by comprising the following steps: (1) preparing a PE antifouling monofilament net wire: uniformly mixing a polyethylene raw material and an antifouling agent, adding the mixture into an extruder, plasticizing the mixture into a uniform solution, extruding the solution, simultaneously enabling an inner core to pass through a head of the extruder to enable the extruded solution to be coated on the outer surface of the inner core, and then cooling and drawing the mixture to obtain a PE antifouling monofilament net thread;

(3) and weaving a plurality of strands of net wires into the netting.

2. The method for preparing netting according to claim 1, wherein the polyethylene raw material in the step (1) comprises the following components in parts by weight: 40-60 parts of polyethylene, 3-10 parts of plasticizer and 1-5 parts of glass fiber.

3. The method for preparing netting according to claim 1, wherein the antifouling agent is composed of the following components in parts by weight: 5-15 parts of pyrithione salt, 3-10 parts of modified nano zinc oxide and 10-20 parts of pure acrylic emulsion.

4. The method for preparing the netting according to claim 3, wherein the method for preparing the modified nano zinc oxide comprises the following steps: dispersing nano zinc oxide in water, adding sodium dodecyl benzene sulfonate solution, ultrasonic dispersing, stoving and crushing to obtain modified zinc oxide, wherein the amount of sodium dodecyl benzene sulfonate is 10-20 wt% of nano zinc oxide.

5. The method for preparing the netting according to claim 1, wherein the surface of the inner core in the step (1) is coated with an antifouling coating, and the antifouling coating is formed by uniformly dispersing pyrethroid and isothiazolinone as antifouling agents in polyurethane resin.

6. The method for preparing netting according to claim 1, wherein the inner core in step (1) comprises a rubber elastic thread and a breakage preventing thread, and the breakage preventing thread is tightly wound on the outer side of the rubber elastic thread from turn to turn.

7. The method for preparing a netting according to claim 6, wherein the inner core is made of one of a high-strength polypropylene fiber material, a high-strength polyamide fiber material and a high-strength polyester fiber material.

8. The method for preparing a netting according to claim 1, 2 or 3, wherein the netting of step (3) is a knotted type netting.