CN108513844B

CN108513844B - Production and use method of one-way water seepage self-crushing mulching film

Info

Publication number: CN108513844B
Application number: CN201810160905.3A
Authority: CN
Inventors: 赵红阳; 赵怀玉; 赵秀刚; 赵玉亭
Original assignee: Puyang Sijiqing Plastic Products Co ltd
Current assignee: Puyang Sijiqing Plastic Products Co ltd
Priority date: 2018-02-27
Filing date: 2018-02-27
Publication date: 2020-05-19
Anticipated expiration: 2038-02-27
Also published as: CN108513844A

Abstract

A method for producing and using a one-way water seepage self-crushing mulching film is a mulching film production technology and overcomes the defects of other technologies, the invention adds 0.8-5% of dodecyl alcohol ester and 0.03-0.05% of α -cyclodextrin in a polyethylene mulching film formula, namely 100% of low-density linear polyethylene, and adds the dodecyl alcohol ester and the α -cyclodextrin in mass fractions into a screw extruder in proportion through a quantitative conveyor, the dodecyl alcohol ester and the α -cyclodextrin are blown out from the middle of a die opening through upward traction without adding water, the temperature of the die opening is controlled to be 250-260 ℃, a ring-mounted cavity structure of the α -cyclodextrin has wind power orientation after a die head is blown out, a large opening is inward, a small opening is outward, the small opening is 4.0-4.7A degrees, the large opening is 5.3-6.0A degrees, the boiling point of the dodecyl alcohol ester is 250 ℃, the dodecyl alcohol ester starts to boil when the temperature is higher than 250 ℃, less than or less than 10% passes through a cavity formed by expanded cyclodextrin in a steam form, a film matrix is punched, and before rolling.

Description

Production and use method of one-way water seepage self-crushing mulching film

Technical Field

The invention relates to a mulching film production technology, in particular to a production and use method of a one-way water seepage self-crushing mulching film.

Background

The current mulching film is widely applied to farmland planting, but most of the mulching films are common polyethylene mulching films.

1. Some have an anti-aging effect such as: the drought-farming anti-aging long-acting autumn mulching film and the preparation process-201110333915.0 provide a drought-farming anti-aging long-acting autumn mulching film which meets the requirements of rain collection and soil moisture preservation in agricultural production in arid and semi-arid regions and autumn, rain and spring use. The anti-aging agent is added on the basis of the common mulching film, and no fundamental change is caused.

2. Some mulching films have water permeability, simple punching process is used, the effect is poor, and complicated water permeability addition agent is added, for example, CN 98119892-application discloses a water permeability polyethylene farmland covering film and a production process thereof, wherein a water permeability addition agent with the weight ratio of 0.1-0.4% is added into a formula of a low-density polyethylene mulching film, after a blank film is blown on a blow molding machine, a smooth surface roller is used for respectively extruding the cut blank film into permeability water permeability mulching films with micron-sized small holes with the hole diameter of 1-15 mu m and the hole density of 10-100 ten thousand/m 2 before rolling. The water permeating assistant is crystal inorganic or organic particle with grain size 2-10 times that of mulching film and melting point not lower than the three-region work temperature of the blow molding machine, such as Na 2O-nSiO 2. H2O, (NH 4) H2 PO 4, NaCl, oligose, etc. The water-permeable microporous mulch film can make rainwater infiltrate by more than 12 mm/(cm 2.5 cm.23 deg.C.h.101.3 kPa), and can inhibit water evaporation, micro-ventilation and temperature regulation under the mulch film, and can increase crop yield compared with common mulch film. However, the holes of the mulching film have basically equal inside and outside diameters, and have no selectivity for permeation of moisture and gas, so that the effects of infiltration and collection when meeting water and evaporation inhibition of moisture under the mulching film are not obvious.

The existing degradable polyethylene mulching film mainly comprises the following components: biodegradation, photodegradation or biodegradation with added light, wherein the degradation of the mulching film is promoted by adding a degradation agent, but the degradation has some problems, such as CN 201410065584-a preparation method of the biodegradation mulching film, abstract: the preparation method of the biodegradable mulching film is characterized by comprising the following steps: firstly, preparing materials according to the weight proportion, and taking: polyethylene: 55-60 parts; cassava starch: 17-20 parts of a solvent; corn starch: 18-22 parts; multi-element biological improving and reducing agent: 5-10 parts; the polyethylene comprises the following components in percentage by weight: 7050: 68-90 parts, 1F 7B: 10-32 parts; the multi-element biological improver comprises the following components in percentage by weight: a crosslinking agent: 40-80 parts; degradation accelerator: 20-40 parts of a solvent; the cross-linking agent is one or any combination of two of di-tert-butylperoxyisopropyl benzene, sodium hexametaphosphate, sodium trimetaphosphate and sodium tripolyphosphate; the degradation promoter comprises one or any combination of two of corn oil, sunflower seed oil, epoxidized soybean oil or manganese stearate; secondly, the production steps are as follows: a. mixing the degradable master batches; b. granulating the degraded master batch; c. blowing to prepare a film; d. perforating the biodegradable mulching film; e. and winding, packaging and warehousing the biodegradable mulching film. The mulching film has the defects that part of microorganisms buried in soil grow and multiply fast, the mulching film decomposes fast, and the part exposed in the air decomposes slower. A light degradation mulch film, such as CN 201510977620-a light degradation polyvinyl chloride mulch film manufacturing method and product, discloses a light degradation polyvinyl chloride mulch film manufacturing method, including the following steps: preparing graphite oxide: preparing graphite oxide by taking graphite powder as a raw material; preparing graphene: putting a certain amount of graphite oxide into deionized water, carrying out ultrasonic treatment for 1-3 hours, and heating the obtained solution in a water bath, wherein the temperature of the water bath is controlled at 75-85 ℃; adding 3-10 g of sodium borohydride for reduction, and easily washing, filtering and drying the final mixture to obtain graphene powder; preparing a composite membrane: putting graphite oxide or graphene into water, carrying out ultrasonic treatment for 1-3 hours, adding polyvinyl chloride and dichloroethane, strongly stirring for 5-8 hours to obtain a mixed solution, flatly paving the mixed solution on a smooth panel, and drying and forming to obtain a graphite oxide polyvinyl chloride composite film or a graphene polyvinyl chloride composite film; the effect is as follows: can effectively improve the photodegradation of the polyvinyl chloride mulching film and reduce white pollution. The mulching film is opposite to a biodegradable mulching film, and the decomposition is faster in a place exposed to light and slower in soil. In addition, there are methods of mixing biodegradation and photodegradation, but none of them can solve the problem of simultaneous degradation.

Disclosure of Invention

the invention aims to provide a production and use method of a one-way water seepage self-crushing mulching film, which can change the addition amount according to different environmental temperatures and different degradation periods of a mulching film, volatilize along with the migration of the mulching film and break the branch of the mulching film, and overcomes the defects of other technologies, the production and use method is realized by adding 0.8-5% of dodecyl alcohol ester and 0.03-0.05% of α -cyclodextrin into a polyethylene mulching film formula, namely 100% of low-density linear polyethylene, adding a quantitative conveyor into a screw extruder according to a certain proportion, ventilating and blowing out from the middle part of a die opening by upward traction, controlling the die opening temperature to be 260 ℃ without adding water, and controlling a ring-mounted cavity structure of the α -cyclodextrin to have a cavity structure with wind power orientation after a blow molding die head, wherein a cavity is oriented inwards, a cavity is outwards, a small opening is 4.0-4.7A DEG, a large opening is 5.3-6.0A, a boiling point of the dodecyl alcohol ester is 250 ℃, a branch of the dodecyl alcohol ester begins to boil and expands along with the steam when the boiling point of the film exceeds 250 ℃, and the addition amount of the film begins to be changed along with the boiling point of the branch of the boiling film, and the branch is changed and the addition amount of the film, and the film is changed along with the change of the boiling point of the boiling side of the boiling point of the film, and the addition amount of the film, and.

Experiments prove that the water seepage comparison experiment of two bags is carried out when the first type of bag is inward in front and the second type of bag is outward in front, the water of the bag inward in front of the first type is quickly permeated outwards, and the water of the bag outward in front of the second type is slowly permeated outwards; at the room temperature of 10-30 ℃, the relative humidity of 30-50%, the bag 10cm-30cm x 10-30cm and the water amount of 50-150ml, after 30-90 minutes, the first type is remained 4-30%, the permeation loss is 70-96%, the second type is remained 80-99%, and the permeation loss is 20-1%, so that when the mulching film is covered, the front surface of the mulching film of the first type is upward.

The water seepage comparison experiments of the two bags are carried out, wherein the bag with the inward front surface of the first type penetrates water outwards fast, and the bag with the outward front surface of the second type penetrates water outwards slowly; at the room temperature of 20 ℃, the relative humidity of 40%, the bag is 20cm x 20cm, the water amount is 100ml, after one hour, 17% of the first type is remained, the permeation is lost by 83%, 91% of the second type is remained, and the permeation is lost by 9%, so when the mulching film is covered, the front surface of the mulching film of the first type is upward.

According to the use method, when the mulching film is covered, the front face is upward, the large opening is outward, the small opening is inward, and part of the dodecanol ester remained in the film matrix is degraded for 30 to 120 days according to the environment temperature of-15 to 30 ℃ of the covering film, and the film is migrated and volatilized, so that the branch of the mulching film is broken; with the help of the existing holes, the film is changed into fragments about 2mm, which can be well dispersed in the soil and can not hinder the growth of the root system of the fabric due to the large blocks; water and air easily enter the back side from the front side and are not easy to come out from the back side, so that the supply of water and air to crops is ensured.

The significance of the invention is as follows: the invention utilizes the dodecyl alcohol ester partially remained in the film matrix when the mulching film is covered, and the film is changed into small fragments with the help of the existing holes, can be well dispersed in the soil, and cannot hinder the growth of the root system of the fabric due to large blocks; the white pollution is greatly reduced; the dodecyl alcohol ester and the cyclodextrin have synergistic effect in the polyethylene resin, and the one deficiency is as follows: during film blowing, the plasticizing effect of the dodecyl alcohol ester helps the cyclodextrin to form funnel micropores, and in a damaged and decomposed stage, the funnel micropores formed by the cyclodextrin help the volatilization and release of the dodecyl alcohol ester, so that more micropores are formed in the thin mulching film, and at the moment, the dodecyl alcohol ester is not just the effect of the plasticizer, and the dodecyl alcohol ester and the plasticizer jointly enable the mulching film to be separated and broken.

Drawings

Fig. 1 is a schematic view of the internal structure of a one-way water seepage self-pulverization mulching film.

Detailed Description

the preparation method comprises the steps of adding 0.8-5% of dodecyl alcohol ester and 0.03-0.05% of α -cyclodextrin in mass fraction ratio into 100% of low-density linear polyethylene film, adding the dodecyl alcohol ester and the α -cyclodextrin in mass fraction ratio into a screw extruder in proportion through a quantitative conveyor, ventilating and blowing out from the middle of a die orifice through upward traction, controlling the temperature of the die orifice to be 250-260 ℃, and enabling a ring-mounted cavity structure of the α -cyclodextrin to have wind power orientation after the α -cyclodextrin is blown out of the die head, wherein the cavity structure comprises a large opening, a small opening, a large opening, a small opening, a winding, boiling the twelve alcohol ester when the boiling point is 250 ℃, the boiling of the dodecyl alcohol ester is started to boil when the boiling point is higher than 250 ℃, and less than 10% of the twelve alcohol ester passes through a cavity formed by the expanded cyclodextrin, the inner side of the film barrel is marked as a front side, the winding.

Example 2, a comparison experiment was conducted for water permeation in two bags, a first type facing inwards and a second type facing outwards, the first type facing inwards and the second type facing outwards, the bags having fast water permeation and the second type facing outwards and the bags having slow water permeation; at the room temperature of 10-30 ℃, the relative humidity of 30-50%, the bag 10cm-30cm x 10-30cm and the water amount of 50-150ml, after 30-90 minutes, the first type is remained 4-30%, the permeation loss is 70-96%, the second type is remained 80-99%, and the permeation loss is 20-1%, so that when the mulching film is covered, the front surface of the mulching film of the first type is upward.

Example 3, a comparison experiment was conducted for water permeation in two bags, the first type being inside facing and the second type being outside facing, the first type being inside facing and the bag water permeation outside the bag being fast and the second type being outside facing and the bag water permeation outside the bag being slow; at the room temperature of 20 ℃, the relative humidity of 40%, the bag is 20cm x 20cm, the water amount is 100ml, after one hour, 17% of the first type is remained, the permeation is lost by 83%, 91% of the second type is remained, and the permeation is lost by 9%, so when the mulching film is covered, the front surface of the mulching film of the first type is upward.

Example 4, the application method of the present invention, when covering the mulching film, the front side is upward, the large opening is outward, the small opening is inward, and part of the dodecanol ester remained in the film matrix is degraded for 30 days to 120 days according to the environmental temperature of-15 ℃ to 30 ℃ of the covering mulching film, and the branch of the mulching film is broken along with the migration and volatilization of the dodecanol ester; with the help of the existing holes, the film is changed into fragments about 2mm, which can be well dispersed in the soil and can not hinder the growth of the root system of the fabric due to the large blocks; water and air easily enter the back side from the front side and are not easy to come out from the back side, so that the supply of water and air to crops is ensured.

Claims

1. A production method of a one-way water seepage self-crushing mulching film is characterized in that 0.8-5% of dodecyl alcohol ester and 0.03-0.05% of α -cyclodextrin in mass percentage are added into low-density linear polyethylene, the dodecyl alcohol ester and the α -cyclodextrin are proportionally added into a screw extruder through a quantitative conveyor, the materials are blown out from the middle of a die opening in a ventilation mode through upward traction, the temperature of the die opening is controlled to be 250-260 ℃, a circular cavity structure of the α -cyclodextrin is provided with a wind power orientation after the α -cyclodextrin is blown out of the die head, a large opening is arranged inwards, a small opening is arranged outwards, a small opening is arranged at 4.0-4.7A degrees, a large opening is arranged at 5.3-6.0A degrees, the boiling point of the dodecyl alcohol ester is 250 ℃, the dodecyl alcohol starts to boil when the boiling point is higher than 250 ℃, less than or less than 10% of the dodecyl alcohol is formed through the expanded cyclodextrin in a steam mode, a film matrix is punched out, the inner side of a film cylinder is cut before rolling, the film is rolled, the film is boiled when the dodecyl alcohol ester is boiled alcohol ester is higher than 250 ℃, the twelve alcohol ester, the cavity ester is retained in the film, the.

2. An experimental method for the unidirectional water seepage self-crushing mulching film produced by the production method according to claim 1, which is characterized in that: the water seepage comparison experiments of the two bags are carried out, wherein the bag with the inward front surface of the first type penetrates water outwards fast, and the bag with the outward front surface of the second type penetrates water outwards slowly; at the room temperature of 10-30 ℃, the relative humidity of 30-50%, the bag 10cm-30cm x 10-30cm and the water amount of 50-150ml, after 30-90 minutes, the first type is remained 4-30%, the permeation loss is 70-96%, the second type is remained 80-99%, and the permeation loss is 20-1%, so that when the mulching film is covered, the front surface of the mulching film of the first type is upward.

3. An experimental method of the unidirectional water seepage self-pulverization mulching film as claimed in claim 2, characterized in that: the front of the first type faces inwards, the front of the second type faces outwards, two bag seepage comparison experiments are carried out, at the room temperature of 20 ℃, the relative humidity of 40%, the bag size of 20cm x 20cm and the water volume of 100ml, after one hour, 17% of the first type is remained, seepage is lost by 83%, 91% of the second type is remained, seepage is lost by 9%, so when the mulching film is covered, the front of the mulching film is upwards.

4. The use method of the unidirectional water seepage self-crushing mulching film produced by the production method according to claim 1 is characterized by comprising the following steps: when the mulching film is covered, the front face is upward, and because the large opening is outward and the small opening is inward, part of the dodecanol ester remained in the film matrix is degraded for 30 to 120 days according to the environmental temperature of-15 to 30 ℃, and the branch of the mulching film is broken along with the migration and volatilization of the dodecanol ester; with the help of the existing holes, the film is changed into fragments about 2mm, which can be well dispersed in the soil and can not hinder the growth of the root system of the fabric due to the large blocks; water and air easily enter the back side from the front side and are not easy to come out from the back side, so that the supply of water and air to crops is ensured.