Production method of low-cost anti-fogging and anti-droplet black sunscreen preservative film

Abstract

The application discloses a production method of a low-cost anti-fogging black sunscreen preservative film, belongs to the technical field of anti-fogging film materials, and utilizes kerosene or heavy oil to generate carbon black with heat through cracking under heating and oxygen deficiency; carbon black particles are attached to the surface of the film; the carbon black particles are cooled and fixed due to the arrangement of a cold air blower above the film; the surface is difficult to be wetted, the anti-fogging effect is realized, the previous smoke generator is a smoke generator generated by the evaporation of mineral oil; the previous smoke bomb is special for fire drill; whether a sealed container such as a boiler leaks and whether air circulates are detected; propylene glycol, white oil and the like are utilized to generate air mist by the smoke generator; the carbon black has certain adsorption; oily substances are adsorbed; the anti-fogging performance of the surface of the film is further enhanced; the operation method is simple; the air mist and the smoke are conveniently recycled; the production cost is low; the black color can be realized without additional black color master batches; the black color is realized at one time; the method can be used for the packaging of vegetables, fruits, flowers, sun exposure, picking and transportation.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of anti-fog film materials, and particularly relates to a production method of a low-cost anti-fog and anti-droplet black sunscreen preservative film. BACKGROUND

[0002] Fruit and vegetable preservation is a practical technology based on the physiological activities of fruits and vegetables to regulate the picked fruits and vegetables. Preservation is to provide a suitable storage environment for fruits and vegetables, moderately maintain the life activities of fruits and vegetables, delay the aging process, and keep the freshness, fragrance and appearance of fruits and vegetables, so as to achieve the purpose of not being out of season and not being rotten in the peak season. Because fruits, vegetables and flowers are tender, they are easily affected by sunlight during transportation and are prone to self-degradation and rot, which brings great economic losses to producers and operators. At present, in order to avoid losses, black sunshade nets are mainly used to cover fruits, vegetables and flowers to block sunlight and achieve the purpose of sun protection. However, the preservation effect cannot be achieved, and the preservation effect is poor. At present, the main methods of fruit and vegetable preservation are low-temperature cold storage and preservative film packaging. Cold storage is difficult to achieve in the outdoor picking environment and has not been popularized, while the preservative film packaging method has the advantages of low cost, simple operation, wide adaptability and obvious effect, and has been widely selected. However, although the transparent preservative film can achieve a certain preservation effect, it cannot prevent sunburn. In addition to the functions of keeping warm and keeping moist, the black preservative film has low light transmittance and less radiation heat transmission. In summer, it can better reduce the temperature of picked fruits, vegetables and flowers. CN200820027846.4 discloses a polyester film for light-proof and preservative food packaging, and CN201610611735.7 discloses a fruit and vegetable preservative film and a preparation method thereof, which discloses the use of anti-fog droplet master batches, but the anti-fog droplet agent has the problem of precipitation, the color master batch is prone to uneven dispersion, the cost is high, and the anti-fog effect is poor. In addition, black preservative film is also widely used in chemical synthesis experiments. Those skilled in the art urgently need to develop a low-cost anti-fog and anti-droplet black sunscreen preservative film production method to meet the existing application market and performance requirements. SUMMARY

[0003] Therefore, the application provides a production method of a low-cost anti-fog and anti-droplet black sunscreen preservative film.

[0004] A low-cost anti-fogging black sunscreen preservative film production method, including the steps of conventional extrusion casting film, which refers to the material is melted and plasticized by the extruder, extruded through the slit die, and then cast on the cooling roll, and then stretched after cooling and setting. Specifically, the extruder extrusion→T-shaped die casting→air knife→1# cooling roll→2# cooling roll. The screw diameter of the extruder is 65mm, L / D=32, and the common tapered screw. The barrel temperature is 180~190℃, 190~200℃, 200~210℃, 210~220℃, 220~230℃, and the head temperature is right one 220~225℃, right two 215~220℃, middle 210~215℃, left one 215~220℃, and left two 220~225℃. The 1# cooling roll is 25~30℃, and the 2# cooling roll is 20~40℃. The method further includes the following steps: (1) smoking and attaching treatment: kerosene lamp or combustion furnace filled with mineral oil, the film is pulled through the ignited kerosene lamp or combustion furnace and smoked above the kerosene lamp or combustion furnace, the carbon smoke particles are generated by incomplete combustion of mineral oil in the kerosene lamp or combustion furnace, and the carbon smoke particles are uniformly distributed on the surface of the film, and the remaining smoke is collected by the recovery air pipe. The kerosene lamp or combustion furnace and the film above are provided with a cold air machine to keep the temperature of the film at 25~30℃.

[0005] Further, when small-batch production is preferred, a kerosene lamp is used for lighting, reducing lighting electricity consumption, and when mass production is used, a combustion furnace can be used, and the heat generated by combustion is used for heating the extruder system.

[0006] The smoke generator is usually generated by evaporation of mineral oil. The smoke generator is a smoke bomb used for fire drill in the past, and can also be used to create stage smoke effect, detect whether the sealed container such as boiler leaks and whether the air is circulated. There is no application in the field of plastic film treatment technology.

[0007] (2) Gas fog evaporation treatment: use a smoke generator, the escaping gas fog is collected by the recovery air pipe, condensed and then used twice, and the surface of the pulled film after the smoking and attaching treatment is treated with a semi-closed sealed treatment liquid according to the gas fog generation process, and then rolled and packaged.

[0008] Further, the treatment liquid in step (2) is polyoxyethylene sorbitan monooleate, propylene glycol, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monolaurate, and white oil, and the weight ratio is 5~7∶13~17∶4~7∶3~5.

[0009] Heavy oil - from natural oil or artificial oil after gasoline, kerosene and diesel liquid residue. Dark black viscous heavy oil, mainly as boiler fuel. Kerosene entered the Chinese market in the early 1900s, and the main use is to light up the lamp, in the period without electric light, whether in rural or urban, every household is necessary, later there is electricity, the poor family does not light up the electric light, still light the kerosene lamp. The kerosene lamp has also forever left us and sank in the long river of history, faded out of the daily life of most people.

[0010] At present, kerosene lamp as a lighting tool, has been eliminated by history, even in the remote mountain village, no one uses it, the wick emits black smoke, often blacken the lampshade. The present application utilizes the inherent defects of kerosene or heavy oil to convert into black sunscreen film anti-fogging effect.

[0011] Further, the diameter of the carbon soot particles in step (1) is 0.5-1 μm.

[0012] Further, the aerosol generating process of step (2) is a spraying distance of 30-60 cm, a temperature of 25°C-60°C, a humidity of 5%-95% RH, and a processing liquid consumption speed of 5-10 mL / min.

[0013] Further, the mineral oil in the kerosene lamp or combustion furnace in step (1) is one or more of kerosene or heavy oil. Preferably, it is No. 2 ordinary kerosene.

[0014] Further, the film pulling speed is 15-25 m / min.

[0015] It only needs one oxygen atom to burn one hydrogen molecule, and only four oxygen atoms to burn one methane molecule, while complete combustion of kerosene, heavy oil and other combustion requires sufficient oxygen to burn. When the air supply is insufficient or the mixing effect is not enough, it will crack due to heat and lack of oxygen, generating carbon black. Carbon black is a solid particle with a diameter less than 1 micron, which is not strong in combination and burns slowly, so once carbon black is generated, it is often difficult to burn, and in severe cases, the smoke will be black due to the presence of carbon black particles, and the chimney will emit black smoke. Therefore, heavy oil and heavy oil and other heavy hydrocarbons crack at high temperature and lack of oxygen during combustion, forming carbon black particles attached to the surface of the film.

[0016] The beneficial effects of the present application are:

[0017] The low-cost anti-fogging black sunscreen preservative film produced by the production method disclosed by the application is laid on the picked thin fruit and fresh flowers, and can play a role in cooling, preservation and sun protection. The kerosene or heavy oil is cracked by heating and oxygen deficiency to generate carbon black with heat, and the carbon black particles are attached to the surface of the film. Since a cold air blower is arranged above the film, the carbon black particles are cooled and fixed, and the surface is difficult to be wetted, so that the anti-fogging effect is realized. The smoke generator is usually used to generate smoke by evaporation of mineral oil. The smoke generator is usually used for smoke bomb for fire drill, and can also be used to produce stage smoke effect, detect whether the sealed container such as boiler leaks or not and whether the air is circulated or not. There is no application in the field of plastic film processing technology. The application utilizes propylene glycol, white oil and other smoke generators to generate aerosol, and the carbon black has a certain adsorption property to adsorb oily substances, and further enhances the anti-fogging performance of the surface of the film. The operation method is simple, the aerosol and smoke are convenient to recycle, the production cost is low, and the black color can be realized without additional black color masterbatch, that is, one stone kills two birds.

[0018] Compared with the prior art, the application has the following advantages:

[0019] The processing and application of the previous black sunscreen preservative film need to use black masterbatch and anti-fogging masterbatch, which are mixed into plastic particles. The previous anti-fogging agent has the problem of precipitation. The application does not use black color masterbatch and anti-fogging masterbatch, reduces the cost of color masterbatch, and performs surface treatment by successively smoking and roasting and aerosol evaporation on one side of the film. The anti-fogging surface is obtained, and the composition of the film does not change and the physical and mechanical properties are not affected. The film can be used for sun protection, picking and preservation of vegetables, fruits and flowers. The vegetables and fruits sealed in the preservative film will release water vapor due to respiration, but the water vapor will not gather on the inner wall of the film to form water mist. Since the black sunscreen preservative film of the application has anti-fogging performance, the air humidity in the film is balanced, the probability of corruption is reduced, and the vegetables, fruits and flowers are not easy to rot and be inactivated by sunlight. The production cost is low. DETAILED DESCRIPTION

[0020] Example 1

[0021] A low-cost anti-fogging black sunscreen preservative film production method, comprising the following steps: first, fumigation and adhesion treatment: the coal oil lamp or combustion furnace is filled with No. 2 coal oil, and the film is drawn through the ignited coal oil lamp or combustion furnace and fumigated and roasted above the coal oil lamp or combustion furnace after cooling and shaping, the drawing speed is 25 m / min, the carbon smoke particles are the carbon smoke particles generated by incomplete combustion of mineral oil in the coal oil lamp or combustion furnace, the carbon smoke particles are uniformly distributed on the surface of the film, the average diameter of the carbon smoke particles is 1 μm, the remaining escaping smoke is collected by the recovery air pipe, and the coal oil lamp or combustion furnace and the film above are provided with a cold air blower so that the temperature of the film is maintained at 25℃; further, wherein the coal oil lamp is preferred for small-batch production, is used for lighting, reduces lighting electricity, and is used for lighting. Shandong Lingding YWQ-FD300DZ smoke generator, No. 2 ordinary coal oil of Tianjin Branch of China Petroleum and Chemical Corporation. Second, aerosol evaporation treatment: the escaping aerosol is collected by the recovery air pipe, condensed and then used again, and the surface of the drawn film after fumigation and adhesion treatment is treated with a semi-closed sealed treatment liquid according to the aerosol generation process, and then wound and packaged after aerosol evaporation treatment, the weight ratio of the treatment liquid is 7:17:7:5, wherein the drawing speed is 25 m / min, the aerosol generation process is spraying distance 60 cm, temperature 25-60 DEG C, humidity 95% RH, and the treatment liquid consumption speed is 10 mL / min.

[0022] Before the above steps, the following steps are further included, including conventional extrusion casting film, which refers to that material is melted and plasticized through an extruder, extruded through a slit die, and then cast on a cooling roller, and then stretched after cooling and shaping, and the specific process is as follows: extruder of DFDA-7042 polyethylene particles of Yulin Energy of Shaanxi Yanchang Zhongmei extrudes → T-shaped die casting → air knife → 1# cooling roller → 2# cooling roller. The screw diameter of the extruder is 65 mm, L / D is 32, and the ordinary gradual change type screw is used. The barrel temperature is 180℃, 190℃, 200℃, 210℃ and 220℃ in sequence, and the head temperature is 220℃, 215℃, 210℃, 215℃ and 220℃ in sequence from right to left. The temperature of the 1# cooling roller is 25℃, and the temperature of the cooling water of the 2# cooling roller is 40℃.

[0023] The anti-fogging performance of the product: the initial drop time of the water droplets or water film gathered on the inner surface of the sample on the rapid flow drop tester is not more than 15 minutes.

[0024] Blank example 1

[0025] The blank example is compared with example 1, which is a conventional extrusion casting film without fumigation and adhesion treatment and aerosol evaporation treatment, and is the same as example 1 except for the above.

[0026] Example 2

[0027] A low-cost anti-fogging black sunscreen preservative film production method, comprising the following steps: first, fumigation and adhesion treatment: kerosene lamp or combustion furnace is filled with No. 2 kerosene, and the film drawn after cooling and shaping is fumigated and roasted above the kerosene lamp or combustion furnace, the drawing speed is 15 m / min, the carbon smoke particles are carbon smoke particles generated by incomplete combustion of mineral oil in the kerosene lamp or combustion furnace, the carbon smoke particles are uniformly distributed on the surface of the film, the average diameter of the carbon smoke particles is 0.5 μm, the rest of the escaping smoke is collected by the recovery air pipe, and the kerosene lamp or combustion furnace and the film above are provided with a cold air blower so that the temperature of the film is kept at 25℃; the combustion furnace is used, and the heat generated by combustion is used for heating the extruder system; the smoke generator YWQ-FD300DZ of Lingding in Shandong, heavy oil of Yulin Refinery of Yanchang Petroleum in Shaanxi is used; second, gas mist evaporation treatment: the escaping gas mist is collected by the recovery air pipe, condensed and used twice, the surface of the drawn film after fumigation and adhesion treatment is treated with a semi-closed sealed treatment liquid, and the treatment liquid is sprayed and evaporated according to the gas mist generation process, then wound and packaged, the weight ratio of the treatment liquid is 7:17:7:5, wherein the drawing speed is 15 m / min, the gas mist generation process is a spraying distance of 30 cm, the temperature is 25℃, the humidity is 55% RH, and the treatment liquid consumption speed is 5 mL / min. The initial drop time of the water droplets or water film gathered on the inner surface of the sample on the rapid flow drop tester is not more than 15 minutes.

[0028] Before the above steps, the following steps are further included, including the conventional extrusion casting film, which refers to the steps of material melting and plasticizing through an extruder, extruding through a slit die, casting on a cooling roller, and stretching after cooling and shaping, and specifically, the polyethylene particles of DFDA-7042 of Yulin Energy of Yanchang Coal in Shaanxi are extruded through an extruder, cast through a T-shaped die, air-knifed, cooled on a 1# cooling roller, and then cooled on a 2# cooling roller. The screw diameter of the extruder is 65 mm, L / D=32, and the screw is a general tapered screw. The barrel temperature is 190℃, 200℃, 210℃, 220℃, 230℃ in sequence, and the head temperature is right one 225℃, right two 220℃, middle 215℃, left one 220℃, and left two 225℃ in sequence. The 1# cooling roller is at 30℃, and the cooling water temperature of the 2# cooling roller is 20℃.

[0029] The anti-fogging performance of the product: the initial drop time of the water droplets or water film gathered on the inner surface of the sample on the rapid flow drop tester is not more than 15 minutes.

[0030] Blank Example 2

[0031] The blank example is compared with Example 2, which is a conventional extrusion casting film without fumigation and adhesion treatment and gas mist evaporation treatment, and is the same as Example 2 except for the above.

[0032] The film performance of Examples 1~2 and Blank Examples 1~2 was detected, and the detection results are shown in Table 1

[0033] Table 1 Performance detection results of the film of Examples 1~2 and Blank Examples 1~2

[0034]

[0035] Note: The test samples were detected according to the following standards and methods: a sufficient number of test samples were cut from the film roll for testing, the standard environment for sample state adjustment and testing was 23℃ according to the standard environment for sample state adjustment and testing of GB / T2918-2018 Plastics, the state adjustment time was not less than 4h, the thickness was measured by a thickness gauge with a precision of 0.001mm according to GB / T6672-2001 Plastics - Determination of thickness - Mechanical measurement method, the appearance was observed under natural light or a daylight lamp, the tensile strength and elongation at break were tested according to GB / T1040.3-2006 Plastics - Determination of tensile properties - Part 3: test conditions for films and sheets, type 5 samples were used, the sample length was 115mm, the test speed was 500mm / min, the tear strength was tested according to QB / T1130 Test method for straight tear properties of plastics, a single sample was used, the test speed was 200mm / min, the light transmittance was measured according to GB / T2410. The determination of drop-free performance was carried out according to Appendix A (normative annex) of GB / T20202-2006, and the water temperature was kept at 90℃. The wetting tension was tested according to GB / T14216-2008. Anti-fog property: beaker (250ml), refrigerator, stopwatch. The length direction and width direction of the film roll were the longitudinal direction and transverse direction of the sample, respectively. Three square samples of 150mm×150mm were cut from the sample along the longitudinal direction, and the serial numbers were marked. 200ml tap water was added to a 250mL beaker, and the sample film was placed on top of the beaker; then the beaker was placed in a refrigerator with a temperature of 4℃, and the cold storage time was 3h, then the sample was taken out and the appearance of the film was observed. 50ml tap water was added to a 250ml beaker, and the sample film was placed on top of the beaker. The beaker was placed in a 60℃ water bath. The change in appearance of the sample film within 3h was recorded by an accurate stopwatch. GB / T 31726-2015 Test method for anti-fog property of plastics film.

Claims

1. A method for producing a low-cost anti-fogging, black, sun-protective, preservative film, comprising the steps of conventional extrusion casting film, i.e. melting and plasticizing the material in an extruder, extruding through a slit die, casting on a cooling roll, and after cooling and setting, stretching, characterized in that Further comprising the following steps: (1) fumigation and adhesion treatment: a kerosene lamp or a combustion furnace is filled with mineral oil, and a thin film that is stretched after being cooled and shaped is pulled through the ignited kerosene lamp or combustion furnace and fumigated and roasted above the kerosene lamp or combustion furnace, carbon smoke particles are carbon smoke particles generated by incomplete combustion of the mineral oil in the kerosene lamp or combustion furnace, the carbon smoke particles are uniformly distributed on the surface of the thin film, and the remaining escaping smoke is collected by a recovery air pipe, a cold air machine is arranged above the kerosene lamp or combustion furnace and the thin film, so that the temperature of the thin film is kept at 25-30℃; (2) aerosol evaporation treatment: the escaping aerosol is collected by the recovery air pipe, condensed and then used again, and the surface of the pulled thin film after the fumigation and adhesion treatment is treated by spraying and evaporating the treatment liquid in a semi-closed and sealed manner according to an aerosol generating process, and then wound and packaged.

2. A process for the production of a low cost anti-fogging, black, sun-protective, preservative film according to claim 1, characterized in that, The weight ratio of the treatment liquid in step (2) is 5-7:13-17:4-7:3-5.

3. A process for the production of a low cost anti-fogging, black, sun-protective, preservative film according to claim 1, characterized in that, The diameter of the carbon smoke particles in step (1) is 0.5-1 μm.

4. A process for the production of a low cost anti-fogging, black, sun-protective, preservative film according to claim 1, characterized in that, The aerosol generating process in step (2) is a spraying distance of 30-60 cm, a temperature of 25-60℃, a humidity of 5%-95% RH, and a treatment liquid consumption speed of 5-10 mL / min.

5. A process for the production of a low cost anti-fogging, black, sun-protective, preservative film according to claim 1, characterized in that, The mineral oil in the kerosene lamp or combustion furnace in step (1) is one or more of kerosene or heavy oil.

6. A process for the production of a low cost anti-fogging, black, sun-protective, preservative film according to claim 1, characterized in that, The pulling speed of the thin film is 15-25 m / min.

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