Production method of degradable heat-seal packaging cast film

Abstract

The invention discloses a production method of a degradable heat-seal packaging cast film, and belongs to the technical field of film processing, polylactic acid, poly (butylene adipate terephthalate) and poly (butylene succinate) polymer granules contain stillingia oil; the melt viscosity and the glass transition temperature can be reduced, and the processability of extrusion casting and the flexibility of the product can be improved. The lacquer wax is used as an auxiliary agent to improve the lubricating processing performance, the extrusion casting process is high in production speed, a cooling roller in the extrusion casting process is low in roller temperature and directly clings to a roller, the cooling effect is good, the thickness uniformity is good, the heat sealing performance is better than that of a blown film, the contractility of the degradable heat-sealing packaging cast film is small when the degradable heat-sealing packaging cast film is heated, heat-sealing bag making is facilitated, and the service life of the degradable heat-sealing packaging cast film is prolonged. The film has good flatness and heat sealability, does not use any chemical adhesive in the processing process, and has stable performance.

Description

Technical Field

[0001] The invention belongs to the technical field of film processing, and in particular relates to a method for producing a degradable heat-sealed packaging cast film. Background Art

[0002] It has replaced composite heat-sealed packaging films in many fields and has become the new favorite of the flexible packaging industry. Vacuum skin packaging is a new packaging method applied to high-end aquatic products, steaks and other products in recent years. It is to cover the product with a layer of heat-sealed plastic film, and use the negative pressure generated by vacuuming to tightly adhere the plastic film to the product without causing wrinkles, thereby achieving a body-fitting effect. CN201811270377.3 discloses a photochromic low-melting polyester film and a preparation method thereof. At present, the heat-sealed packaging cast films on the market cannot be degraded. If they are buried in the soil, the plasticizer in the plastic will penetrate into the soil and water, and eventually enter the human body with water and plants. At the same time, plastic molecules can also enter the human body and cause harm to the human body. Therefore, those skilled in the art are in urgent need of developing a production method for degradable heat-sealed packaging cast film. Summary of the invention

[0003] The purpose of the invention is to provide a method for producing a degradable heat-sealed packaging cast film in view of the existing problems.

[0004] A method for producing a degradable heat-sealing packaging cast film comprises the following steps: 1. uniformly mixing a polymer with linalool and lacquer wax, and then extruding and granulating the mixture to obtain polymer pellets; 2. drying the polymer pellets in an oven at 80°C for 8h, and extruding the polymer pellets using an extrusion casting molding machine, wherein the heating temperatures of various zones of the extruder are 160-170°C, 170-180°C, 180-190°C, 190-200°C, and 190-200°C, and the head temperature is 185-195°C, the polymer melt is extruded from a T-slit die, adheres to a casting roller under an air knife airflow, and is stretched by the casting roller to produce a degradable heat-sealing packaging cast film.

[0005] Furthermore, in step 2, the temperature of the cooling roller is 5-10°C.

[0006] Furthermore, in step 2, the temperature of the casting roller is 75-90°C.

[0007] Furthermore, in step 2, the width of the wind knife is 0.05-0.06 mm, the angle of the wind knife is 45-60°, the blowing temperature of the wind knife is 80-100°C, and the air volume is 10-12 m 3 / min.

[0008] Furthermore, the mass ratio of the polymer in step 1 to catalpa oil and lacquer wax is 100:7-11:3-5.

[0009] Furthermore, the extrusion granulation process in step 1 is 165-170°C in zone 1, 175-180°C in zone 2, 180-190°C in zone 3, and 190°C in the die.

[0010] Furthermore, the polymer in step 1 is one of polylactic acid, polybutylene terephthalate adipate, and polybutylene succinate.

[0011] The present invention has the following beneficial effects: The invention discloses a method for producing a degradable heat-sealable packaging cast film. The polymer pellets contain linalool, which can reduce melt viscosity and glass transition temperature and improve the processability of extrusion casting and the flexibility of the product. The use of lacquer wax as an auxiliary agent can improve the lubrication processing performance. The extrusion casting process has a high production speed. The cooling roller temperature in the extrusion casting process is low, and the roller is directly attached to the roller, so the cooling effect is good and the thickness uniformity is good. The heat sealing performance is better than that of the inflation film. The degradable heat-sealable packaging cast film has a small shrinkage when heated, which is conducive to heat-sealing bag making, and has good flatness and heat sealing properties. No chemical adhesive is used during the processing, and the performance is stable. DETAILED DESCRIPTION

[0012] The present invention is described below with specific examples, but is not intended to be limiting of the present invention. Example 1

[0013] Lacquer wax LHS-3; Shoucheng Chemical Co., Ltd. linalool acid value 15, specific gravity 0.937g / cm 3 . 290 type polylactic acid 190℃, 2.16kg melt index 40g / 10min. SDLZ1500 extrusion casting machine.

[0014] A method for producing a degradable heat-sealed packaging cast film comprises the following steps: 1. uniformly mixing a polymer with linden oil and lacquer wax and then extruding and granulating the mixture, wherein the first zone is 165°C, the second zone is 175°C, the third zone is 185°C, and the head is 190°C, and the mass ratio of the polymer to the linden oil and the lacquer wax is 100:8:4, to obtain polymer pellets; 2. drying the polymer pellets in an oven at 80°C for 8h, and extruding the polymer pellets using an extrusion casting molding machine, wherein the heating temperatures of each zone of the extruder are 165°C, 175°C, 185°C, 195°C, and 195°C, and the temperature of the cooling roller is 8°C; the temperature of the casting roller is 80°C; the air knife width is 0.055mm, the air knife angle is 50°, the air knife blowing temperature is 90°C, and the air volume is 11m 3 / min; the die head temperature is 185~195℃, the polymer melt is extruded from the T-slit die, adheres to the casting roller under the airflow of the air knife, and is stretched by the casting roller to form a biodegradable heat-sealed packaging cast film. Example 2

[0015] Lacquer wax LHS-1. Hongcheng Biological Catalpa oleifera acid value 15, specific gravity 0.937g / cm 3 ; T16 type 190℃, 2.16kg melt index 5g / 10min polybutylene terephthalate adipate PBAT. SDLZ1500 extrusion casting machine.

[0016] A method for producing a degradable heat-sealed packaging cast film comprises the following steps: 1. uniformly mixing a polymer with linden oil and lacquer wax and then extruding and granulating the mixture, wherein the first zone is 165°C, the second zone is 175°C, the third zone is 180°C, and the head is 190°C, and the mass ratio of the polymer to the linden oil and the lacquer wax is 100:7:3, to obtain polymer pellets; 2. drying the polymer pellets in an oven at 80°C for 8h, and extruding the polymer pellets using an extrusion casting molding machine, wherein the heating temperatures of each zone of the extruder are 160°C, 170°C, 180°C, 190°C, and 190°C, and the temperature of the cooling roller is 5°C; the temperature of the casting roller is 75°C; the air knife width is 0.05mm, the air knife angle is 45°, the air knife blowing temperature is 80°C, and the air volume is 10m 3 / min; the die head temperature is 185°C, the polymer melt is extruded from the T-slit die, adheres to the casting roller under the airflow of the air knife, and is stretched by the casting roller to form a biodegradable heat-sealed packaging cast film. Example 3

[0017] Fumei lipid chemical paint wax. Dawu industrial oil catalpa oil acid value 15, specific gravity 0.938g / cm 3 . TH803 type 190℃, 2.16kg, melt index 30g / 10min polybutylene succinate (PBS); SDLZ1500 extrusion casting machine.

[0018] A method for producing a degradable heat-sealed packaging cast film comprises the following steps: 1. uniformly mixing a polymer with linden oil and lacquer wax and then extruding and granulating the mixture, wherein the first zone is 165°C, the second zone is 175°C, the third zone is 180°C, and the head is 190°C, and the mass ratio of the polymer to the linden oil and the lacquer wax is 100:11:5, to obtain polymer pellets; 2. drying the polymer pellets in an oven at 80°C for 8h, and extruding them using an extrusion casting molding machine, wherein the heating temperatures of each zone of the extruder are 170°C, 180°C, 190°C, 200°C, and 200°C, the temperature of the cooling roller is 10°C, the temperature of the casting roller is 90°C, the width of the wind knife is 0.06mm, the angle of the wind knife is 60°, the blowing temperature of the wind knife is 100°C, and the air volume is 12m 3 / min; the die head temperature is 195°C, the polymer melt is extruded from the T-slit die, adheres to the casting roller under the airflow of the air knife, and is stretched by the casting roller to form a biodegradable heat-sealed packaging cast film.

[0019] The performance of the films of Examples 1 to 3 was tested, and the test results are shown in Table 1.

[0020] Table 1 Performance test results of the films of Examples 1 to 3

[0021] Note: The sampling method shall be in accordance with the provisions of 5.1 of GB / T27740-2011. The sample state adjustment and the standard environment of the test shall be in accordance with the provisions of 5.2 of GB / T27740-2011. The appearance shall be in accordance with the provisions of 5.3 of GB / T27740-2011. The dimensional deviation shall be in accordance with the provisions of 5.4 of GB / T27740-2011. The physical properties shall be in accordance with the provisions of 5.5 of GB / T27740-2011. The volatile solid content of the biodegradability shall be in accordance with the provisions of 6.10 of GB / T18006.3-2020, and the degradation performance shall be in accordance with the provisions of 6.11 of GB / T18006.3-2020.

Claims

1. A method for producing a degradable heat-sealable packaging cast film, characterized in that: The following steps are involved:

1. The polymer is mixed evenly with zelkova oil and lacquer wax, and then extruded into granules to obtain polymer pellets.

2. The polymer pellets are dried in an oven at 80°C for 8 hours, and extruded using an extrusion casting molding machine. The heating temperatures of each zone of the extruder are 160-170°C, 170-180°C, 180-190°C, 190-200°C, and 190-200°C. The head temperature is 185-195°C. The polymer melt is extruded from a T-slit die, adheres to a casting roller under an air knife airflow, and is stretched by the casting roller to form a degradable heat-sealed packaging cast film.

2. The method for producing a degradable heat-sealable packaging cast film according to claim 1, characterized in that: The temperature of the cooling roller in step 2 is 5-10°C.

3. The method for producing a degradable heat-sealable packaging cast film according to claim 1, characterized in that: The temperature of the casting roller in step 2 is 75-90°C.

4. The method for producing a degradable heat-sealable packaging cast film according to claim 1, characterized in that: In step 2, the width of the wind knife is 0.05-0.06 mm, the angle of the wind knife is 45-60°, the blowing temperature of the wind knife is 80-100°C, and the air volume is 10-12 m 3 / min.

5. The method for producing a degradable heat-sealable packaging cast film according to claim 1, characterized in that: The mass ratio of the polymer to the catalpa oil and lacquer wax in the step 1 is 100:7-11:3-5.

6. The method for producing a degradable heat-sealable packaging cast film according to claim 1, characterized in that: The extrusion granulation process of step 1 is as follows: zone 1 is 165-170°C, zone 2 is 175-180°C, zone 3 is 180-190°C, and die head is 190°C.

7. The method for producing a degradable heat-sealable packaging cast film according to claim 1, characterized in that: The polymer in step 1 is one of polylactic acid, polybutylene terephthalate adipate and polybutylene succinate.

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