An antistatic polyethylene film, its preparation method and application

Abstract

The present invention relates to an antistatic polyethylene film, its preparation method and application; an antistatic polyethylene film is provided, which includes an outer layer and an inner layer; the outer layer includes a first layer made of linear low density polyethylene and high density polyethylene, a second layer made of linear low density polyethylene, high density polyethylene and ethylene elastomer, and a third layer made of linear low density polyethylene, high density polyethylene and metallocene polyethylene; the inner layer includes: a fourth layer made of linear low density polyethylene and low density polyethylene, a fifth layer made of linear low density polyethylene, high density polyethylene and ethylene elastomer, and a sixth layer made of linear low density polyethylene, low density polyethylene, metallocene polyethylene and antistatic agent; the present invention uses a single material for packaging, realizing recycling; the antistatic agent improves the packaging speed of the automatic packaging machine; the biaxially oriented polyethylene film has a high tensile strength and can meet the requirements of wet wipe packaging.

Description

Technical Field

[0001] The present invention relates to the field of packaging, and in particular to an antistatic polyethylene film and its preparation method and application. Background Art

[0002] At present, wet wipes are packaged using composite packaging films. The packaging films made of different materials are difficult to degrade, cannot be recycled and reused, and the resulting "white pollution" has a great impact on society and the environment. A large amount of land is required to bury plastic waste, which greatly affects sustainable development.

[0003] Therefore, there is an urgent need for an antistatic polyethylene film made of a single material that is environmentally friendly and can be applied to wet wipe packaging. Summary of the Invention

[0004] The purpose of the present invention is to provide an antistatic polyethylene film and its preparation method and application in view of the deficiencies in the prior art.

[0005] To achieve the above purpose, the technical solutions adopted by the present invention are as follows:

[0006] The first aspect of the present invention is to provide an antistatic polyethylene film, including: an outer layer made of a biaxially oriented polyethylene film and an inner layer made of an aluminized cast polyethylene film;

[0007] Among them, the outer layer includes: a first layer made of linear low-density polyethylene and high-density polyethylene, a second layer made of linear low-density polyethylene, high-density polyethylene, and ethylene elastomer, and a third layer made of linear low-density polyethylene, high-density polyethylene, and metallocene polyethylene;

[0008] The inner layer includes: a fourth layer made of linear low-density polyethylene and low-density polyethylene, a fifth layer made of linear low-density polyethylene, high-density polyethylene, and ethylene elastomer, and a sixth layer made of linear low-density polyethylene, low-density polyethylene, metallocene polyethylene, and antistatic agent;

[0009] The moisture permeability of the antistatic polyethylene film is 1.005 g / (m 2 ·24 h) - 1.215 g / (m 2 ·24 h); the oxygen permeability is 1.08 mL / (m 2 ·24 h) - 1.261 mL / (m 2 ·24 h); the tensile strength in the longitudinal direction MD is 138 N / 15 mm - 148 N / 15 mm, and in the transverse direction TD is 132 N / 15 mm - 135 N / 15 mm; the elongation rate in the longitudinal direction MD is 262% - 276%, and in the transverse direction TD is 248% - 262%; the surface resistivity is 1.7×10 9 Ω - 3.0×109 Ω。

[0010] Preferably, the thickness of the outer layer is 18 μm - 20 μm; in the outer layer, the ratio of the first layer, the second layer, and the third layer is 30:40:30.

[0011] Preferably, in the first layer, the addition ratio of the linear low-density polyethylene to the high-density polyethylene is (60 - 70):(30 - 40);

[0012] In the second layer, the addition ratio of the linear low-density polyethylene, the high-density polyethylene, and the ethylene elastomer is (50 - 60):(20 - 30):(10 - 20);

[0013] In the third layer, the addition ratio of the linear low-density polyethylene, the high-density polyethylene, and the metallocene polyethylene is (50 - 60):(20 - 30):(10 - 20).

[0014] Preferably, the inner layer further includes an aluminized layer, and the thickness of the aluminized layer is 0.5 μm - 1.5 μm.

[0015] Preferably, the thickness of the inner layer is 25 μm - 30 μm; in the inner layer, the ratio of the fourth layer, the fifth layer, and the sixth layer is 30:40:30.

[0016] Preferably, in the fourth layer, the addition ratio of the linear low-density polyethylene to the low-density polyethylene is (70 - 75):(25 - 30);

[0017] In the fifth layer, the addition ratio of the linear low-density polyethylene, the high-density polyethylene, and the ethylene elastomer is (60 - 65):(25 - 30):(5 - 10);

[0018] In the sixth layer, the addition ratio of the linear low-density polyethylene, the low-density polyethylene, the metallocene polyethylene, and the antistatic agent is (45 - 50):(20 - 25):(26 - 29):(1 - 4).

[0019] Preferably, the antistatic agent is potassium alkylphenol polyoxyethylene ether phosphate.

[0020] The second aspect of the present invention is to provide a method for preparing the above antistatic polyethylene film, and the steps include:

[0021] S1. Weigh the raw materials in proportion, perform multi-layer co-extrusion blown film treatment and biaxial stretching treatment, and obtain the outer layer by three-layer co-extrusion;

[0022] S2. Weigh the raw materials proportionally, and then obtain the inner layer after extrusion casting and vacuum aluminizing treatments.

[0023] S3. Print, laminate, and slit the outer layer prepared in step S1 and the inner layer prepared in step S2 to obtain the antistatic polyethylene film.

[0024] Preferably, in step S1, the three-layer coextrusion includes: the raw materials are extruded through the annular gap of the die head of the extruder into a cylindrical film tube, and compressed air is blown in from the side air inlet of the die head for transverse inflation; among them, the temperatures of the first layer in the first, second, third, fourth, screen changer, and runner zones of the extruder are 175°C, 181°C, 186°C, 200°C, 185°C, and 185°C respectively; the temperatures of the second layer in the first, second, third, fourth, screen changer, and runner zones of the extruder are 176°C, 180°C, 187°C, 205°C, 190°C, and 191°C respectively; the temperatures of the third layer in the first, second, third, fourth, screen changer, and runner zones of the extruder are 174°C, 180°C, 185°C, 186°C, 185°C, and 180°C respectively; the temperatures at the first, second zones of the die head and the die lip are 202°C, 193°C, and 180°C respectively; the rotation speed of the extruder is 1250 rpm, and the blow-up ratio is 2.3.

[0025] In step S3, the lamination includes: applying glue to the outer layer through a wire mesh roller, with a unwind tension of 4 kg / cm 2 , and the glue application amount is 2.8 g / m 2 ; after laminating with the inner layer to obtain a composite film, place the composite film in an oven for drying treatment. The drying treatment is a four-stage drying, and the temperatures of the drying treatment are 60°C, 75°C, 80°C, and 80°C in sequence. The wind speed of the drying treatment is 30 m / s; the tension of the oven is 3 kg / cm 2 ; the unwind tension of the inner layer is 4 kg / cm 2 , the winding tension of the composite film is 8 kg / cm 2 , and the taper is 40%.

[0026] The third aspect of the present invention is to provide the application of the above antistatic polyethylene film in the preparation of wet wipe packaging.

[0027] The present invention adopts the above technical solutions, and compared with the prior art, has the following technical effects:

[0028] The present invention uses a single material for packaging, realizing recycling, recovery, and circular utilization, and promoting sustainable development; the addition of an antistatic agent improves the packaging speed of the automatic packaging machine, improves production efficiency, and reduces costs; compared with blown film, the biaxially oriented polyethylene film has uniform thickness, high tensile strength, excellent puncture resistance, impact resistance, and good optical properties, which can meet the requirements of wet wipe packaging. Detailed implementation mode

[0029] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0030] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other.

[0031] The present invention will be further described below in conjunction with specific embodiments, but it is not limited to the present invention.

[0032] Embodiment 1

[0033] This embodiment provides an antistatic polyethylene film;

[0034] It includes: an outer layer made of a biaxially stretched polyethylene film and an inner layer made of an aluminized cast polyethylene film;

[0035] Among them, the outer layer includes: a first layer made of linear low-density polyethylene and high-density polyethylene, a second layer made of linear low-density polyethylene, high-density polyethylene and ethylene elastomer, and a third layer made of linear low-density polyethylene, high-density polyethylene and metallocene polyethylene; the thickness of the outer layer is 18 μm; in the outer layer, the ratio of the first layer, the second layer and the third layer is 30:40:30; in the first layer, the addition ratio of the linear low-density polyethylene and the high-density polyethylene is 60:40; in the second layer, the addition ratio of the linear low-density polyethylene, the high-density polyethylene and the ethylene elastomer is 50:30:20; in the third layer, the addition ratio of the linear low-density polyethylene, the high-density polyethylene and the metallocene polyethylene is 60:20:20;

[0036] The inner layer includes: a fourth layer made of linear low density polyethylene and low density polyethylene, a fifth layer made of linear low density polyethylene, high density polyethylene and ethylene elastomer, a sixth layer made of linear low density polyethylene, low density polyethylene, metallocene polyethylene and antistatic agent, and an aluminized layer; the thickness of the aluminized layer is 1 μm; the thickness of the inner layer is 25 μm; in the inner layer, the ratio of the fourth layer, the fifth layer and the sixth layer is 30:40:30; in the fourth layer, the addition ratio of the linear low density polyethylene to the low density polyethylene is 75:25; in the fifth layer, the addition ratio of the linear low density polyethylene, the high density polyethylene to the ethylene elastomer is 60:30:10; in the sixth layer, the addition ratio of the linear low density polyethylene, the low density polyethylene, the metallocene polyethylene to the antistatic agent is 50:20:28:2; the antistatic agent is potassium alkylphenol polyoxyethylene ether phosphate;

[0037] The moisture permeability of the antistatic polyethylene film is 1.005 g / (m 2 ·24 h), and the oxygen permeability is 1.08 mL / (m 2 ·24 h); the longitudinal MD tensile strength is 148 N / 15 mm, the transverse TD tensile strength is 135 N / 15 mm, the longitudinal MD elongation is 262%, and the transverse TD elongation is 248%; the surface resistivity is 1.7×10 9 Ω.

[0038] Example 2

[0039] This example provides a preparation method of the antistatic polyethylene film described in Example 1. The steps include:

[0040] S1. Weigh the raw materials according to the ratio, perform multi-layer co-extrusion blown film treatment and biaxial stretching treatment, and obtain the outer layer by three-layer co-extrusion; the three-layer co-extrusion includes: the raw materials are extruded into a cylindrical film tube through the annular gap of the head of the extruder, and compressed air is blown in from the air inlet on the side of the head for transverse blowing; among them, the temperatures of the first layer in the first, second, third, fourth, screen changer and runner zones of the extruder are 175 °C, 181 °C, 186 °C, 200 °C, 185 °C and 185 °C respectively; the temperatures of the second layer in the first, second, third, fourth, screen changer and runner zones of the extruder are 176 °C, 180 °C, 187 °C, 205 °C, 190 °C and 191 °C respectively; the temperatures of the third layer in the first, second, third, fourth, screen changer and runner zones of the extruder are 174 °C, 180 °C, 185 °C, 186 °C, 185 °C and 180 °C respectively; the temperatures of the first zone, second zone and die of the die head are 202 °C, 193 °C and 180 °C respectively; the rotation speed of the extruder is 1250 rpm, and the blow-up ratio is 2.3;

[0041] S2. Weigh the raw materials proportionally, and after extrusion casting and vacuum aluminizing treatments, the inner layer is obtained.

[0042] S3. Print, laminate, and slit the outer layer prepared in step S1 and the inner layer prepared in step S2 to obtain the antistatic polyethylene film. Laminating includes: applying glue to the outer layer through a wire roller, with a unwind tension of 4 kg / cm 2 , and the glue application amount is 2.8 g / m 2 ; after laminating with the inner layer to obtain a composite film, place the composite film in an oven for drying treatment. The drying treatment is a four-stage drying, and the temperatures of the drying treatment are 60 °C, 75 °C, 80 °C, and 80 °C in sequence. The wind speed of the drying treatment is 30 m / s; the tension of the oven is 3 kg / cm 2 ; the unwind tension of the inner layer is 4 kg / cm 2 , and the winding tension of the composite film is 8 kg / cm 2 , and the taper is 40%.

[0043] Example 3

[0044] This example provides another antistatic polyethylene film.

[0045] It includes: an outer layer made of a biaxially oriented polyethylene film and an inner layer made of an aluminized cast polyethylene film.

[0046] Among them, the outer layer includes: a first layer made of linear low-density polyethylene and high-density polyethylene, a second layer made of linear low-density polyethylene, high-density polyethylene, and ethylene elastomer, and a third layer made of linear low-density polyethylene, high-density polyethylene, and metallocene polyethylene; the thickness of the outer layer is 20 μm; in the outer layer, the ratio of the first layer, the second layer, and the third layer is 30:40:30; in the first layer, the addition ratio of the linear low-density polyethylene to the high-density polyethylene is 70:30; in the second layer, the addition ratio of the linear low-density polyethylene, the high-density polyethylene, and the ethylene elastomer is 60:20:20; in the third layer, the addition ratio of the linear low-density polyethylene, the high-density polyethylene, and the metallocene polyethylene is 50:30:20.

[0047] The inner layer includes: a fourth layer made of linear low-density polyethylene and low-density polyethylene, a fifth layer made of linear low-density polyethylene, high-density polyethylene, and ethylene elastomer, a sixth layer made of linear low-density polyethylene, low-density polyethylene, metallocene polyethylene, and antistatic agent, and an aluminized layer; the thickness of the aluminized layer is 1 μm; the thickness of the inner layer is 30 μm; in the inner layer, the ratio of the fourth layer, the fifth layer, and the sixth layer is 30:40:30; in the fourth layer, the addition ratio of the linear low-density polyethylene to the low-density polyethylene is 75:25; in the fifth layer, the addition ratio of the linear low-density polyethylene, the high-density polyethylene, and the ethylene elastomer is 60:30:10; in the sixth layer, the addition ratio of the linear low-density polyethylene, the low-density polyethylene, the metallocene polyethylene, and the antistatic agent is 60:10:29:1; the antistatic agent is potassium alkylphenol polyoxyethylene ether phosphate;

[0048] The moisture permeability of the antistatic polyethylene film is 1.215 g / (m 2 ·24 h), and the oxygen permeability is 1.261 mL / (m 2 ·24 h); the longitudinal MD tensile strength is 138 N / 15 mm, the transverse TD tensile strength is 132 N / 15 mm, the longitudinal MD elongation rate is 276%, the transverse TD elongation rate is 262%; the surface resistivity is 3.0×10 9 Ω.

[0049] Comparative Example

[0050] This comparative example provides a wet wipe roll film, including: a polyester substrate, a polyester aluminized film, and a polyethylene film; the total thickness is 70 μm, the water vapor transmission rate is 4.04 g / (m 2 ·24 h), the oxygen transmission rate is 1.42 mL / (m 2 ·24 h), the longitudinal MD tensile strength is 91.6 N / 15 mm, the transverse TD tensile strength is 118.2 N / 15 mm, the longitudinal MD elongation rate is 110.7%, the transverse TD elongation rate is 123%, and the surface resistivity is 1.65×10 12 Ω.

[0051] In summary, the present invention uses a single material for packaging, achieving recycling and promoting sustainable development; the addition of the antistatic agent improves the packaging speed of the automatic packaging machine, increases production efficiency, and reduces costs; compared with blown film, the biaxially oriented polyethylene film has uniform thickness, high tensile strength, excellent puncture resistance, impact resistance, and good optical properties, which can meet the requirements of wet wipe packaging.

[0052] The above are only the preferred embodiments of the present invention, and thus do not limit the implementation manners and protection scope of the present invention. For those skilled in the art, it should be realized that all the equivalent replacements and obvious changes made by using the content of the specification of the present invention should be included within the protection scope of the present invention.

Claims

1. An antistatic polyethylene film, characterized in that, it comprises: an outer layer made of a biaxially stretched polyethylene film and an inner layer made of an aluminized cast polyethylene film; wherein, the outer layer comprises: a first layer made of linear low density polyethylene and high density polyethylene, a second layer made of linear low density polyethylene, high density polyethylene and ethylene elastomer, and a third layer made of linear low density polyethylene, high density polyethylene and metallocene polyethylene; the inner layer comprises: a fourth layer made of linear low density polyethylene and low density polyethylene, a fifth layer made of linear low density polyethylene, high density polyethylene and ethylene elastomer, and a sixth layer made of linear low density polyethylene, low density polyethylene, metallocene polyethylene and an antistatic agent; the antistatic agent is potassium alkylphenol polyoxyethylene ether phosphate; The moisture permeability of the antistatic polyethylene film is 1.005 g / (m 2 ·24 h) - 1.215 g / (m 2 ·24 h); the oxygen permeability is 1.08 mL / (m 2 ·24 h) - 1.261 mL / (m 2 ·24 h); the tensile strength in the longitudinal direction MD is 138 N / 15 mm - 148 N / 15 mm, and in the transverse direction TD is 132 N / 15 mm - 135 N / 15 mm; the elongation rate in the longitudinal direction MD is 262% - 276%, and in the transverse direction TD is 248% - 262%; the surface resistivity is 1.7×10 9 Ω - 3.0×10 9 Ω.

2. The antistatic polyethylene film according to claim 1, characterized in that, the thickness of the outer layer is 18μm - 20μm; in the outer layer, the ratio of the first layer, the second layer and the third layer is 30:40:

30.

3. The antistatic polyethylene film according to claim 1, characterized in that, in the first layer, the addition ratio of the linear low density polyethylene and the high density polyethylene is (60 - 70):(30 - 40); in the second layer, the addition ratio of the linear low density polyethylene, the high density polyethylene and the ethylene elastomer is (50 - 60):(20 - 30):(10 - 20); in the third layer, the addition ratio of the linear low density polyethylene, the high density polyethylene and the metallocene polyethylene is (50 - 60):(20 - 30):(10 - 20).

4. The antistatic polyethylene film according to claim 1, characterized in that, the inner layer further comprises an aluminized layer, and the thickness of the aluminized layer is 0.5μm - 1.5μm.

5. The antistatic polyethylene film according to claim 1, characterized in that, the thickness of the inner layer is 25μm - 30μm; in the inner layer, the ratio of the fourth layer, the fifth layer and the sixth layer is 30:40:

30.

6. The antistatic polyethylene film according to claim 1, characterized in that, in the fourth layer, the addition ratio of the linear low density polyethylene and the low density polyethylene is (70 - 75):(25 - 30); in the fifth layer, the addition ratio of the linear low density polyethylene, the high density polyethylene and the ethylene elastomer is (60 - 65):(25 - 30):(5 - 10); in the sixth layer, the addition ratio of the linear low density polyethylene, the low density polyethylene, the metallocene polyethylene and the antistatic agent is (45 - 50):(20 - 25):(26 - 29):(1 - 4).

7. The preparation method of the antistatic polyethylene film according to any one of claims 1 - 6, characterized in that the steps comprise: S1. Weigh the raw materials according to the ratio, carry out multi - layer co - extrusion blow - film treatment and biaxial stretching treatment, and the outer layer is obtained by three - layer co - extrusion. S2. Weigh the raw materials proportionally, and then obtain the inner layer after extrusion casting treatment and vacuum aluminizing treatment; S3. Print, laminate and slit the outer layer obtained in step S1 and the inner layer obtained in step S2 to obtain the antistatic polyethylene film.

8. According to the preparation method described in claim 7, it is characterized in that in step S1, the three-layer coextrusion includes: the raw materials are extruded through the annular gap of the head of the extruder into a cylindrical film tube, and compressed air is blown in from the air inlet on the side of the head for transverse blowing; among them, the temperatures of the first layer in the first, second, third, fourth, screen changer and runner zones of the extruder are 175°C, 181°C, 186°C, 200°C, 185°C and 185°C respectively; the temperatures of the second layer in the first, second, third, fourth, screen changer and runner zones of the extruder are 176°C, 180°C, 187°C, 205°C, 190°C and 191°C respectively; the temperatures of the third layer in the first, second, third, fourth, screen changer and runner zones of the extruder are 174°C, 180°C, 185°C, 186°C, 185°C and 180°C respectively; the temperatures at the first, second zones of the die head and the die orifice are 202°C, 193°C and 180°C respectively; the rotation speed of the extruder is 1250 rpm, and the blowing ratio is 2.3; In step S3, the lamination includes: applying glue to the outer layer through a gravure roll, with a unwind tension of 4 kg / cm 2 , and the glue application amount is 2.8 g / m 2 ; after laminating with the inner layer to obtain a laminated film, placing the laminated film in an oven for drying treatment, the drying treatment is a four-stage drying, and the temperatures of the drying treatment are 60°C, 75°C, 80°C, and 80°C in sequence, and the wind speed of the drying treatment is 30 m / s; the tension of the oven is 3 kg / cm 2 ; the unwind tension of the inner layer is 4 kg / cm 2 , and the winding tension of the laminated film is 8 kg / cm 2 , and the taper is 40%.

9. The application of the antistatic polyethylene film according to any one of claims 1-6 in the preparation of wet wipe packaging.