A non-stick, easy-tear film in both directions, its preparation method and application

Abstract

This invention relates to the field of composite film technology, providing a non-stick powder easy-tear film in both longitudinal and transverse directions, its preparation method, and its application. The non-stick powder easy-tear film provided by this invention is made by co-extrusion blown film of three layers: an outer layer, a middle layer, and an inner layer. By strictly controlling the types and proportions of raw materials, as well as the melt index and density of the raw materials in the outer, middle, and inner layers, the film achieves easy tearing in both longitudinal and transverse directions. The addition of an antistatic agent to the inner layer effectively reduces powder adhesion and improves heat-sealing performance. Applying this non-stick powder easy-tear film to powder packaging achieves non-stick packaging and facilitates easy opening after heat sealing, demonstrating broad application prospects.

Description

Technical Field

[0001] This invention relates to the field of composite film technology, and in particular to a non-stick, easy-tear film in both longitudinal and transverse directions, its preparation method, and its application. Background Technology

[0002] PE film refers to a thin film made from polyethylene granules. It has advantages such as good moisture resistance, low moisture permeability, non-toxicity, odorlessness, good low temperature resistance, good chemical stability, and good acid and alkali resistance. It is widely used in various industries such as pharmaceuticals, chemicals, food, and printing.

[0003] When polyethylene film is used for packaging powders (such as flour, milk powder, soy milk powder, and pharmaceutical powder), there are two problems: first, the powder tends to stick to the surface of the packaging film, affecting its use; second, once sealed, it is not easy to open and requires tools, making it inconvenient to use. Summary of the Invention

[0004] In view of this, the present invention provides a non-stick powder easy-tear film in both directions, its preparation method, and its application. The non-stick powder easy-tear film provided by the present invention does not easily stick to powder and is easy to tear in both directions, making it convenient to open the packaging and suitable for packaging various powders.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0006] A non-stick, easy-tear film in both directions is made by co-extrusion blown film of three layers: outer layer, middle layer, and inner layer.

[0007] The raw materials for preparing the outer layer, by mass, include: 30-90 parts of first high-pressure low-density polyethylene, 10-50 parts of first linear low-density polyethylene, and 0.5-1 part of processing aids.

[0008] The raw materials for preparing the middle layer, by mass parts, include: 30-90 parts of second high-pressure low-density polyethylene, 20-60 parts of second linear low-density polyethylene, and 0.5-1 part of processing aids;

[0009] The raw materials for preparing the inner layer, by mass parts, include: 30-90 parts of third high-pressure low-density polyethylene, 10-50 parts of metallocene polyethylene, 10-20 parts of medium-density polyethylene, 1-5 parts of antistatic agent, and 0.5-1 part of processing aid.

[0010] The first high-pressure low-density polyethylene has a melt index of 2 g / 10 min and a density of 0.924 g / cm³. 3 The first linear low-density polyethylene has a melt index of 2 g / 10 min and a density of 0.918 g / cm³. 3 ;

[0011] The second high-pressure low-density polyethylene has a melt index of 6-8 g / 10 min and a density of 0.915-0.925 g / cm³. 3 The second linear low-density polyethylene has a melt index of 2 g / 10 min and a density of 0.918 g / cm³. 3 ;

[0012] The third high-pressure low-density polyethylene has a melt index of 2 g / 10 min and a density of 0.918 g / cm³. 3 .

[0013] Preferably, the metallocene polyethylene has a melt index of 2 g / 10 min and a density of 0.918 g / cm³. 3 ;

[0014] The medium-density polyethylene has a melt index of 0.8 g / 10 min and a density of 0.935 g / cm³. 3 ;

[0015] The antistatic agent has a melt index of 18–22 g / 10 min and a density of 0.950–0.965 g / cm³. 3 ;

[0016] The processing aids used in the outer, middle, and inner layers have a melt index of 1.8–3.0 g / 10 min and a density of 0.925–0.940 g / cm³. 3 .

[0017] Preferably, the first high-pressure low-density polyethylene is of type 2426H, and the first linear low-density polyethylene is of type 201XV.

[0018] The second high-pressure low-density polyethylene is of type 1C7A; the second linear low-density polyethylene is of type 201KI.

[0019] Preferably, the third high-pressure low-density polyethylene is of type 2420H, the metallocene polyethylene is of type 2018MB, the medium-density polyethylene is of type 2038.68, and the antistatic agent is of type VLA55.

[0020] Preferably, the processing aid used in the outer, middle and inner layers is PA0895LD.

[0021] Preferably, based on the total mass of the outer layer, middle layer and inner layer as 100%, the mass fraction of the outer layer is 25-30%, the mass fraction of the middle layer is 40-50%, and the mass fraction of the inner layer is 25-30%; the thickness of the non-stick powder easy-tear film in both the longitudinal and transverse directions is 40-130 μm.

[0022] The present invention also provides a method for preparing the non-stick, cross-sectional, and transverse easy-tear film described in the above-mentioned scheme, comprising the following steps:

[0023] The raw materials for the outer, middle, and inner layers are co-extruded and blown into a film to obtain the non-sticky, easily tearable film in both the longitudinal and transverse directions.

[0024] Preferably, the process of the three-layer co-extrusion blown film specifically includes: feeding the raw materials for the preparation of the outer layer, middle layer and inner layer into the outer layer, middle layer and inner layer extruders respectively for melt plasticization, conveying the obtained adhesive liquid to the die head, extruding and blowing film to obtain film bubbles, and after the film bubbles are cooled, performing bubble stabilization, upper traction, corona treatment, edge trimming, lower traction and winding in sequence to obtain the non-stick powder easy-tear film in both longitudinal and transverse directions.

[0025] Preferably, the outer, middle, and inner extruders are each equipped with five heating zones, which are designated as zones 1 to 5 according to the order in which the raw materials pass through. The temperatures of zones 1, 2, 3, 4, and 5 of the outer extruder are 150±5℃, 160±5℃, 160±5℃, 158±5℃, and 158±5℃, respectively. The temperatures of zones 1, 2, 3, 4, and 5 of the middle extruder are 145±5℃, 150±5℃, 150±5℃, 150±5℃, and 150±5℃, respectively. The temperatures of zones 1, 2, 3, 4, and 5 of the inner extruder are 165±5℃, 175±5℃, 175±5℃, 173±5℃, and 170±5℃, respectively.

[0026] The mold head is divided into 4 heating zones, which are numbered 1 to 4 according to the order in which the adhesive passes through. The temperature of zone 1 is 170±5℃, zone 2 is 173±5℃, zone 3 is 175±5℃, and zone 4 is 175±5℃.

[0027] The present invention also provides the application of the non-stick powder easy-tear film in the longitudinal and transverse directions as described in the above-described scheme or the non-stick powder easy-tear film prepared by the preparation method described in the above-described scheme in powder packaging.

[0028] This invention provides a non-stick, easily tearable film, made from three co-extruded layers: an outer layer, a middle layer, and an inner layer. By weight, the outer layer comprises: 30-90 parts of a first high-pressure low-density polyethylene (HDPE), 10-50 parts of a first linear low-density polyethylene (LLDPE), and 0.5-1 part of processing aids. The middle layer comprises: 30-90 parts of a second HDPE, 20-60 parts of a second linear low-density polyethylene (LLDPE), and 0.5-1 part of processing aids. The inner layer comprises: 30-90 parts of a third HDPE, 10-50 parts of metallocene polyethylene, 10-20 parts of medium-density polyethylene (MDPE), 1-5 parts of an antistatic agent, and 0.5-1 part of processing aids. The first HDPE has a melt index of 2 g / 10 min and a density of 0.924 g / cm³. 3 The first linear low-density polyethylene has a melt index of 2 g / 10 min and a density of 0.918 g / cm³. 3 The second high-pressure low-density polyethylene has a melt index of 7 g / 10 min and a density of 0.918 g / cm³. 3 The second linear low-density polyethylene has a melt index of 2 g / 10 min and a density of 0.918 g / cm³. 3 The third high-pressure low-density polyethylene has a melt index of 2 g / 10 min and a density of 0.918 g / cm³. 3 This invention strictly controls the types and proportions of raw materials, as well as the melt index and density of the outer, middle, and inner layers of the film, to achieve easy tearing in both directions. The addition of an antistatic agent to the inner layer effectively reduces powder adhesion and improves heat-sealing performance. Applying this non-stick, easy-tear film to powder packaging achieves powder-free packaging and facilitates easy opening after heat sealing, demonstrating broad application prospects. Attached Figure Description

[0029] Figure 1 The results of the powder adhesion test on the non-sticky, easy-tear film prepared in both the longitudinal and transverse directions according to Example 1 of the present invention;

[0030] Figure 2 The results show the powder adhesion test results of the polyethylene film prepared in Comparative Example 2. Detailed Implementation

[0031] This invention provides a non-stick, easy-tear film that is made of three layers: an outer layer, a middle layer, and an inner layer, through co-extrusion blown film production.

[0032] The raw materials for preparing the outer layer, by mass, include: 30-90 parts of first high-pressure low-density polyethylene, 10-50 parts of first linear low-density polyethylene, and 0.5-1 part of processing aids.

[0033] The raw materials for preparing the middle layer, by mass parts, include: 30-90 parts of second high-pressure low-density polyethylene, 20-60 parts of second linear low-density polyethylene, and 0.5-1 part of processing aids;

[0034] The raw materials for preparing the inner layer, by mass parts, include: 30-90 parts of third high-pressure low-density polyethylene, 10-50 parts of metallocene polyethylene, 10-20 parts of medium-density polyethylene, 1-5 parts of antistatic agent, and 0.5-1 part of processing aid.

[0035] The first high-pressure low-density polyethylene has a melt index of 2 g / 10 min and a density of 0.924 g / cm³. 3 The first linear low-density polyethylene has a melt index of 2 g / 10 min and a density of 0.918 g / cm³. 3 ;

[0036] The second high-pressure low-density polyethylene has a melt index of 7 g / 10 min and a density of 0.918 g / cm³. 3 The second linear low-density polyethylene has a melt index of 2 g / 10 min and a density of 0.918 g / cm³. 3 ;

[0037] The third high-pressure low-density polyethylene has a melt index of 2 g / 10 min and a density of 0.918 g / cm³. 3 .

[0038] The outer layer is prepared from 30-90 parts, preferably 40-80 parts, of a first high-pressure low-density polyethylene, by mass fraction. The melt index of the first high-pressure low-density polyethylene is preferably 2 g / 10 min, and the density is preferably 0.924 g / cm³. 3 In a specific embodiment of the present invention, the first high-pressure low-density polyethylene is preferably of type 2426H and manufactured by CNOOC Shell.

[0039] Based on the mass fraction of the first high-pressure low-density polyethylene, the raw materials for preparing the outer layer include 10-50 parts of the first linear low-density polyethylene, preferably 20-40 parts; the melt index of the first linear low-density polyethylene is 2 g / 10 min, and the density is 0.918 g / cm³. 3 In a specific embodiment of the present invention, the first linear low-density polyethylene is preferably of type 201XV and manufactured by Exxon.

[0040] Based on the mass fraction of the first high-pressure low-density polyethylene, the raw materials for preparing the outer layer include 0.5 to 1 part of processing aids, preferably 0.6 to 0.8 parts; the melt index of the processing aids used in the outer layer is preferably 1.8 to 3.0 g / min, more preferably 2.3 g / min, and the density is preferably 0.925 to 0.940 g / cm³. 3 More preferably, it is 0.932 g / cm³. 3 The processing aid is preferably a functional masterbatch prepared from fluoropolymer and polyolefin resin; in a specific embodiment of the present invention, the processing aid used in the outer layer is preferably PA0895LD, with a melt index of 2.3 g / min and a density of 0.932 g / cm³. 3 The manufacturer is Suzhou Constance Engineering Plastics Co., Ltd.; the above-mentioned processing aids used in this invention can effectively reduce die accumulation, reduce crystal points, lower extrusion pressure, and improve production efficiency.

[0041] By mass, the raw materials for preparing the middle layer include 30-90 parts, preferably 40-80 parts, of second high-pressure low-density polyethylene; the melt index of the second high-pressure low-density polyethylene is 6-8 g / 10 min, preferably 7 g / 10 min, and the density is 0.915-0.925 g / cm³. 3 The preferred value is 0.918 g / cm³. 3 In a specific embodiment of the present invention, the second high-pressure low-density polyethylene is preferably 1C7A, with a melt index of 7 g / 10 min and a density of 0.918 g / cm³. 3 The manufacturer is Yanshan Petrochemical; the second high-pressure low-density polyethylene has good tear and processability.

[0042] Based on the weight percentage of the second high-pressure low-density polyethylene, the raw materials for preparing the middle layer include 20-60 parts of the second linear low-density polyethylene, preferably 30-50 parts; the melt index of the second linear low-density polyethylene is 2 g / 10 min, and the density is 0.918 g / cm³. 3 In a specific embodiment of the present invention, the second linear low-density polyethylene is preferably of type 201KI and manufactured by Exxon.

[0043] Based on the weight percentage of the second high-pressure low-density polyethylene, the raw materials for preparing the middle layer include 0.5 to 1 part of processing aids, preferably 0.6 to 0.8 parts; the melt index, density and specific type of the processing aids used in the middle layer are the same as those used in the outer layer, and will not be repeated here.

[0044] The inner layer is prepared from 30-90 parts, preferably 40-80 parts, of a third high-pressure low-density polyethylene, by weight. The melt index of the third high-pressure low-density polyethylene is 2 g / 10 min, and its density is 0.918 g / cm³. 3 In a specific embodiment of the present invention, the third high-pressure low-density polyethylene is model 2420H and is manufactured by CNOOC Shell.

[0045] Based on the mass fraction of the third high-pressure low-density polyethylene, the raw materials for preparing the inner layer include 10 to 50 parts of metallocene polyethylene, preferably 20 to 40 parts; the melt index of the metallocene polyethylene is 2 g / 10 min, and the density is 0.918 g / cm³. 3 In a specific embodiment of the present invention, the metallocene polyethylene is model 2018MB and is manufactured by Exxon.

[0046] Based on the mass fraction of the third high-pressure low-density polyethylene, the raw materials for preparing the inner layer include 10-20 parts of medium-density polyethylene, preferably 13-16 parts; the medium-density polyethylene has a melt index of 0.8 g / 10 min and a density of 0.935 g / cm³. 3 In a specific embodiment of the present invention, the medium-density polyethylene is of type 2038.68 and is manufactured by Dow Chemical.

[0047] Based on the mass fraction of the third high-pressure low-density polyethylene, the raw materials for preparing the inner layer include 1 to 5 parts of antistatic agent, preferably 2 to 4 parts; the melt index of the antistatic agent is preferably 18 to 22 g / 10 min, more preferably 20 g / 10 min, and the density is preferably 0.950 to 0.965 g / cm³. 3 More preferably, it is 0.96 g / cm³. 3 In a specific embodiment of the present invention, the antistatic agent is model VLA55, manufactured by Shulman. The antistatic agent used in this invention has good processing properties, effectively reducing powder adhesion and improving heat-sealing performance.

[0048] Based on the mass fraction of the third high-pressure low-density polyethylene, the raw materials for preparing the inner layer include 0.5 to 1 part of processing aids, preferably 0.6 to 0.8 parts. The melt index, density, and specific type of the processing aids used in the inner layer are the same as those used in the outer layer, and will not be repeated here.

[0049] In this invention, with the total mass of the outer layer, middle layer and inner layer as 100%, the mass fraction of the outer layer is preferably 25-30%, the mass fraction of the middle layer is preferably 40-50%, and the mass fraction of the inner layer is preferably 25-30%; the thickness of the non-stick powder easy-tear film in both directions is preferably 40-130 μm, more preferably 80 μm.

[0050] In this invention, the longitudinal tensile strength of the non-stick, easy-tear film is preferably 27-31 MPa, more preferably 27.7-30.3 MPa, the transverse tensile strength is preferably 16-17.5 MPa, more preferably 16.5-17.3 MPa, the longitudinal elongation at break is preferably 180-190%, the transverse elongation at break is preferably 560-590%, more preferably 565-586%, the longitudinal trouser tear force is preferably less than 1 N, more preferably 0.3-0.4 N, and the transverse trouser tear force is preferably less than 1 N, more preferably 0.4-0.5 N.

[0051] The present invention also provides a method for preparing the non-stick, cross-sectional, and transverse easy-tear film described in the above-mentioned scheme, comprising the following steps:

[0052] The raw materials for the outer, middle, and inner layers are co-extruded and blown into a film to obtain the non-sticky, easily tearable film in both the longitudinal and transverse directions.

[0053] In this invention, the process of three-layer co-extrusion blown film specifically includes: feeding the raw materials for the preparation of the outer layer, middle layer and inner layer into the outer layer, middle layer and inner layer extruders respectively for melt plasticization, conveying the obtained adhesive liquid to the die head, extruding and blowing film to obtain film bubbles, and after the film bubbles are cooled, performing bubble stabilization, upper traction, corona treatment, edge trimming, lower traction and winding in sequence to obtain the non-stick powder easy-tear film in both longitudinal and transverse directions.

[0054] In this invention, the outer extruder, middle extruder, and inner extruder are each equipped with five heating zones, which are sequentially designated as zones 1 to 5 according to the order in which the raw materials pass through. The preferred temperatures for zones 1, 2, 3, 4, and 5 of the outer extruder are 150±5℃, 160±5℃, 158±5℃, and 158±5℃, respectively. For the middle extruder, the preferred temperatures for zones 1, 2, 3, 4, and 5 are 145±5℃, 150±5℃, 150±5℃, and 150±5℃, respectively. For the inner extruder, the preferred temperatures for zones 1, 2, 3, 4, and 5 are 165±5℃, 175±5℃, 175±5℃, 173±5℃, and 170±5℃, respectively.

[0055] In this invention, the pressure of the outer extruder is preferably 355 bar, the pressure of the middle extruder is preferably 308 bar, and the pressure of the inner extruder is preferably 386 bar.

[0056] In this invention, the mold head is divided into 4 heating zones, which are numbered 1 to 4 according to the order in which the adhesive passes through. The temperature of zone 1 of the mold head is preferably 170±5℃, the temperature of zone 2 is preferably 173±5℃, the temperature of zone 3 is preferably 175±5℃, and the temperature of zone 4 is preferably 175±5℃.

[0057] This invention also provides the application of the non-stick, transversely tearable film described in the above-described scheme or the non-stick, transversely tearable film prepared by the above-described preparation method in powder packaging. This invention does not have special requirements regarding the type of powder; it can specifically be flour, milk powder, soy milk powder, pepper powder, or medicinal powder.

[0058] The technical solutions of this invention will be clearly and completely described below with reference to the embodiments thereof. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0059] The manufacturers, melt indexes, and densities of the raw materials used in the following examples are shown in Table 1.

[0060] Table 1 Raw material manufacturers, melt index, and density

[0061]

[0062] Example 1

[0063] The non-stick, easy-tear film in this embodiment is made of three co-extruded blown film layers: an outer layer, a middle layer, and an inner layer. The weight percentages of the materials in each of the three layers are as follows: 30% for the outer layer, 40% for the middle layer, and 30% for the inner layer.

[0064] The amount of raw materials used in each layer is shown in Table 2. The total thickness of the non-stick powder and the easy-tear film in both directions is 80 μm. The preparation method is as follows:

[0065] The raw materials for the outer, middle, and inner layers are mixed in proportion by an automatic batching system and then fed into the outer, middle, and inner layer extruders. After the raw materials are melted and plasticized, they are fed into the die head for extrusion and blown film. After being cooled by air, the film is flattened by the stabilizing ring and herringbone arrangement and then enters the corona treatment device for corona treatment via guide rollers. After the edges are trimmed, the film is wound into the front and rear winding devices via the lower traction clamping rollers to obtain a non-stick, easy-tear film in both directions.

[0066] The temperatures and pressures of the outer, middle, and inner layer extruders and dies are shown in Table 3.

[0067] Table 2. Raw material usage (parts by mass) for Examples 1-3 and Comparative Example 2

[0068]

[0069] Table 3 Temperature and pressure of extruder and die head

[0070] temperature Zone 1 / ℃ Zone 2 / ℃ Zone 3 / ℃ Zone 4 / ℃ 5 zones / ℃ Pressure (bar) outer layer 150 160 160 158 158 355 Middle layer 145 150 150 150 150 308 Inner layer 165 175 175 173 170 386 mold head 170 173 175 175 / /

[0071] Example 2

[0072] The non-stick, easy-tear film in this embodiment is made by co-extrusion blown film of three layers: outer layer, middle layer, and inner layer. The weight percentage of each layer is as follows: outer layer 30%, middle layer 40%, and inner layer 30%. The amount of raw materials used in each layer is shown in Table 2. The preparation method is the same as in Example 1, and the film thickness is 80 μm.

[0073] Example 3

[0074] The non-stick, easy-tear film in this embodiment is made by co-extrusion blown film of three layers: outer layer, middle layer, and inner layer. The weight percentage of each layer is as follows: outer layer 30%, middle layer 40%, and inner layer 30%. The amount of raw materials used in each layer is shown in Table 2. The preparation method is the same as in Example 1, and the film thickness is 80 μm.

[0075] Comparative Example 1

[0076] The polyethylene film in this embodiment is made by co-extrusion blown film of three layers: outer layer, middle layer, and inner layer. The weight percentages of the materials in each layer are as follows: outer layer 30%, middle layer 40%, and inner layer 30%. The raw material 1C7A in the middle layer is replaced with 2426H, manufactured by CNOOC Shell, and the specific dosage is shown in Table 4. The preparation method is the same as in Example 1, and the film thickness is 80 μm.

[0077] Table 4 Comparative Example 1 Raw Material Usage

[0078]

[0079] Comparative Example 2

[0080] The polyethylene film in this comparative example is made by co-extrusion blown film of three layers: outer layer, middle layer and inner layer. The weight percentage of each layer is as follows: outer layer 30%, middle layer 40%, and inner layer 30%. The raw material usage of each layer is shown in Table 2. The preparation method is the same as in Example 1, and the film thickness is 80 μm.

[0081] Performance testing:

[0082] The mechanical properties, tear strength, and powder adhesion of the films prepared in Examples 1-3 and Comparative Examples 1-2 were tested, and the results are shown in Table 5. The method for testing powder adhesion was as follows: soy milk powder was sprinkled on the heat-sealed cover (inner layer) of the film, shaken to ensure full contact between the soy milk powder and the heat-sealed cover, and then the soy milk powder was poured out to observe whether powder adhered.

[0083] Table 5 Performance Test Results

[0084]

[0085] As can be seen from the data in Table 1, the non-stick powder easy-tear film prepared by the present invention has excellent mechanical properties in both longitudinal and transverse directions, and has low tear strength, making it easy to tear and convenient to open the packaging.

[0086] Figure 1 The results show the powder adhesion test of the non-stick, easy-tear film prepared in Example 1 of this invention in both longitudinal and transverse directions. Figure 2 The results show the powder adhesion test results of the polyethylene film prepared in Comparative Example 2. Figures 1-2 It can be seen that the film prepared in Example 1 does not stick to powder, while the film prepared in Comparative Example 2 has more powder stuck to its surface.

[0087] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A non-stick, easy-tear film in both directions, characterized in that, It is made of three layers: outer layer, middle layer, and inner layer, through co-extrusion blown film. The outer layer is prepared by the following raw materials in parts by weight: 30-90 parts of first high-pressure low-density polyethylene, 10-50 parts of first linear low-density polyethylene, and 0.5-1 part of processing aids. The raw materials for preparing the middle layer are, by mass parts: 30-90 parts of second high-pressure low-density polyethylene, 20-60 parts of second linear low-density polyethylene, and 0.5-1 parts of processing aids; The raw materials for preparing the inner layer are, by mass parts: 30-90 parts of third high-pressure low-density polyethylene, 10-50 parts of metallocene polyethylene, 10-20 parts of medium-density polyethylene, 1-5 parts of antistatic agent, and 0.5-1 parts of processing aid. The first high-pressure low-density polyethylene has a melt index of 2 g / 10 min and a density of 0.924 g / cm³. 3 The first linear low-density polyethylene has a melt index of 2 g / 10 min and a density of 0.918 g / cm³. 3 ; The second high-pressure low-density polyethylene has a melt index of 6~8 g / 10min and a density of 0.915~0.925 g / cm³. 3 The second linear low-density polyethylene has a melt index of 2 g / 10 min and a density of 0.918 g / cm³. 3 ; The third high-pressure low-density polyethylene has a melt index of 2 g / 10 min and a density of 0.918 g / cm³. 3 The longitudinal tear strength of the non-stick, easy-tear film is less than 1N for trousers and less than 1N for trousers. The metallocene polyethylene has a melt index of 2 g / 10 min and a density of 0.918 g / cm³. 3 ; The medium-density polyethylene has a melt index of 0.8 g / 10 min and a density of 0.935 g / cm³. 3 ; The antistatic agent has a melt index of 18-22 g / 10 min and a density of 0.950-0.965 g / cm³. 3 ; The processing aids used in the outer, middle, and inner layers have a melt index of 1.8–3.0 g / 10 min and a density of 0.925–0.940 g / cm³. 3 .

2. The non-stick, easy-tear film according to claim 1, characterized in that, The first high-pressure low-density polyethylene is of type 2426H, and the first linear low-density polyethylene is of type 201XV. The second high-pressure low-density polyethylene is of type 1C7A; the second linear low-density polyethylene is of type 201KI.

3. The non-stick, easy-tear film according to claim 1, characterized in that, The third high-pressure low-density polyethylene is model 2420H, the metallocene polyethylene is model 2018MB, the medium-density polyethylene is model 2038.68, and the antistatic agent is model VLA55.

4. The non-stick, easy-tear film according to claim 1, characterized in that, The processing aid used in the outer, middle and inner layers is PA0895LD.

5. The non-stick, easy-tear film according to claim 1, characterized in that, With the total mass of the outer, middle, and inner layers as 100%, the mass fraction of the outer layer is 25-30%, the mass fraction of the middle layer is 40-50%, and the mass fraction of the inner layer is 25-30%; the thickness of the non-stick powder easy-tear film in both the longitudinal and transverse directions is 40-130 μm.

6. The method for preparing the non-stick, cross-sectional, easy-tear film according to any one of claims 1 to 5, characterized in that, Includes the following steps: The raw materials for the preparation of the outer, middle and inner layers are co-extruded and blown into a film to obtain the non-sticky powder easy-tear film in both the longitudinal and transverse directions.

7. The preparation method according to claim 6, characterized in that, The process of the three-layer co-extrusion blown film specifically includes: feeding the raw materials for the preparation of the outer layer, middle layer and inner layer into the outer layer, middle layer and inner layer extruders respectively for melting and plasticizing, conveying the obtained adhesive liquid to the die head, extruding and blowing film to obtain film bubbles, and after the film bubbles are cooled, performing bubble stabilization, upper traction, corona treatment, edge trimming, lower traction and winding in sequence to obtain the non-stick powder easy-tear film in both longitudinal and transverse directions.

8. The preparation method according to claim 7, characterized in that, The outer, middle, and inner extruders are each equipped with five heating zones, numbered 1 to 5 according to the order in which the raw materials pass through. The temperatures of zones 1, 2, 3, 4, and 5 of the outer extruder are 150±5℃, 160±5℃, 158±5℃, and 158±5℃, respectively. The temperatures of zones 1, 2, 3, 4, and 5 of the middle extruder are 145±5℃, 150±5℃, 150±5℃, 150±5℃, and 150±5℃, respectively. The temperatures of zones 1, 2, 3, 4, and 5 of the inner extruder are 165±5℃, 175±5℃, 175±5℃, 173±5℃, and 170±5℃, respectively. The mold head is divided into 4 heating zones, which are numbered 1 to 4 according to the order in which the adhesive passes through. The temperature of zone 1 is 170±5℃, zone 2 is 173±5℃, zone 3 is 175±5℃, and zone 4 is 175±5℃.

9. The application of the non-stick powder easy-tear film according to any one of claims 1 to 5 or the non-stick powder easy-tear film prepared by the preparation method according to any one of claims 6 to 8 in powder packaging.

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