Simulated tissue paper environment-friendly recoverable composite membrane and preparation method thereof

Abstract

The invention belongs to the technical field of thin films, and particularly relates to a tissue paper-imitated environment-friendly recoverable composite film and a preparation method thereof. The material disclosed by the invention is formed by compounding an outer film and an inner film by adopting an adhesive through a solvent-free compounding machine; the outer film is prepared from a layer A, a layer B and a layer C which are sequentially connected through three-layer co-extrusion film blowing stretching, the inner film is prepared from a layer D, a layer E and a layer F which are sequentially connected through three-layer co-extrusion film blowing stretching, and the layer A is connected with the layer D. The imitated tissue paper environment-friendly recoverable composite film product is similar to paper in appearance, soft in touch feeling, high in sealing strength and high in tensile strength.

Description

Technical Field

[0001] The invention relates to the technical field of thin films, in particular to an environmentally friendly and recyclable composite film similar to tissue paper and a preparation method thereof. Background Art

[0002] The existing fields of single composite material technology are innovating and expanding in the direction of single material recycling, functionalization, alloying, modification and thinning, so as to promote the environmentally friendly and recyclable composite packaging, carbon reduction, low carbon, green and circular sustainable development.

[0003] The existing paper-feel packaging in China must use paper plastic or paper-feel coating to achieve texture. These two methods are not only difficult to recycle and have high stiffness, but also produce organic gas emissions during the production process. The sealing strength and tensile strength are both low, and cannot meet the client's anti-deformation performance requirements when used on automatic high-speed packaging lines and the heat resistance requirements during heat sealing. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a tissue paper-like environmentally friendly recyclable composite film and a preparation method thereof. The tissue paper-like environmentally friendly recyclable composite film has an appearance similar to paper, a soft touch, high sealing strength and high tensile strength.

[0005] In order to achieve one of the purposes of the present invention, the present invention adopts the following technical solutions:

[0006] A tissue paper-like environmentally friendly recyclable composite film, the material is made of an outer film and an inner film compounded by an adhesive through a solvent-free compounding machine; the outer film is made by three-layer co-extrusion blown film stretching of sequentially connected A layer, B layer and C layer, and the inner film is made by three-layer co-extrusion blown film stretching of sequentially connected D layer, E layer and F layer, and the A layer is connected to the D layer.

[0007] Preferably, layer A and layer C are both composed of 25-30 parts by mass of polyolefin plastomer (POE), 69-74 parts by mass of inorganic masterbatch and 1 part by mass of processing aid; layer B is composed of 15 parts by mass of metallocene low-density polyethylene, 70-75 parts by mass of inorganic masterbatch, 9-14 parts by mass of high-pressure polyethylene and 1 part by mass of processing aid.

[0008] Preferably, the grade of the polyolefin plastomer is PL1881 produced by Dow Chemical Company, the grade of the metallocene low-density polyethylene is 2012MC produced by Exxon, the grade of the high-pressure polyethylene is 2420H produced by Yangzi Petrochemical Company, and the grade of the processing aid is 100991-K produced by Beijing Aaron Company; the inorganic masterbatch is made by blending the metallocene low-density polyethylene and powdered calcium carbonate in a mass ratio of 1:1 through a twin-screw granulator, and the grade of the powdered calcium carbonate is Flim Link520 produced by Inge Ceramics Company.

[0009] Preferably, the D layer and the F layer are composed of 40-50 parts by mass of polyolefin plastomer, 29-39 parts by mass of metallocene low-density polyethylene, 20 parts by mass of high-pressure polyethylene and 1 part by mass of processing aid; the E layer is composed of 50 parts by mass of metallocene low-density polyethylene, 22 parts by mass of white masterbatch, 27 parts by mass of high-pressure polyethylene and 1 part by mass of processing aid.

[0010] Preferably, the brand of the polyolefin plastomer is PL1881 produced by Dow Chemical Company, the brand of the metallocene low-density polyethylene is 2012MC produced by Exxon, the brand of the high-pressure polyethylene is 2420H produced by Yangzi Petrochemical Company, the brand of the white masterbatch is EM9016 produced by Huangshan Shangfu Company, and the white masterbatch is extruded by blending titanium dioxide and polyethylene; the brand of the processing aid is 100991-K produced by Beijing Aaron Company.

[0011] Among them, the density of polyolefin plastomer is 0.904g / cm 3 , melt index is 1.0g / 10min.190℃ / 2.16kg; density of metallocene low-density polyethylene is 0.912g / cm 3 , the melt index is 2.0g / 10min.190℃ / 2.16kg; the density of calcium carbonate is 2.7-2.95g / cm 3 The density of inorganic masterbatch after twin-screw blending is 1.72-1.78g / cm 3 , melt index is 1.2-2.0g / 10min.190℃ / 2.16kg; density of high pressure polyethylene is 0.925g / cm 3 , melt index is 2.0g / 10min.190℃ / 2.16kg; density of processing aid is 0.940g / cm 3 , the melt index is 2.5g / 10min.190℃ / 2.16kg.

[0012] Preferably, the thickness ratio of layer A, layer B and layer C is (20-30):(40-60):(20-30); the thickness ratio of layer D, layer E and layer F is (20-30):(40-60):(20-30).

[0013] Preferably, the mass ratio of the main agent to the curing agent in the adhesive is 100:70, the brand of the main agent is LA7728 produced by Henkel, and the brand of the curing agent is LA6028 produced by Henkel.

[0014] The viscosity of the main agent is 1125±275mpas and the density is 1.17g / cm 3 ; The viscosity of the curing agent is 5000±2000mpas and the density is 1.10g / cm3 The viscosity of the two components after mixing at 40°C is 1500mpas; a sleeve-type silicone roller is used to transfer the adhesive from the metering steel rod to the quantitative steel rod, and the glue is applied by outer film, and the glue amount is 1.4±0.3g / m 2 .

[0015] In order to achieve the second object of the present invention, the present invention provides a method for preparing an environmentally friendly and recyclable composite film similar to tissue paper, comprising the following steps:

[0016] S1. Preparation of outer film: The materials of layer A, layer B and layer C are respectively put into the barrel of the film blowing machine for melt co-extrusion, and sequentially undergo extrusion melting, bubble pulling, automatic side thickness, bubble stopping, primary traction, MDO stretching and shaping, corona, secondary traction and winding to form a film bubble to obtain a three-layer co-extrusion blown outer film;

[0017] S2. Preparation of inner film: the materials of layer D, layer E and layer F are respectively put into the barrel of the film blowing machine for melt co-extrusion, and the processes of extrusion melting, bubble pulling, automatic side thickness, bubble stopping, primary traction, corona, secondary traction and winding are carried out in sequence to form film bubbles to obtain a three-layer co-extrusion blown inner film;

[0018] S3, the outer film and the inner film are suspended and stored for 24 hours, and then composited by an adhesive through a solvent-free composite machine to obtain a composite film.

[0019] Preferably, in step S1, the melting section temperature of the film blowing machine is 40-80°C, the extrusion section temperature is 185-195°C, the die head temperature is 190°C, and the extrusion volume is 500-630kg / h; the blowing ratio of the bubble is 1:(1.5-2.8); the tension of the first traction is 150N, the tension of the second traction is 120N, and the pressing force of the winding is 100N-200N to ensure the normal operation of the base film; the rotation time of the automatic side thickness is 35min-60min to ensure that each point of the film can be stably and automatically adjusted to ensure the uniformity of the film thickness; the stretching ratio of MDO stretching and shaping is 3.8-5.0, and the eight roller temperature settings are such as PH175°C, PH285°C, SD roller 90°C, FD roller temperature 94°C, shaping roller AD195°C, AD2 95°C, cooling roller CD1 temperature 40°C, CD230°C, to ensure the smooth operation of the film.

[0020] Preferably, in step S2, the melting section temperature of the film blowing machine is 40-80°C, the extrusion section temperature is 185-195°C, the die head temperature is 190°C, and the extrusion volume is 500-630kg / h; the blowing ratio of the bubble is 1:(1.2-2.5); the tension of the first traction is 120N, the tension of the second traction is 80N, and the clamping force of the winding is 80N-120N to ensure the normal operation of the base film; the rotation time of the automatic side thickness is 55min-85min to ensure that each point of the film can be stably and automatically adjusted to ensure the uniformity of the film thickness.

[0021] The composite film material after solvent-free compounding can then pass through a corona machine to make the surface energy of the composite film reach more than 38 dynes. The composite film material can be subsequently processed by printing, gluing, etc. The material can simulate recycling disposal, and the film material can be rolled up or cut into pieces, and directly used in a twin-screw or single-screw granulator at a temperature of 190 degrees Celsius to present a uniform white masterbatch with uniform color. No smoke or odor is generated during the granulation process. The recycled masterbatch can continue to be used as packaging express bags, industrial packaging bags, etc.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1) The present invention forms a cotton paper-like environment-friendly green composite film material by compounding an outer film and an inner film with a special solvent-free adhesive. The whole preparation process is green and environmentally friendly. The product has a similar appearance to paper, is soft to the touch, has high sealing strength, high tensile strength, etc., and can meet the needs of the client's automatic high-speed packaging line for anti-deformation ability and good heat resistance during heat sealing. It has changed consumers' perception of plastic packaging, fully embodies the soft, hygienic, silky and other characteristics of the packaged items, and fills the gap in the domestic paper-feel packaging that must use paper plastic and paper-feel coating to achieve texture. At the same time, the process production greatly improves the problems of difficult recycling, high stiffness, and organic gas emissions of packaging composite films in traditional processes.

[0024] 2) The cotton-like soft functional composite film of the present invention is composed of a multi-layer structure, using a high molecular polymer as a substrate, and its microstructure is regulated by a special additive (POE), giving the membrane material excellent flexibility and good mechanical strength, so that the final composite film has the advantages of cotton-like softness, high tensile strength, excellent sealing performance, single material recyclability, and thinning.

[0025] 3) In the present invention, the outer membrane adopts an inorganic filler blending design, so that the surface of the composite membrane has special softness and elasticity, simulating the touch of natural fabrics, and enhancing the affinity and comfort of the product; the composite membrane not only has excellent air permeability, but is also suitable for occasions such as medical dressings and smart wearable devices that require balancing the humidity of the internal and external environments; and a recyclable single material is selected, combined with an environmentally friendly preparation process, to ensure that the composite membrane can be re-degraded after recycling, thereby reducing environmental pollution and achieving environmentally friendly recyclability.

[0026] 4) Advantages of the composite membrane of the present invention compared with the prior art:

[0027] ①. It can significantly improve the user experience. The design of soft cotton touch makes the composite film material more skin-friendly and comfortable in touch, especially in products that directly contact the skin, which significantly improves user satisfaction;

[0028] ②. The comprehensive performance is better. It not only maintains the air permeability and excellent mechanical and physical properties of traditional membrane materials, but also realizes new functions such as antibacterial and recyclable through structural penetration, which can meet the needs of more customers and the market trend of recyclability.

[0029] ③. It has a wider application prospect. With its unique performance combination, the composite film has broad application prospects in packaging, medical treatment, environmental protection, electronic protection and other fields. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present invention.

[0031] Example 1

[0032] A kind of environmentally friendly and recyclable composite film similar to cotton paper, the proportion of its materials is shown in the following table 1:

[0033] Table 1

[0034]

[0035] A tissue paper-like environmentally friendly recyclable composite film and a preparation method thereof, comprising the following steps:

[0036] S1. Preparation of outer film: The materials of layer A, layer B and layer C are respectively put into the barrel of the film blowing machine for melt co-extrusion, and sequentially undergo extrusion melting, bubble pulling, automatic side thickness, bubble stopping, primary traction, MDO stretching and shaping, corona, secondary traction and winding to form a film bubble to obtain a three-layer co-extrusion blown outer film;

[0037] Among them, the melting section temperature of the film blowing machine is 50℃, the extrusion section temperature is 190℃, the die head temperature is 190℃, and the extrusion volume is 530kg / h; the blowing ratio of the bubble is 1:2.2; the primary traction tension is set to 150N, the secondary traction tension is 120N, and the winding pressure is 140N to ensure the normal operation of the base film; the rotation time of the automatic side thickness is 80min to ensure that each point of the base film can be stably and automatically adjusted to ensure the uniformity of the thickness of the base film; the MDO stretching ratio is 4.065, and the eight-roll temperature parameters are set to PH170℃, PH285℃, SD roller 90℃, FD roller temperature 95℃, shaping roller AD192℃, shaping roller AD294℃, cooling roller CD150℃, CD230℃ to ensure the flatness and shaping of the base film and the stability of the line speed.

[0038] S2. Preparation of inner film: the materials of layer D, layer E and layer F are respectively put into the barrel of the film blowing machine for melt co-extrusion, and the processes of extrusion melting, bubble pulling, automatic side thickness, bubble stopping, primary traction, corona, secondary traction and winding are carried out in sequence to form film bubbles to obtain a three-layer co-extrusion blown inner film;

[0039] Among them, the melting section temperature of the film blowing machine is 50℃, the extrusion section temperature is 180℃, the die head temperature is 180℃, and the extrusion volume is 520kg / h; the blowing ratio of the bubble is 1:1.8; the primary traction tension is set to 150N, the secondary traction tension is 70N, and the winding clamping force is 100N to ensure the normal operation of the base film; the rotation time of the automatic side thickness is 35min to ensure that each point of the base film can be stably and automatically adjusted to ensure the uniformity of the thickness of the base film.

[0040] S3, the outer film and the inner film are suspended and stored for 24 hours, and then composited by an adhesive through a solvent-free composite machine to obtain a composite film 1.

[0041] Example 2

[0042] A kind of environmentally friendly and recyclable composite film similar to cotton paper, the proportion of its materials is shown in Table 2 below:

[0043] Table 2

[0044]

[0045]

[0046] A tissue paper-like environmentally friendly recyclable composite film and a preparation method thereof, comprising the following steps:

[0047] S1. Preparation of outer film: The materials of layer A, layer B and layer C are respectively put into the barrel of the film blowing machine for melt co-extrusion, and sequentially undergo extrusion melting, bubble pulling, automatic side thickness, bubble stopping, primary traction, MDO stretching and shaping, corona, secondary traction and winding to form a film bubble to obtain a three-layer co-extrusion blown outer film;

[0048] Among them, the melting section temperature of the film blowing machine is 50℃, the extrusion section temperature is 190℃, the die head temperature is 190℃, and the extrusion volume is 510kg / h; the blowing ratio of the bubble is 1:2.2; the primary traction tension is set to 120N, the secondary traction tension is 70N, and the winding pressure is 140N to ensure the normal operation of the base film; the automatic side thickness rotation time is 80min to ensure that each point of the base film can be stably and automatically adjusted to ensure the uniformity of the thickness of the base film; the MDO stretching ratio is 4.212, and the eight-roll temperature parameters are set to PH170℃, PH285℃, SD roller 90℃, FD roller temperature 90℃, shaping roller AD192℃, shaping roller AD292℃, cooling roller CD130℃, CD220℃ to ensure the flatness and shaping of the base film and the stability of the line speed.

[0049] S2. Preparation of inner film: the materials of layer D, layer E and layer F are respectively put into the barrel of the film blowing machine for melt co-extrusion, and the processes of extrusion melting, bubble pulling, automatic side thickness, bubble stopping, primary traction, corona, secondary traction and winding are carried out in sequence to form film bubbles to obtain a three-layer co-extrusion blown inner film;

[0050] Among them, the melting section temperature of the film blowing machine is 55°C, the extrusion section temperature is 182°C, the die head temperature is 182°C, the extrusion volume is 520kg / h, and the blowing ratio of the bubble is 1:1.8; the primary traction tension is set to 130N, the secondary traction tension is 70N, and the winding clamping force is 90N to ensure the normal operation of the base film; the automatic side thickness rotation time is 55min to ensure that each point of the base film can be stably and automatically adjusted to ensure the uniformity of the base film thickness.

[0051] S3, the outer film and the inner film are suspended and stored for 24 hours, and then composited by an adhesive through a solvent-free composite machine to obtain a composite film 2.

[0052] The composite film 1-2 prepared in the above embodiment 1-2 and the ordinary PE white film / PE white film were tested for performance, and the comparison results are shown in Table 3 below:

[0053] Table 3

[0054]

[0055]

[0056] Among them, tensile strength: measures the toughness of the film, tensile strength, and composite film crack resistance to meet the requirements;

[0057] 10% tensile force: an indicator to measure the film's ability to resist deformation during processing;

[0058] Elongation at break %: represents film toughness, deformation resistance, etc.;

[0059] Friction coefficient: The surface friction coefficient value, 0.40-0.6 is close to the parameters of tissue paper;

[0060] Interlayer peel strength: The interlayer bonding strength of the composite film is used to measure the material strength and tearability.

[0061] Right-angle tear: measures the tearability of packaging materials;

[0062] Flexural modulus: an indicator to measure the softness of the composite film;

[0063] Puncture strength: an indicator to measure the toughness of the film and its ability to resist product puncture;

[0064] Glossiness: measures the surface texture of cotton paper, the higher the value, the worse the texture;

[0065] Whiteness: Measures the hiding power of film materials. The higher the value, the closer it is to tissue paper.

[0066] As can be seen from Table 3 above, the elastic modulus, appearance and feel of tissue paper, whiteness, sealing performance, etc. of the product of the present invention are significantly better than those of PE white film / PE white film material products. Therefore, the composite film of the present invention has good toughness and tensile strength, can meet the requirements of the packaging material to withstand various external forces during use, and has good ductility, thereby improving its safety and stability during use; and the friction coefficient range of 0.4-0.6 is close to the parameters of tissue paper, which helps to give the composite film material a tissue paper-like touch and improve user experience; the lower bending modulus indicates that the composite film is softer and easier to adapt to packaging requirements of different shapes and sizes, which is of great significance for improving the aesthetics of the packaging and user experience, and the lower glossiness and higher whiteness make the film look more natural and soft, which helps to improve the overall visual effect of the packaging, which is fully in line with the development prospects of the industry.

[0067] In step S3 of Example 1-2, the temperature of the glue mixer is 42±2°C, the temperature of the glue delivery pipe is 42°C, the temperature of the fixed roller and the metering roller is set to 42°C, the coating roller is stably set to 55°C, the pressure of the transfer roller and the pressure roller is set to 0.4Mpa, and the gap between the fixed roller and the metering roller is set to 80±5um; the speed ratio of the metering roller and the transfer roller is 20% to ensure that the glue can be evenly spread and the amount of glue applied is stable; the unwinding tension is set to 10±2kg, the second unwinding tension is 5±2kg, the drying tunnel tension is 6±2kg, the winding tension is 10±2kg, the winding tension decrease curve is 75%, and the winding pressure roller pressure is 0.4±0.05Mpa; the solvent-free laminating machine is started at a line speed of 280±20 meters / min, and the machine is placed horizontally after winding, and the aging condition is 45°C oven aging for 24 hours; after aging, printing, gluing and other processing can be carried out.

[0068] The present invention belongs to the technical field of single composite material composite packaging, and has new breakthroughs in eliminating the plastic feeling, recyclability, thinning and low carbon, shading rate (whiteness) and other functions. Compared with the traditional polyethylene composite film material, it has obvious advantages, and the consumer experience is very novel, which promotes consumer desire and product expression. It can be widely used in daily paper packaging, clothing, gifts, labels and other packaging, and has obvious advantages in cost control, recycling and reuse, and simple recycling and disposal.

Claims

1. A tissue paper-like environmentally friendly recyclable composite film, characterized in that: The material is made of an outer film and an inner film compounded by an adhesive through a solvent-free compounding machine; the outer film is made by three-layer co-extrusion blown film stretching of sequentially connected A layer, B layer and C layer, and the inner film is made by three-layer co-extrusion blown film stretching of sequentially connected D layer, E layer and F layer, and the A layer is connected to the D layer.

2. The environmentally friendly and recyclable composite film similar to tissue paper according to claim 1, characterized in that: The A layer and the C layer are both composed of 25-30 parts by mass of polyolefin plastomer, 69-74 parts by mass of inorganic masterbatch and 1 part by mass of processing aid; the B layer is composed of 15 parts by mass of metallocene low-density polyethylene, 70-75 parts by mass of inorganic masterbatch, 9-14 parts by mass of high-pressure polyethylene and 1 part by mass of processing aid.

3. The environmentally friendly and recyclable composite film similar to tissue paper according to claim 2, characterized in that: The brand of the polyolefin plastomer is PL1881 produced by Dow Chemical Company, the brand of the metallocene low-density polyethylene is 2012MC produced by Exxon, the brand of the high-pressure polyethylene is 2420H produced by Yangzi Petrochemical Company, and the brand of the processing aid is 100991-K produced by Beijing Aaron Company; the inorganic masterbatch is prepared by blending metallocene low-density polyethylene and powdered calcium carbonate in a mass ratio of 1:1 through a twin-screw granulator, and the brand of the powdered calcium carbonate is Flim Link520 produced by Ingersoll-Maldives.

4. The environmentally friendly and recyclable composite film similar to tissue paper according to claim 1, characterized in that: The D layer and the F layer are both composed of 40-50 parts by mass of polyolefin plastomers, 29-39 parts by mass of metallocene low-density polyethylene, 20 parts by mass of high-pressure polyethylene and 1 part by mass of processing aids; the E layer is composed of 50 parts by mass of metallocene low-density polyethylene, 22 parts by mass of white masterbatch, 27 parts by mass of high-pressure polyethylene and 1 part by mass of processing aids.

5. The environmentally friendly and recyclable composite film similar to tissue paper according to claim 4, characterized in that: The brand of the polyolefin plastomer is PL1881 produced by Dow Chemical Company, the brand of the metallocene low-density polyethylene is 2012MC produced by Exxon, the brand of the high-pressure polyethylene is 2420H produced by Yangzi Petrochemical Company, the brand of the white masterbatch is EM9016 produced by Huangshan Shangfu Company, and the brand of the processing aid is 100991-K produced by Beijing Aaron Company.

6. The environmentally friendly and recyclable composite film similar to tissue paper according to claim 1, characterized in that: The thickness ratio of the A layer, the B layer and the C layer is (20-30): (40-60): (20-30); the thickness ratio of the D layer, the E layer and the F layer is (20-30): (40-60): (20-30).

7. The environmentally friendly and recyclable composite film similar to tissue paper according to claim 1, characterized in that: The mass ratio of the main agent to the curing agent in the adhesive is 100:

70. The brand of the main agent is LA7728 produced by Henkel, and the brand of the curing agent is LA6028 produced by Henkel.

8. A method for preparing the environmentally friendly and recyclable composite film similar to tissue paper according to any one of claims 1 to 7, characterized in that: The steps include: S1. Preparation of outer film: The materials of layer A, layer B and layer C are respectively put into the barrel of the film blowing machine for melt co-extrusion, and sequentially undergo extrusion melting, bubble pulling, automatic side thickness, bubble stopping, primary traction, MDO stretching and shaping, corona, secondary traction and winding to form a film bubble to obtain a three-layer co-extrusion blown outer film; S2. Preparation of inner film: the materials of layer D, layer E and layer F are respectively put into the barrel of the film blowing machine for melt co-extrusion, and the processes of extrusion melting, bubble pulling, automatic side thickness, bubble stopping, primary traction, corona, secondary traction and winding are carried out in sequence to form film bubbles to obtain a three-layer co-extrusion blown inner film; S3, the outer film and the inner film are suspended and stored for 24 hours, and then composited by an adhesive through a solvent-free composite machine to obtain a composite film.

9. The method for preparing a tissue paper-like environmentally friendly recyclable composite film according to claim 8, characterized in that: In step S1, the melting section temperature of the film blowing machine is 40-80°C, the extrusion section temperature is 185-195°C, the die head temperature is 190°C, and the extrusion volume is 500-630kg / h; the blowing ratio of the bubble is 1:(1.5-2.8); the tension of the first traction is 150N, the tension of the second traction is 120N, and the pressing force of the winding is 100N-200N; the rotation time of the automatic side thickness is 35min-60min; the stretching ratio of the MDO stretch setting is 3.8-5.

0.

10. The method for preparing the environmentally friendly and recyclable composite film similar to tissue paper according to claim 8, characterized in that: In step S2, the melting section temperature of the film blowing machine is 40-80°C, the extrusion section temperature is 185-195°C, the die head temperature is 190°C, and the extrusion volume is 500-630kg / h; the blowing ratio of the bubble is 1:(1.2-2.5); the tension of the first traction is 120N, the tension of the second traction is 80N, and the pressing force of the winding is 80N-120N; the rotation time of the automatic side thickness is 55min-85min.

Images