A water barrier aluminum foil and a method for manufacturing the same

Abstract

This invention provides a water-blocking aluminum foil and its preparation method. The water-blocking aluminum foil comprises a shielding aluminum foil layer and a water-blocking resin layer, arranged layer by layer from the outside to the inside. The preparation process of the water-blocking aluminum foil includes the formulation and filtration of the water-blocking coating, and the coating, drying, post-curing, and winding of the water-blocking aluminum foil. Through a special dispersion process and curing conditions, a water-absorbing coating is applied to the surface of the aluminum foil, improving the uniformity of the coating on the aluminum foil surface, enhancing the film strength and film-forming effect. When the material comes into contact with water, it quickly absorbs water and expands in the thickness direction, filling the gaps between the water-blocking aluminum foil and the core material, thus achieving the water-blocking effect.

Description

Technical Field

[0001] This invention relates to the field of water-blocking aluminum foil manufacturing technology, and particularly to a water-blocking aluminum foil and its preparation method. Background Technology

[0002] Shielding tape is typically a metal braided tape or metal foil tape, widely used for shielding cables and wire harnesses, and grounding equipment enclosures. Its working principle is based on wrapping the cable with the shielding tape. When electromagnetic waves are present in the surrounding environment, the tape reflects them back to their source, reducing the spread of electromagnetic radiation. The tape also absorbs some energy, weakening the electromagnetic signal and thus achieving a shielding effect. However, most cables are currently installed underground, placing them in humid environments. Over time, moisture can seep into the cable shielding tape, causing structural damage.

[0003] Chinese patent CN1434095A discloses a water-blocking material for communication optical cables and its preparation method; CN1607413A discloses a single-layer expansion water-blocking tape for optical cables; and CN119142005A discloses an expansion water-blocking nonwoven fabric for cables, its preparation method, and its application. Their structures all involve coating a water-blocking coating onto a nonwoven fabric to form water-blocking yarn, which is used for the outer layer protection of cables and does not have a shielding effect. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention discloses a water-blocking aluminum foil and its preparation method.

[0005] The technical solution adopted in this invention is as follows: a water-blocking aluminum foil, comprising a shielding aluminum foil and a water-blocking resin layer arranged layer by layer from the outside to the inside; the water-blocking resin layer is made of solvent-based composite adhesive, which comprises the following raw materials in parts by weight: 25-40 parts of polyol resin, 1-10 parts of isocyanate curing agent, 5-20 parts of water-blocking powder, and 40-60 parts of diluent.

[0006] Furthermore, the polyol resin includes one or more of low hydroxyl value polyester polyol resins and medium-to-high hydroxyl value polyester polyol resins.

[0007] Furthermore, the isocyanate curing agent is one or more of toluene diisocyanate, diphenylmethane diisocyanate, TMP-TDI adduct, isophorone diisocyanate trimer, and hexamethylene diisocyanate trimer.

[0008] Furthermore, the water-blocking powder has a particle size of 20-2500 mesh, and the material of the water-blocking powder is one or more of sodium bentonite, calcium bentonite, and sodium polyacrylate resin.

[0009] Furthermore, the diluent is one or more selected from ethyl acetate, butyl acetate, cyclohexane, methylcyclohexane, toluene, xylene, and methyl isobutyl ketone.

[0010] Furthermore, the thickness of the aluminum foil substrate of the shielding strip is 12~100μm, and the material is any one of 1025 aluminum, 1025 aluminum-PP composite film, and 1025 aluminum-PET composite film.

[0011] Furthermore, the thickness of the water-blocking resin layer is 50-200 μm, and the water absorption swelling rate in the thickness direction is ≥8% within 10 minutes of immersion.

[0012] A method for preparing water-blocking aluminum foil, characterized by comprising the following steps: Step S1: Prepare the adhesive by mixing solvent-based composite adhesive according to the specified ratio; Step S2, filtration: The solvent-based composite adhesive is simultaneously filtered online at room temperature and pressure, with a filter element pore size of 20-120um; In step S2, a stainless steel single-core liquid filter is selected for filtration, paired with a high dirt-holding multi-layer wound meltblown polypropylene filter element, and online filtration is performed simultaneously at room temperature and pressure.

[0013] Step S3, coating: Use a comma-shaped scraper to apply solvent-based composite adhesive to the aluminum foil substrate of the shielding tape. The coating speed is controlled at 5-30m / min. In step S3, a comma-shaped doctor blade is used for coating. The gap between the two doctor blades is measured and fixed using a Mitutoyo 184-307S steel feeler gauge. Solvent-based composite adhesives are supplied continuously via online filtration to reduce solvent evaporation from the coating head. The material tank is stirred online using a reciprocating stirring rod to prevent powder settling and ensure coating uniformity. A fixed release film edge protector is added between the comma-shaped doctor blade baffle and the aluminum foil to prevent direct contact between the doctor blade and the aluminum foil while reducing friction with the aluminum foil edge, thus reducing the risk of edge curling and film breakage.

[0014] Step S4, drying: The coated shielding aluminum foil is sent into an oven for drying at a temperature of 60-120℃ for 1-10 minutes. Step S5: Rewinding. Turn on the cooling roller and rewind the dried shielding aluminum foil inward. Step S6, post-curing: Place the coated and rolled-up shielding tape into a forced-air drying oven for curing. The curing temperature is 40-60℃ and the curing time is 3-7 days.

[0015] Furthermore, in step S1, the polyol resin is first placed in a flat-plate sawtooth dispersion dish for dispersion and stirring, then the water-blocking powder is diluted and dispersed with a diluent, and then the diluted water-blocking powder is added to the polyol resin under stirring. Subsequently, the curing agent is added, and the mixture is stirred at 1000-3000 rpm for 20-40 minutes at 23°C.

[0016] Furthermore, in step S5, a 6-inch paper tube is used to wind the water-blocking resin layer inwards, while the cooling roller is turned on to accelerate the cooling of the shielding aluminum foil and the water-blocking resin layer, to prevent insufficient material cooling or excessive temperature during winding, which could cause the adhesive layer to stick to the back of the aluminum foil. The winding speed is 5-30m / min, which is synchronized with the coating line speed.

[0017] The beneficial effects of this invention are as follows: The water-blocking resin layer design of this application uses polyurethane resin and isocyanate curing agent to undergo a chemical cross-linking reaction to form a three-dimensional network structure, which locks the water-blocking powder resin in the network structure, improves the structural stability of the product, prevents powder precipitation and falling off during processing, winding and bending, greatly extends the service life of the product, and ensures that the water-blocking effect will not decrease due to insufficient mechanical properties of the material.

[0018] This application, through the selection and compounding of water-blocking powder type and particle size, can adjust the water absorption rate, expansion ratio and water absorption speed of the water-blocking resin layer to cope with diverse application scenarios.

[0019] The water-blocking aluminum foil preparation method of this application achieves uniform dispersion of water-blocking powder and solvent-based resin in a continuous production process. Through online stirring in the glue tank, online filtration of the high-pollution-holding wound filter element, and continuous stirring of the flexible stirring rod in the glue tank, the stability of the continuous production process is ensured, solving the problems of powder agglomeration and coating lines, and reducing powder filtration loss. At the same time, by improving coating smoothness, the gap between material strips in the initial wrapping stage is effectively reduced, effectively improving the water-blocking effect of the water-blocking aluminum foil. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of water-blocking aluminum foil; Figure 2 This is a flowchart illustrating the preparation method of water-blocking aluminum foil.

[0021] Among them, 1. shielding aluminum foil, 2. water-blocking resin layer. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the following detailed description of the proposed solutions, in conjunction with the accompanying drawings and specific embodiments, is provided. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0023] Example 1: As Figure 1-2 As shown, a water-blocking aluminum foil includes a shielding aluminum foil 1 and a water-blocking resin layer 2 arranged layer by layer from the outside to the inside. The water-blocking resin layer 2 is made of solvent-based composite adhesive, which includes the following raw materials in parts by weight: polyol resin: 35 parts of medium-high hydroxyl value polyester polyol resin (Evonik Dynacoll 7110), curing agent: 5 parts of toluene diisocyanate (Wanhua Chemical TDI100), 5 parts of diphenylmethane diisocyanate (Wanhua MDI50), water-blocking powder: 6 parts of 300-mesh sodium polyacrylate resin (Songhua SAP300), water-blocking powder: 6 parts of 1250-mesh calcium-based bentonite (Jinghangji 1250-mesh), solvent: 35 parts of ethyl acetate, 15 parts of toluene, with a mixed solid content of 50%, and the dry adhesive thickness is set to 100±10 μm; the shielding aluminum foil 1 is a 1025-O state pure aluminum foil with a thickness of 40 μm.

[0024] A process for preparing water-blocking aluminum foil includes the following steps: Step S1: Prepare solvent-based composite adhesive according to the above proportions. First, place the polyester polyol resin in a flat serrated dispersion tray for dispersion and stirring. First, dilute the water-blocking powder mixture with ethyl acetate, then add the diluted water-blocking powder mixture to the polyester polyol resin under stirring. Then, add the curing agent and stir at 1000 rpm for 40 minutes at 23°C.

[0025] Step S2, filtration: Select a stainless steel single-core liquid filter and a high-pollution-holding multilayer wound meltblown polypropylene filter element with a pore size of 100um to simultaneously filter the solvent-based composite adhesive online at room temperature and pressure. The maximum agglomeration particle size of the resulting adhesive is <100um.

[0026] Step S3, Coating: Use a comma-shaped scraper to coat the filtered solvent-based composite adhesive onto the aluminum foil substrate of the shielding tape. The coating speed is controlled at 5m / min.

[0027] Step S4, drying: The coated shielding aluminum foil is sent into an oven for drying. The drying temperature process parameters are 60℃ / 80℃ / 100℃ / 100℃ / 120℃ / 120℃ / 100℃. Each oven section is 3 meters long, the total length is 21 meters, the machine speed is 6m / min, and the corresponding oven dwell time is calculated to be 10min.

[0028] Step S5, winding: Use a 6-inch paper tube to wind the water-blocking resin layer inwards. Set the winding speed to 6m / min, synchronized with the machine speed. Set the cooling roller temperature to 20℃. Turn on the cooling roller to accelerate the cooling of the shielding aluminum foil and the water-blocking resin layer, to prevent insufficient material cooling or excessive temperature during winding, which could cause the adhesive layer to stick to the back of the aluminum foil.

[0029] Step S6, post-curing: Place the coated and rolled-up shielding tape into a forced-air drying oven for curing at a temperature of 40°C for 7 days.

[0030] Finally, samples of the prepared product were retained for testing.

[0031] Example 2: A water-blocking aluminum foil, comprising a shielding aluminum foil 1 and a water-blocking resin layer 2 arranged layer by layer from the outside to the inside; the water-blocking resin layer 2 is made of solvent-based composite adhesive, which comprises the following raw materials in parts by weight: polyol resin: 10 parts of medium-high hydroxyl value polyester polyol resin (Evonik Dynacoll 7110), 25 parts of low hydroxyl value polyester polyol resin (Evonik Dynacoll 7361), water-blocking powder: 6 parts of 200-mesh sodium polyacrylate resin (Songhua SAP300), curing agent: 5 parts of hexamethylene diisocyanate trimer (Mitsui Chemicals N3300), solvent: 25 parts of cyclohexane, 25 parts of xylene, with a mixed solid content of 50%, and the dry adhesive thickness is set to 100±10um; the shielding aluminum foil 1 is 1025 aluminum with a thickness of 40μm.

[0032] A process for preparing water-blocking aluminum foil includes the following steps: Step S1: Prepare solvent-based composite adhesive according to the above proportions. First, place the polyester polyol resin in a flat serrated dispersion tray for dispersion and stirring. First, dilute the water-blocking powder mixture with a mixed solvent of cyclohexane and xylene. Then, add the diluted water-blocking powder mixture to the polyester polyol resin under stirring. Subsequently, add the curing agent and stir at 1800 rpm for 35 minutes at 23°C.

[0033] Step S2, filtration: Select a stainless steel single-core liquid filter and a high-pollution-holding multilayer wound meltblown polypropylene filter element with a pore size of 20um to simultaneously filter the solvent-based composite adhesive online at room temperature and pressure. The maximum agglomeration particle size of the resulting adhesive is <20um.

[0034] Step S3, Coating: Use a comma-shaped scraper to coat the filtered solvent-based composite adhesive onto the aluminum foil substrate of the shielding tape. The coating speed is controlled at 15m / min.

[0035] Step S4, drying: The coated shielding aluminum foil is sent into an oven for drying. The drying temperature process parameters are 60℃ / 80℃ / 100℃ / 100℃ / 120℃ / 120℃ / 100℃. Each oven section is 3 meters long, the total length is 21 meters, the machine speed is 6m / min, and the corresponding oven dwell time is calculated to be 7min.

[0036] Step S5, winding: Use a 6-inch paper tube to wind the water-blocking resin layer inwards. Set the winding speed to 6m / min, synchronized with the machine speed. Set the cooling roller temperature to 20℃. Turn on the cooling roller to accelerate the cooling of the shielding aluminum foil and the water-blocking resin layer, to prevent insufficient material cooling or excessive temperature during winding, which could cause the adhesive layer to stick to the back of the aluminum foil.

[0037] Step S6, post-curing: Place the coated and rolled-up shielding tape into a forced-air drying oven for curing at a temperature of 45°C for 6 days.

[0038] Finally, samples of the prepared product were retained for testing.

[0039] Example 3: A water-blocking aluminum foil, comprising a shielding aluminum foil 1 and a water-blocking resin layer 2 arranged layer by layer from the outside to the inside; the water-blocking resin layer 2 is made of solvent-based composite adhesive, which comprises the following raw materials in parts by weight: polyol resin: 25 parts of medium-high hydroxyl value polyester polyol resin (Evonik Dynacoll 7110), 10 parts of low hydroxyl value polyester polyol resin (Evonik Dynacoll 7361), water-blocking powder: 12 parts of 325 mesh calcium-based bentonite (Jinghang calcium-based 325 mesh), curing agent: 5 parts of TMP-TDI adduct (Wanhua Chemical TL-75E), solvent: 25 parts of butyl acetate, 25 parts of methylcyclohexane, mixed solid content 50%, and the dry adhesive thickness is set to 100±10um; the shielding aluminum foil is a 1025 aluminum-PET composite film with a thickness of 40μm.

[0040] A process for preparing water-blocking aluminum foil includes the following steps: Step S1: Prepare solvent-based composite adhesive according to the above proportions. First, place the polyester polyol resin in a flat serrated dispersion tray for dispersion and stirring. First, dilute the water-blocking powder mixture with a mixed solvent of butyl acetate and methylcyclohexane. Then, add the diluted water-blocking powder mixture to the polyester polyol resin under stirring. Subsequently, add the curing agent and stir at 2500 rpm for 28 minutes at 23°C.

[0041] Step S2, filtration: Select a stainless steel single-core liquid filter and a high-pollution-holding multilayer wound meltblown polypropylene filter element with a pore size of 50um to simultaneously filter the solvent-based composite adhesive online at room temperature and pressure. The maximum agglomeration particle size of the resulting adhesive is <50um.

[0042] Step S3, Coating: Use a comma-shaped scraper to coat the filtered solvent-based composite adhesive onto the aluminum foil substrate of the shielding tape. The coating speed is controlled at 20m / min.

[0043] Step S4, drying: The coated shielding aluminum foil is sent into an oven for drying. The drying temperature process parameters are 60℃ / 80℃ / 100℃ / 100℃ / 120℃ / 120℃ / 100℃. Each oven section is 3 meters long, the total length is 21 meters, the machine speed is 6m / min, and the corresponding oven dwell time is calculated to be 4min.

[0044] Step S5, winding: Use a 6-inch paper tube to wind the water-blocking resin layer inwards. Set the winding speed to 6m / min, synchronized with the machine speed. Set the cooling roller temperature to 20℃. Turn on the cooling roller to accelerate the cooling of the shielding aluminum foil and the water-blocking resin layer, to prevent insufficient material cooling or excessive temperature during winding, which could cause the adhesive layer to stick to the back of the aluminum foil.

[0045] Step S6, post-curing: Place the coated and rolled-up shielding tape into a forced-air drying oven for curing at 50°C for 4 days.

[0046] Finally, samples of the prepared product were retained for testing.

[0047] Example 4: Figure 1-2 As shown, a water-blocking aluminum foil includes a shielding aluminum foil 1 and a water-blocking resin layer 2 arranged layer by layer from the outside to the inside; the water-blocking resin layer 2 is made of solvent-based composite adhesive, which includes the following raw materials in parts by weight: polyol resin: 35 parts of low hydroxyl value polyester polyol resin (Evonik Dynacoll 7361), water-blocking powder: 10 parts of 300 mesh sodium polyacrylate resin (Songhua SAP300), 6 parts of 325 mesh sodium bentonite (Jinghang sodium 325 mesh), curing agent: 5 parts of isophorone diisocyanate trimer (Covestro Desmodur Z4470 BA), solvent: 30 parts of ethyl acetate, 20 parts of methyl isobutyl ketone, the mixed solid content is 50%, and the dry adhesive thickness is set to 100±10um; the shielding aluminum foil 1 is a 1025 aluminum-PET composite film with a thickness of 40μm.

[0048] A process for preparing water-blocking aluminum foil includes the following steps: Step S1: Prepare solvent-based composite adhesive according to the above proportions. First, place the polyester polyol resin in a flat serrated dispersion tray for dispersion and stirring. First, dilute the water-blocking powder mixture with a mixed solvent of ethyl acetate and methyl isobutyl ketone. Then, add the diluted water-blocking powder mixture to the polyester polyol resin under stirring. Subsequently, add the curing agent and stir at 3000 rpm for 20 minutes at 23°C.

[0049] Step S2, filtration: Select a stainless steel single-core liquid filter and a high-pollution-holding multilayer wound meltblown polypropylene filter element with a pore size of 120um to simultaneously filter the solvent-based composite adhesive online at room temperature and pressure. The maximum agglomeration particle size of the resulting adhesive is <120um.

[0050] Step S3, Coating: Use a comma-shaped scraper to coat the filtered solvent-based composite adhesive onto the aluminum foil substrate of the shielding tape. The coating speed is controlled at 30m / min.

[0051] Step S4, drying: The coated shielding aluminum foil is sent into an oven for drying. The drying temperature process parameters are 60℃ / 80℃ / 100℃ / 100℃ / 120℃ / 120℃ / 100℃. Each oven section is 3 meters long, the total length is 21 meters, the machine speed is 6m / min, and the corresponding oven dwell time is calculated to be 1min.

[0052] Step S5, winding: Use a 6-inch paper tube to wind the water-blocking resin layer inwards. Set the winding speed to 6m / min, synchronized with the machine speed. Set the cooling roller temperature to 20℃. Turn on the cooling roller to accelerate the cooling of the shielding aluminum foil and the water-blocking resin layer, to prevent insufficient material cooling or excessive temperature during winding, which could cause the adhesive layer to stick to the back of the aluminum foil.

[0053] Step S6, post-curing: Place the coated and rolled-up shielding tape into a forced-air drying oven for curing at 60℃ for 7 days.

[0054] Finally, samples of the prepared product were retained for testing.

[0055] Comparative Example 1: Other conditions are the same as in Example 1, except that water-blocking powder is not added.

[0056] Comparative Example 2: Other conditions are the same as in Example 1. The filter element is a conventional pleated polypropylene filter element with a pore size of 100um. The solvent-based composite adhesive is filtered online simultaneously at room temperature and pressure, and the maximum agglomeration particle size of the resulting adhesive is <100um.

[0057] Table 1 shows a performance comparison of Embodiments 1-4 of this application with Comparative Examples 1 and 2: The water-blocking aluminum foils prepared in the examples and comparative examples were subjected to the following performance tests: referring to the People's Republic of China Communications Industry Standard YD / T 1115.1-20X "Water-blocking Materials for Communication Cables and Optical Cables" Part 1 Water-blocking Tape: 1-minute expansion height, expansion height, moisture content, and thickness were measured after timing and removal using a thickness gauge. Table 1: Water-blocking performance and process continuity test

[0058] Note: The production time when the filter element pressure is ≥0.2Mpa is the maximum continuous production time.

[0059] As can be seen from Table 1, Examples 1-4 of this application demonstrate the adjustability of water absorption swelling height and adhesive layer moisture content under different ratios, enabling targeted applications under different combinations of cable and optical fiber core wire structures to cope with diverse application scenarios.

[0060] This application uses a three-dimensional network structure of resin to bind the water-blocking powder to the flexible resin layer, while also firmly bonding the shielding aluminum foil and the water-blocking layer together, so that the water-blocking film has electromagnetic shielding function in addition to water blocking function.

[0061] In terms of manufacturing process, this invention achieves continuous production through the application of online stirring and high-soiling-capacity wound filter elements, thereby improving coating uniformity and product stability.

[0062] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0063] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A water-blocking aluminum foil, characterized in that, It includes a shielding aluminum foil strip and a water-blocking resin layer arranged layer by layer from the outside to the inside; the water-blocking resin layer is made of solvent-based composite adhesive, which includes the following raw materials in parts by weight: 25-40 parts of polyol resin, 1-10 parts of isocyanate curing agent, 5-20 parts of water-blocking powder, and 40-60 parts of diluent.

2. The water-blocking aluminum foil according to claim 1, characterized in that, The polyol resin includes one or more of low hydroxyl value polyester polyol resin and medium-to-high hydroxyl value polyester polyol resin.

3. The water-blocking aluminum foil according to claim 1, characterized in that, The isocyanate curing agent is one or more of toluene diisocyanate, diphenylmethane diisocyanate, TMP-TDI adduct, isophorone diisocyanate trimer, and hexamethylene diisocyanate trimer.

4. The water-blocking aluminum foil according to claim 1, characterized in that, The water-blocking powder has a particle size of 20-2500 mesh, and the material of the water-blocking powder is one or more of sodium bentonite, calcium bentonite, and sodium polyacrylate resin.

5. The water-blocking aluminum foil according to claim 1, characterized in that, The diluent is one or more of ethyl acetate, butyl acetate, cyclohexane, methylcyclohexane, toluene, xylene, and methyl isobutyl ketone.

6. The water-blocking aluminum foil according to claim 1, characterized in that, The thickness of the aluminum foil substrate of the shielding strip is 12~100μm, and the material is any one of 1025 aluminum, 1025 aluminum-PP composite film, and 1025 aluminum-PET composite film.

7. The water-blocking aluminum foil according to claim 1, characterized in that, The thickness of the water-blocking resin layer is 50-200 μm, and the water absorption swelling rate in the thickness direction is ≥8% within 10 minutes of immersion.

8. A method for preparing a water-blocking aluminum foil according to any one of claims 1-7, characterized in that, Includes the following steps: Step S1: Prepare solvent-based composite adhesive according to the specified ratio; Step S2, filtration: The solvent-based composite adhesive is simultaneously filtered online at room temperature and pressure, with a filter element pore size of 20-120um; Step S3, coating: Use a comma-shaped scraper to apply solvent-based composite adhesive to the aluminum foil substrate of the shielding tape. The coating speed is controlled at 5-30m / min. Step S4, drying: The coated shielding aluminum foil is sent into an oven for drying at a temperature of 60-120℃ for 1-10 minutes. Step S5: Rewinding. Turn on the cooling roller and rewind the dried shielding aluminum foil inward. Step S6, post-curing: Place the coated and rolled-up shielding tape into a forced-air drying oven for curing. The curing temperature is 40-60℃ and the curing time is 3-7 days.

9. The method for preparing a water-blocking aluminum foil according to claim 8, characterized in that: In step S1, the polyol resin is first placed in a flat-plate sawtooth dispersion dish for dispersion and stirring. Then, the water-blocking powder is diluted and dispersed with a diluent. The diluted water-blocking powder is then added to the polyol resin under stirring. Subsequently, the curing agent is added, and the mixture is stirred at 1000-3000 rpm for 20-40 minutes at 23°C.

10. The preparation process of a water-blocking aluminum foil according to claim 8, characterized in that: In step S5, a 6-inch paper tube is used to wind the water-blocking resin layer inwards, while the cooling roller is turned on to accelerate the cooling of the shielding aluminum foil and the water-blocking resin layer. This prevents the material from not cooling fast enough or the temperature from being too high during winding, which could cause the adhesive layer to stick to the back of the aluminum foil. The winding speed is 5-30 m / min, which is synchronized with the coating line speed.

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