Improved coating machine composite photocuring process based on slurry pretreatment

Abstract

The invention discloses an improved coating machine composite photocuring process based on slurry pretreatment, which comprises the following steps: step 1, comprehensive preparation in the early stage of construction, step 2, multi-stage deep pretreatment of slurry, step 3, precise pretreatment of a coating machine, step 4, layered precise coating operation, and step 5, composite photocuring segmented treatment. Step 6, process dynamic detection and adjustment, step 7, post-treatment and finished product shaping, and step 8, environmental protection and safety guarantee measures. In the slurry pretreatment link, multi-stage filtration and vacuum defoaming are combined, and pre-crosslinking modification is matched, so that the defects of coating bubbles, pinholes, particle impurities and the like are eliminated from the source, and the dispersity and the stability of the slurry are improved; the precise pretreatment of the coating machine is combined with the layered differentiated coating mode, precise control over the thickness of each coating is achieved, the problems of sagging, coating missing and the like are avoided, and the flatness of the coatings is improved.

Description

Technical Field

[0001] This invention relates to the field of composite photocuring technology, specifically to an improved coating machine composite photocuring process based on slurry pretreatment. Background Technology

[0002] In the field of coating and photocuring processes, coating quality directly determines the performance and lifespan of the end product. In traditional processes, the slurry is only simply stirred or filtered once before use, which generally leads to the following problems: First, unevenly dispersed agglomerated particles and tiny impurities in the slurry are not completely removed, resulting in defects such as pinholes, pitting, and scratches in the coating after application. Second, residual air bubbles in the slurry cannot be expelled in time during the coating process, forming pores after curing, reducing the density and mechanical properties of the coating. Third, the physicochemical properties of the slurry, such as temperature and viscosity, are not precisely matched with the operating parameters of the coating machine, resulting in uneven coating thickness, sagging, or discontinuous coating. Fourth, traditional photocuring often uses single-band, single-intensity UV irradiation, which leads to inconsistent curing rates between the surface and interior of the coating during curing, easily generating internal stress, causing the coating to crack and peel off, and resulting in poor compatibility between different coatings and insufficient interlayer bonding. Fifth, the coating machine is not specifically pre-treated before construction, and residual impurities in the equipment and coating gap deviations directly affect the coating accuracy. At the same time, the process lacks a dynamic adjustment mechanism, making it unable to respond in time to fluctuations in slurry performance and environmental parameters during construction. Summary of the Invention

[0003] The purpose of this invention is to provide an improved coating machine composite photocuring process based on slurry pretreatment to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution: an improved coating machine composite photocuring process based on slurry pretreatment, comprising the following steps: Step 1: Comprehensive preparation before construction: Conduct appearance and performance testing on the substrate, conduct a comprehensive inspection of the coating machine and UV curing equipment, prepare suitable slurry, auxiliary materials and testing tools, and adjust the construction environment parameters; Step 2: Multi-stage deep pretreatment of slurry: First-stage filtration, second-stage fine filtration, vacuum degassing, temperature adaptation and adjustment and pre-crosslinking modification are performed in sequence to optimize the slurry's dispersibility, fluidity and stability; Step 3: Precise pretreatment of the coating machine: Clean the key components of the coating machine, calibrate the coating gap, transmission speed and pressure parameters, and adjust the stability of the feeding system; Step 4, Layered Precision Coating Operation: Apply primer, intermediate coat and top coat in sequence using a differentiated coating method. Perform preliminary drying treatment after each coat to control the thickness and surface smoothness of each coat. Step 5, Composite UV Curing Segmented Processing: First, pre-curing is performed to remove residual solvent, then main curing is performed to achieve complete cross-linking of the coating, and finally post-curing is performed to stabilize the coating performance. All three curing stages are performed using a combination of multi-band UV lamps. Step 6, Dynamic Process Detection and Adjustment: After each coating layer is applied, the thickness and flatness are tested. After each section is cured, the degree of curing and adhesion are tested. The coating and curing parameters are adjusted in real time based on the test results. Step 7, Post-processing and Finished Product Shaping: The cured coating is subjected to gradient cooling, excess coating at the edges is trimmed, and protective film or surface polishing is performed as needed. Step 8: Environmental Protection and Safety Measures: During construction, waste gas and waste liquid will be collected and treated, equipment operating noise will be controlled, workers will wear special protective equipment, and safe operating procedures for equipment will be implemented.

[0005] Furthermore, step one specifically includes: Substrate inspection: Select the substrate to be coated, check its surface defects, and test the surface tension, water absorption rate, and tensile strength parameters of the substrate to ensure that they meet the coating requirements; Equipment inspection: Check the operation of the coating machine's transmission system, feeding system, and temperature control system; confirm that the UV lamps of the UV curing equipment are working properly and that the power adjustment function is effective; and test the grounding and insulation performance of each piece of equipment. Excipient preparation: Prepare excipients that are compatible with the base material, ensuring that the excipients are within their expiration date and have not deteriorated; prepare testing tools and calibrate the accuracy of the testing tools; Environmental control: The ambient temperature during construction should be controlled at 20-28℃ and the relative humidity at 40%-60%. Dust control devices should be installed to ensure that the particle size of suspended particulate matter in the air is ≤10μm, so as to avoid dust contamination of the coating.

[0006] Furthermore, step two specifically involves: Primary filtration: The raw slurry is passed through a filtration device equipped with a 100-150 mesh stainless steel filter screen. The filtration pressure is controlled at 0.3-0.5 MPa. During the filtration process, the filter screen is backwashed every 30 minutes to remove solid impurities and agglomerates with a particle size greater than 100 μm from the slurry. Secondary fine filtration: The slurry after primary filtration is passed into a 500-800 mesh ceramic filter element filtration device at a filtration pressure of 0.1-0.2MPa to intercept tiny particles with a diameter greater than 20μm. The ceramic filter element is replaced every 2 hours to avoid the accumulation of impurities. Vacuum degassing treatment: Inject the slurry after secondary fine filtration into a vacuum degassing tank, close the tank door and evacuate to a vacuum degree of -0.08 to -0.095 MPa, maintain the degassing time for 30-60 minutes, and stir slowly at a speed of 20-30 r / min during the degassing process, with the stirring direction along the tangential direction of the tank wall to avoid generating new bubbles; Temperature adaptation and adjustment: The temperature of the slurry is adjusted to 25-35℃ through the jacketed temperature control system of the degassing tank, and the temperature fluctuation is controlled within ±1℃. After adjustment, the slurry is continuously stirred and kept warm at a speed of 15-20r / min to prevent secondary agglomeration of the slurry. Pre-crosslinking modification treatment: Add 0.5%-2% of silane coupling agent to the slurry after the temperature is suitable, mix at a stirring speed of 30-40 r / min for 20-30 min, and use ultrasonic-assisted dispersion during the mixing process. The ultrasonic frequency is 20-40 kHz and the power is 500-800 W to achieve the initial crosslinking of the slurry molecular chains.

[0007] Furthermore, step three specifically involves: Component cleaning: Select the cleaning method according to the material of the coating roller. Wipe metal coating rollers with anhydrous ethanol and rubber coating rollers with a special neutral detergent. After wiping, dry with a lint-free cloth to ensure that there are no residual impurities or oil stains on the surface of the coating roller. After scraping off the residual slurry with the blade, soak the scraper in acetone for 10-15 minutes, let it dry, and then install it. After rinsing the inner wall of the material tank with a high-pressure water gun, dry it until there is no moisture residue. Parameter calibration: Adjust the coating gap using a thickness calibrator to control the gap error within ±0.01mm; debug the transmission system to stabilize the substrate transmission speed at 5-20m / min, with speed fluctuation ≤±0.2m / min; adjust the coating pressure to control it within 0.1-0.3MPa according to the substrate material and thickness. Feeding system commissioning: Start the feeding pump and feed the pretreated slurry into the feed tank. Adjust the feeding flow rate to 10-50L / h to ensure that the liquid level of the slurry in the feed tank is stable at 1 / 2-2 / 3 of the height of the feed tank. Observe the feeding pipeline for leaks and blockages to ensure uniform and continuous feeding.

[0008] Furthermore, step four specifically involves: Primer application: The primer is applied using a micro-gravure coating method. The anilox roller has a cell depth of 30-50μm and a substrate transfer speed of 5-10m / min. The thickness of the primer after application is controlled at 5-15μm. After the primer is applied, it is placed in a hot air drying oven for preliminary drying at a temperature of 40-60℃ for 1-3 minutes to remove 30%-50% of the solvent from the slurry. Intermediate coat application: After the primer has dried, apply the intermediate coat using a comma-shaped scraper, keeping the angle between the scraper and the substrate between 30° and 45°, and the coating pressure between 0.15 and 0.25 MPa. The intermediate coat thickness should be controlled at 20-50 μm. After the intermediate coat, perform a second drying process at 50-70°C for 2-4 minutes, until the solvent removal rate reaches 60%-80%. Topcoat application: After the intermediate coat dries, apply the topcoat using a slotted spray method. Adjust the slot width to 0.1-0.3 mm, and control the material flow rate in conjunction with the substrate transfer speed. Control the topcoat thickness to 10-30 μm. After the topcoat, perform three drying cycles at a temperature of 45-65℃ for 1-2 minutes. Keep the residual solvent content below 5%. After each coating layer is applied, use a coating thickness gauge to select 5-8 test points evenly in the width direction of the substrate, measure the thickness and record it. Use a flatness tester to check the surface flatness to ensure that the coating is free of drips, omissions, and obvious scratches.

[0009] Furthermore, step five specifically includes: Pre-curing treatment: After three drying cycles, the substrate is sent into a pre-curing oven. The pre-curing oven is equipped with 2-3 low-power UV lamps with a wavelength of 365nm and a power of 80-120W / cm per lamp. The lamps are 15-20cm away from the substrate surface. The substrate transfer speed is kept consistent with the topcoat application. The pre-curing time is 5-10s to allow the coating surface to be initially cured and remove any remaining solvent. Main curing treatment: The pre-cured substrate enters the main curing oven, which is equipped with 4-6 medium-high intensity UV lamps, using a dual-band combination of 254nm and 365nm. The power of a single lamp is 150-250W / cm, the lamp distance from the substrate surface is 10-15cm, the transmission speed is adjusted to 3-8m / min, and the main curing time is 15-30s, so as to achieve complete cross-linking of the coating molecular chains. Post-curing treatment: The substrate after primary curing enters the post-curing oven, which is equipped with 2-3 low-intensity UV lamps with a wavelength of 365nm, a single lamp power of 50-100W / cm, a lamp distance of 20-25cm from the substrate surface, a transmission speed of 8-12m / min, and a post-curing time of 8-15s to eliminate internal stress in the coating and stabilize the coating performance. During the three-stage curing process, nitrogen gas is introduced into the curing oven through an inert gas protection device to control the oxygen content in the oven to ≤5% and prevent the coating from oxidizing and turning yellow; the temperature in the curing oven is monitored in real time to ensure that the temperature does not exceed 80℃ to prevent the substrate from deforming.

[0010] Furthermore, step six specifically involves: Coating inspection and adjustment: After each coating layer is applied, the thickness is measured with a coating thickness gauge. If the thickness deviation exceeds ±0.5μm, the coating gap or material flow rate is adjusted. The surface flatness is checked with a flatness tester. If there are sagging or missed coating, the substrate conveying speed or coating pressure is adjusted. Curing Inspection and Adjustment: After pre-curing, use a curing degree tester to check the curing degree of the coating. If the curing degree is less than 60%, increase the power of the pre-curing UV lamp or reduce the transmission speed. After main curing, use an adhesion tester to perform a cross-cut adhesion test. If the adhesion level is less than 2, adjust the power, wavelength combination, or curing time of the main curing UV lamp. After post-curing, check the gloss and scratch resistance of the coating. If the gloss deviation exceeds ±5° or the scratch resistance does not meet the standard, adjust the post-curing parameters. Environmental and slurry testing: The ambient temperature, humidity and dust content of the construction environment are tested every hour. If they exceed the set range, the environmental control system is activated for adjustment. The viscosity and dispersibility of the pretreated slurry are tested every 2 hours. If the viscosity change exceeds ±5mPa・s or agglomeration occurs, degassing and stirring are repeated.

[0011] Furthermore, step seven specifically includes: Gradient cooling: The post-cured finished product is sent into the cooling channel, which is divided into three sections. The first section has a cooling temperature of 50-60℃, the second section has a cooling temperature of 30-40℃, and the third section has a cooling temperature of 20-25℃. The cooling time for each section is 2-3 minutes to avoid sudden cooling that could cause the coating to crack. Edge trimming: Use an automatic edge trimming machine to trim excess coating from the edges of the substrate. The trimming width is controlled at 5-10mm to ensure that the finished product has neat edges and no burrs. Finishing process: Depending on product requirements, choose to apply a protective film or polish the surface. For film application, use a transparent PET protective film with a film application pressure of 0.05-0.1MPa to ensure that the film and coating adhere without air bubbles. For surface polishing, use a non-woven polishing wheel at a polishing speed of 10-15m / min and polish 1-2 times to improve the gloss of the coating. Finished product inspection: Sampling inspections are conducted on the finalized finished products. The inspection items include coating thickness, flatness, adhesion, gloss, scratch resistance, and yellowing resistance. Only products that meet the design requirements can be put into storage.

[0012] Furthermore, the environmental protection measures in step eight are specifically as follows: Waste gas treatment: Activated carbon adsorption devices and UV photolysis purification equipment are installed at the exhaust outlets of the coating machine, drying oven, and curing oven. The waste gas is treated to meet national emission standards before being discharged. Waste liquid treatment: Collect cleaning waste liquid and slurry residue generated during construction, store them separately in special sealed containers, and entrust a professional environmental protection agency to carry out harmless treatment; Dust and noise control: Dust covers are installed at the feed inlet and outlet of the coating machine, and dust in the work area is cleaned regularly; vibration reduction measures are taken for the coating machine, UV lamp and fan, and silencers are installed to ensure that the noise in the work area is ≤85dB(A). Resource recycling: Unused pre-treated slurry is sealed and refrigerated for reuse within its shelf life; base material scraps are sorted and recycled to achieve resource recycling.

[0013] Furthermore, the safety measures in step eight specifically include: Personal protective equipment: Workers must wear UV-protective clothing, protective glasses, gas masks, and solvent-resistant gloves to avoid damage from UV radiation and chemicals; Equipment safety: The UV curing equipment is equipped with an interlock protection device that automatically cuts off the UV lamp power when the equipment door is opened; the coating machine is equipped with an emergency stop button, and the transmission system is equipped with guardrails to prevent personnel from being pulled in; Electrical safety: All electrical equipment must be properly grounded; the insulation performance of the wiring must be checked regularly to prevent short circuits and leakage; dry powder fire extinguishers and emergency lighting equipment must be provided in the construction area; and emergency plans for fire and chemical spills must be developed. Operating Procedures: All operators must undergo pre-job training to familiarize themselves with the process flow, equipment operation methods, and safety precautions. Only those who pass the assessment are allowed to work. Smoking and open flame operations are strictly prohibited in the construction area, and unauthorized operation of equipment is strictly prohibited.

[0014] Compared with the prior art, the beneficial effects of the present invention are: This invention employs a multi-stage filtration and vacuum degassing process in the slurry pretreatment stage, combined with pre-crosslinking modification, to eliminate defects such as bubbles, pinholes, and particulate impurities in the coating from the source, thereby improving the slurry's dispersibility and stability. The precise pretreatment by the coating machine, combined with a layered differentiated coating method, enables precise control of the thickness of each coating layer, avoiding problems such as sagging and missed coatings, and improving coating smoothness. The three-stage composite light curing combined with multi-band UV irradiation, supplemented by inert gas protection, solves the problem of inconsistent curing rates between the surface and interior layers during traditional curing processes, eliminating internal stress in the coating and enhancing interlayer bonding and weather resistance. The dynamic process monitoring and adjustment mechanism can promptly respond to fluctuations in process parameters, prevent defect accumulation, and significantly improve product qualification rate. Attached Figure Description

[0015] Figure 1 This is a flowchart of the method of the present invention. Detailed Implementation

[0016] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0017] Please see Figure 1 This invention provides an improved coating machine composite photocuring process based on slurry pretreatment, comprising the following steps: Step 1: Comprehensive Preparation Before Construction: Conduct appearance and performance testing on the substrate; perform a comprehensive inspection of the coating machine and UV curing equipment; prepare suitable slurry, auxiliary materials, and testing tools; and adjust the construction environment parameters. Specifically: Substrate inspection: Select the substrate to be coated and check its surface for defects such as scratches, oil stains, and damage. Test the surface tension, water absorption rate, and tensile strength parameters of the substrate to ensure that they meet the coating requirements. Equipment inspection: Check the operation of the coating machine's transmission system, feeding system, and temperature control system; confirm that the UV lamps of the UV curing equipment are working properly and that the power adjustment function is effective; and test the grounding and insulation performance of each piece of equipment. Material preparation: Prepare UV-curable paste, thinner, coupling agent, defoamer and other auxiliary materials that are compatible with the substrate, and ensure that the auxiliary materials are within the expiration date and have not deteriorated; prepare testing tools such as coating thickness gauge, gloss meter, adhesion tester and bubble detector, and calibrate the accuracy of the testing tools; Environmental control: The ambient temperature during construction should be controlled at 20-28℃ and the relative humidity at 40%-60%. Dust control devices should be installed to ensure that the particle size of suspended particulate matter in the air is ≤10μm, so as to avoid dust contamination of the coating. Step 2: Multi-stage deep pretreatment of slurry: This involves sequential primary filtration, secondary fine filtration, vacuum degassing, temperature adaptation and adjustment, and pre-crosslinking modification to optimize the slurry's dispersibility, flowability, and stability; specifically: Primary filtration: The raw slurry is passed through a filtration device equipped with a 100-150 mesh stainless steel filter screen. The filtration pressure is controlled at 0.3-0.5 MPa. During the filtration process, the filter screen is backwashed every 30 minutes to remove solid impurities and agglomerates with a particle size greater than 100 μm from the slurry. Secondary fine filtration: The slurry after primary filtration is passed into a 500-800 mesh ceramic filter element filtration device at a filtration pressure of 0.1-0.2MPa to intercept tiny particles with a diameter greater than 20μm. The ceramic filter element is replaced every 2 hours to avoid the accumulation of impurities. Vacuum degassing treatment: Inject the slurry after secondary fine filtration into a vacuum degassing tank, close the tank door and evacuate to a vacuum degree of -0.08~-0.095MPa, maintain the degassing time for 30-60min, and stir slowly at a speed of 20-30r / min during the degassing process, with the stirring direction along the tangential direction of the tank wall to avoid generating new bubbles; Temperature adaptation and adjustment: The temperature of the slurry is adjusted to 25-35℃ through the jacketed temperature control system of the degassing tank, and the temperature fluctuation is controlled within ±1℃. After adjustment, the slurry is continuously stirred and kept warm at a speed of 15-20r / min to prevent secondary agglomeration of the slurry. Pre-crosslinking modification treatment: Add 0.5%-2% of silane coupling agent to the slurry after the temperature is suitable, mix at a stirring speed of 30-40 r / min for 20-30 min, and use ultrasonic-assisted dispersion during the mixing process. The ultrasonic frequency is 20-40 kHz and the power is 500-800 W to achieve the initial crosslinking of the slurry molecular chains. Step 3: Precise Pre-treatment of the Coating Machine: Clean the key components of the coating machine, such as the coating roller, doctor blade, and material trough; calibrate the coating gap, transmission speed, and pressure parameters; and adjust the stability of the feeding system. Specifically: Component cleaning: Select the cleaning method according to the material of the coating roller. Wipe metal coating rollers with anhydrous ethanol and rubber coating rollers with a special neutral detergent. After wiping, dry with a lint-free cloth to ensure that there are no residual impurities or oil stains on the surface of the coating roller. After scraping off the residual slurry with the blade, soak the scraper in acetone for 10-15 minutes, let it dry, and then install it. After rinsing the inner wall of the material tank with a high-pressure water gun, dry it until there is no moisture residue. Parameter calibration: Adjust the coating gap using a thickness calibrator to control the gap error within ±0.01mm; debug the transmission system to stabilize the substrate transmission speed at 5-20m / min, with speed fluctuation ≤±0.2m / min; adjust the coating pressure to control it within 0.1-0.3MPa according to the substrate material and thickness. Feeding system commissioning: Start the feeding pump and feed the pretreated slurry into the trough. Adjust the feeding flow rate to 10-50L / h to ensure that the liquid level of the slurry in the trough is stable at 1 / 2-2 / 3 of the trough height. Observe the feeding pipeline for leaks and blockages to ensure uniform and continuous feeding. Step 4: Precise Layered Coating: Apply the primer, intermediate coat, and topcoat sequentially using a differentiated coating method. Perform preliminary drying after each coat to control the thickness and surface smoothness of each layer. Specifically: Primer application: The primer is applied using a micro-gravure coating method. The anilox roller has a cell depth of 30-50μm and a substrate transfer speed of 5-10m / min. The thickness of the primer after application is controlled at 5-15μm. After the primer is applied, it is placed in a hot air drying oven for preliminary drying at a temperature of 40-60℃ for 1-3 minutes to remove 30%-50% of the solvent from the slurry. Intermediate coat application: After the primer has dried, apply the intermediate coat using a comma-shaped scraper, keeping the angle between the scraper and the substrate between 30° and 45°, and the coating pressure between 0.15 and 0.25 MPa. The intermediate coat thickness should be controlled at 20-50 μm. After the intermediate coat, perform a second drying process at 50-70°C for 2-4 minutes, until the solvent removal rate reaches 60%-80%. Topcoat application: After the intermediate coat dries, apply the topcoat using a slotted spray method. Adjust the slot width to 0.1-0.3 mm, and control the material flow rate in conjunction with the substrate transfer speed. Control the topcoat thickness to 10-30 μm. After the topcoat, perform three drying cycles at a temperature of 45-65℃ for 1-2 minutes. Keep the residual solvent content below 5%. After each coating layer is applied, use a coating thickness gauge to select 5-8 test points evenly in the width direction of the substrate, measure the thickness and record it, and use a flatness tester to check the surface flatness to ensure that the coating is free of sagging, missing coating, and obvious scratches. Step 5, Composite Photocuring Segmented Treatment: First, pre-curing is performed to remove residual solvents, then main curing is performed to achieve complete cross-linking of the coating, and finally post-curing is performed to stabilize the coating performance. All three curing stages are carried out using a combination of multi-band UV lamps; specifically: Pre-curing treatment: After three drying cycles, the substrate is sent into a pre-curing oven. The pre-curing oven is equipped with 2-3 low-power UV lamps with a wavelength of 365nm and a power of 80-120W / cm per lamp. The lamps are 15-20cm away from the substrate surface. The substrate transfer speed is kept consistent with the topcoat application. The pre-curing time is 5-10s to allow the coating surface to be initially cured and remove any remaining solvent. Main curing treatment: The pre-cured substrate enters the main curing oven, which is equipped with 4-6 medium-high intensity UV lamps, using a dual-band combination of 254nm and 365nm. The power of a single lamp is 150-250W / cm, the lamp distance from the substrate surface is 10-15cm, the transmission speed is adjusted to 3-8m / min, and the main curing time is 15-30s, so as to achieve complete cross-linking of the coating molecular chains. Post-curing treatment: The substrate after primary curing enters the post-curing oven, which is equipped with 2-3 low-intensity UV lamps with a wavelength of 365nm, a single lamp power of 50-100W / cm, a lamp distance of 20-25cm from the substrate surface, a transmission speed of 8-12m / min, and a post-curing time of 8-15s to eliminate internal stress in the coating and stabilize the coating performance. During the three-stage curing process, nitrogen gas is introduced into the curing oven through an inert gas protection device to control the oxygen content in the oven to ≤5% and prevent the coating from oxidizing and turning yellow; the temperature in the curing oven is monitored in real time to ensure that the temperature does not exceed 80℃ to prevent the substrate from deforming. Step Six: Dynamic Process Monitoring and Adjustment: After each coating layer is applied, the thickness and flatness are measured. After each section has cured, the degree of curing and adhesion are measured. Based on the test results, the coating and curing parameters are adjusted in real time. Specifically: Coating inspection and adjustment: After each coating layer is applied, the thickness is measured with a coating thickness gauge. If the thickness deviation exceeds ±0.5μm, the coating gap or material flow rate is adjusted. The surface flatness is checked with a flatness tester. If there are sagging or missed coating, the substrate conveying speed or coating pressure is adjusted. Curing Inspection and Adjustment: After pre-curing, use a curing degree tester to check the curing degree of the coating. If the curing degree is less than 60%, increase the power of the pre-curing UV lamp or reduce the transmission speed. After main curing, use an adhesion tester to perform a cross-cut adhesion test. If the adhesion level is less than 2, adjust the power, wavelength combination, or curing time of the main curing UV lamp. After post-curing, check the gloss and scratch resistance of the coating. If the gloss deviation exceeds ±5° or the scratch resistance does not meet the standard, adjust the post-curing parameters. Environmental and slurry testing: The ambient temperature, humidity and dust content of the construction environment are tested every hour. If they exceed the set range, the environmental control system is activated for adjustment. The viscosity and dispersibility of the pretreated slurry are tested every 2 hours. If the viscosity change exceeds ±5mPa・s or agglomeration occurs, degassing and stirring are repeated. Step 7, Post-processing and Finished Product Shaping: The cured coating undergoes gradient cooling, excess coating at the edges is trimmed, and protective film coating or surface polishing is applied as needed; specifically: Gradient cooling: The post-cured finished product is sent into the cooling channel, which is divided into three sections. The first section has a cooling temperature of 50-60℃, the second section has a cooling temperature of 30-40℃, and the third section has a cooling temperature of 20-25℃. The cooling time for each section is 2-3 minutes to avoid sudden cooling that could cause the coating to crack. Edge trimming: Use an automatic edge trimming machine to trim excess coating from the edges of the substrate. The trimming width is controlled at 5-10mm to ensure that the finished product has neat edges and no burrs. Finishing process: Depending on product requirements, choose to apply a protective film or polish the surface. For film application, use a transparent PET protective film with a film application pressure of 0.05-0.1MPa to ensure that the film and coating adhere without air bubbles. For surface polishing, use a non-woven polishing wheel at a polishing speed of 10-15m / min and polish 1-2 times to improve the gloss of the coating. Finished product inspection: Sampling inspections are conducted on the finalized finished products. The inspection items include coating thickness, flatness, adhesion, gloss, scratch resistance, and yellowing resistance. Only products that meet the design requirements can be put into storage. Step 8. Environmental Protection and Safety Measures: During construction, waste gas and waste liquid will be collected and treated; equipment operating noise will be controlled; workers will wear specialized protective equipment; and safe operating procedures for the equipment will be implemented. Specific environmental protection measures include: Waste gas treatment: Activated carbon adsorption devices and UV photolysis purification equipment are installed at the exhaust outlets of the coating machine, drying oven, and curing oven. The waste gas is treated to meet national emission standards before being discharged. Waste liquid treatment: Collect cleaning waste liquid and slurry residue generated during construction, store them separately in special sealed containers, and entrust a professional environmental protection agency to carry out harmless treatment; Dust and noise control: Dust covers are installed at the feed inlet and outlet of the coating machine, and dust in the work area is cleaned regularly; vibration reduction measures are taken for equipment such as coating machines, UV lamps, and fans, and silencers are installed to ensure that the noise in the work area is ≤85dB(A). Resource recycling: Unused pre-treated slurry is sealed and refrigerated for reuse within its shelf life; substrate scraps are sorted and recycled to achieve resource recycling. The specific safety measures are as follows: Personal protective equipment: Workers must wear UV-protective clothing, protective glasses, gas masks, and solvent-resistant gloves to avoid damage from UV radiation and chemicals; Equipment safety: The UV curing equipment is equipped with an interlock protection device that automatically cuts off the UV lamp power when the equipment door is opened; the coating machine is equipped with an emergency stop button, and the transmission system is equipped with guardrails to prevent personnel from being pulled in; Electrical safety: All electrical equipment must be properly grounded; the insulation performance of the wiring must be checked regularly to prevent short circuits and leakage; dry powder fire extinguishers and emergency lighting equipment must be provided in the construction area; and emergency plans for fire and chemical spills must be developed. Operating Procedures: All operators must undergo pre-job training to familiarize themselves with the process flow, equipment operation methods, and safety precautions. Only those who pass the assessment are allowed to work. Smoking and open flame operations are strictly prohibited in the construction area, and unauthorized operation of equipment is strictly prohibited.

[0018] Example: Application of PET thin film optical coating preparation project An electronic materials company needs to produce high-precision PET optical films for displays. The coatings must be uniform in thickness, have strong adhesion, stable gloss, and be free of bubbles and pinholes. Traditional processes suffer from insufficient slurry treatment and uneven curing, resulting in a product qualification rate of only 75%. The process described in this invention is used to optimize production.

[0019] Step 1: Comprehensive Preparations Before Construction Substrate testing: Select a 100μm thick PET film, check for scratches and oil stains on the surface, test the surface tension to be 42mN / m, water absorption rate ≤0.3%, tensile strength ≥200MPa, which meets the coating requirements; Equipment inspection: Using a GF-1200 coating machine and an HG-UV-8 composite light curing equipment, the coating machine's transmission system was checked to ensure smooth operation, the feed pump had no leaks, the 8 UV lamps of the light curing equipment were lit normally, the power adjustment range was 0-300W / cm, and the equipment was properly grounded. Auxiliary material preparation: Select acrylic UV-curable slurry, along with matching thinner, KH-550 silane coupling agent, and silicone defoamer; prepare a coating thickness gauge, gloss meter, cross-cut tester, adhesion tester, and bubble detector, and ensure their accuracy meets the standards after calibration; Environmental control: The temperature in the cleanroom is controlled at 25℃ and the relative humidity at 50%. The air purification system is turned on to ensure that the particle size of suspended particulate matter in the air is ≤10μm.

[0020] Step 2: Multi-stage deep pretreatment of slurry Primary filtration: The acrylic slurry is passed through a 120-mesh stainless steel filter screen at a filtration pressure of 0.4 MPa. The filter screen is backwashed with high-pressure air every 30 minutes to remove large particulate impurities. Secondary fine filtration: The slurry after primary filtration is passed into a 600-mesh ceramic filter element filtration device at a filtration pressure of 0.15MPa. The ceramic filter element is replaced every 2 hours to trap tiny particles. Vacuum degassing: The slurry is injected into a vacuum degassing tank, and a vacuum is drawn to -0.09MPa. The degassing time is maintained for 45 minutes. The slurry is stirred at a speed of 25r / min along the tangential direction of the tank wall until no new bubbles are generated. Temperature adaptation: The slurry temperature is adjusted to 30℃ through the jacket temperature control system, with a temperature fluctuation of ±0.5℃, and the mixture is stirred and kept warm at a speed of 18r / min; Pre-crosslinking modification: Add 1% KH-550 silane coupling agent of the total mass of the slurry, stir at 35r / min for 25min, and simultaneously turn on 30kHz, 600W ultrasonic-assisted dispersion to complete the slurry pretreatment.

[0021] Step 3: Precision pretreatment by the coating machine Component cleaning: wipe the metal coating roller with anhydrous ethanol, wipe the rubber scraper with neutral detergent and soak it in acetone for 12 minutes, let it dry and install it, and rinse the material tank with a high-pressure water gun and then dry it. Parameter calibration: The coating gap was adjusted to 0.05mm with an error of ±0.005mm using a thickness calibrator; the transmission speed was adjusted to 8m / min with a fluctuation of ±0.1m / min; and the coating pressure was adjusted to 0.2MPa. Feeding system commissioning: Start the feeding pump, feed flow rate 30L / h, the slurry level in the tank is stable at 2 / 3 of the tank height, and there is no leakage or blockage in the feeding pipeline.

[0022] Step 4: Layered Precision Coating Primer application: Micro-recessed coating method is adopted, with an anilox roller cell depth of 40μm, substrate conveying speed of 8m / min, and coating thickness of 10μm; it is sent into a hot air drying oven and dried at 45℃ for 2min to remove 40% of the solvent; the thickness deviation is checked to be ±0.3μm, and the flatness meets the standard; Intermediate coat application: Apply with a comma-shaped scraper, with the scraper at a 35° angle to the substrate, applying pressure of 0.2 MPa, and an intermediate coat thickness of 30 μm; dry at 55°C for 3 min to remove 70% of the solvent; check for thickness deviation of ±0.4 μm, with no sagging. Topcoat application: slot coating, slot width 0.2mm, feed flow rate and conveying speed are linked and controlled, topcoat thickness 20μm; dry at 50℃ for 1.5min, residual solvent content ≤3%; thickness deviation is detected to be ±0.3μm, and the surface is free of missed coating and scratches.

[0023] Step 5: Composite Photocuring Segmentation Processing Pre-curing: The product is placed in a pre-curing oven with three 365nm low-power UV lamps, a lamp spacing of 18cm, a transmission speed of 8m / min, a curing time of 8s, and a curing degree of 65%, with no solvent residue or odor. Main curing: Enter the main curing oven, 5 dual-band UV lamps (including a combination of 254nm and 365nm, 200W / cm per lamp), lamp spacing 12cm, transmission speed 5m / min, curing time 20s, molecular chains are completely cross-linked. Post-curing: The substrate enters a post-curing oven with two 365nm low-intensity UV lamps (80W / cm each), a lamp spacing of 22cm, a transmission speed of 10m / min, and a curing time of 12s. Nitrogen gas is introduced throughout the process, the oxygen content in the oven is ≤3%, the temperature is controlled at 70℃, and there is no substrate deformation.

[0024] Step Six: Dynamic Process Monitoring and Adjustment Coating inspection: After primer, intermediate coat and top coat, 6 inspection points are selected for each section. The thickness deviation is ≤ ±0.4μm and the flatness meets the standard. No parameter adjustment is required. Curing test: The degree of curing after pre-curing is 65%, which meets the requirements; the adhesion test after main curing is Grade 1 by cross-cut test; the gloss after post-curing is 92°, and the scratch resistance meets the standard. Environmental and slurry testing: The ambient temperature is tested every hour at 25±1℃ and the humidity is tested at 50±2%, with dust content meeting the standard; the slurry viscosity is tested every 2 hours, with a change of ≤±3mPa・s and no agglomeration.

[0025] Step 7: Post-processing and Finished Product Shaping Gradient cooling: The first section of the cooling channel is 55°C, the second section is 35°C, and the third section is 25°C. Each section is cooled for 2.5 minutes, slowly cooling down to room temperature without coating cracking. Edge trimming: The automatic edge trimming machine trims the edges by 8mm, resulting in a finished width of 1200mm with neat, burr-free edges; Shaping process: A 12μm transparent PET protective film is used for lamination, with a lamination pressure of 0.08MPa, ensuring no air bubbles during bonding; Finished product inspection: 100 products were sampled and inspected. The coating thickness deviation was ≤ ±0.4μm, the adhesion was grade 1, the gloss was 90-93°, and there were no bubbles or pinhole defects. The pass rate was increased to 98%.

[0026] Step 8: Environmental Protection and Safety Measures Environmental protection measures: Exhaust gases from the coating machine, drying oven, and curing oven are purified by activated carbon adsorption and UV photolysis before being discharged, with VOCs content measured to be ≤10mg / m³. 3 Cleaning waste liquid and slurry residue are sealed and stored, and entrusted to a professional organization for disposal; vibration damping pads and silencers are installed on the equipment, and the noise in the working area is ≤80dB(A); Safety measures: Workers must wear UV-protective clothing, protective glasses, gas masks, and solvent-resistant gloves; UV equipment must be equipped with interlocking protection devices, and coating machines must be equipped with guardrails and emergency stop buttons; dry powder fire extinguishers must be provided in the workshop, open flame operations are strictly prohibited, and all personnel must be trained and qualified before starting work.

[0027] Example Effects The project was originally planned to have a production cycle of 15 days, but after adopting the process of this invention, the actual production cycle was reduced to 10 days, saving 33% of the construction period; the product qualification rate increased from 75% to 98%, the coating performance was stable, meeting the stringent requirements of optical films for display screens, significantly reducing production costs and enhancing market competitiveness.

[0028] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An improved coating machine composite photocuring process based on slurry pretreatment, characterized in that: Includes the following steps: Step 1: Comprehensive preparation before construction: Conduct appearance and performance testing on the substrate, conduct a comprehensive inspection of the coating machine and UV curing equipment, prepare suitable slurry, auxiliary materials and testing tools, and adjust the construction environment parameters; Step 2: Multi-stage deep pretreatment of slurry: First-stage filtration, second-stage fine filtration, vacuum degassing, temperature adaptation and adjustment and pre-crosslinking modification are performed in sequence to optimize the slurry's dispersibility, fluidity and stability; Step 3: Precise pretreatment of the coating machine: Clean the key components of the coating machine, calibrate the coating gap, transmission speed and pressure parameters, and adjust the stability of the feeding system; Step 4, Layered Precision Coating Operation: Apply primer, intermediate coat and top coat in sequence using a differentiated coating method. Perform preliminary drying treatment after each coat to control the thickness and surface smoothness of each coat. Step 5, Composite UV Curing Segmented Processing: First, pre-curing is performed to remove residual solvent, then main curing is performed to achieve complete cross-linking of the coating, and finally post-curing is performed to stabilize the coating performance. All three curing stages are performed using a combination of multi-band UV lamps. Step 6, Dynamic Process Detection and Adjustment: After each coating layer is applied, the thickness and flatness are tested. After each section is cured, the degree of curing and adhesion are tested. The coating and curing parameters are adjusted in real time based on the test results. Step 7, Post-processing and Finished Product Shaping: The cured coating is subjected to gradient cooling, excess coating at the edges is trimmed, and protective film or surface polishing is performed as needed. Step 8: Environmental Protection and Safety Measures: During construction, waste gas and waste liquid will be collected and treated, equipment operating noise will be controlled, workers will wear special protective equipment, and safe operating procedures for equipment will be implemented.

2. The improved coating machine composite photocuring process based on slurry pretreatment according to claim 1, characterized in that: Step one specifically involves: Substrate inspection: Select the substrate to be coated, check its surface defects, and test the surface tension, water absorption rate, and tensile strength parameters of the substrate to ensure that they meet the coating requirements; Equipment inspection: Check the operation of the coating machine's transmission system, feeding system, and temperature control system; confirm that the UV lamps of the UV curing equipment are working properly and that the power adjustment function is effective; and test the grounding and insulation performance of each piece of equipment. Excipient preparation: Prepare excipients that are compatible with the base material, and ensure that the excipients are within their expiration date and have not deteriorated; Prepare the testing tools and calibrate their accuracy. Environmental control: The ambient temperature during construction should be controlled at 20-28℃ and the relative humidity at 40%-60%. Dust control devices should be installed to ensure that the particle size of suspended particulate matter in the air is ≤10μm, so as to avoid dust contamination of the coating.

3. The improved coating machine composite photocuring process based on slurry pretreatment according to claim 1, characterized in that: Step two specifically involves: Primary filtration: The raw slurry is passed through a filtration device equipped with a 100-150 mesh stainless steel filter screen. The filtration pressure is controlled at 0.3-0.5 MPa. During the filtration process, the filter screen is backwashed every 30 minutes to remove solid impurities and agglomerates with a particle size greater than 100 μm from the slurry. Secondary fine filtration: The slurry after primary filtration is passed into a 500-800 mesh ceramic filter element filtration device at a filtration pressure of 0.1-0.2MPa to intercept tiny particles with a diameter greater than 20μm. The ceramic filter element is replaced every 2 hours to avoid the accumulation of impurities. Vacuum degassing treatment: Inject the slurry after secondary fine filtration into a vacuum degassing tank, close the tank door and evacuate to a vacuum degree of -0.08 to -0.095 MPa, maintain the degassing time for 30-60 minutes, and stir slowly at a speed of 20-30 r / min during the degassing process, with the stirring direction along the tangential direction of the tank wall to avoid generating new bubbles; Temperature adaptation and adjustment: The temperature of the slurry is adjusted to 25-35℃ through the jacketed temperature control system of the degassing tank, and the temperature fluctuation is controlled within ±1℃. After adjustment, the slurry is continuously stirred and kept warm at a speed of 15-20r / min to prevent secondary agglomeration of the slurry. Pre-crosslinking modification treatment: Add 0.5%-2% of silane coupling agent to the slurry after the temperature is suitable, mix at a stirring speed of 30-40 r / min for 20-30 min, and use ultrasonic-assisted dispersion during the mixing process. The ultrasonic frequency is 20-40 kHz and the power is 500-800 W to achieve the initial crosslinking of the slurry molecular chains.

4. The improved coating machine composite photocuring process based on slurry pretreatment according to claim 1, characterized in that: Step three specifically involves: Component cleaning: Select the cleaning method according to the material of the coating roller. Wipe metal coating rollers with anhydrous ethanol and rubber coating rollers with a special neutral detergent. After wiping, dry with a lint-free cloth to ensure that there are no residual impurities or oil stains on the surface of the coating roller. After scraping off the residual slurry with the blade, soak the scraper in acetone for 10-15 minutes, let it dry, and then install it. After rinsing the inner wall of the material tank with a high-pressure water gun, dry it until there is no moisture residue. Parameter calibration: Adjust the coating gap using a thickness calibrator to control the gap error within ±0.01mm; debug the transmission system to stabilize the substrate transmission speed at 5-20m / min, with speed fluctuation ≤±0.2m / min; adjust the coating pressure to control it within 0.1-0.3MPa according to the substrate material and thickness. Feeding system commissioning: Start the feeding pump and feed the pretreated slurry into the feed tank. Adjust the feeding flow rate to 10-50L / h to ensure that the liquid level of the slurry in the feed tank is stable at 1 / 2-2 / 3 of the height of the feed tank. Observe the feeding pipeline for leaks and blockages to ensure uniform and continuous feeding.

5. The improved coating machine composite photocuring process based on slurry pretreatment according to claim 1, characterized in that: Step four specifically involves: Primer application: The primer is applied using a micro-gravure coating method. The anilox roller has a cell depth of 30-50μm and a substrate transfer speed of 5-10m / min. The thickness of the primer after application is controlled at 5-15μm. After the primer is applied, it is placed in a hot air drying oven for preliminary drying at a temperature of 40-60℃ for 1-3 minutes to remove 30%-50% of the solvent from the slurry. Intermediate coat application: After the primer has dried, apply the intermediate coat using a comma-shaped scraper, keeping the angle between the scraper and the substrate between 30° and 45°, and the coating pressure between 0.15 and 0.25 MPa. The intermediate coat thickness should be controlled at 20-50 μm. After the intermediate coat, perform a second drying process at 50-70°C for 2-4 minutes, until the solvent removal rate reaches 60%-80%. Topcoat application: After the intermediate coat dries, apply the topcoat using a slotted spray method. Adjust the slot width to 0.1-0.3 mm, and control the material flow rate in conjunction with the substrate transfer speed. Control the topcoat thickness to 10-30 μm. After the topcoat, perform three drying cycles at a temperature of 45-65℃ for 1-2 minutes. Keep the residual solvent content below 5%. After each coating layer is applied, use a coating thickness gauge to select 5-8 test points evenly in the width direction of the substrate, measure the thickness and record it. Use a flatness tester to check the surface flatness to ensure that the coating is free of drips, omissions, and obvious scratches.

6. The improved coating machine composite photocuring process based on slurry pretreatment according to claim 1, characterized in that: Step five specifically involves: Pre-curing treatment: After three drying cycles, the substrate is sent into a pre-curing oven. The pre-curing oven is equipped with 2-3 low-power UV lamps with a wavelength of 365nm and a power of 80-120W / cm per lamp. The lamps are 15-20cm away from the substrate surface. The substrate transfer speed is kept consistent with the topcoat application. The pre-curing time is 5-10s to allow the coating surface to be initially cured and remove any remaining solvent. Main curing treatment: The pre-cured substrate enters the main curing oven, which is equipped with 4-6 medium-high intensity UV lamps, using a dual-band combination of 254nm and 365nm. The power of a single lamp is 150-250W / cm, the lamp distance from the substrate surface is 10-15cm, the transmission speed is adjusted to 3-8m / min, and the main curing time is 15-30s, so as to achieve complete cross-linking of the coating molecular chains. Post-curing treatment: The substrate after primary curing enters the post-curing oven, which is equipped with 2-3 low-intensity UV lamps with a wavelength of 365nm, a single lamp power of 50-100W / cm, a lamp distance of 20-25cm from the substrate surface, a transmission speed of 8-12m / min, and a post-curing time of 8-15s to eliminate internal stress in the coating and stabilize the coating performance. During the three-stage curing process, nitrogen gas is introduced into the curing oven through an inert gas protection device to control the oxygen content in the oven to ≤5% and prevent the coating from oxidizing and turning yellow; the temperature in the curing oven is monitored in real time to ensure that the temperature does not exceed 80℃ to prevent the substrate from deforming.

7. The improved coating machine composite photocuring process based on slurry pretreatment according to claim 1, characterized in that: Step six specifically involves: Coating inspection and adjustment: After each coating layer is applied, the thickness is measured with a coating thickness gauge. If the thickness deviation exceeds ±0.5μm, the coating gap or material flow rate is adjusted. The surface flatness is checked with a flatness tester. If there are sagging or missed coating, the substrate conveying speed or coating pressure is adjusted. Curing Inspection and Adjustment: After pre-curing, use a curing degree tester to check the curing degree of the coating. If the curing degree is less than 60%, increase the power of the pre-curing UV lamp or reduce the transmission speed. After main curing, use an adhesion tester to perform a cross-cut adhesion test. If the adhesion level is less than 2, adjust the power, wavelength combination, or curing time of the main curing UV lamp. After post-curing, check the gloss and scratch resistance of the coating. If the gloss deviation exceeds ±5° or the scratch resistance does not meet the standard, adjust the post-curing parameters. Environmental and slurry testing: The ambient temperature, humidity and dust content of the construction environment are tested every hour. If they exceed the set range, the environmental control system is activated for adjustment. The viscosity and dispersibility of the pretreated slurry are tested every 2 hours. If the viscosity change exceeds ±5mPa・s or agglomeration occurs, degassing and stirring are repeated.

8. The improved coating machine composite photocuring process based on slurry pretreatment according to claim 1, characterized in that: Step seven specifically involves: Gradient cooling: The post-cured finished product is sent into the cooling channel, which is divided into three sections. The first section has a cooling temperature of 50-60℃, the second section has a cooling temperature of 30-40℃, and the third section has a cooling temperature of 20-25℃. The cooling time for each section is 2-3 minutes to avoid sudden cooling that could cause the coating to crack. Edge trimming: Use an automatic edge trimming machine to trim excess coating from the edges of the substrate. The trimming width is controlled at 5-10mm to ensure that the finished product has neat edges and no burrs. Shaping process: Depending on product requirements, choose to apply a protective film or polish the surface. The film is made of transparent PET protective film, and the filming pressure is 0.05-0.1MPa to ensure that the film and coating are adhered to each other without bubbles. Surface polishing uses a non-woven polishing wheel at a speed of 10-15 m / min and 1-2 polishing passes to improve the coating gloss. Finished product inspection: Sampling inspections are conducted on the finalized finished products. The inspection items include coating thickness, flatness, adhesion, gloss, scratch resistance, and yellowing resistance. Only products that meet the design requirements can be put into storage.

9. The improved coating machine composite photocuring process based on slurry pretreatment according to claim 1, characterized in that: The environmental protection measures in step eight are as follows: Waste gas treatment: Activated carbon adsorption devices and UV photolysis purification equipment are installed at the exhaust outlets of the coating machine, drying oven, and curing oven. The waste gas is treated to meet national emission standards before being discharged. Waste liquid treatment: Collect cleaning waste liquid and slurry residue generated during construction, store them separately in special sealed containers, and entrust a professional environmental protection agency to carry out harmless treatment; Dust and noise control: Dust covers are installed at the feed inlet and outlet of the coating machine, and dust in the work area is cleaned regularly; vibration reduction measures are taken for the coating machine, UV lamp and fan, and silencers are installed to ensure that the noise in the work area is ≤85dB(A). Resource recycling: Unused pre-treated slurry is sealed and refrigerated for reuse within its shelf life; base material scraps are sorted and recycled to achieve resource recycling.

10. The improved coating machine composite photocuring process based on slurry pretreatment according to claim 1, characterized in that: The specific safety measures in step eight are as follows: Personal protective equipment: Workers must wear UV-protective clothing, protective glasses, gas masks, and solvent-resistant gloves to avoid damage from UV radiation and chemicals; Equipment safety: The UV curing equipment is equipped with an interlock protection device that automatically cuts off the UV lamp power when the equipment door is opened; the coating machine is equipped with an emergency stop button, and the transmission system is equipped with guardrails to prevent personnel from being pulled in; Electrical safety: All electrical equipment must be properly grounded; the insulation performance of the wiring must be checked regularly to prevent short circuits and leakage; dry powder fire extinguishers and emergency lighting equipment must be provided in the construction area; and emergency plans for fire and chemical spills must be developed. Operating Procedures: All operators must undergo pre-job training to familiarize themselves with the process flow, equipment operation methods, and safety precautions. Only those who pass the assessment are allowed to work. Smoking and open flame operations are strictly prohibited in the construction area, and unauthorized operation of equipment is strictly prohibited.

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