Curtain wall glue injection and maintenance method in high temperature and high humidity environment

Abstract

The application discloses a curtain wall glue injection and maintenance method in a high-temperature and high-humidity environment. A micro-environment regulation cover is arranged in a glue joint area. Dry air is used to form a high-speed air curtain to blow the surface of a base material to release deep heat accumulation. Dry air is introduced during glue injection to maintain a positive pressure difference to form a dynamic barrier. After glue injection, humid and hot air is immediately switched to perform first-stage maintenance. After the sealant is dry, the micro-environment in the cover is gradually changed to the external environment in stages to complete second-stage maintenance. The method can effectively relieve interface stress, block dewing risk, improve curing uniformity and reduce stress impact when the cover is removed in a high-temperature and high-humidity working condition, and is mainly used for sealant glue injection and maintenance construction of curtain wall engineering in coastal and tropical areas.

Description

Technical Field

[0001] This invention relates to the field of building curtain wall construction technology, specifically to a method for applying sealant and maintaining curtain walls under high temperature and high humidity conditions. Background Technology

[0002] High temperature and high humidity environments are typical harsh conditions faced during curtain wall sealant application and curing. In such environments, the high moisture content in the air and temperatures far exceeding those of conventional construction windows pose multiple threats to the application and curing quality of the sealant.

[0003] In curtain wall sealant application, the sealant typically relies on the substrate surface to form a reliable bonding interface to achieve structural sealing. However, high temperature and high humidity environments present several challenges: First, the metal profiles and glass panels of the curtain wall components accumulate heat during sun exposure, resulting in high internal temperatures. After sealant application, this heat release creates a temperature gradient from the inside out, causing inconsistent curing rates along the sealant thickness. This leads to asymmetric curing shrinkage stress, potentially causing interface warping or cohesive failure within the sealant. Second, high temperature and humidity air easily forms a condensation film on the low temperature substrate surface, blocking direct adhesion between the sealant and the substrate. Simultaneously, the primer is prone to moisture absorption and failure. Third, the traditional method of isolating the sealant with dry air throughout the process results in insufficient moisture supply for sealant curing. Direct exposure to the outside environment causes rapid surface crusting, hindering deep curing. Fourth, removing protective devices immediately after curing causes drastic temperature and humidity changes, leading to stress impacts on the sealant and resulting in surface cracking or interface detachment.

[0004] In summary, the application and curing of adhesives to curtain walls in high-temperature and high-humidity environments faces multiple technical challenges, including asymmetric curing due to deep heat storage and slow release of the substrate, condensation failure on the bonding surface, difficulty in balancing moisture supply and curing uniformity, and stress impact caused by environmental changes. A method that can systematically solve these problems is urgently needed. Summary of the Invention

[0005] One object of the present invention is to address at least the aforementioned deficiencies and to provide at least the advantages that will be described later.

[0006] To achieve these objectives and other advantages of the present invention, a method for applying and maintaining sealant to a curtain wall under high temperature and high humidity conditions is provided, comprising: erecting a microenvironment control hood to form a closed space in the sealant joint area to be sealed; the microenvironment control hood is equipped with a sealed operating sleeve, and / or has an operating port on the hood, the operating port being equipped with an openable and closable sealing cover or flexible curtain to maintain the sealing of the hood during the sealant application process; after the erection is completed, a high-speed air curtain is first formed inside the hood along the sealant joint direction using dry air. The air velocity is 1.5~3.0 m / s, and the surface of the substrate on both sides of the adhesive joint is continuously blown for 15~30 minutes to accelerate the release of deep heat stored in the substrate. The temperature of the dry air is 30~40℃. After the surface temperature of the metal profile and glass panel drops to within 2℃ of the air temperature inside the enclosure, the air velocity is reduced to 0.1~0.5 m / s, and the adhesive injection stage begins. Throughout the adhesive injection stage, from applying the primer to applying the sealant into the adhesive joint, dry air is introduced into the microenvironment control enclosure to regulate the microenvironment inside the enclosure. The temperature is maintained at 18~25℃ and the relative humidity is maintained at ≤40%. By adjusting the air intake flow and exhaust valve opening, a positive pressure difference of 5~20Pa is maintained between the inside of the enclosure and the outside atmosphere to form a dynamic pressure barrier against the intrusion of high-temperature and high-humidity air from the outside. After the sealant is applied, the incoming gas is immediately switched to humid and hot air, raising the temperature of the microenvironment inside the enclosure to 30~38℃ and the relative humidity to 55~70%. The sealant is then cured in the first stage in this humid and hot microenvironment to promote deep curing. After the sealant is surface dry, the microenvironment inside the enclosure is controlled and regulated in at least two stages: the first stage adjusts the microenvironment inside the enclosure to a stable intermediate condition of 25~28℃ and 45~55% relative humidity with a temperature change rate ≤2℃ / h and a relative humidity change rate ≤5%RH / h, and maintains this for 12~24 hours; the second stage transitions the microenvironment inside the enclosure from the aforementioned stable intermediate condition to the actual external environmental conditions with the same temperature and humidity change rate limits, completing the second stage of curing.

[0007] The above solution effectively reduces the temperature gradient of the adhesive layer caused by substrate heat accumulation by using high-speed air curtain forced convection to peel away the deep heat storage of the substrate before adhesive injection, making the substrate temperature and the air inside the enclosure nearly isothermal. This significantly alleviates the risk of interface warping and adhesive cohesive failure caused by asymmetric curing shrinkage stress. During the adhesive injection stage, a dynamic barrier is formed by dry air combined with a 5-20 Pa positive pressure difference, preventing condensation on the bonding surface and moisture absorption failure of the primer caused by the intrusion of high-temperature and high-humidity air, while also providing a stable operating environment for sealant application. Immediately after adhesive injection, the system switches to a humid and hot microenvironment with a temperature of 30-38℃ and a relative humidity of 55-70%. The environment is precisely matched to the dual requirements of moisture-curing sealants for both moisture and temperature. This avoids insufficient moisture supply caused by continuous drying and prevents excessively rapid skinning of the surface caused by direct exposure, achieving uniform curing of the sealant layer from the surface inward. Through a two-stage gradual transition after surface drying with strictly limited rates of temperature and humidity change, the curing shrinkage stress and thermal expansion and contraction stress are released smoothly. The long-term maintenance of stable conditions in between provides a sufficient window for stress relaxation of the sealant, effectively preventing surface cracking and interface debonding caused by sudden environmental changes. Ultimately, this achieves reliable control of the entire chain of sealant injection and maintenance for curtain walls in high-temperature and high-humidity environments.

[0008] Preferably, in the curtain wall sealant injection and curing method under high temperature and high humidity environment of the present invention, the sealant is a moisture-curing sealant. In the first stage of curing, a humidity sensor is set at a distance of 5-15 cm from the sealant joint inside the microenvironment control cover to continuously collect the relative humidity value inside the cover at a sampling frequency of not less than 0.1 Hz, and the collected values ​​are processed by moving average to generate a smooth humidity change curve. When the absolute value of the slope of the smooth humidity change curve changes from continuously greater than 0.05%RH / min to continuously less than 0.01%RH / min, and after a delay of 5-15 minutes after the change, it is determined that the sealant has reached the surface dry state, and the phased controlled adjustment of the microenvironment inside the cover is started accordingly.

[0009] The above-mentioned scheme achieves accurate determination of the surface drying state by capturing the characteristic inflection point change in the rate of humidity decrease before and after the surface drying of moisture-curing sealant, without opening the enclosure or touching the sealant surface. Before surface drying, the sealant surface has not yet formed a film, and moisture can evaporate relatively freely into the enclosure, resulting in a rapid decrease in relative humidity inside the enclosure. After surface drying, the dense surface hinders moisture mass transfer, and the rate of decrease drops sharply to a slow level. By filtering out disturbances through high sampling frequency and moving average processing, the transition point is locked using a dual-threshold slope, and a 5-15 minute delay is set to confirm surface drying stability. This effectively avoids misjudgments caused by factors such as air intake fluctuations, and provides a reliable start-up basis for phased controlled adjustment.

[0010] Preferably, in the curtain wall grouting and curing method under high temperature and high humidity conditions of the present invention, after the grouting is completed, in the initial stage of switching to the introduction of humid and hot air, transitional humid and hot air pre-adjusted to 30-38°C and relative humidity of 35-45% is introduced into the enclosure at an air intake rate lower than the normal air intake rate required to maintain the positive pressure difference of 5-20Pa. After the temperature inside the enclosure rises to above 28°C, the air intake flow rate is restored to the normal air intake flow rate, while the relative humidity of the introduced air is gradually increased to the target value of 55-70%. The air intake rate lower than the normal air intake flow rate is 40%-60% of the normal air intake flow rate.

[0011] The proposed solution employs a gradual switching strategy for temperature and humidity. Initially, hot air at the target temperature is used, but the relative humidity is controlled at a mid-range level of 35-45%, with a dew point significantly lower than the target humid air. This ensures no condensation occurs when the air comes into contact with the still-low-temperature sealant surface. Once the internal temperature rises above 28°C and the sealant surface temperature is simultaneously increased, the humidity is gradually increased to the target value. At this point, because the sealant surface temperature is already above the dew point of the humid air, the risk of condensation is naturally eliminated. This method resolves the condensation conflict during the switching between hot and humid conditions without adding any additional devices; it achieves this simply by controlling the timing of the intake air humidity.

[0012] Preferably, in the curtain wall adhesive injection and curing method under high temperature and high humidity environment of the present invention, after the adhesive injection is completed, while switching to the introduction of humid and hot air, by setting guide vanes or diffusers at the air inlet of the microenvironment control cover, the air intake direction of the humid and hot air is first adjusted to face the metal profile and glass panel surface of the curtain wall component, and the air is evenly delivered to the space inside the cover in a diffuse manner for 5 to 10 minutes, so that the temperature difference between the substrate and the humid and hot air does not exceed 1°C, and then the air intake direction is adjusted to concentrate on the adhesive joint area for adhesive curing.

[0013] The aforementioned solution proposes a timed airflow organization strategy of first warming the substrate and then curing the sealant. Initially, the humid airflow is not directly directed at the sealant joint; instead, it diffuses across the profiles and panels of the curtain wall components, using the heat carried by the humid air itself to rapidly raise the substrate temperature and eliminate the temperature difference between the substrate and the humid air. Once the substrate is preheated to the same temperature as the humid air, the airflow is then focused on the sealant joint for curing. At this point, the temperatures on both sides of the sealant—the inner side in contact with the substrate and the outer side in contact with the humid air—are nearly identical, allowing the curing reaction to proceed synchronously. This fundamentally avoids the internal stress accumulation and interface weakening caused by curing rate delamination. This method does not require any additional heating devices; it achieves a coordinated equilibrium of the temperature fields of the substrate and the sealant simply by arranging the timing and path of the airflow.

[0014] Preferably, in the curtain wall grouting and curing method of the present invention under high temperature and high humidity environment, after the microenvironment inside the cover is transitioned to be consistent with the actual external environment in the second stage of curing, the microenvironment control cover is not removed immediately. Instead, the air intake is closed and the cover is kept sealed and left to stand for 10 to 20 minutes. This allows the air inside the cover to passively exchange with the external environment through the inherent micropermeability of the PVC membrane material itself or the micro gaps at the edge seals, gradually approaching the external humidity. Then, the cover is slowly removed at a peeling speed of no more than 5 cm / s.

[0015] The above-mentioned solution proposes a delayed buffering strategy of first stopping the air intake and allowing the sealant to stand still before removing the cover. It is recognized that once the microenvironment inside the cover transitions to the same level as the outside environment, immediately removing the cover is equivalent to abruptly switching the colloid from a quasi-equilibrium state protected by the cover to a completely open convective environment, which will instantly amplify the moisture exchange rate. By first shutting off the air intake, the air inside the cover is passively exchanged with the outside environment only through the micro-permeability of the cover itself. During the 10-20 minute standing period, the rate at which the humidity inside the cover approaches the humidity outside is naturally limited by the permeation resistance of the cover, forming a low-energy-consumption wetting buffer slope. This allows the sealant surface to gradually adapt to the humidity change and complete a small amount of moisture expansion and relaxation, thereby eliminating the swelling-shrinkage stress peak caused by the sudden removal of the cover, effectively suppressing the swelling-shrinkage stress peak at the moment of removal, and reducing the probability of micro-cracks on the sealant surface.

[0016] Preferably, in the curtain wall sealant injection and curing method under high temperature and high humidity environment of the present invention, during the first stage of curing, the following intermittent venting operation is also performed: every 20 to 40 minutes, the venting valve is fully opened and the intake flow of hot and humid air is increased simultaneously, so that the positive pressure difference between the inside of the enclosure and the outside is maintained at a level higher than 20 Pa and not exceeding 40 Pa for 10 to 30 seconds, thereby completing a rapid gas replacement and expelling the volatile byproducts generated by the sealant curing reaction; the opening degree of the venting valve and the intake flow are restored to the state required to maintain the positive pressure difference of 5 to 20 Pa.

[0017] The above-mentioned solution involves a rapid gas replacement lasting only 10-30 seconds every 20-40 minutes during the humid curing period. This extremely short airflow pulse refreshes the gas inside the enclosure, a time too short to cause substantial fluctuations in temperature and relative humidity near the sealant joint, yet effectively removes accumulated volatile byproducts. This ensures that the humidity sensor's monitoring reflects actual changes in water molecule concentration, guaranteeing the accuracy of surface dryness determination. Simultaneously, it eliminates the thermodynamic hindrance of byproducts to the curing reaction. The intermittent operation mode immediately restores the positive pressure differential after purification, ensuring that high-humidity external air cannot infiltrate.

[0018] Preferably, the method for applying and maintaining sealant to a curtain wall under high temperature and high humidity conditions of the present invention, when determining that the sealant has reached the surface dry state, also satisfies the following conditions: the temperature inside the cover has been continuously and stably maintained within the range of 30~38℃ for at least 5 minutes, and the temperature fluctuation within these 5 minutes does not exceed ±0.5℃.

[0019] The above scheme proposes a pseudo-inflection point elimination strategy based on dual temperature stability verification. It recognizes that the inflection point of humidity decrease rate caused by true surface drying inevitably occurs after film formation on the colloid surface and the transformation of the moisture transfer mechanism. At this point, the heating provided by the humid air inside the enclosure and the heat dissipated by the colloid reaction have reached equilibrium, and the temperature inside the enclosure should be within a stable range. Pseudo-humidity inflection points caused by sudden changes in air intake parameters or airflow disturbances are often accompanied by significant temperature fluctuations or transient shifts. By adding a temperature stability condition, surface drying is only confirmed as effective when both temperature and humidity signals point to the solidification entering a steady-state stage. This helps filter out temperature and humidity coupled oscillation signals generated during the over-gas supply and diffusion preheating stages, making the triggering timing of staged controlled regulation more accurate and reliable.

[0020] Preferably, in the curtain wall grouting and curing method under high temperature and high humidity environment of the present invention, the intermittent venting operation is not performed in the initial stage of switching to the introduction of hot and humid air after the grouting is completed; the intermittent venting operation is then performed after the substrate preheating is completed and the temperature inside the cover has been continuously and stably maintained in the range of 30~38℃ for at least 5 minutes.

[0021] The above-mentioned scheme proposes a timing decoupling strategy for delayed venting operation. The venting operation is delayed until the substrate preheating is completed and the temperature inside the enclosure stabilizes within the target range. This makes the initial stage of wet heat curing a quiet establishment period without venting disturbance, avoiding the interference of venting pulses on the still unstable temperature and humidity field and the surface dryness determination process of the humidity sensor. At the same time, it ensures that the substrate preheating process is not affected by micro-pressure fluctuations. After the curing microenvironment has fully entered a steady state, intermittent venting is started to remove by-products. At this time, the venting operation can be continuously executed until the end of the first stage of curing, fully ensuring the by-product removal function without affecting the stability of the curing conditions.

[0022] Preferably, in the curtain wall sealant injection and curing method under high temperature and high humidity conditions of the present invention, activated carbon fiber felt is pre-attached to the inner wall of the microenvironment control cover during the installation of the microenvironment control cover or before the start of sealant injection, so as to continuously capture the volatile byproducts released in the early stage of sealant curing by physical adsorption; the specific surface area of ​​the activated carbon fiber felt is 800~1500m². 2 / g, with a thickness of 1~3mm, and its placement inside the cover avoids an area with a radius of not less than 10cm around the humidity sensor.

[0023] The above scheme proposes a passive adsorption bridging strategy for byproduct control during the exhaust silence period. Activated carbon fiber felt is introduced as a temporary byproduct buffer during the window of exhaust absence. Utilizing its high specific surface area and rapid adsorption characteristics, the byproducts initially released by the sealant are captured and temporarily stored in real time, ensuring that the air inside the enclosure is mainly composed of water molecules. This guarantees the accuracy of the humidity sensor's surface dryness determination and the thermodynamic driving force of the curing reaction. The fiber felt is placed away from the humidity sensor to prevent momentary interference to the sensor readings from local adsorption or desorption, thus maintaining stable curing conditions during the silence period.

[0024] Preferably, in the curtain wall sealant injection and maintenance method under high temperature and high humidity conditions of the present invention, the sealant is a moisture-curing sealant; the activated carbon fiber felt undergoes hydrophobic modification treatment, which involves immersing the activated carbon fiber felt in a 3%~8% fluorocarbon resin impregnation solution for 10~30 minutes, then drying it at 60~80℃ for 20~40 minutes, and then heat-setting it at 120~150℃ for 15~30 minutes, so that a fluorocarbon resin coating layer is formed on the fiber surface of the activated carbon fiber felt; the activated carbon fiber felt after the hydrophobic modification treatment has an equilibrium adsorption capacity for water vapor at 30℃ and 60% relative humidity that does not exceed 20% of the saturated adsorption capacity of the volatile byproducts released by the sealant curing at the same temperature at 30℃ and a byproduct gas phase concentration of 2000ppm. Specifically, the byproduct gas phase concentration is calculated based on the main volatile components released by the sealant curing.

[0025] The above solution modifies activated carbon fiber felt by coating it with fluorocarbon resin to create a hydrophobic surface. This process imparts hydrophobic selectivity to the surface of the fiber felt without altering its porous adsorption structure. The water vapor adsorption capacity is limited to less than 20% of the saturated adsorption capacity of by-products. This allows the fiber felt to preferentially adsorb organic by-products with weak molecular polarity in humid and hot air, ensuring both precise maintenance of humidity within the enclosure and sufficient by-product capture capacity. Specific impregnation concentration, time, drying, and heat setting process parameters ensure the repeatability of the hydrophobic modification effect. At the same time, the upper limit of the heat setting temperature avoids damage to the fiber itself, enabling the fiber felt to continuously and efficiently perform its selective purification function during the exhaust silence period.

[0026] First, this invention uses high-speed air curtain forced convection pretreatment before adhesive injection to remove deep heat storage in the component. Combined with substrate diffusion preheating in the early stage of humid heat curing, the temperature field of the substrate and the adhesive tends to be balanced, effectively reducing the curing rate difference in the thickness direction of the adhesive layer and significantly mitigating the risk of interface debonding and adhesive cohesive damage caused by asymmetric shrinkage.

[0027] Secondly, during the adhesive injection stage, a dynamic moisture barrier is formed by dry air and positive pressure difference to prevent the intrusion of high temperature and high humidity air, which can lead to condensation on the substrate and failure of the primer. After adhesive injection, the humidity inside the cover is stably controlled throughout the curing cycle by a combination of transitional humidity and heat switching, intermittent exhaust and selective adsorption by activated carbon fiber felt, avoiding interference from condensate film and by-products, and ensuring uniform moisture curing.

[0028] Third, the non-contact surface dryness determination method based on the dual verification of the inflection point of humidity decrease rate and temperature stability provides a reliable triggering time for cooling and dehumidification; the phased and rate-limited gradual transition combined with static buffering before removing the cover controls the rate of change of temperature and humidity of the colloid, effectively slowing down the concentrated release of curing shrinkage stress and thermal expansion and contraction difference stress, reducing the risk of surface cracking and interface debonding.

[0029] Fourth, by intermittently and rapidly venting to remove curing byproducts, and by delaying the start of venting and using hydrophobic modified activated carbon fiber felt for adsorption, the contradiction between venting and the establishment of temperature and humidity, as well as the competitive adsorption of water vapor, is resolved. This helps to maintain precise control of humidity inside the enclosure and prevent byproducts from interfering with the curing reaction and sensor monitoring, thus providing a stable and clean environment for the deep curing of the sealant. Detailed Implementation

[0030] The present invention will be further described in detail below with reference to embodiments, so that those skilled in the art can implement it based on the description. Example 1

[0031] A method for applying sealant and maintaining curtain walls under high temperature and high humidity conditions, the equipment used includes: a microenvironment control hood, a dry air supply system, a humid and hot air supply system, an air intake flow regulating valve, an exhaust valve, and a temperature sensor and a humidity sensor.

[0032] The microenvironment control cover is made of transparent, flexible PVC membrane material and has a rectangular shell structure. Magnetic sealing strips or hook-and-loop fasteners are installed around the perimeter of the cover to ensure a tight fit with the metal profiles and glass panels of the curtain wall components, creating a sealed space in the adhesive joint area. The length of the cover is determined based on the adhesive joint length of a single construction operation, typically 1.5–3.0 meters; the width is 0.5–1.0 meters; and the height is 0.3–0.6 meters, sufficient to cover the adhesive joint and the substrate area of ​​20–40 centimeters on each side.

[0033] The enclosure has at least one air inlet and at least one exhaust outlet. The air inlet is located at one end or in the middle of the enclosure, and the exhaust outlet is located at the other end or at the top of the enclosure. The air inlet is connected to a dry air supply system and a humid air supply system respectively via a switching valve assembly, which is a three-way solenoid valve or a manual three-way ball valve, used to switch between dry air and humid air. The exhaust outlet is connected to an exhaust valve, which is an adjustable-opening solenoid proportional valve or a manual butterfly valve.

[0034] The dry air supply system comprises an air compressor, a refrigerated dryer, and an air temperature control module connected in sequence. The air compressor provides compressed air, the refrigerated dryer lowers the dew point of the compressed air to below -20°C to remove moisture, and the air temperature control module, with its built-in electric heater and cooling fins, can regulate the temperature of the dry air within the range of 10~40°C. The outlet of the dry air supply system is connected to the first inlet of the switching valve assembly via a pipeline.

[0035] The humidified and hot air supply system includes an air compressor, a humidifier, and an air heating module connected in sequence. The humidifier is an ultrasonic humidifier or a steam humidifier, capable of adjusting the relative humidity of the air within the range of 20% to 95%. The air heating module has a built-in electric heater, capable of adjusting the air temperature within the range of 20 to 50°C. The outlet of the humidified and hot air supply system is connected to the second inlet of the switching valve assembly via a pipeline.

[0036] The intake flow regulating valve is located on the pipeline between the outlet of the switching valve assembly and the intake port of the hood, and is used to regulate the airflow entering the hood. The exhaust valve is located at the exhaust port of the hood, and is used to regulate the amount of gas discharged from the hood.

[0037] The enclosure houses temperature and humidity sensors. The temperature sensor is a Pt100 platinum resistance temperature sensor or a thermocouple temperature sensor, while the humidity sensor is a capacitive humidity sensor. Both are connected to an external control unit via signal lines. The control unit is a PLC programmable controller or a microcontroller, with built-in temperature and humidity control algorithms. It automatically adjusts the operating parameters of the intake flow regulating valve, exhaust valve, air temperature control module, and humidifier based on sensor feedback signals. Additionally, a micro-differential pressure sensor is installed inside the enclosure to detect the pressure difference between the enclosure and the outside atmosphere in real time. The micro-differential pressure sensor has a range of 0~100Pa and an accuracy of ±1Pa. A patch thermocouple or non-contact infrared temperature sensor is attached to the substrate surface to monitor the substrate surface temperature.

[0038] Specifically, the following steps are included: Step 1: Erect a microenvironment control hood over the sealant joint area. Cover the metal profiles and glass panels above and on both sides of the sealant joint, using magnetic sealing strips or hook and loop fasteners to ensure the edges of the hood are tightly fitted to the curtain wall components, creating a closed microenvironment space. After erection, check the sealing of each edge of the hood to ensure there are no obvious leaks.

[0039] Step 2: After installation, connect the switching valve group to the dry air supply system. Turn on the air compressor and refrigerated dryer, and start the air temperature control module to set the dry air temperature to the current air temperature inside the enclosure, which is typically 30~40℃. Adjust the air intake flow regulating valve to allow dry air to enter the enclosure at a higher flow rate, forming a high-speed air curtain along the direction of the sealant joints. Ensure the air curtain velocity reaches 1.5~3.0 m / s using the wind speed sensor installed inside the enclosure or by calculating based on the air intake flow rate and the cross-sectional area of ​​the enclosure.

[0040] The high-speed air curtain continuously blows along the direction of the sealant joint onto the surfaces of the metal profiles and glass panels on both sides of the joint for 15-30 minutes. During this process, the high-speed airflow continuously removes heat from the substrate surface through forced convection, accelerating the removal of heat stored deep within the curtain wall components due to sunlight, which would be slowly released after sealant application.

[0041] The surface temperature of the substrate is monitored in real time by a temperature sensor attached to the substrate surface, while the temperature of the incoming dry air is monitored by a temperature sensor inside the enclosure. When the difference between the substrate surface temperature and the air temperature inside the enclosure does not exceed 2°C, the deep heat storage peeling is considered complete. At this point, the airflow regulating valve is adjusted to reduce the flow rate of the dry air entering the enclosure, reducing the air velocity inside the enclosure to 0.1~0.5m / s, and the adhesive injection stage begins.

[0042] Step 3: Throughout the entire adhesive application stage, from applying the primer to filling the joints with sealant, continue to circulate dry air into the microenvironment control enclosure. Adjust and maintain the temperature of the dry air at 18-25°C using the air temperature control module, and ensure the dew point of the circulated air is below -20°C using a freeze dryer, thus maintaining the relative humidity of the microenvironment inside the enclosure at ≤40%.

[0043] Simultaneously, the control unit adjusts the opening of the intake flow regulating valve and the exhaust valve to maintain a positive pressure difference of 5-20 Pa between the inside of the enclosure and the outside atmosphere. Specifically, a micro-differential pressure sensor detects the pressure difference between the inside and outside of the enclosure in real time and feeds it back to the control unit. When the pressure difference is below 5 Pa, the control unit increases the opening of the intake flow regulating valve or decreases the opening of the exhaust valve; when the pressure difference is above 20 Pa, the control unit decreases the opening of the intake flow regulating valve or increases the opening of the exhaust valve. This creates a dynamic pressure barrier, preventing hot and humid external air from penetrating into the enclosure.

[0044] In this microenvironment, operators apply the primer and sealant using either the pre-drilled opening on the enclosure or a sealed operating sleeve while wearing gloves. When using the sealed operating sleeve, the sleeve fits snugly against the operator's arm, keeping the enclosure closed throughout the application process and maintaining a stable positive pressure differential. When using the opening, it is kept closed by a flexible, closable curtain or sealing cover when not in use. After the operator inserts their arm and application tool into the opening, the flexible curtain naturally contracts around the arm or tool, creating a restricted annular gap. The continuously flowing dry air inside the enclosure, controlled by the intake and exhaust valves, allows for a small amount of leakage through this gap, maintaining a positive pressure differential of 5-20 Pa. After application, the arm and tool are removed from the opening, and the flexible curtain or sealing cover is completely closed, restoring the enclosure to a fully sealed state.

[0045] Step 4: After the adhesive is applied, the control unit switches the air intake from the dry air supply system to the humid air supply system via the switching valve assembly. The switching process is completed within seconds. Activate the humidifier and air heating module, adjusting the temperature of the incoming air to 30-38℃ and the relative humidity to 55-70%. Simultaneously adjust the opening of the air intake flow regulating valve and the exhaust valve to maintain the positive pressure difference within the enclosure within the range of 5-20 Pa.

[0046] The sealant undergoes its first stage of curing in this humid microenvironment. The humid air provides the necessary moisture and suitable temperature for the sealant's moisture-curing reaction, promoting deep curing from the surface inwards. This first stage of curing continues until the sealant reaches a surface-dry state. The surface-dry state can be determined by visually observing the change in gloss on the transparent film of the cover, from a moist gloss to a matte finish. Alternatively, a blunt-tipped probe can be used to lightly touch the sealant surface through the operating sleeve; the sealant should not be sticky to the touch. Directly pressing the sealant surface with fingers should be avoided to prevent physical marks.

[0047] Step 5: Once the sealant reaches surface dryness, the control unit begins to adjust the microenvironment inside the enclosure in stages.

[0048] Phase 1 Adjustment: The microenvironment inside the enclosure is gradually adjusted from the current 30-38℃ and 55-70% RH to a stable intermediate condition of 25-28℃ and 45-55% RH, with a temperature change rate not exceeding 2℃ / h and a relative humidity change rate not exceeding 5%RH / h. During the adjustment process, the control unit, based on real-time feedback from the temperature and humidity sensors, uses a PID algorithm to control the heating power of the air heating module and the humidification output of the humidifier, gradually reducing the temperature and humidity of the incoming air, allowing the temperature and humidity inside the enclosure to decrease steadily at the set rate. After reaching the stable intermediate condition, this condition is maintained for 12-24 hours.

[0049] The second stage of adjustment: After maintaining the intermediate stable conditions, the microenvironment inside the enclosure is further transitioned to conditions consistent with the external normal temperature and humidity environment by using the same temperature and humidity change rate limits, i.e., temperature change rate ≤2℃ / h and relative humidity change rate ≤5%RH / h. At this point, the temperature and humidity inside the enclosure are close to or equal to the external environmental levels.

[0050] After the second stage of curing is completed, the dry air supply system and the hot and humid air supply system are shut down, the microenvironment control cover is removed, and the entire glue injection and curing operation is completed.

[0051] Example 2 A method for applying sealant and maintaining curtain walls under high temperature and humidity conditions, based on Example 1, involves continuously collecting relative humidity values ​​inside the enclosure at a sampling frequency of no less than 0.1Hz during the first stage of maintenance in step four. A humidity sensor, positioned 5-15cm away from the sealant joint inside the microenvironment control enclosure, continuously collects these values ​​via a signal line to the control unit. The control unit performs a moving average processing on the collected discrete humidity data points, with a moving average window width of 10-30 sampling points to generate a smooth humidity change curve, eliminating instantaneous humidity spikes caused by airflow disturbances, exhaust valve operation, and other factors.

[0052] In the initial stage of the first curing phase, before a dense skin has formed on the sealant surface, moisture from the internal solvent or reaction byproducts can evaporate relatively freely into the air inside the enclosure. At this time, the relative humidity inside the enclosure decreases rapidly due to the dynamic equilibrium between the continuous introduction of warm, humid air and the evaporation of moisture from the sealant. As the sealant surface gradually hardens and forms a dense skin, the mass transfer resistance of moisture migrating from the interior of the sealant to the surface and evaporating into the air inside the enclosure increases significantly. Consequently, the rate of decrease in relative humidity inside the enclosure slows down, forming a identifiable inflection point on the smooth humidity change curve.

[0053] The control unit calculates the absolute value of the slope of the smoothed humidity change curve over adjacent time periods in real time, representing the change in relative humidity per unit time. When the absolute value of this slope changes from consistently greater than 0.05%RH / min (i.e., a decrease in relative humidity exceeding 0.05 percentage points per minute) to consistently less than 0.01%RH / min (i.e., a decrease in relative humidity less than 0.01 percentage points per minute), it indicates that an effective skin has formed on the surface of the sealant, and the rate of moisture evaporation has been significantly reduced. After this change, the control unit does not immediately trigger phased adjustments but instead sets a 5-15 minute delay confirmation period to eliminate misjudgments caused by brief disturbances. After the delay confirmation period expires, it is preliminarily determined that the sealant has reached a surface-dry state.

[0054] Meanwhile, the control unit also monitors temperature changes synchronously via an internal temperature sensor. When determining surface dryness, the following temperature stability conditions must also be met: the internal temperature must have been continuously and stably maintained within the target range of 30~38℃ for at least 5 minutes, and the maximum temperature fluctuation within this 5-minute period must not exceed ±0.5℃. This dual verification mechanism is used to exclude the following situation: during the active adjustment phase of the intake parameters, changes in the intake parameters themselves can cause a temporary change in the rate of change of humidity inside the hood, forming a false inflection point similar to the characteristics of the true surface dryness inflection point. The temperature stability condition effectively filters out such signal interference caused by operation.

[0055] Only when both the humidity inflection point condition and the temperature stability condition are met will the control unit finally determine that the sealant has reached the surface dry state, and automatically begin to execute the phased controlled adjustment described in step five of Example 1.

[0056] The remaining operations are exactly the same as in Example 1.

[0057] Example 3 A method for applying sealant and maintaining curtain walls under high temperature and high humidity conditions, based on Example 1, in step four, after the sealant application is completed, the initial stage of introducing humid and hot air is switched. Instead of immediately introducing air with the target temperature and humidity into the enclosure, the following transition procedure is performed: First, the air intake source is switched to the humidified air supply system via the switching valve assembly, but the humidifier's humidification level is set to a low level, pre-adjusting the incoming air to a transitional humidified air with a temperature of 30-38℃ and a relative humidity of only 35-45%. Simultaneously, the intake flow rate regulating valve is set to 40%-60% of the normal opening required to maintain a positive pressure differential, meaning transitional humidified air is introduced into the enclosure at a low intake rate. Here, "normal intake flow rate" refers to the intake flow rate required to maintain a positive pressure differential of 5-20 Pa during the stable maintenance phase.

[0058] During this transition phase, although the temperature of the transitional humid air has reached the target range, its dew point temperature is significantly lower than that of the target humid air due to the low relative humidity. At this time, the sealant surface and the internal components are still at a relatively low temperature of 18~25°C during the sealant application phase. When in contact with the transitional humid air, condensation will not occur because the sealant surface temperature is higher than the dew point temperature of the transitional air.

[0059] A continuous supply of warm, humid air is introduced, and the internal temperature is monitored in real time by a sensor. When the internal temperature rises above 28°C, it indicates that the temperature of the sealant surface and internal components has been sufficiently increased. At this point, the control unit gradually increases the humidification output of the humidifier, raising the relative humidity of the incoming air from 35-45% to the target value of 55-70% within 5-10 minutes, while simultaneously restoring the airflow to the normal level required to maintain a positive pressure differential.

[0060] After that, the normal humid and hot curing stage begins, with the curing conditions being the same as step four of Example 1.

[0061] The remaining operations are exactly the same as in Example 1.

[0062] Example 4 A method for applying sealant and maintaining curtain walls under high temperature and high humidity conditions, based on Example 1, in step four, after the sealant application is completed, while switching to introduce humid and hot air, the air inlet of the cover is equipped with an adjustable direction guide vane, or the cover is equipped with two or more air inlets at different positions, and different air inlets are selected by switching valve to achieve air supply in different directions.

[0063] In the initial stage of introducing humid and hot air, i.e., the first 5 to 10 minutes, adjust the guide vanes to face the metal profiles and glass panel surfaces of the curtain wall components, or switch the air intake to face the substrate surface, so that the humid and hot air is evenly distributed into the space inside the enclosure in a diffused manner. Dispersed air supply can be achieved by installing a diffuser at the air intake. The diffuser disperses the concentrated airflow into a low-speed scattered airflow with a large diffusion angle, so that the humid and hot air preferentially contacts and exchanges heat with the metal profiles and glass panel surfaces on both sides of the sealant joint, rather than being directly blown into the sealant joint area.

[0064] During this diffused airflow process, the surface temperature of the metal profile and glass panel is monitored in real time by temperature sensors attached to the substrate surface. As the hot and humid air continues to pass over the substrate surface, the substrate temperature gradually rises. When the substrate temperature reaches a level approximately the same as the temperature of the incoming hot and humid air, and the temperature difference does not exceed 1°C, the substrate preheating is considered complete.

[0065] At this point, adjust the angle of the guide vanes or switch the air intake interface to direct the intake direction of the hot and humid air towards the sealant joint area. The concentrated airflow blows directly onto the sealant joint with a narrow diffusion angle, ensuring that the sealant in the joint area fully contacts the hot and humid air. Continue to maintain the concentrated airflow mode thereafter for sealant curing.

[0066] The guide vanes can be adjusted manually or automatically by a micro stepper motor driven by the control unit. In automatic adjustment mode, the control unit automatically switches the airflow direction from diffusion mode to concentration mode based on feedback from the substrate temperature sensor once the substrate temperature reaches the target.

[0067] The remaining operations are exactly the same as in Example 1.

[0068] The substrate preheating strategy described in this embodiment can be combined with the transitional humidity and heat switching strategy described in Embodiment 3. When implemented in combination, a transitional humidity of 35% to 45% is used for air supply in the initial stage of substrate preheating. After the substrate preheating is completed, the air supply humidity is simultaneously increased to the target value of 55% to 70%, and the airflow direction is switched to concentrate towards the adhesive joint area.

[0069] Example 5 A method for sealing and curing curtain walls under high temperature and high humidity conditions, based on Example 1, involves step five, where the second stage of curing transitions the microenvironment inside the enclosure to match the actual external environment. At this point, the temperature and relative humidity inside the enclosure are essentially equal to the external levels. However, although the sealant has initially cured and formed, the cross-linking density has not yet reached its final level, making it still quite sensitive to rapid changes in the external environment.

[0070] After the microenvironment inside the enclosure transitions to match the external environment, the microenvironment control enclosure is not immediately removed. The control unit issues a command to close the valve at the air inlet and simultaneously completely close the exhaust valve, ceasing the introduction of any gas into the enclosure, thus placing the enclosure into a sealed, static state. The duration of this sealed static state is 10-20 minutes. During this static period, since no fresh air is introduced, the air inside the enclosure exchanges slowly and passively with the outside environment through two pathways: first, the inherent micropermeability of the PVC membrane material itself allows gas molecules to slowly diffuse bidirectionally through the micropores of the membrane material; second, the extremely fine gaps between the magnetic sealing strips or hook-and-loop fasteners at the edges of the enclosure and the surface of the curtain wall components create limited leakage channels. Under the action of these two passive exchange mechanisms, the humidity of the air inside the enclosure gradually approaches the humidity of the outside environment at a controlled, slow rate, forming a natural wetting buffer slope, rather than a sudden, abrupt change due to exposure to the external convective environment.

[0071] After standing for 10-20 minutes, the sealant surface has gradually adapted to the humidity changes during this buffer period, undergoing slight expansion or contraction. At this point, slowly release the magnetic sealing strip or hook and loop fasteners at the edge of the cover and remove the cover from the sealant area to complete the entire curing process.

[0072] The remaining operations are exactly the same as in Example 1.

[0073] Example 6 A method for sealant application and curing of curtain walls under high temperature and humidity conditions, based on Example 4, involves the sealant undergoing a continuous moisture-curing reaction in the first stage of the curing process in step four, releasing volatile byproducts such as alcohols and ketones. These byproducts gradually accumulate within the enclosed microenvironment control enclosure. To remove these byproducts, this embodiment, while continuously introducing humid and hot air to maintain the curing environment, adds the following intermittent venting operation: Every 20-40 minutes, the interval can be set in the control unit according to the type and amount of sealant applied, for example, a midpoint of 30 minutes. The control unit simultaneously sends commands to the exhaust valve and the air intake flow regulating valve to perform a rapid gas replacement. The specific operation is as follows: the exhaust valve is fully opened to 100%, while simultaneously increasing the intake flow of humid air. The increase in intake flow is controlled based on real-time feedback from the micro-differential pressure sensor. The control unit dynamically adjusts the opening of the intake valve through a PID algorithm, maintaining the positive pressure difference between the inside of the enclosure and the outside environment at a level higher than 20 Pa and not exceeding 40 Pa during the replacement period, for example, stably controlled within the range of 25-35 Pa. This positive pressure difference is 5-20 Pa higher than that during normal curing, driving the gas inside the enclosure to be discharged from the exhaust valve at a relatively fast speed, while fresh humid air quickly replenishes it, completing a complete gas replacement within 10-30 seconds.

[0074] The 10-30 second duration is determined based on the following: the internal volume of the enclosure is typically tens to hundreds of liters (depending on the enclosure size). Under a driving pressure difference of 25-35 Pa, taking a nominal exhaust valve diameter of DN15-DN25 as an example, the exhaust flow rate through a fully open exhaust valve is sufficient to discharge an air volume equivalent to the internal volume of the enclosure within 10-30 seconds. In practical engineering applications, the specific replacement time can be calculated based on the internal volume of the enclosure and the flow coefficient (Cv value) of the selected exhaust valve to ensure it falls within the 10-30 second range. After replacement is completed, the control unit restores the exhaust valve opening to the normal adjustment range and restores the intake flow rate to the state required to maintain a positive pressure difference of 5-20 Pa, and continues normal maintenance.

[0075] This intermittent venting operation is repeated periodically during the humid curing period to periodically remove the byproducts continuously released by the sealant curing reaction from the outside of the enclosure and prevent their accumulation.

[0076] After the adhesive is applied, the initial stage of introducing humid and hot air is initiated. At this time, the humid and hot air is being diffused onto the substrate surface, and the temperature and humidity field inside the enclosure has not yet stabilized. During this initial stage, intermittent exhaust operations are not performed, and the control unit suppresses the initiation of the exhaust sequence.

[0077] Once the substrate is preheated, i.e., after 5-10 minutes of diffused hot and humid air circulation, the substrate temperature rises to the same level as the hot and humid air, and the temperature inside the enclosure has been continuously and stably maintained within the range of 30-38°C for at least 5 minutes, the control unit starts the timing cycle of intermittent exhaust operation and begins to run continuously according to the rhythm of rapid replacement every 20-40 minutes as described above until the first stage of curing is completed.

[0078] The remaining operations are exactly the same as in Example 4.

[0079] Example 7 A method for applying sealant and maintaining curtain walls under high temperature and high humidity conditions, based on Example 6, further includes: After the microenvironment control hood is erected and before adhesive injection begins, or during pre-preparation of the hood before erection, the activated carbon fiber felt is attached to the inner wall of the hood using double-sided tape or Velcro. The activated carbon fiber felt is attached to the inner surface of the top and side walls of the hood, above and to the sides of the adhesive seam area. The placement of the activated carbon fiber felt inside the hood must avoid the installation location of the humidity sensor in Example 2. Specifically, the straight-line distance between the edge of the activated carbon fiber felt and the humidity sensor probe should be no less than 10 cm to avoid instantaneous abnormal fluctuations in the gas composition near the sensor caused by local adsorption or desorption of the fiber felt, thus ensuring the accuracy of the humidity monitoring signal upon which the surface dryness determination depends.

[0080] The specific surface area of ​​activated carbon fiber felt is 800~1500m². 2 / g, with a thickness of 1~3mm. This specific surface area range ensures that the fiber felt has abundant adsorption sites and a large adsorption capacity for volatile organic byproduct molecules, while the thickness range provides sufficient adsorption material without excessively occupying the internal volume of the enclosure.

[0081] During the quiet period when intermittent venting is not performed—specifically, the time between the initial stage of the humid-heat switching after adhesive application and the completion of substrate preheating and temperature stabilization—the sealant begins its moisture-curing reaction from the moment it comes into contact with humid air, simultaneously releasing volatile byproducts. Due to the suspension of venting, these byproducts accumulate rapidly inside the enclosure. At this time, the activated carbon fiber felt, adhering to the inner wall of the enclosure, continuously captures the volatile byproduct molecules released during the initial curing stage of the sealant through physical adsorption, temporarily storing them within the microporous structure of the fiber felt. This suppresses the continuous rise in the concentration of gaseous byproducts inside the enclosure, maintaining a water-based gas environment during the quiet period, ensuring accurate humidity sensor response to the actual humidity and the thermodynamic driving force of the curing reaction.

[0082] Once the intermittent exhaust operation begins, a rapid gas replacement lasting 10-30 seconds is performed every 20-40 minutes. During each replacement, the concentration of gaseous byproducts inside the hood rapidly decreases due to the rapid dilution and discharge of fresh, warm, and humid air. Based on the gas-solid adsorption equilibrium principle, as the concentration of byproduct molecules in the gas phase decreases, the byproduct molecules adsorbed on the surface of the activated carbon felt will naturally desorb from the felt surface under the drive of the concentration difference, re-enter the gas phase, and be discharged outside the hood through the exhaust valve with the rapid replacement airflow. Thus, the activated carbon fiber felt adsorbs byproducts during each exhaust interval and desorbs and regenerates during each exhaust replacement, forming an "adsorption-desorption-regeneration" cycle that continuously performs its purification function without requiring replacement or additional regeneration.

[0083] The specific process for hydrophobic modification is as follows: First, prepare a fluorocarbon resin impregnation solution with a concentration of 3% to 8%. The fluorocarbon resin used is a commercially available polytetrafluoroethylene dispersion or a fluorocarbon resin emulsion for fluorocarbon coatings, diluted with deionized water to the target concentration. Completely immerse the activated carbon fiber felt in the impregnation solution for 10 to 30 minutes, ensuring the fluorocarbon resin fully wets the surface and internal pores of each fiber in the felt.

[0084] After impregnation, remove the activated carbon fiber felt, drain excess liquid, and place it in an oven at 60-80℃ for 20-40 minutes to allow the solvent to evaporate slowly and the fluorocarbon resin to initially form a film on the fiber surface. The drying temperature should be controlled below 80℃ to avoid rapid solvent boiling, which could cause pinholes or unevenness in the resin layer. After drying, raise the oven temperature to 120-150℃ and heat-set for 15-30 minutes to allow the fluorocarbon resin to fully cross-link and cure on the fiber surface, forming a uniform and dense hydrophobic coating layer. The heat-setting temperature should not exceed 150℃, as this is below the thermal decomposition temperature of the activated carbon fiber, to avoid damaging the fiber structure.

[0085] The remaining operations are exactly the same as in Example 6.

[0086] After the hydrophobic modification treatment is completed, before the activated carbon fiber felt is installed on the inner wall of the cover, an adsorption performance test should be conducted to confirm that its equilibrium adsorption capacity for water vapor does not exceed 20% of the saturated adsorption capacity for by-products before it can be put into use. Comparative test

[0087] I. Test Environment and Equipment.

[0088] The experiment was conducted in a controlled environment test chamber, which can simulate high temperature and high humidity climatic conditions. The ambient temperature was set at 35±2℃ and the relative humidity at 80±5%, simulating typical high temperature and high humidity conditions in coastal areas during summer.

[0089] The curtain wall components used in the test were 6063-T5 aluminum alloy profiles and 6mm thick tempered glass panels commonly used in engineering projects. A 20mm wide and 15mm deep adhesive joint was reserved between the profiles and the glass panels. The sealant used in the test was a commercially available single-component moisture-curing silicone sealant, and the primer was a matching silane coupling agent primer.

[0090] The microenvironment control enclosure is made of transparent flexible PVC membrane material, measuring 2.0 meters in length, 0.6 meters in width, and 0.4 meters in height, with magnetic sealing strips around its edges. The dry air supply system consists of an air compressor, a refrigerated dryer, and an air temperature control module, while the humid air supply system consists of an air compressor, an ultrasonic humidifier, and an air heating module. The control unit uses a PLC programmable controller. The temperature and humidity sensors inside the enclosure are a Pt100 platinum resistance temperature sensor and a capacitive humidity sensor. The micro-differential pressure sensor has a range of 0~100Pa and an accuracy of ±1Pa. The substrate surface temperature is monitored using a patch-type K-type thermocouple.

[0091] II. Test Plan Seven example groups and three comparative groups were set up, with three identical specimens prepared in each group, and the average value of the results was taken.

[0092] Examples 1 to 7 were constructed and maintained according to the methods of Examples 1 to 7 of the present invention.

[0093] Comparative Example 1: No microenvironment control cover was set up, and no temperature and humidity control measures were taken. The glue was directly injected and naturally cured for 7 days in the high temperature and high humidity environment of the test chamber.

[0094] Comparative Example 2: A microenvironment control hood was erected, but dry air at 22°C and 35% relative humidity was only introduced throughout the glue injection and curing process. High-speed air curtain heat removal, switching to humid and hot air, and phased gradual transition were not implemented. The hood was removed directly after 7 days of curing.

[0095] Comparative Example 3: A microenvironment control cover was set up. During the glue injection stage, the dry air was circulated as in Example 1. After glue injection, the air was immediately switched to the target humid and hot air curing at a temperature of 35°C and a relative humidity of 60%. However, after the surface was dry, the cover was directly removed and the test chamber environment was exposed. The phased gradual transition was not performed.

[0096] III. Test Items and Methods 1. Substrate surface temperature monitoring: In the high-speed air curtain purging process of Example 1, the substrate surface temperature and the air temperature inside the cover were recorded every 2 minutes by using K-type thermocouples attached to the surface of the profile and glass panel. The difference between the two was calculated to evaluate the heat storage and peeling effect and the time required to achieve a temperature difference ≤2℃.

[0097] 2. Surface Drying Time Recording and Accuracy Assessment: For Example 2 group, the surface drying time automatically determined by the control unit was recorded; simultaneously, two experienced operators visually observed the change in gloss of the adhesive surface (from a wet gloss to a matte finish) through the transparent film of the cover, using the manually determined surface drying time as a reference. The deviation between the automatic and manual determination times was calculated to assess the accuracy of the surface drying determination. For the remaining Example groups and comparative groups, the surface drying time was determined manually.

[0098] 3. Inspection of condensation film at the bonding interface: During the glue injection stage and the wet and hot switching stage of each example group and comparative example group, visually observe whether a condensation film is formed on the bonding surface of the substrate through the transparent film of the cover. After 24 hours after glue injection, observe whether there are bubbles or whitening at the interface between the glue and the substrate through the transparent film.

[0099] 4. Bond strength test: Performance testing was conducted 7 days after the completion of adhesive application and curing. Following the tensile bond strength test method in GB / T 13477 "Test Methods for Building Sealing Materials", a universal testing machine was used to perform tensile tests on the specimens at a tensile rate of 5 mm / min. The maximum tensile strength (MPa) and failure mode (cohesive failure or interfacial debonding) were recorded. The average value of 3 specimens in each group was taken.

[0100] 5. Adhesive Layer Curing Uniformity Test: After 7 days of curing, cut adhesive slices along the thickness direction of the adhesive layer. Use a Shore A hardness tester to measure the hardness at the surface, at 1 / 3 depth from the surface (shallow layer), and at 2 / 3 depth from the surface (deep layer), taking 5 measurements for each layer and averaging the results. Calculate the hardness difference between the surface and deep layers; a smaller difference indicates better curing uniformity.

[0101] 6. Observation of microcracks on the adhesive layer surface: After 7 days of curing, observe the adhesive layer surface for microcracks using an optical microscope with a magnification of 30x, and record the number of cracks (take 5 fields of view along the length of each adhesive joint and take the average value). At the same time, observe whether there are any gaps at the bonding interface between the adhesive and the substrate.

[0102] 7. Evaluation of the adsorption performance of activated carbon fiber felt: After the curing of the group in Example 7, the activated carbon fiber felt inside the cover was removed, and the types and total amount of by-products adsorbed in the fiber felt were analyzed by gas chromatography-mass spectrometry; at the same time, the moisture content of the fiber felt was determined by Karl Fischer moisture analyzer, and the ratio of the amount of by-products adsorbed to the amount of moisture adsorbed was calculated to verify the selective adsorption effect of hydrophobic modification.

[0103] IV. Experimental Results and Analysis Table 1: Substrate Surface Temperature Monitoring Results

[0104] It should be noted that the slight drop in air temperature inside the enclosure from 32.0℃ to 31.2℃ in Table 1 is a normal fluctuation during the stabilization process of the inlet air temperature and does not violate the laws of heat exchange. During the purging process, a high-speed air curtain continuously introduces dry air at approximately 32℃ at a flow rate of 1.5~3.0 m / s, while simultaneously expelling the gas inside the enclosure through the exhaust valve. The enclosure is an open system, not a closed system. The deep heat stored in the substrate is carried away by the airflow through forced convection and is then discharged outside the enclosure with the exhaust, without accumulating inside. Therefore, the air temperature inside the enclosure is dominated by the temperature and flow rate of the inlet air, tending towards the inlet air temperature, rather than significantly increasing due to the heat released by the substrate. The slight drop of 0.8℃ can be explained by the following factors: the slight cooling effect caused by the expansion of compressed air entering the enclosure after depressurization, and the small adjustment process required by the air temperature control module to reach thermal equilibrium in the initial stage, both of which are within the accuracy error range of the measuring instrument (Pt100 platinum resistance temperature sensor) of ±0.5℃. The substrate cooled down by about 14-16°C within 20 minutes, while the air temperature inside the cover remained relatively stable at 31-32°C. This demonstrates that the high-speed air curtain forced convection continuously vented the heat stored in the substrate outside the cover, achieving a good heat removal and storage effect.

[0105] According to the data in Table 1, before the high-speed air curtain purging (0 minutes), the surface temperatures of the aluminum alloy profile and glass panel, due to simulated solar heat storage, reached as high as 48.5℃ and 46.2℃ respectively, with temperature differences of 16.5℃ and 14.2℃ between them and the air inside the enclosure. As the high-speed air curtain continued to purge, the surface temperature of the substrate rapidly decreased. The profile temperature dropped to 34.2℃ (temperature difference 2.9℃) at 15 minutes, and the glass panel temperature dropped to 34.0℃ (temperature difference 2.7℃). By 20 minutes, the temperature differences between the profile and glass and the air decreased to 1.6℃ and 1.3℃ respectively, both meeting the criterion of ≤2℃. This indicates that the forced convection of the high-speed air curtain can effectively strip away the deep heat storage in the substrate within 20 minutes, making the substrate and the air inside the enclosure tend to be isothermal, thus eliminating the heat source of continuous heat release from the substrate for subsequent adhesive application.

[0106] Table 2: Comparison of Drying Time and Judgment Accuracy Data

[0107] According to the data in Table 2, the automatic determination of the surface drying time in Example 2 was 86 minutes, which was only 2 minutes different from the manual determination of 84 minutes. The error was within an acceptable range, indicating that the automatic determination method based on the dual verification of the inflection point of humidity decrease rate and temperature stability has high accuracy.

[0108] The surface drying time of each embodiment group (except for the comparison) is concentrated in the range of 83 to 88 minutes, indicating that each preferred embodiment does not have an adverse effect on the normal surface drying time of the sealant.

[0109] Comparative Example 1 (natural exposure) had a surface drying time of only 52 minutes, significantly shorter than the groups in the Examples. This is because, under high temperature and humidity, the colloid surface directly contacts excessive moisture, causing rapid skin formation, but deep curing is not completed simultaneously. Excessive surface drying is a key indicator of uneven curing. Comparative Example 2 (fully dry) had a surface drying time of 210 minutes, far exceeding the groups in the Examples, indicating a severe shortage of moisture supply under dry conditions, inhibiting the curing reaction. Comparative Example 3 had a surface drying time of 82 minutes, similar to the groups in the Examples, but subsequent tests on bond strength and curing uniformity showed significant defects in curing uniformity and bonding quality.

[0110] Table 3: Observation Results of Bonding Interface Quality

[0111] In Comparative Example 1, a significant condensation film was observed on the substrate surface during adhesive application, directly leading to numerous bubbles and whitening between the sealant and the substrate. After tensile failure, large areas of the interface detached. In Comparative Example 2, although no condensation film appeared, insufficient moisture supply to the bottom of the sealant and incomplete curing due to the entire drying process resulted in localized whitening and partial interface detachment. In Comparative Example 3, a brief fogging phenomenon was observed on the sealant surface during the transition between humidity and heat; a small number of bubbles appeared after curing.

[0112] No condensation film or interfacial bubbles / whitening were observed in any of the seven groups of Examples 1 to 7, and the interfaces remained intact after tensile failure. In Example 3, the transition between hot and cold temperatures was effectively avoided by using a gradual change in humidity, while in Example 4, preheating the substrate ensured a more even temperature distribution across the colloid, further reducing the probability of interfacial defects.

[0113] Table 4: Bond Strength Test Results

[0114] Table 5: Test results of adhesive layer curing uniformity

[0115] Comparative Example 1 showed a surface hardness as high as 35.2 Shore A, but a deep hardness of only 22.3 Shore A, with a hardness difference of 12.9, exhibiting a typical "hard outside, soft inside" uneven curing characteristic. Comparative Example 2 had a generally low hardness and a hardness difference of 5.3, indicating that insufficient moisture supply led to incomplete overall curing and continued differences between the inside and outside. Comparative Example 3 had a hardness difference of 7.3, higher than all the groups in the examples, confirming that the lack of a gradual transition and the temperature difference between the two sides of the colloid in the early stage of humid heat curing both led to stratification of the curing rate.

[0116] In the examples, the surface and deep hardness difference between each group was within the range of 1.1 to 2.5 Shore A, and the curing uniformity was significantly better than that of the comparative examples. Among them, the hardness difference between groups 3 and 4 was the smallest, indicating that the transitional humid heat switching eliminated the obstruction of the condensate film to the uniform penetration of moisture, and the preheating of the substrate eliminated the temperature gradient between the inside and outside of the adhesive layer. These two methods were the most effective in improving curing uniformity.

[0117] Table 6: Observation results of microcracks on the adhesive layer surface

[0118] No microcracks or interfacial debonding gaps were observed on the adhesive surface of any of the groups in Examples 1 to 7 under a 30x microscope, indicating that the method of the present invention can effectively protect the adhesive from stress impact damage during curing and after removal of the cover.

[0119] Comparative Example 1 showed the highest density of microcracks, averaging 8.5 cracks per field of view, with numerous interfacial debonding gaps. This was a result of the combined effects of substrate condensation, uneven curing, and direct environmental exposure. Comparative Examples 2 and 3 also showed 2.3 and 3.8 microcracks per field of view, respectively, indicating that both insufficient curing due to continuous drying and stress impact from the lack of a gradual transition can cause microscopic damage to the colloid.

[0120] Table 7: Adsorption performance of activated carbon fiber felt

[0121] The total amount of byproducts adsorbed by the hydrophobically modified activated carbon fiber felt was 68.5 mg / g, while the amount of moisture adsorbed was only 11.2 mg / g, approximately 6.1 times that of moisture. Moisture adsorption accounted for 16.3% of the total byproduct adsorption, lower than the 20% upper limit set in claim 10, confirming that the hydrophobic modification treatment effectively suppressed the competitive adsorption of water vapor by the fiber felt, enabling it to preferentially capture organic byproducts in a humid and hot environment. This data corroborates the low hardness difference of 2.4 Shore A in the adhesive strength test results and adhesive layer curing uniformity test results of Example 7, indicating that the fiber felt effectively purified the gas environment inside the enclosure during the quiescent period, ensuring curing quality.

[0122] V. Conclusion 1. The method of the present invention achieves high-quality curtain wall adhesive injection and curing in a high-temperature and high-humidity environment through the coordinated action of multiple steps, including high-speed air curtain forced convection heat storage, dry air positive pressure adhesive injection, humid heat curing, and phased gradual transition.

[0123] 2. The dual verification method for humidity inflection point and temperature stability in Example 2 can accurately determine the time of surface dryness under non-contact conditions, with a deviation of only 2 minutes from manual determination, providing a reliable trigger basis for phased controlled adjustment.

[0124] 3. The transitional humid heat switching in Example 3 and the substrate preheating in Example 4 significantly improved curing uniformity from two dimensions: eliminating condensation film and balancing the temperature gradient of the adhesive layer. The hardness difference of the adhesive layer was as low as 1.2 and 1.1 Shore A, respectively. These are the two most effective preferred technologies for improving curing quality.

[0125] 4. The removal buffer, intermittent exhaust delayed start and hydrophobic modified activated carbon fiber felt further optimized the curing process in terms of reducing wet impact during removal, avoiding temperature and humidity disturbance caused by exhaust, and purifying byproducts during the quiescent period. No microcracks appeared in any of the example groups, and the bonding interface was intact.

[0126] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. It can be applied to various fields suitable for the present invention. Further modifications can be readily implemented by those skilled in the art.

Claims

1. A method for applying sealant and maintaining curtain walls under high temperature and high humidity conditions, characterized in that, include: A microenvironment control hood is erected in the glue seam area to be glued to form a closed space. The microenvironment control hood is equipped with a sealed operation sleeve and / or an operation port is opened on the hood body and the operation port is equipped with an openable and closable sealing cover or flexible curtain to maintain the hood body's sealing during the glue injection process. After the installation is completed, a high-speed air curtain along the direction of the adhesive joint is first formed inside the enclosure with dry air. The air curtain wind speed is 1.5~3.0m / s. The surface of the substrate on both sides of the adhesive joint is continuously blown for 15~30 minutes to accelerate the release of deep heat stored in the substrate. The temperature of the dry air is 30~40℃. After the surface temperature of the metal profile and glass panel drops to no more than 2℃ from the temperature of the air inside the enclosure, the wind speed is reduced to 0.1~0.5m / s, and the adhesive injection stage begins. During the entire adhesive injection stage, from applying the primer to applying the sealant into the joint, dry air is introduced into the microenvironment control hood to maintain the microenvironment temperature inside the hood at 18~25℃ and the relative humidity at ≤40%. By adjusting the air intake flow rate and the opening of the exhaust valve, a positive pressure difference of 5~20Pa is maintained inside the hood relative to the outside atmosphere to form a dynamic pressure barrier against the intrusion of high temperature and high humidity air from the outside. After the sealant is applied, the gas is immediately switched to hot and humid air to raise the temperature of the microenvironment inside the enclosure to 30-38°C and the relative humidity to 55-70%. The sealant is then cured in the first stage in this hot and humid microenvironment to promote deep curing of the sealant. After the sealant has dried to the touch, the microenvironment inside the enclosure is subjected to controlled adjustment in at least two stages: In the first stage, the microenvironment inside the enclosure is adjusted to a stable intermediate condition of 25~28℃ and 45~55% relative humidity with a temperature change rate ≤2℃ / h and a relative humidity change rate ≤5%RH / h, and maintained for 12~24 hours; In the second stage, the microenvironment inside the enclosure is transitioned from the aforementioned stable intermediate condition to the actual external environmental conditions with the same temperature and humidity change rate limits, thus completing the second stage of curing.

2. The method for applying sealant and maintaining curtain walls under high temperature and high humidity conditions as described in claim 1, characterized in that: The sealant is a moisture-curing sealant. During the first stage of curing, a humidity sensor is installed at a distance of 5 to 15 cm from the sealant seam inside the microenvironment control cover. The relative humidity value inside the cover is continuously collected at a sampling frequency of not less than 0.1 Hz, and the collected values ​​are processed by moving average to generate a smooth humidity change curve. When the absolute value of the slope of the smooth humidity change curve changes from continuously greater than 0.05%RH / min to continuously less than 0.01%RH / min, and after a delay of 5 to 15 minutes after the change, it is determined that the sealant has reached the surface dry state, and the phased controlled adjustment of the microenvironment inside the cover begins accordingly.

3. The method for applying sealant and maintaining curtain walls under high temperature and high humidity conditions as described in claim 1, characterized in that: After the glue injection is completed, switch to the initial stage of introducing humid and hot air. First, introduce transitional humid and hot air pre-adjusted to 30-38°C and relative humidity of 35-45% into the hood at an air intake rate lower than the normal air intake flow rate required to maintain the positive pressure difference of 5-20Pa. After the temperature inside the hood rises to above 28°C, restore the air intake flow rate to the normal air intake flow rate, and at the same time gradually increase the relative humidity of the introduced air to the target value of 55-70%. Wherein, the intake rate lower than the normal intake flow rate is 40% to 60% of the normal intake flow rate.

4. The method for applying sealant and maintaining curtain walls under high temperature and high humidity conditions as described in claim 1, characterized in that: After the adhesive is applied, while switching to humid and hot air, guide vanes or diffusers are installed at the air inlet of the microenvironment control cover. The direction of the humid and hot air intake is first adjusted to face the metal profiles and glass panel surfaces of the curtain wall components. The air is then evenly distributed into the space inside the cover in a diffused manner for 5 to 10 minutes. When the temperature difference between the substrate and the humid and hot air does not exceed 1°C, the air intake direction is then adjusted to concentrate on the adhesive joint area for adhesive curing.

5. The method for applying sealant and maintaining curtain walls under high temperature and high humidity conditions as described in claim 1, characterized in that: After the second stage of maintenance transitions the microenvironment inside the cover to match the actual external environment, the microenvironment control cover is not removed immediately. Instead, the air intake is closed and the cover is kept sealed and left to stand for 10-20 minutes. This allows the air inside the cover to passively exchange with the external environment through the inherent micropermeability of the PVC membrane material or the micro gaps at the edge seals, gradually approaching the external humidity. Then, the cover is slowly removed at a speed not exceeding 5 cm / s.

6. The method for applying sealant and maintaining curtain walls under high temperature and high humidity conditions as described in claim 1, characterized in that, During the first phase of maintenance, the following intermittent air venting operations were also performed: Every 20 to 40 minutes, fully open the exhaust valve and simultaneously increase the intake flow of humid and hot air, so that the positive pressure difference inside the hood relative to the outside is maintained at a level higher than 20 Pa but not exceeding 40 Pa for 10 to 30 seconds, thereby completing a rapid gas replacement and expelling the volatile byproducts generated by the curing reaction of the sealant; restore the opening of the exhaust valve and the intake flow to the state required to maintain the positive pressure difference of 5 to 20 Pa.

7. The method for applying sealant and maintaining curtain walls under high temperature and high humidity conditions as described in claim 2, characterized in that, When determining that the sealant has reached the surface dry state, the following conditions must also be met: the temperature inside the cover has been continuously and stably maintained within the range of 30~38℃ for at least 5 minutes, and the temperature fluctuation within these 5 minutes does not exceed ±0.5℃.

8. A method for applying sealant and maintaining curtain walls under high temperature and high humidity conditions as described in any one of claims 4, characterized in that, During the initial stage of switching to humid and hot air after the glue injection is completed, the intermittent venting operation is temporarily not performed; After the substrate preheating is completed and the temperature inside the cover has been continuously and stably maintained within the range of 30~38℃ for at least 5 minutes, the intermittent exhaust operation can be started.

9. The method for applying sealant and maintaining curtain walls under high temperature and high humidity conditions as described in claim 8, characterized in that, When setting up the microenvironment control cover or before the glue injection begins, the activated carbon fiber felt is pre-attached to the inner wall of the microenvironment control cover to continuously capture the volatile byproducts released during the initial curing of the sealant through physical adsorption. The specific surface area of ​​the activated carbon fiber felt is 800~1500 m². 2 / g, with a thickness of 1~3mm, and its placement inside the cover avoids an area with a radius of not less than 10cm around the humidity sensor.

10. The method for applying sealant and maintaining curtain walls under high temperature and high humidity conditions as described in claim 9, characterized in that, The sealant is a moisture-curing sealant; the activated carbon fiber felt undergoes hydrophobic modification treatment, which involves immersing the activated carbon fiber felt in a 3%~8% fluorocarbon resin impregnation solution for 10~30 minutes, removing it and drying it at 60~80℃ for 20~40 minutes, and then heat-setting it at 120~150℃ for 15~30 minutes, so that a fluorocarbon resin coating layer is formed on the fiber surface of the activated carbon fiber felt; The activated carbon fiber felt after hydrophobic modification treatment has an equilibrium adsorption capacity for water vapor at a temperature of 30°C and a relative humidity of 60%, which does not exceed 20% of the saturated adsorption capacity of the volatile byproducts released by the curing of the sealant at the same temperature of 30°C and a byproduct gas phase concentration of 2000ppm.

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