Production process of skylight ceiling wet-process cast steel fabric and compound die of skylight ceiling wet-process cast steel fabric

Abstract

The invention discloses a skylight ceiling production technology, and aims to provide a skylight ceiling wet cast steel fabric production process and a compound die thereof, and the technical scheme is characterized by comprising the following steps: S1, selecting a cast steel base material; s2, preheating the standard base material at a constant temperature, monitoring the temperature in real time, and turning to S3 after the standard base material is qualified; s3, the preheated base material is coated with a wet glue layer, the thickness of the glue layer is controlled, and the process conditions are automatically adjusted according to the environment temperature and humidity; s4, three layers of composite materials are laid in sequence, preliminary attachment is conducted through rolling, tension is monitored in real time, and correction is conducted to guarantee alignment precision; s5, moving the laminated body into a compound die, vacuumizing to set negative pressure, and then sealing a die cavity; s6, hot press molding is started, temperature and pressure are controlled, the temperature gradient in the mold is monitored, and heating and cooling are dynamically adjusted to maintain heat balance; s7, after pressure maintaining is finished, pressure relief is slowly conducted, and compressed air is blown in to remove residues when the mold is opened; and S8, taking out a finished product. The method is suitable for the technical field of skylight ceiling production.

Description

Technical Field

[0001] This invention relates to a skylight roof production technology, and more specifically, to a production process for wet-cast steel fabric for skylight roofs with precise control of various process parameters and its composite mold. Background Technology

[0002] With the increasing demand for lightweight and comfortable vehicles, sunroof roofs require higher standards for material strength, flatness, and composite structural stability. Traditional dry processes suffer from uneven adhesive layer distribution, weak interfacial bonding, poor composite layer adhesion, and a tendency to generate internal air bubbles, making it difficult to meet the stringent standards of high-end models for surface quality and internal density. While wet molding can improve wettability, existing technologies lack systematic coordination in areas such as multi-layer composite precision and temperature control during hot pressing, easily leading to air bubbles and delamination, resulting in substandard finished products. Therefore, there is an urgent need to develop a production process for wet-process cast steel fabric for sunroof roofs that precisely controls various process parameters, along with its composite mold. Summary of the Invention

[0003] To address the shortcomings of existing technologies, the present invention aims to provide a production process for wet-cast steel fabric for skylight roofs and its composite mold that allows for precise control of various process parameters.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a production process for wet-cast steel fabric for skylight canopies, comprising the following steps: S1. Select a cast steel substrate as the initial molding carrier. The cast steel substrate is a medium carbon alloy steel plate with a thickness between 3.0-5.5 mm. After sandblasting, the surface is degreased and cleaned. The surface roughness Ra after cleaning is ≤2.5 μm. The residual oil content is detected by X-ray fluorescence spectrometry. When the detection value is lower than 5 ppm, it is judged as qualified for cleaning. When the detection value is higher than 5 ppm, alkaline cleaning is repeated and the test is repeated until the standard is met. S2. Place the clean and qualified cast steel substrate in an oven preheated to 80±5℃ for constant temperature preheating for 15-20 minutes. During this period, monitor the surface temperature T1 of the substrate in real time using an infrared thermometer. Set the temperature fluctuation range ΔT1<±3℃. When three consecutive sets of data meet the condition of 78℃≤T1≤82℃, the preheating is considered complete. If the standard is not met, extend the preheating time to a maximum of 30 minutes. If the standard is still not met after the time limit, replace the substrate. S3. A wet adhesive layer is uniformly coated onto the preheated cast steel substrate surface. The wet adhesive is a polyurethane-modified epoxy resin emulsion with a solid content of 45%-50% and a viscosity of 6000-8000 cP. The coating method uses a doctor blade coater with a coating speed controlled at 1.2-1.8 m / min and a coating thickness of 0.12-0.18 mm. During the coating process, the coating thickness d is monitored in real time using an online laser thickness gauge. When d deviates from the target value of ±0.02 mm for more than 3 seconds, the doctor blade gap is automatically adjusted and feedback correction is provided. At the same time, the ambient humidity H and temperature T2 of the coating area are collected. When H > 65% or T2 < 20℃, the heating and dehumidification system is activated to reduce H to below 60% and T2 to rise above 22℃ before continuing the coating process. S4. A multi-layer composite material is sequentially laid on the wet adhesive layer. The multi-layer material includes: a first layer of PET nonwoven fabric with a thickness of 0.08-0.12 mm, a second layer of thermoplastic polyurethane film with a thickness of 0.10-0.15 mm, and a third layer of flame-retardant nonwoven fabric with a thickness of 0.06-0.09 mm. The layers are initially bonded together by roller pressing. The roller pressing pressure is 0.8-1.2 MPa, and the roller speed is 1.0-1.5 m / min. During the bonding process, the transverse tension Fh of each layer of material is monitored by a high-precision tension sensor. When the fluctuation of Fh is greater than ±10 N / m, the correction device is triggered to adjust the angle of the fabric feeding mechanism to ensure that the alignment error of each layer is ≤ ±0.5 mm. S5. Transfer the laid multi-layer material as a whole into the composite mold. The composite mold is made of high-temperature resistant alloy steel. The mold cavity is equipped with cooling channels and heating elements. Before closing the mold, the mold cavity is vacuumed to reduce the internal pressure to below -0.08MPa, and then the exhaust valve is closed. S6. Start the compound die stamping process. Heat the die to 160-180℃, pressurize at a rate of 0.5-1.0 mm / s, with a maximum pressure of 120-150 MPa and a holding time of 180-240 s. During this period, monitor the temperature T3 at the center point of the die cavity and the temperature T4 at the edge using an embedded thermocouple array. Calculate the temperature gradient ΔT = T3 - T4. When ΔT > 12℃, the system determines that there is a risk of local overheating. It then reduces the center heating power by 15% and activates the edge auxiliary heating, continuously monitoring the trend of ΔT. If the rate of decrease of ΔT within 60 s is less than 0.5℃ / min, the circulating water flow rate of the die is further adjusted to improve the cooling efficiency by 20%. When ΔT stabilizes within the range of 8-12℃ and T3 remains at 170±5℃, it is determined to be in thermal equilibrium. Proceed to S7. S7. After the pressure holding is completed, the mold is slowly depressurized at a speed of 0.3-0.6 mm / s. During the depressurization process, the mold opening and closing stroke L is recorded by the displacement sensor. When L reaches 85% of the total stroke, the system starts the air blowing device to inject compressed air into the mold cavity. The gas pressure is 0.3-0.5 MPa, and the blowing time is not less than 10 seconds, which is used to remove residual colloids and dust. S8. Remove the molded part and perform surface quality inspection. Use a three-dimensional optical scanner to measure the surface flatness. The allowable deviation is ≤0.3mm. At the same time, use an ultrasonic flaw detector to check for internal bubbles or delamination defects. When the defect area ratio is >1.5%, it is judged as unqualified; otherwise, it is qualified.

[0005] The present invention is further configured such that, in step S3, there is a dynamic matching relationship between d and T1 of the wet adhesive layer: when T1 is in the range of 78-80℃, d is set to 0.12mm; when T1 is in the range of 80-82℃, d is set to 0.15mm; when T1 > 82℃, d is automatically adjusted to 0.18mm, and this adjustment process satisfies the following conditions: 1) The rate of change of d does not exceed 0.03 mm / min; 2) During the adjustment period d, the ambient humidity H must be maintained between 55% and 65%; otherwise, the adjustment should be paused and the dehumidification program should be started. 3) S4 can only proceed after T1 has been detected to be stable within the target range twice consecutively and d has been adjusted to the correct position. If all three conditions are met, the coating parameters are confirmed to be valid; otherwise, the system will enter alarm mode and alert the operator.

[0006] The present invention is further configured such that: in step S4, the mass ratio of PET nonwoven fabric: thermoplastic polyurethane film: flame-retardant nonwoven fabric is 1:1.2:0.8, and the total thickness of the three layers is ≤0.35mm; during the laying process, if wrinkles or misalignments are found in any layer of material, the system will analyze the defect location based on image recognition algorithm, and determine whether to interrupt the laying based on the relationship between the current cumulative laying length L0 and the standard length Lb: when L0 / Lb>0.7 and the number of defects is ≥3, the system determines that the batch is abnormal, automatically stops the material supply and executes the rework process; otherwise, if L0 / Lb≤0.7, only the defective section is cut off and the laying continues, but the number of abnormalities is recorded, and if the cumulative number exceeds 5, the machine is forced to stop for maintenance.

[0007] The present invention is further configured such that the compound die stamping process in S6 also includes: S61. When the rate of increase of the mold cavity center temperature T3 is detected as dT3 / dt > 2℃ / min, the system judges that the temperature rise is too fast. At this time, the heating power is reduced by 10% and the cooling water flow rate is increased by 20% simultaneously. S62. Subsequently, continuously monitor the trend of T3. If dT3 / dt decreases to below 1.5℃ / min within 30s and T3 does not exceed 180℃, the regulation is deemed effective, and the current parameters are maintained. S63. If dT3 / dt is still higher than 1.5℃ / min or T3 is close to 180℃, further reduce the heating power to 70% of the original value and turn on the mold edge spray cooling device. The spray frequency is set to once every 10 seconds, and each spray lasts for 0.8 seconds. S64. After the spray is turned on, the system reassesses the upward trend of T3. If dT3 / dt drops below 0.8℃ / min within 60s and T3≤175℃, it is determined to be a safe and controllable state, and the heating power is restored to the normal level. S65. If the above adjustments are ineffective, T3 continues to rise and dT3 / dt > 1.0℃ / min, the system will determine that there is a risk of thermal runaway, immediately terminate heating and start the emergency cooling procedure, and issue an alarm to notify the operator.

[0008] The present invention is further configured such that, in step S7, the control method for mold depressurization and air blowing includes: S71. At the same time as the mold begins to depressurize, the system activates the pressure sensor to monitor the residual pressure Pt in the mold cavity; S72. When Pt drops from the initial value of 1.0 MPa to 0.3 MPa, the system starts the air blowing device; S73. After the air blowing device is started, the actual air blowing volume Q is monitored by the flow meter, and the target value of Q is set to 0.8m. 3 / min, allowable deviation ±0.1m 3 / min; S74. If Q deviates from the target value by more than 0.1m 3 If the flow rate is 1 / min and the duration is >5s, the system will determine that the blowing is abnormal, automatically switch to the backup air source and recalibrate the flow valve. S75. During the blowing process, the average depressurization speed v = L / t is calculated by combining the relationship between the mold opening and closing stroke L and time t obtained by the displacement sensor. When v < 0.3 mm / s, the system judges that the depressurization is too slow and increases the blowing pressure to 0.5 MPa. Conversely, if v > 0.6 mm / s, it is considered that the depressurization is too fast and the blowing pressure is reduced to 0.3 MPa. S76. After the blowing is completed, when Pt drops below 0.05MPa and L reaches more than 95% of the total stroke, the part retrieval operation is allowed; otherwise, the part retrieval instruction is delayed.

[0009] The present invention is further configured such that: the composite mold includes, but is not limited to, a lower mold body for placing raw materials, an upper mold body adapted to the lower mold body for stamping, and a drive component for driving the upper mold body and the lower mold body to close; The lower mold body includes, but is not limited to, a base. The base is provided with a molding cavity adapted to the shape of the sunroof. Several spaced-apart support ribs are provided between the base and the molding cavity for support. Multiple positioning components for precise positioning are provided around the base. An annular sealing groove for sunroof molding and preventing overflow is provided at the center of the molding cavity. A cooling channel and a heating element are also provided between the base and the molding cavity. The cooling channel runs through the bottom and side walls of the entire lower mold body, is arranged in a serpentine shape, and is connected to an interface provided on one side of the base. The interface is used to connect to an external cooling system.

[0010] The beneficial effects of this invention are: 1. Compared to existing technologies, the production process of the wet-process cast steel fabric for skylight canopies in this invention ensures high-quality molding through meticulous control of the entire process. S1 involves sandblasting, degreasing, cleaning, and rigorous testing of the cast steel substrate to ensure that the substrate's cleanliness and roughness meet standards, laying the foundation for subsequent adhesive adhesion and composite molding, and avoiding poor bonding caused by substrate impurities. S2 involves precise preheating control and temperature fluctuation limitation to reduce the impact of substrate thermal deformation. S3-S4 involve dynamic adjustment of adhesive parameters, environmental conditions, and multi-layer material bonding to ensure coating uniformity and alignment accuracy of each layer, improving the fabric's structural stability. S5-S7 involve vacuum treatment, hot pressing parameter optimization, and pressure relief blowing design to effectively avoid defects such as bubbles and delamination, while ensuring the integrity of the molded parts during demolding. S8 involves multi-dimensional testing methods to strictly control the surface flatness and internal quality of the product. The entire process is logically rigorous and parameters are quantified, achieving quality control from raw materials to finished products, resulting in fabrics that combine high strength, good adhesion, and excellent appearance.

[0011] 2. The production process of the wet-process cast steel fabric for skylight canopies in this invention clearly defines the dynamic matching relationship and additional conditions between the wet adhesive layer thickness d and the substrate preheating temperature T1, significantly improving the accuracy and adaptability of the coating process. Setting corresponding d values ​​according to different T1 ranges avoids problems such as uneven adhesive layer curing rate and insufficient adhesion due to temperature differences, ensuring the bonding effect between the adhesive layer and the substrate and subsequent composite materials. Limiting the rate of change of d prevents coating defects caused by sudden thickness changes, while controlling environmental humidity avoids moisture affecting adhesive layer performance. Continuous testing further ensures the stability of parameter matching. This allows the coating process to dynamically respond to substrate temperature fluctuations, reducing the risk of product defects due to temperature deviations. Simultaneously, it improves the level of automation in the production process, reducing manual intervention, ensuring product quality consistency, and increasing production efficiency, providing a stable and reliable foundation for subsequent composite molding processes.

[0012] 3. In this invention, the mass ratio and total thickness of the three-layer composite material are limited, and an intelligent judgment and handling mechanism for layup defects is established to effectively ensure the rationality and layup quality of the multi-layer composite structure. The specific mass ratio and total thickness limit ensures that the fabric has both lightweight, flexibility and structural strength, meeting the usage requirements of skylights and canopies. The image recognition algorithm accurately locates wrinkles and misalignment defects, and combined with the judgment logic of the layup length ratio, it realizes the graded handling of defects: timely shutdown and rework when batch abnormalities occur to avoid resource waste, and precise removal and continuous monitoring of small-scale defects to ensure production continuity. The mandatory shutdown and maintenance requirement based on the cumulative number of abnormalities can promptly investigate equipment problems such as the fabric feeding mechanism, reducing the generation of defects from the root. This design not only ensures the composite effect of multi-layer materials and improves the stability and consistency of product structure, but also improves production efficiency, reduces production costs, and enhances the practicality and reliability of the process through intelligent defect handling.

[0013] 4. In this invention, a control mechanism is established to address the heating rate issue in the composite die stamping process, effectively mitigating the risk of thermal runaway and ensuring molding quality. When the heating rate is too fast, a combination of methods, including gradient adjustment of heating power, cooling water flow rate, and activation of edge spray cooling devices, can quickly suppress abnormal temperature rise, preventing material degradation, uneven curing of the adhesive layer, or deformation of the molded parts caused by localized overheating of the mold cavity. The judgment criteria and time limits for each control step ensure the timeliness and effectiveness of the control, preventing the problem from escalating. The emergency cooling procedure provides safety assurance in extreme situations, avoiding equipment damage and batch scrapping of products. This design refines the temperature control logic of composite die stamping, improves the process's response and handling capabilities to temperature anomalies, maintains the mold cavity temperature within a stable and reasonable range, ensures the dimensional accuracy, structural integrity, and performance stability of the molded parts, and enhances the safety and controllability of the production process, providing strong support for the stable production of high-quality products. Attached Figure Description

[0014] Figure 1 This is a flowchart illustrating the production process of the wet-process cast steel fabric for the skylight canopy of the present invention.

[0015] Figure 2 This is a schematic diagram of the lower mold body of the present invention.

[0016] Figure 1-2 Reference numerals: 1. Base; 2. Mold cavity; 3. Support rib; 4. Positioning component; 5. Annular sealing groove; 6. Cooling channel; 7. Heating element; 8. Interface. Detailed Implementation

[0017] Reference Figure 1-2 The production process of the wet-cast steel fabric for the skylight canopy of the present invention and its composite mold embodiment are further explained.

[0018] For ease of explanation, spatial relative terms such as “up,” “down,” “left,” and “right” are used in the embodiments to describe the relationship of one element or feature shown in the figures relative to another element or feature. It should be understood that, in addition to the orientations shown in the figures, spatial terms are intended to include different orientations of the device in use or operation. For example, if the device in the figures is inverted, an element described as being “down” of other elements or features would be positioned “up” of those other elements or features. Therefore, the exemplary term “down” can encompass both up and down orientations. The device may be positioned in other ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0019] Moreover, relational terms such as “first” and “second” are used merely to distinguish one component from another that has the same name, without necessarily requiring or implying any such actual relationship or order between the components.

[0020] Figures 1 to 2 The production process of a wet-cast steel fabric for a skylight canopy, as shown, includes the following steps: S1. Select a cast steel substrate as the initial molding carrier. The cast steel substrate is a medium carbon alloy steel plate with a thickness between 3.0-5.5 mm. After sandblasting, the surface is degreased and cleaned. The surface roughness Ra after cleaning is ≤2.5 μm. The residual oil content is detected by X-ray fluorescence spectrometry. When the detection value is lower than 5 ppm, it is judged as qualified for cleaning. When the detection value is higher than 5 ppm, alkaline cleaning is repeated and the test is repeated until the standard is met. S2. Place the clean and qualified cast steel substrate in an oven preheated to 80±5℃ for constant temperature preheating for 15-20 minutes. During this period, monitor the surface temperature T1 of the substrate in real time using an infrared thermometer. Set the temperature fluctuation range ΔT1<±3℃. When three consecutive sets of data meet the condition of 78℃≤T1≤82℃, the preheating is considered complete. If the standard is not met, extend the preheating time to a maximum of 30 minutes. If the standard is still not met after the time limit, replace the substrate. S3. A wet adhesive layer is uniformly coated onto the preheated cast steel substrate surface. The wet adhesive is a polyurethane-modified epoxy resin emulsion with a solid content of 45%-50% and a viscosity of 6000-8000 cP. The coating method uses a doctor blade coater with a coating speed controlled at 1.2-1.8 m / min and a coating thickness of 0.12-0.18 mm. During the coating process, the coating thickness d is monitored in real time using an online laser thickness gauge. When d deviates from the target value of ±0.02 mm for more than 3 seconds, the doctor blade gap is automatically adjusted and feedback correction is provided. At the same time, the ambient humidity H and temperature T2 of the coating area are collected. When H > 65% or T2 < 20℃, the heating and dehumidification system is activated to reduce H to below 60% and T2 to rise above 22℃ before continuing the coating process. S4. A multi-layer composite material is sequentially laid on the wet adhesive layer. The multi-layer material includes: a first layer of PET nonwoven fabric with a thickness of 0.08-0.12 mm, a second layer of thermoplastic polyurethane film with a thickness of 0.10-0.15 mm, and a third layer of flame-retardant nonwoven fabric with a thickness of 0.06-0.09 mm. The layers are initially bonded together by roller pressing. The roller pressing pressure is 0.8-1.2 MPa, and the roller speed is 1.0-1.5 m / min. During the bonding process, the transverse tension Fh of each layer of material is monitored by a high-precision tension sensor. When the fluctuation of Fh is greater than ±10 N / m, the correction device is triggered to adjust the angle of the fabric feeding mechanism to ensure that the alignment error of each layer is ≤ ±0.5 mm. S5. Transfer the laid multi-layer material as a whole into the composite mold. The composite mold is made of high-temperature resistant alloy steel. The mold cavity 2 is equipped with a cooling channel 6 and a heating element 7. Before closing the mold, the mold cavity 2 is vacuumed to reduce the internal pressure to below -0.08MPa, and then the exhaust valve is closed. S6. Start the compound die stamping process. Heat the die to 160-180℃, pressurize at a rate of 0.5-1.0 mm / s, with a maximum pressure of 120-150 MPa and a holding time of 180-240 s. During this period, monitor the temperature T3 at the center point and T4 at the edge of the die cavity 2 using an embedded thermocouple array. Calculate the temperature gradient ΔT = T3 - T4. When ΔT > 12℃, the system determines that there is a risk of local overheating. It then reduces the center heating power by 15% and activates the edge auxiliary heating, continuously monitoring the trend of ΔT. If the rate of decrease of ΔT within 60 s is less than 0.5℃ / min, the circulating water flow rate of the die is further adjusted to improve the cooling efficiency by 20%. When ΔT stabilizes within the range of 8-12℃ and T3 remains at 170±5℃, it is determined to be in thermal equilibrium. Proceed to S7. S7. After the pressure holding is completed, the mold is slowly depressurized at a speed of 0.3-0.6 mm / s. During the depressurization process, the mold opening and closing stroke L is recorded by the displacement sensor. When L reaches 85% of the total stroke, the system starts the air blowing device to inject compressed air into the mold cavity 2. The gas pressure is 0.3-0.5 MPa, and the blowing time is not less than 10 seconds, which is used to remove residual colloid and dust. S8. Remove the molded part and perform surface quality inspection. Use a 3D optical scanner to measure the surface flatness. The allowable deviation is ≤0.3mm. At the same time, use an ultrasonic flaw detector to check for internal bubbles or delamination defects. When the defect area ratio is >1.5%, it is judged as unqualified; otherwise, it is qualified. Through meticulous control throughout the entire process, the high-quality molding of the wet-process cast steel fabric for the skylight canopy is ensured. S1 involves sandblasting, degreasing, cleaning, and rigorous testing of the cast steel substrate to ensure its cleanliness and roughness meet standards, laying the foundation for subsequent adhesive adhesion and composite molding, and avoiding weak bonding due to substrate impurities. S2 precise preheating control and temperature fluctuation limits reduce the impact of substrate thermal deformation. S3-S4 dynamic adjustment of adhesive parameters, environmental conditions, and multi-layer material bonding ensures coating uniformity and alignment accuracy of each layer, improving the fabric's structural stability. S5-S7 vacuum treatment, hot-pressing parameter optimization, and pressure relief blowing design effectively avoid defects such as bubbles and delamination, while ensuring the integrity of the molded parts during demolding. S8 multi-dimensional testing methods strictly control the surface flatness and internal quality of the product. The entire process is logically rigorous and parameters are quantified, achieving quality control from raw materials to finished products, resulting in fabrics with high strength, good adhesion, and excellent appearance.

[0021] In step S3, there is a dynamic matching relationship between d and T1 of the wet adhesive layer: when T1 is in the range of 78-80℃, d is set to 0.12mm; when T1 is in the range of 80-82℃, d is set to 0.15mm; when T1 > 82℃, d is automatically adjusted to 0.18mm, and this adjustment process meets the following conditions: 1) The rate of change of d does not exceed 0.03 mm / min; 2) During the adjustment period d, the ambient humidity H must be maintained between 55% and 65%; otherwise, the adjustment should be paused and the dehumidification program should be started. 3) S4 can only proceed after T1 has been detected to be stable within the target range twice consecutively and d has been adjusted to the correct position. If all three conditions above are met, the coating parameters can be confirmed as valid; otherwise, the system will enter alarm mode and alert the operator. By clearly defining the dynamic matching relationship and additional conditions between the wet adhesive layer thickness d and the substrate preheating temperature T1, the accuracy and adaptability of the coating process are significantly improved. Setting corresponding d values ​​according to different T1 ranges avoids problems such as uneven adhesive layer curing rates and insufficient adhesion caused by temperature differences, ensuring the bonding effect between the adhesive layer and the substrate and subsequent composite materials. Limiting the rate of change of d prevents coating defects caused by sudden thickness changes, while controlling ambient humidity prevents moisture from affecting adhesive layer performance. Continuous testing and confirmation further ensure the stability of parameter matching. This allows the coating process to dynamically respond to substrate temperature fluctuations, reducing the risk of product non-conformity due to temperature deviations. Simultaneously, it improves the level of automation in the production process, reduces manual intervention, ensures product quality consistency, and increases production efficiency, providing a stable and reliable foundation for subsequent composite molding processes.

[0022] In step S4, the mass ratio of PET nonwoven fabric: thermoplastic polyurethane film: flame-retardant nonwoven fabric is 1:1.2:0.8, and the total thickness of the three layers is ≤0.35mm. During the laying process, if wrinkles or misalignments are found in any layer, the system will analyze the defect location based on image recognition algorithms and determine whether to interrupt the laying process based on the relationship between the current cumulative laying length L0 and the standard length Lb: when L0 / Lb>0.7 and the number of defects is ≥3, the system determines that the batch is abnormal, automatically stops the material supply, and executes the rework process; otherwise, if L0 / Lb≤0.7, only the defective section is cut off and the laying continues, but the number of abnormalities is recorded. If the cumulative number exceeds 5, the machine will be forced to stop for maintenance. By limiting the mass ratio and total thickness of the three-layer composite material and establishing an intelligent judgment and handling mechanism for layup defects, the rationality and layup quality of the multi-layer composite structure are effectively guaranteed. Specific mass ratio and total thickness limits ensure that the fabric combines lightweight, flexibility, and structural strength to meet the needs of skylight roofs. Image recognition algorithms accurately locate wrinkles and misalignments, and combined with the judgment logic of layup length ratio, enabling graded defect handling: timely shutdown and rework in case of batch anomalies to avoid resource waste; precise removal and continuous monitoring of small-scale defects to ensure production continuity; mandatory shutdown and maintenance requirements based on the cumulative number of anomalies to promptly identify equipment problems such as the fabric feeding mechanism and reduce defect generation at the source. This design not only ensures the composite effect of multi-layer materials and improves the structural stability and consistency of the product, but also improves production efficiency, reduces production costs, and enhances the practicality and reliability of the process through intelligent defect handling.

[0023] The compound die stamping process in S6 also includes: S61. When the rate of temperature rise of T3 at the center of mold cavity 2 is detected to be dT3 / dt > 2℃ / min, the system judges that the temperature rise is too fast. At this time, the heating power is reduced by 10% and the cooling water flow rate is increased by 20% simultaneously. S62. Subsequently, continuously monitor the trend of T3. If dT3 / dt decreases to below 1.5℃ / min within 30s and T3 does not exceed 180℃, the regulation is deemed effective, and the current parameters are maintained. S63. If dT3 / dt is still higher than 1.5℃ / min or T3 is close to 180℃, further reduce the heating power to 70% of the original value and turn on the mold edge spray cooling device. The spray frequency is set to once every 10 seconds, and each spray lasts for 0.8 seconds. S64. After the spray is turned on, the system reassesses the upward trend of T3. If dT3 / dt drops below 0.8℃ / min within 60s and T3≤175℃, it is determined to be a safe and controllable state, and the heating power is restored to the normal level. S65. If the above adjustments are ineffective, T3 continues to rise and dT3 / dt > 1.0℃ / min, the system will determine that there is a risk of thermal runaway, immediately terminate heating and start the emergency cooling procedure, and at the same time issue an alarm to notify the operator. By addressing the heating rate issue in the compound die stamping process, a control mechanism was established to effectively mitigate the risk of thermal runaway and ensure molding quality. When the heating rate is too fast, a combination of methods, including gradient adjustment of heating power, cooling water flow rate, and activation of edge spray cooling devices, can quickly suppress abnormal temperature rises, preventing material degradation, uneven adhesive curing, or deformation of the molded parts caused by localized overheating of the mold cavity 2. The judgment criteria and time limits for each control step ensure the timeliness and effectiveness of the control, preventing the problem from escalating. The emergency cooling procedure provides a safety guarantee in extreme situations, avoiding equipment damage and batch scrapping of products. This design refines the temperature control logic of compound die stamping, improves the process's response and handling capabilities to temperature anomalies, maintains the temperature of the mold cavity 2 within a stable and reasonable range, ensures the dimensional accuracy, structural integrity, and performance stability of the molded parts, and enhances the safety and controllability of the production process, providing strong support for the stable production of high-quality products.

[0024] In S7, the control method for mold depressurization and air blowing includes: S71. At the same time as the mold begins to depressurize, the system activates the pressure sensor to monitor the residual pressure Pt in the mold cavity 2; S72. When Pt drops from the initial value of 1.0 MPa to 0.3 MPa, the system starts the air blowing device; S73. After the air blowing device is started, the actual air blowing volume Q is monitored by the flow meter, and the target value of Q is set to 0.8m. 3 / min, allowable deviation ±0.1m 3 / min; S74. If Q deviates from the target value by more than 0.1m 3 If the flow rate is 1 / min and the duration is >5s, the system will determine that the blowing is abnormal, automatically switch to the backup air source and recalibrate the flow valve. S75. During the blowing process, the average depressurization speed v = L / t is calculated by combining the relationship between the mold opening and closing stroke L and time t obtained by the displacement sensor. When v < 0.3 mm / s, the system judges that the depressurization is too slow and increases the blowing pressure to 0.5 MPa. Conversely, if v > 0.6 mm / s, it is considered that the depressurization is too fast and the blowing pressure is reduced to 0.3 MPa. S76. After the blowing is completed, when Pt drops below 0.05MPa and L reaches more than 95% of the total stroke, the part retrieval operation is allowed; otherwise, the part retrieval instruction is delayed. The linkage control between residual pressure and mold stroke ensures precise triggering of the air blowing action. Compressed air effectively removes residual colloids and dust from mold cavity 2, preventing impurities from affecting the quality of subsequent products and the service life of the mold. The precise limitation of air volume and the design of a backup air source for emergency switching ensure the stability of the cleaning effect and prevent incomplete cleaning due to air source problems. The linkage adjustment between depressurization speed and air blowing pressure avoids damage to the molded parts caused by excessive depressurization and ensures cleaning efficiency through pressure adaptation. The clear limitation of part removal conditions further ensures the integrity of the molded parts and avoids deformation caused by premature part removal. It improves the level of fine control of the demolding process, reduces the risk of surface defects and mold failure of molded parts, extends the service life of the mold, and improves part removal efficiency, ensuring production continuity.

[0025] The composite mold includes, but is not limited to, a lower mold body for placing raw materials, an upper mold body adapted to the lower mold body for stamping, and a drive assembly for driving the upper mold body and the lower mold body to close. The lower mold body includes, but is not limited to, a base 1. The base 1 is provided with a molding cavity 2 adapted to the shape of the skylight roof. Several spaced support ribs 3 are provided between the base 1 and the molding cavity 2 for support. Multiple positioning components 4 for precise positioning are provided around the base 1. An annular sealing groove 5 for skylight molding and preventing overflow is provided in the center of the molding cavity 2. A cooling channel 6 and a heating element 7 are also provided between the base 1 and the molding cavity 2. The cooling channel 6 runs through the bottom and side wall of the entire lower mold body, is arranged in a serpentine shape, and is connected to an interface 8 provided on one side of the base 1. The interface 8 is used to connect to an external cooling system. This composite mold structure is precisely adapted to the aforementioned production process, providing key equipment support for efficient and high-quality molding. The molding cavity 2 of the lower mold body is adapted to the shape of the skylight roof, ensuring the dimensional accuracy of the molded parts. The supporting ribs 3 enhance the stability of the mold structure, the positioning components 4 achieve precise positioning of the raw materials, and the annular sealing groove 5 effectively prevents overflow, improving the product appearance quality and raw material utilization rate. The serpentine cooling channel 6 runs through the lower mold body and, in conjunction with the heating element 7, can quickly achieve temperature regulation and uniform distribution in the mold cavity 2, meeting the strict requirements of the process for temperature gradient. The interface 8 between the cooling channel 6 and the external cooling system facilitates system integration and parameter control. The entire mold is made of high-temperature resistant alloy steel, which has both high strength and heat resistance, and can withstand the high pressure and high temperature environment in the process, extending its service life. With its reasonable structure and complete functions, it can accurately match the temperature control, stamping and forming requirements in the process, ensuring the smooth implementation of the production process, improving the product molding quality and production efficiency, and has significant practicality and adaptability. The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any ordinary changes and substitutions made by those skilled in the art within the scope of the technical solution of the present invention should be included within the protection scope of the present invention.

Claims

1. A production process for wet-cast steel fabric for skylight canopies, characterized in that: Includes the following steps: S1. Select a cast steel substrate as the initial molding carrier. The cast steel substrate is a medium carbon alloy steel plate with a thickness between 3.0-5.5 mm. After sandblasting, the surface is degreased and cleaned. The surface roughness Ra after cleaning is ≤2.5 μm. The residual oil content is detected by X-ray fluorescence spectrometry. When the detection value is lower than 5 ppm, it is judged as qualified for cleaning. When the detection value is higher than 5 ppm, alkaline cleaning is repeated and the test is repeated until the standard is met. S2. Place the clean and qualified cast steel substrate in an oven preheated to 80±5℃ for constant temperature preheating for 15-20 minutes. During this period, monitor the surface temperature T1 of the substrate in real time using an infrared thermometer. Set the temperature fluctuation range ΔT1<±3℃. When three consecutive sets of data meet the condition of 78℃≤T1≤82℃, the preheating is considered complete. If the standard is not met, extend the preheating time to a maximum of 30 minutes. If the standard is still not met after the time limit, replace the substrate. S3. A wet adhesive layer is uniformly coated onto the preheated cast steel substrate surface. The wet adhesive is a polyurethane-modified epoxy resin emulsion with a solid content of 45%-50% and a viscosity of 6000-8000 cP. The coating method uses a doctor blade coater with a coating speed controlled at 1.2-1.8 m / min and a coating thickness of 0.12-0.18 mm. During the coating process, the coating thickness d is monitored in real time using an online laser thickness gauge. When d deviates from the target value of ±0.02 mm for more than 3 seconds, the doctor blade gap is automatically adjusted and feedback correction is provided. At the same time, the ambient humidity H and temperature T2 of the coating area are collected. When H > 65% or T2 < 20℃, the heating and dehumidification system is activated to reduce H to below 60% and T2 to rise above 22℃ before continuing the coating process. S4. A multi-layer composite material is sequentially laid on the wet adhesive layer. The multi-layer material includes: a first layer of PET nonwoven fabric with a thickness of 0.08-0.12 mm, a second layer of thermoplastic polyurethane film with a thickness of 0.10-0.15 mm, and a third layer of flame-retardant nonwoven fabric with a thickness of 0.06-0.09 mm. The layers are initially bonded together by roller pressing. The roller pressing pressure is 0.8-1.2 MPa, and the roller speed is 1.0-1.5 m / min. During the bonding process, the transverse tension Fh of each layer of material is monitored by a high-precision tension sensor. When the fluctuation of Fh is greater than ±10 N / m, the correction device is triggered to adjust the angle of the fabric feeding mechanism to ensure that the alignment error of each layer is ≤ ±0.5 mm. S5. Transfer the laid multi-layer material as a whole into the composite mold. The composite mold is made of high-temperature resistant alloy steel. The mold cavity (2) is equipped with a cooling channel (6) and a heating element (7). Before closing the mold, the mold cavity (2) is vacuumed to reduce the internal pressure to below -0.08MPa. Then the exhaust valve is closed. S6. Start the compound die stamping process. Heat the die to 160-180℃, pressurize at a speed of 0.5-1.0mm / s, pressurize at a maximum pressure of 120-150MPa, and hold for 180-240s. During this period, monitor the temperature T3 at the center point and the temperature T4 at the edge of the die cavity (2) using an embedded thermocouple array. Calculate the temperature gradient ΔT = T3 - T4. When ΔT > 12℃, the system determines that there is a risk of local overheating. Then, reduce the central heating power by 15% and turn on the edge auxiliary heating. Continuously monitor the trend of ΔT. If the rate of decrease of ΔT within 60s is less than 0.5℃ / min, further adjust the flow rate of the die circulating water to improve the cooling efficiency by 20%. When ΔT is stable in the range of 8-12℃ and T3 is maintained at 170±5℃, it is determined to be in thermal equilibrium. Proceed to S7. S7. After the pressure holding is completed, the mold is slowly depressurized at a speed of 0.3-0.6 mm / s. During the depressurization process, the mold opening and closing stroke L is recorded by the displacement sensor. When L reaches 85% of the total stroke, the system starts the air blowing device to inject compressed air into the mold cavity (2). The gas pressure is 0.3-0.5 MPa, and the blowing time is not less than 10s, which is used to remove residual colloids and dust. S8. Remove the molded part and perform surface quality inspection. Use a three-dimensional optical scanner to measure the surface flatness. The allowable deviation is ≤0.3mm. At the same time, use an ultrasonic flaw detector to check for internal bubbles or delamination defects. When the defect area ratio is >1.5%, it is judged as unqualified; otherwise, it is qualified.

2. The production process of wet-cast steel fabric for skylight canopies according to claim 1, characterized in that, In step S3, there is a dynamic matching relationship between d and T1 of the wet adhesive layer: when T1 is in the range of 78-80℃, d is set to 0.12mm; when T1 is in the range of 80-82℃, d is set to 0.15mm; when T1 > 82℃, d is automatically adjusted to 0.18mm, and this adjustment process meets the following conditions: 1) The rate of change of d does not exceed 0.03 mm / min; 2) During the adjustment period d, the ambient humidity H must be maintained between 55% and 65%; otherwise, the adjustment should be paused and the dehumidification program should be started. 3) S4 can only proceed after T1 has been detected to be stable within the target range twice consecutively and d has been adjusted to the correct position. If all three conditions are met, the coating parameters are confirmed to be valid; otherwise, the system will enter alarm mode and alert the operator.

3. The production process of wet-cast steel fabric for skylight canopies according to claim 1, characterized in that, In step S4, the mass ratio of PET nonwoven fabric: thermoplastic polyurethane film: flame-retardant nonwoven fabric is 1:1.2:0.8, and the total thickness of the three layers is ≤0.35mm. During the laying process, if wrinkles or misalignments are found in any layer, the system will analyze the defect location based on image recognition algorithm and determine whether to interrupt the laying based on the relationship between the current cumulative laying length L0 and the standard length Lb: when L0 / Lb>0.7 and the number of defects is ≥3, the system determines that the batch is abnormal, automatically stops the material supply and executes the rework process; otherwise, if L0 / Lb≤0.7, only the defective section is cut off and the laying continues, but the number of abnormalities is recorded. If the cumulative number exceeds 5, the machine will be forced to stop for maintenance.

4. The production process of wet-cast steel fabric for skylight canopies according to claim 1, characterized in that, The compound die stamping process in S6 also includes: S61. When the rate of temperature rise of the center temperature T3 of the mold cavity (2) is detected to be dT3 / dt > 2℃ / min, the system judges that the temperature rise is too fast. At this time, the heating power is reduced by 10% and the cooling water flow rate is increased by 20% simultaneously. S62. Subsequently, continuously monitor the trend of T3. If dT3 / dt decreases to below 1.5℃ / min within 30s and T3 does not exceed 180℃, the regulation is deemed effective, and the current parameters are maintained. S63. If dT3 / dt is still higher than 1.5℃ / min or T3 is close to 180℃, further reduce the heating power to 70% of the original value and turn on the mold edge spray cooling device. The spray frequency is set to once every 10 seconds, and each spray lasts for 0.8 seconds. S64. After the spray is turned on, the system reassesses the upward trend of T3. If dT3 / dt drops below 0.8℃ / min within 60s and T3≤175℃, it is determined to be a safe and controllable state, and the heating power is restored to the normal level. S65. If the above adjustments are ineffective, T3 continues to rise and dT3 / dt > 1.0℃ / min, the system will determine that there is a risk of thermal runaway, immediately terminate heating and start the emergency cooling procedure, and issue an alarm to notify the operator.

5. The production process of wet-cast steel fabric for skylight canopies according to claim 1, characterized in that, In S7, the control method for mold depressurization and air blowing includes: S71. At the same time as the mold begins to depressurize, the system starts the pressure sensor to monitor the residual pressure Pt in the mold cavity (2); S72. When Pt drops from the initial value of 1.0 MPa to 0.3 MPa, the system starts the air blowing device; S73. After the air blowing device is started, the actual air blowing volume Q is monitored by the flow meter, and the target value of Q is set to 0.8m. 3 / min, allowable deviation ±0.1m 3 / min; S74. If Q deviates from the target value by more than 0.1m 3 If the flow rate is 1 / min and the duration is >5s, the system will determine that the blowing is abnormal, automatically switch to the backup air source and recalibrate the flow valve. S75. During the blowing process, the average depressurization speed v = L / t is calculated by combining the relationship between the mold opening and closing stroke L and time t obtained by the displacement sensor. When v < 0.3 mm / s, the system judges that the depressurization is too slow and increases the blowing pressure to 0.5 MPa. Conversely, if v > 0.6 mm / s, it is considered that the depressurization is too fast and the blowing pressure is reduced to 0.3 MPa. S76. After the blowing is completed, when Pt drops below 0.05MPa and L reaches more than 95% of the total stroke, the part retrieval operation is allowed; otherwise, the part retrieval instruction is delayed.

6. A composite mold suitable for the production process of wet-cast steel fabric for skylight canopies as described in any one of claims 1-5, characterized in that, The composite mold includes, but is not limited to, a lower mold body for placing raw materials, an upper mold body adapted to the lower mold body for stamping, and a drive assembly for driving the upper mold body and the lower mold body to close. The lower mold body includes, but is not limited to, a base (1). The base (1) is provided with a molding cavity (2) that is adapted to the shape of the skylight roof. A number of spaced support ribs (3) are provided between the base (1) and the molding cavity (2) for support. A number of positioning components (4) for precise positioning are provided around the base (1). An annular sealing groove (5) for skylight molding and preventing overflow is provided in the center of the molding cavity (2). A cooling channel (6) and a heating element (7) are also provided between the base (1) and the molding cavity (2). The cooling channel (6) runs through the bottom and side wall of the entire lower mold body, is arranged in a serpentine shape, and is connected to an interface (8) provided on one side of the base (1). The interface (8) is used to connect to an external cooling system.

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