A polytetrafluoroethylene glass fiber building membrane and a preparation method thereof

Abstract

The application discloses a polytetrafluoroethylene glass fiber building film material, which comprises a glass fiber cloth, pretreatment protective layers arranged on two sides of the glass fiber cloth, a dense layer and a polyperfluoroethylene propylene resin outer layer arranged in sequence, and a non-porous film is formed through the polyperfluoroethylene propylene resin outer layer, and the holes formed by the dense layer are filled, so that the dense layer is complete. The problems of low tensile strength, poor folding resistance and surface cracking of the existing glass fiber building film material are solved.

Description

Technical Field

[0001] This invention relates to the technical field of architectural membrane materials, specifically to a polytetrafluoroethylene glass fiber architectural membrane material and its preparation method. Background Technology

[0002] As an emerging industry, architectural membrane materials possess strong advantages and broad market prospects. With their lightweight, aesthetic appeal, light transmission, energy efficiency, safety, durability, artistic appeal, and environmental friendliness, they are widely used in various large-scale construction projects, such as large stadiums, commercial public facilities, amusement parks, exhibition halls, airport terminals, and railway stations. Architectural membrane materials are considered the fifth type of building material after steel, cement, wood, and glass. They can not only be applied to the same areas as traditional building materials but also offer unparalleled advantages in areas where traditional building materials are difficult to use, such as large-span spatial structures.

[0003] Currently, most membrane structure buildings in China use PVC building membranes, which are made of high-strength polyester fabric as the base and coated with PVC resin. However, the disadvantages of PVC building membranes in terms of self-cleaning, aging resistance, and fire resistance limit their lifespan to less than 15 years, generally limiting their use to temporary structures. Due to the high maintenance and cleaning costs of PVC membranes, high-performance PTFE building membranes are gradually gaining popularity. PTFE membranes use ultra-fine glass fiber fabric as the base and are coated with PTFE resin, allowing them to fully utilize the advantages of glass fiber's high strength and other mechanical properties, as well as the advantages of polytetrafluoroethylene's aging resistance and self-cleaning properties. They exhibit superior performance, especially in self-cleaning and aging resistance.

[0004] However, during the production of architectural membrane materials, repeated high temperatures reduce the mechanical strength of glass fibers, mainly manifested in low tensile strength and poor folding resistance. In addition, the polytetrafluoroethylene layer on the surface of architectural membrane materials produced by existing processes is cracked, affecting the anti-aging and corrosion resistance of the coating. Summary of the Invention

[0005] In order to solve one or more technical problems existing in the prior art, one of the objectives of this application is to provide a polytetrafluoroethylene glass fiber architectural membrane material, which solves the problems of low tensile strength, poor folding resistance and surface cracking of existing glass fiber architectural membrane materials.

[0006] The second objective of this application is to provide a method for preparing polytetrafluoroethylene (PTFE) glass fiber architectural membrane materials, which can solve the problems of low tensile strength and poor folding resistance of glass fibers caused by repeated high temperatures, as well as cracking of the PTFE layer on the surface of the architectural membrane material, thereby improving the anti-aging and corrosion resistance of the coating.

[0007] To address the aforementioned technical problems, one of the objectives of this application is achieved through the following technical solution:

[0008] A polytetrafluoroethylene (PTFE) glass fiber architectural membrane material includes a glass fiber cloth, a pre-treated protective layer, a dense layer, and a polytetrafluoroethylene propylene resin outer layer sequentially disposed on both sides of the glass fiber cloth. The polytetrafluoroethylene propylene resin outer layer forms a non-porous film, which fills the pores formed by the dense layer, thereby making the dense layer intact.

[0009] Preferably, the pretreated protective layer is formed by impregnating the glass fiber cloth with a silane coupling agent and an active organosilicon softener, followed by drying.

[0010] Preferably, the dense layer is made by impregnating a mixture of polytetrafluoroethylene resin emulsion and hollow glass microspheres onto the glass fiber cloth and then sintering it.

[0011] To solve the aforementioned existing technical problems, the second objective of this application is achieved by the following technical solution:

[0012] A method for preparing a polytetrafluoroethylene glass fiber architectural membrane material, the method comprising:

[0013] S1. Substrate forming: Glass fibers with a twist of 135±15 twists / meter are woven into glass fiber cloth after being twisted.

[0014] S2. High-temperature surface treatment: The glass fiber cloth is baked at 350-380℃ in an oven at a speed of 1-3m / min to remove most of the sizing agent from the surface of the glass fiber.

[0015] S3. Surface pretreatment: The silane coupling agent is poured into water to prepare a diluted aqueous dispersion A with an active silane weight ratio of 0.1-1.0%. The softener is diluted in water to form a diluted aqueous dispersion B with an active organosilicon content. The diluted aqueous dispersion A and diluted aqueous dispersion B are mixed and then the glass fiber cloth is impregnated. Then, it is dried at a speed of 0.5-1.5 m / min and a temperature of 100-120°C.

[0016] S4. Multiple PTFE impregnation and sintering: 3-5% by weight of polyethylene glycol octylphenyl ether emulsifier is added to a PTFE resin dispersion with a solid content of 60% and mixed evenly to form a PTFE resin emulsion. Glass microspheres are then added to the PTFE resin emulsion and mixed evenly to form a PTFE resin mixture. Glass fiber cloth is impregnated in the PTFE resin mixture and sintered. The sintering temperature is 360-400℃ and the speed is 1-3m / min. This process is repeated 8 times. After repeated sintering, a dense layer of PTFE resin is formed on the surface of the glass fiber cloth.

[0017] S5. Surface treatment with polytetrafluoroethylene propylene: The glass fiber cloth with a dense layer on the surface is impregnated and sintered in polytetrafluoroethylene propylene at a sintering temperature of 360-400℃ and a speed of 1-3m / min. After sintering, a polytetrafluoroethylene propylene resin outer layer is formed, thereby producing polytetrafluoroethylene glass fiber building membrane material.

[0018] S6. Winding and forming: The finished product formed in step S5 is wound up by a winding machine to form polytetrafluoroethylene glass fiber building membrane material raw material, which is then packaged and stored.

[0019] Preferably, the silane coupling agent is a silane coupling agent containing ethylene benzyl and amino organic functional groups as well as trimethoxysilyl inorganic functional groups.

[0020] Preferably, the softener is a nonionic emulsion of polydimethylsiloxane.

[0021] Optionally, the twisted yarn raw material of the glass fiber cloth in step S1 is electronic-grade glass fiber with a diameter of 3-6 micrometers.

[0022] Optionally, the woven fiberglass cloth has a unit area mass of not less than 450 g / m².

[0023] Preferably, the glass microspheres are soda lime borosilicate hollow glass microspheres with a diameter of 15 to 40 micrometers, and the glass microspheres are added to the polytetrafluoroethylene resin emulsion at a weight ratio of 10 to 15%.

[0024] Preferably, the weight ratio of softener in the diluted aqueous dispersion B is 3-8%.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0026] (1) The use of twisted fiberglass cloth improves the folding resistance of building membrane materials.

[0027] (2) Silane coupling agents with ethylene benzyl and amino organic functional groups and trimethoxysilyl inorganic functional groups are selected to improve the tensile strength of glass fiber cloth and reduce the strength loss of glass fiber cloth caused by repeated high temperature during the impregnation of polytetrafluoroethylene.

[0028] (3) Use polydimethylsiloxane nonionic emulsion softener to reduce the stiffness of building membrane materials.

[0029] (4) Using polytetrafluoroethylene propylene resin for surface treatment can reduce coating pores and make the coating more compact.

[0030] (5) Use soda lime borosilicate hollow glass microspheres to reduce coating cracking.

[0031] (6) This enables the finished building membrane material to solve the problems of low tensile strength and poor folding resistance of glass fiber caused by repeated high temperature and cracking of polytetrafluoroethylene layer on the surface of building membrane material, thereby improving the anti-aging performance and corrosion resistance of coating. Attached Figure Description

[0032] Figure 1 This is a side view of the product of the present invention, showing the positional relationship between the layers;

[0033] Figure 2 This is a process flow diagram of the present invention;

[0034] Figure 3 This is a photograph of the coating in this invention under 1000x magnification, without surface treatment with polytetrafluoroethylene propylene resin.

[0035] Figure 4 This is a photograph of the finished product after surface treatment with polytetrafluoroethylene propylene resin, magnified 1000 times.

[0036] Figure 5 This is a photograph of the polytetrafluoroethylene layer magnified 1000 times when hollow glass microspheres are not added in this invention.

[0037] Figure 6 A photograph showing the polytetrafluoroethylene layer magnified 1000 times after hollow glass microspheres were added to this invention.

[0038] In the diagram: 1. Fiberglass cloth; 2. Protective layer; 3. Dense layer; 4. Poly(fluoroethylene) propylene resin outer layer. Detailed Implementation

[0039] The present application will now be further described in conjunction with the accompanying drawings and specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0040] In the description of this application, it should be understood that the terms "upper", "lower", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0041] The terms "first," "second," etc., used in this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class, without limiting the number of objects; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0042] Example 1:

[0043] like Figure 1 As shown, a polytetrafluoroethylene (PTFE) glass fiber architectural membrane material includes a glass fiber cloth 1, a pre-treated protective layer 2, a dense layer 3, and a polytetrafluoroethylene propylene resin outer layer 4 sequentially disposed on both sides of the glass fiber cloth 1. The polytetrafluoroethylene propylene resin outer layer 4 forms a non-porous film, filling the pores formed by the dense layer 3, thereby making the dense layer 3 intact.

[0044] This technology enables the retention rate of tensile breaking strength of architectural membrane materials after folding to reach over 80%, resulting in higher tensile strength, better corrosion resistance, and better aging resistance. Simultaneously, the pre-treatment protective layer 2 allows for better film formation on the glass fiber surface, giving the product excellent chemical stability, low flammability, corrosion resistance, and good aging resistance. The bonding between the dense layer 3 and the polytetrafluoroethylene propylene resin outer layer 4 allows the polytetrafluoroethylene propylene resin outer layer 4 to form a non-porous film on the outer area of ​​the dense layer 3, thereby filling the pores formed in the dense layer 3 and ensuring the integrity of the dense layer 3. This solves the problems of low tensile strength, poor folding resistance, and surface cracking in existing glass fiber architectural membrane materials.

[0045] A further improvement is that the pretreatment protective layer 2 is made by impregnating the glass fiber cloth 1 with a silane coupling agent and an active organosilicon softener, and then drying and shaping it.

[0046] The pretreated protective layer 2 formed by drying with silane coupling agent and active organosilicon softener can improve the tensile strength of glass fiber. In particular, the tensile strength of glass fiber can be increased by 40-50% by the action of silane coupling agent.

[0047] A further improvement is made in that the dense layer 3 is made by impregnating the glass fiber cloth 1 with a mixture of polytetrafluoroethylene resin emulsion and hollow glass microspheres and then sintering it.

[0048] Insulating glass microspheres, as inorganic fillers, possess advantages such as light weight, large volume, good dispersibility, fluidity, and stability. They can reduce cracking caused by shrinkage during polytetrafluoroethylene resin emulsion film formation, increase the thickness of the surface coating on the glass fiber cloth, and prevent cracking. Furthermore, insulating glass microspheres also have the advantages of low thermal conductivity and heat insulation; during repeated sintering, they can reduce heat transfer and minimize the loss of mechanical strength of the glass fibers due to repeated high temperatures.

[0049] Example 2:

[0050] like Figure 2 As shown, a method for preparing a polytetrafluoroethylene (PTFE) glass fiber architectural membrane material includes:

[0051] S1. Substrate forming: Glass fibers with a twist of 135±15 twists / meter are woven into glass fiber cloth 1 after passing through twisted yarn;

[0052] Generally, untwisted fiberglass cloth 1 has poor folding resistance after being made into architectural membrane materials. The tensile breaking strength retention rate after folding is only about 50%. During the splicing, welding or installation of the membrane material, it is prone to cracking, making it unusable as a building structural material. When the architectural membrane material is folded and then put into use, the fold is prone to breakage. In general, the twist of the twisted yarn is too low and does not significantly improve the folding resistance. The twist is too high and it will affect the effective penetration of coupling agent, softener and polytetrafluoroethylene into the twisted yarn. Therefore, the base material was improved so that the new fiberglass cloth 1 is woven from fiberglass twisted yarn with a twist of 135±15 twists / meter. The fiberglass cloth 1 woven from twisted yarn can achieve a tensile breaking strength retention rate of more than 80% after folding after being made into architectural membrane materials, and the formed fiberglass cloth 1 has high tensile strength.

[0053] Under the same conditions, architectural membrane materials using 80 twists / meter of double-twisted yarn can retain more than 60% of their tensile breaking strength after folding; those using 100 twists / meter can retain more than 70%; and those using 135 twists / meter can retain more than 80%. There is no significant difference in the tensile breaking strength retention rate between architectural membrane materials using double-twisted yarn with a twist rate of 135 twists / meter or higher and those using 135 twists / meter. Therefore, using 135 twists / meter double-twisted yarn results in the lowest cost and the simplest manufacturing process.

[0054] S2. High-temperature surface treatment: The glass fiber cloth 1 is baked at 350-380℃ in an oven at a speed of 1-3m / min to remove most of the sizing agent from the surface of the glass fiber.

[0055] Because existing glass fibers contain sizing agents during the production process, the surface of the formed glass fiber cloth 1 is covered with sizing agents, mainly starch-based sizing agents. Therefore, by surface high-temperature treatment, these sizing agents can be decomposed and removed at high temperatures. Removing the sizing agents facilitates the subsequent processing of glass fibers with coupling agents, softeners, and polytetrafluoroethylene.

[0056] High-temperature baking of glass fiber at 350-380℃ can also burn off the fuzz on the surface of the glass fiber, resulting in a smoother surface of the finished product.

[0057] S3. Surface pretreatment: The silane coupling agent is poured into water to prepare a diluted aqueous dispersion A with an active silane weight ratio of 0.1-1.0%. The softener is diluted in water to form a diluted aqueous dispersion B with an active organosilicon content. The diluted aqueous dispersion A and diluted aqueous dispersion B are mixed and then the glass fiber cloth 1 is impregnated. Then, it is dried at a speed of 0.5-1.5 m / min and a temperature of 100-120°C.

[0058] Because the surface of the glass fiber cloth 1 in the existing process is not treated with a coupling agent, the tensile strength of the glass fiber decreases due to repeated high-temperature production during the process. Therefore, a surface pretreatment is performed on the glass fiber cloth 1 before impregnation with polytetrafluoroethylene. During the pretreatment, the silanol in the silane coupling agent can condense on the surface of the glass fiber, thereby improving the tensile strength of the glass fiber. In particular, after the glass fiber cloth 1 is immersed in a diluted aqueous dispersion A for surface treatment and then dried, the silanol in the silane coupling agent can be condensed on the surface of the glass fiber during the drying process, thereby increasing the tensile strength of the glass fiber by 40-50%. However, when the ratio of silane coupling agent to water exceeds 1.0%, it is easy to polymerize on the surface of the glass fiber after drying, which will affect the subsequent treatment of the glass fiber with the softener. Therefore, it is recommended to prepare a diluted aqueous dispersion A with an active silane content of 0.1-1.0% (by weight). Generally, a diluted aqueous dispersion A with an active silane content of 0.5% (by weight) is selected to achieve stable results. The concentration can also be adjusted appropriately according to the tensile strength requirements of the finished building membrane material.

[0059] S4. Repeated PTFE impregnation and sintering: 3-5% by weight of polyethylene glycol octylphenyl ether emulsifier is added to a PTFE resin dispersion with a solid content of 60% and mixed evenly to form a PTFE resin emulsion. Glass microspheres are then added to the PTFE resin emulsion and mixed evenly to form a PTFE resin mixture. Glass fiber cloth 1 is impregnated in the PTFE resin mixture and sintered. The sintering temperature is 360-400℃ and the speed is 1-3m / min. This process is repeated 8 times. After repeated sintering, a dense layer 3 of PTFE resin is formed on the surface of the glass fiber cloth 1.

[0060] A polytetrafluoroethylene (PTFE) resin dispersion with a solid content of 60% is selected as the main coating. It can withstand 250℃ for a long time, has good corrosion resistance, and good aging resistance. At the same time, polyethylene glycol octylphenyl ether emulsifier promotes emulsion stability and prevents separation and precipitation during repeated impregnation. Generally, polyethylene glycol octylphenyl ether emulsifier is added to the PTFE resin dispersion at a weight ratio of 3-5%. The PTFE resin dispersion is a colloid formed by PTFE resin with an average particle size of 0.2-0.3 micrometers suspended in liquid water. The emulsifier can increase the viscosity of the PTFE resin emulsion, thereby reducing the intermolecular distance of PTFE resin. This allows the PTFE resin to better form a film-like PTFE layer on the glass fiber surface, thus giving the product excellent chemical stability, low flammability, corrosion resistance, and good aging resistance. Hollow glass microspheres, as inorganic fillers, have the advantages of being lightweight yet large in volume, highly dispersible, fluid, and stable. They can reduce cracking caused by shrinkage during polytetrafluoroethylene resin film formation, increase the thickness of the coating on the glass fiber cloth surface, and prevent cracking. Actual comparison images are shown below. Figure 5 and Figure 6 As shown, Figure 5 This is a photograph of the polytetrafluoroethylene layer under 1000x magnification when hollow glass microspheres are not added in this invention. It can be seen from the image that there are obvious cracks. Figure 6 The photograph shows the polytetrafluoroethylene layer after adding hollow glass microspheres to this invention, magnified 1000 times. It can be seen from the image that there are no obvious cracks.

[0061] S5. Surface treatment with polytetrafluoroethylene propylene: The glass fiber cloth 1 with a dense layer 3 on the surface is impregnated and sintered in polytetrafluoroethylene propylene at a sintering temperature of 360-400℃ and a speed of 1-3m / min. After sintering, a polytetrafluoroethylene propylene resin outer layer 4 is formed, thereby obtaining polytetrafluoroethylene glass fiber building membrane material.

[0062] S6. Winding and forming: The finished product formed in step S5 is wound up by a winding machine to form polytetrafluoroethylene glass fiber building membrane material raw material, which is then packaged and stored.

[0063] The outermost layer is impregnated and sintered with perfluoroethylene propylene resin at a sintering temperature of 360–400℃ and a sintering speed of 1–3 m / min. Because polytetrafluoroethylene resin is prone to pore formation during film formation, perfluoroethylene propylene resin, with its low porosity, can form a non-porous film on the outer layer, filling the pores in the polytetrafluoroethylene layer and making the outer dense layer 3 more complete. The product coating, when magnified 1000 times, shows… Figure 3 and Figure 4 As shown, Figure 3 This is a photograph of the coating magnified 1000 times without surface treatment with polytetrafluoroethylene propylene resin. Obvious pores can be seen in the image. Figure 4 This is a magnified photo of the finished product after surface treatment with perfluoroethylene propylene resin, magnified 1000 times. The image shows virtually no pores and a more complete surface film. This solves the problems of low tensile strength and poor folding endurance of glass fibers, as well as cracking of the PTFE layer on the surface of existing PTFE fiberglass architectural membrane materials caused by repeated high-temperature treatment during preparation. It also improves the coating's anti-aging and corrosion resistance.

[0064] A further improvement is made in that the silane coupling agent is a silane coupling agent containing ethylene benzyl and amino organic functional groups as well as trimethoxysilyl inorganic functional groups.

[0065] It can improve the tensile strength of glass fiber cloth 1 and reduce the strength loss caused by repeated high temperature during the impregnation of glass fiber cloth 1 with polytetrafluoroethylene. At the same time, this silane coupling agent is resistant to high temperature and will not decompose and deactivate due to repeated high temperature during the impregnation of polytetrafluoroethylene.

[0066] A further improvement is made in that the softener is a nonionic emulsion of polydimethylsiloxane.

[0067] Because pre-treated glass fibers are prone to forming complexes, they can significantly reduce their flexibility during the subsequent impregnation and sintering process with polytetrafluoroethylene (PTFE) resin. Therefore, a nonionic emulsion of polydimethylsiloxane (PDMS) is used as the softener. Due to its nonionic nature, PDMS can be uniformly dispersed in nonionic, anionic, and cationic surfactants or polymer systems without forming complexes or reacting with silane coupling agents and PTFE. This protects the glass fiber surface and reduces the loss of flexibility during repeated PTFE impregnation and sintering. Furthermore, the use of a PDMS softening emulsion softens and protects the glass fibers, reducing the stiffness of the finished architectural membrane material by 30-50%.

[0068] A further improvement is that the twisted yarn raw material of the glass fiber cloth 1 in step S1 is electronic-grade glass fiber with a diameter of 3-6 micrometers.

[0069] Ordinary glass fiber has low tensile strength, which makes architectural membrane materials prone to breakage during use, making them unsuitable for large-scale construction projects such as stadium domes and sports field roofs. Therefore, the twisted yarn of glass fiber cloth 1 uses electronic-grade glass fiber yarn, which enables the tensile breaking strength of the twisted glass fiber yarn to reach more than 0.5N / Tex, resulting in good tensile strength. This effectively solves the problem that existing architectural membrane materials cannot be used in large-scale construction projects such as stadium domes and sports field roofs.

[0070] Optionally, the woven fiberglass cloth 1 has a unit area mass of not less than 450g / ㎡.

[0071] When engineering design requirements necessitate tensile breaking strength ≥ 5000 N / 5 cm, tensile breaking strength retention rate after folding ≥ 80%, tensile breaking strength retention rate under damp heat aging ≥ 80%, and tensile breaking strength retention rate under acid resistant ≥ 80%, conventional fiberglass cloth 1, woven with a unit area mass, cannot meet these requirements during preparation. This can easily lead to cracking problems during the installation or use of the architectural membrane material. Therefore, the unit area mass of fiberglass cloth 1 should be no less than 450 g / ㎡, enabling the tensile breaking strength of the architectural membrane material to reach over 5000 N / 5 cm, thereby solving the cracking problem during installation or use.

[0072] The glass fiber cloth 1 prepared using the above-described process has a unit area mass of 680 g / m² and a coating of 570 g / m². The test results are shown in Table 1. Table 1:

[0073]

[0074]

[0075] As can be seen from Table 1, the tensile breaking strength and tensile breaking strength after folding of polytetrafluoroethylene glass fiber architectural membrane material have been effectively improved. After humid heat aging treatment, its tensile breaking strength performance has not decreased significantly. In particular, the tensile breaking strength retention rate can reach more than 90%. In some acidic environments, the tensile breaking strength has not decreased, thus effectively solving the problem of cracking of architectural membrane materials during installation or use.

[0076] A further improvement is made in that the glass microspheres are made of soda lime borosilicate hollow glass microspheres with a diameter of 15 to 40 micrometers, and the glass microspheres are added to the polytetrafluoroethylene resin emulsion at a weight ratio of 10 to 15%.

[0077] Generally, 20-micron soda lime borosilicate hollow glass microspheres are selected, which have a relatively uniform and stable dispersion effect in polytetrafluoroethylene dispersion. Other particle sizes of soda lime borosilicate hollow glass microspheres can also be selected according to the actual dispersion situation. In addition, hollow glass microspheres also have the advantages of low thermal conductivity and heat insulation. During repeated sintering, they can reduce heat transfer and reduce the loss of mechanical strength of glass fibers caused by repeated high temperatures.

[0078] A further improvement is made in that the weight ratio of softener in the diluted aqueous dispersion B is 3-8%.

[0079] Because existing processes do not soften the surface of the glass fiber cloth 1, the glass fiber hardens due to repeated high-temperature heating during production. This results in a high degree of stiffness in the finished architectural membrane material, making it difficult to install and process. The tensile strength after folding is significantly reduced, affecting various mechanical properties. Therefore, a diluted aqueous dispersion B with an active organosilicon content of 3-8% by weight is formulated. This diluted aqueous dispersion B effectively softens the product, reducing the loss of softness during the subsequent repeated impregnation and sintering of the glass fiber with polytetrafluoroethylene resin. This results in a more flexible finished architectural membrane material with a higher retention rate of tensile breaking strength after folding. The percentage of active organosilicon should not be too high or too low. Below 3%, it has no effect on the stiffness of the finished architectural membrane material, while above 8%, it does not improve the stiffness. Therefore, it is controlled between 3-8%, with a typical concentration of 5% active organosilicon in the diluted aqueous dispersion B.

[0080] The above embodiments are merely preferred embodiments of this application and should not be construed as limiting the scope of protection of this application. Any non-substantial changes and substitutions made by those skilled in the art based on this application shall fall within the scope of protection claimed by this application.

Claims

1. A method for preparing a polytetrafluoroethylene glass fiber architectural membrane, characterized in that: The preparation method of the polytetrafluoroethylene glass fiber architectural membrane material includes: S1. Substrate forming: Glass fibers with a twist of 135±15 twists / meter are woven into glass fiber cloth after being twisted. (1) S2. High-temperature surface treatment: The glass fiber cloth (1) is baked at 350-380°C in an oven at a speed of 1-3 m / min to remove most of the sizing agent from the surface of the glass fiber. S3. Surface pretreatment: The silane coupling agent is poured into water to prepare a diluted aqueous dispersion A with an active silane weight ratio of 0.1~1.0%. The softener is diluted in water to form a diluted aqueous dispersion B with an active organosilicon content. The diluted aqueous dispersion A and diluted aqueous dispersion B are mixed and then the glass fiber cloth (1) is impregnated. Then, it is dried at a speed of 0.5~1.5m / min and a temperature of 100~120℃. The silane coupling agent is a silane coupling agent containing vinyl benzyl and amino organic functional groups and trimethoxysilyl inorganic functional groups. S4. Multiple PTFE impregnation and sintering: 3-5% by weight of polyethylene glycol octylphenyl ether emulsifier is added to a PTFE resin dispersion with a solid content of 60% and mixed evenly to form a PTFE resin emulsion. Glass microspheres are then added to the polytetrafluoroethylene resin emulsion and mixed evenly to form a polytetrafluoroethylene resin mixture. The glass microspheres are hollow glass microspheres of soda lime borosilicate with a diameter of 15-40 micrometers. The glass microspheres are added to the polytetrafluoroethylene resin emulsion at a weight ratio of 10-15%. The polytetrafluoroethylene resin dispersion is a colloid formed by suspending polytetrafluoroethylene resin with an average particle size of 0.2-0.3 micrometers in liquid water. The glass fiber cloth (1) is impregnated in the polytetrafluoroethylene resin mixture. The impregnated glass fiber cloth (1) is sintered at a temperature of 360-400℃ and a speed of 1-3 m / min. The sintering is repeated 8 times. After repeated sintering, a dense layer (3) of polytetrafluoroethylene resin is formed on the surface of the glass fiber cloth (1). S5. Surface treatment with polytetrafluoroethylene: The glass fiber cloth (1) with a dense layer (3) on the surface is impregnated and sintered in polytetrafluoroethylene at a temperature of 360~400℃ and a speed of 1~3m / min. After sintering, a polytetrafluoroethylene resin outer layer (4) is formed, thereby obtaining the polytetrafluoroethylene glass fiber building membrane. S6. Winding and forming: The finished product formed in step S5 is wound up by a winding machine to form polytetrafluoroethylene glass fiber building membrane material raw material, which is then packaged and stored.

2. The method for preparing a polytetrafluoroethylene glass fiber architectural membrane according to claim 1, characterized in that: The softener is a nonionic emulsion of polydimethylsiloxane.

3. The method for preparing a polytetrafluoroethylene glass fiber architectural membrane according to claim 1, characterized in that: The twisted yarn raw material of the glass fiber cloth (1) in step S1 is electronic grade glass fiber with a diameter of 3-6 micrometers.

4. The method for preparing a polytetrafluoroethylene glass fiber architectural membrane according to claim 2, characterized in that: The woven glass fiber cloth (1) has a unit area mass of not less than 450 g / m².

5. The method for preparing a polytetrafluoroethylene glass fiber architectural membrane according to claim 1, characterized in that: The softener in the diluted aqueous dispersion B has a weight ratio of 3-8%.

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