Building window anti-seepage structure and construction method thereof

Abstract

The building window anti-leakage structure comprises an auxiliary frame and a window frame, a sealing layer is arranged between the window frame and the auxiliary frame, the sealing layer is in a rectangular frame shape and sleeves the window frame, and the window frame and the auxiliary frame are matched to extrude the sealing layer; a first rectangular cavity opened towards the window frame is formed in the auxiliary frame, a second rectangular cavity opened towards the auxiliary frame is formed in the position, corresponding to the first rectangular cavity, of the window frame, and the first rectangular cavity and the second rectangular cavity jointly form a rectangular frame-shaped balance cavity; the auxiliary frame is arranged between the window frame and the window frame, a balance chamber and a sealing layer are sequentially arranged from outside to inside, the balance chamber is arranged around the window frame, a microporous breathable film is fixedly installed on the inner wall, close to the outside, of the balance chamber, the microporous breathable film is in a rectangular frame shape, and the microporous breathable film spans and covers a joint between the window frame and the auxiliary frame. The sealing effect is good, and water can be effectively prevented from entering a window and a room.

Description

Technical Field

[0001] This invention belongs to the field of building windows, and more specifically, relates to a waterproof structure for building windows and its construction method. Background Technology

[0002] With the rapid development of modern industrialized construction, building doors and windows, as an important component of the building's external envelope, directly affect the building's energy consumption, comfort, and lifespan. Among the various performance indicators of building doors and windows, water tightness and air tightness are key dimensions for measuring window quality. However, leakage problems (especially at the joints between the window frame and the wall, and at the connection between the window frame and the subframe) have long been a persistent problem in the construction industry, seriously affecting the user experience and the stability of the building structure.

[0003] Currently, the industry primarily uses sealant for waterproofing building windows. Traditional installation methods often employ single or multiple layers of silicone building sealant to seal the gaps between the subframe and the wall (or window frame). This method is a typical passive waterproofing approach, and its effectiveness highly depends on the continuity and adhesion strength of the sealant layer. However, in practical applications, sealant exposed to strong ultraviolet radiation, drastic seasonal temperature differences, and complex structural displacement environments for extended periods is highly susceptible to aging, embrittlement, or peeling cracks. Once tiny cracks appear in the sealant layer, rainwater can enter the room through siphoning, and this damage is often inconspicuous, making repair extremely difficult.

[0004] During strong winds and heavy rain, the wind pressure on the outside rises rapidly, while the internal cavity of the window or the interior remains under relatively low pressure. Because of the unavoidable assembly gaps at the joint between the window frame and the subframe, the huge pressure difference between the inside and outside creates a powerful suction pump, forcibly pushing or even spraying rainwater adhering to the edges of the gaps into the room. In most existing window structures, the cavity between the window frame and the subframe exists only as an installation allowance and has not undergone rigorous aerodynamic design. These cavities are usually messy and discontinuous, becoming weak points for waterproofing. When the external wind pressure suddenly increases dramatically, if there is no sealant at the joint between the window frame and the subframe on the outside, or if the sealant is aged and cracked, rainwater can easily seep into the room through the joint, leading to frequent leaks. Summary of the Invention

[0005] In view of the above-mentioned defects or improvement needs of the existing technology, the present invention provides a building window anti-leakage structure and its construction method, which has a good sealing effect and can effectively prevent water from entering the window and the room.

[0006] To achieve the above objectives, according to one aspect of the present invention, a waterproof structure for building windows is provided, comprising a subframe embedded in a wall opening and a window frame fixedly connected to the subframe, wherein: A sealing layer is provided between the window frame and the subframe. The sealing layer is rectangular and fits onto the window frame. The window frame and the subframe cooperate to press the sealing layer. The subframe has a first rectangular cavity opening towards the window frame, and the window frame has a second rectangular cavity opening towards the subframe at a position corresponding to the first rectangular cavity. The first and second rectangular cavities together form a rectangular frame-shaped balancing chamber. The balancing chamber and the sealing layer are arranged sequentially from the outside to the inside. The balancing chamber is arranged around the window frame. A microporous breathable membrane is fixedly installed on the inner wall of the balancing chamber near the outside. The microporous breathable membrane is rectangular frame-shaped and spans and covers the seam between the window frame and the subframe.

[0007] Preferably, both the subframe and the window frame are welded from multiple profiles; A magnetic sheet is fixedly installed on the inner wall of the balance chamber near the outside. Adsorption elements are fixed on the inner and outer peripheries of the microporous breathable membrane on the side away from the outside. The magnetic sheet and the adsorption elements cooperate to clamp the microporous breathable membrane, thereby fixing the microporous breathable membrane on the inner wall of the balance chamber near the outside. The adsorption element is an iron foil or a soft magnetic strip.

[0008] Preferably, it also includes an arc-shaped elastic scraper; Both the subframe and the window frame are welded together from multiple profiles. The inner and outer peripheries of the microporous breathable membrane are fixed to the inner wall of the balance chamber near the outside by means of adhesive bonding. The end of the arc-shaped elastic scraper furthest from the outside is fixedly installed on the balance chamber, and the end of the arc-shaped elastic scraper closest to the outside is a free end. The free end is used to press the microporous breathable membrane onto the inner wall of the balance chamber and move it on the microporous breathable membrane when the arc-shaped elastic scraper undergoes elastic deformation, thereby adhering the microporous breathable membrane to the balance chamber. After the microporous breathable membrane is installed in place, the free end presses the edge of the microporous breathable membrane tightly.

[0009] Preferably, the microporous breathable membrane is adhered to the inner wall of the balance chamber near the outside by neutral silicone adhesive, and the neutral silicone adhesive has a 100% tensile strength of 0.2MPa~0.35MPa at 23°C.

[0010] Preferably, the microporous breathable membrane is made of expanded polytetrafluoroethylene, polypropylene, or polyethylene, with a pore size of 0.1 μm to 10 μm.

[0011] Preferably, there are three sealing layers, which are an outer sealing layer, a middle sealing layer and an inner sealing layer in sequence, and the balance chamber, the outer sealing layer, the middle sealing layer and the inner sealing layer are arranged in sequence from the outside to the inside. An outer sealing layer mounting groove is provided on the subframe and / or the window frame, a middle sealing layer mounting groove is provided on the subframe and / or the window frame, and an inner sealing layer mounting groove is provided on the subframe and / or the window frame. The outer sealing layer, the middle sealing layer, and the inner sealing layer are respectively installed in the outer sealing layer mounting groove, the middle sealing layer mounting groove, and the inner sealing layer mounting groove.

[0012] Preferably, the outer sealing layer is a water-swellable waterproofing strip, the middle sealing layer is an EPDM foam composite strip, and the inner sealing layer is a silicone sealing strip.

[0013] Preferably, the space between the subframe and the wall is filled with polyurethane foam.

[0014] Preferably, it also includes a polyurethane waterproof coating applied to the wall opening, wherein the polyurethane foam is disposed on the polyurethane waterproof coating.

[0015] According to another aspect of the present invention, a construction method for the aforementioned building window waterproofing structure is also provided, comprising the following steps: 1) The subframe is pre-embedded in the wall opening, and polyurethane foam is filled between the subframe and the wall for initial sealing and fixation; 2) Install the sealing layer in the pre-set sealing layer mounting groove on the subframe and / or window frame; 3) Before the window frame enters the subframe, one edge of the microporous breathable membrane is pre-attached and fixed to the inner wall of the first rectangular cavity or the second rectangular cavity near the outside. 4) The window frame is installed into the subframe, so that the sealing layer is compressed to form a sealing barrier. At the same time, the first rectangular cavity and the second rectangular cavity are connected to form a balanced chamber. The microporous breathable membrane is fixed to the inner wall of the balanced chamber near the outside by means of adhesive or magnetic attraction. 5) Fix the window frame and the subframe together.

[0016] In summary, compared with the prior art, the above-described technical solutions conceived by this invention can achieve the following beneficial effects: 1) The building window waterproofing structure of the present invention uses a rectangular frame for the sealing layer, which is formed by the cooperation and compression of the window frame and the sub-frame, creating a continuous, closed barrier without dead angles. Compared with the traditional linear seal, this nested structure has stronger integrity and can generate more balanced radial and axial sealing pressure.

[0017] 2) The building window anti-leakage structure of the present invention includes a balancing chamber arranged around the window frame to form a closed loop. When external wind pressure acts on the outside of the window, the air entering the balancing chamber experiences a rapid decrease in velocity due to the sudden increase in the chamber's volume, converting dynamic pressure into static pressure. Through the action of the microporous breathable membrane, the pressure inside the balancing chamber can quickly reach dynamic equilibrium with the outdoor environment, eliminating leakage caused by the pressure difference between the inside and outside.

[0018] 3) The building window anti-leakage structure of the present invention has a microporous breathable membrane fixedly installed on the inner wall of the balance chamber near the outside, which gives the entire structure the function of intelligent breathing.

[0019] Microporous breathable membranes utilize the pore size characteristics of materials (typically at the micrometer level), with pores much larger than air molecules but much smaller than the diameter of water molecule clusters and liquid water droplets. This allows for molecular-level gas exchange between the interior of the window vent and the external environment. When gusts of wind or sudden pressure changes occur outside, air can freely pass through the microporous breathable membrane into the vent, balancing the outdoor wind pressure and the air pressure within the vent. This prevents rainwater from entering the vent through the seams between the subframe and the window frame, and further prevents it from seeping into the room. Liquid water, limited by its diameter and surface tension, cannot penetrate the microporous breathable membrane. This characteristic transforms the window from a passive blockage into an active absorber, changing from passive defense to active pressure regulation.

[0020] Microporous breathable membranes possess a certain degree of flexibility. When the frame structure formed by the subframe and window frame undergoes slight displacement due to wind load or temperature stress, the microporous breathable membrane can deform accordingly without breaking. This installation method, which spans the joints, not only covers the gaps most prone to leakage but also provides a soft connection sealing layer that is more durable and resilient than traditional rigid sealant.

[0021] 4) The leak-proof structure for building windows of the present invention, due to the combination of the balanced chamber and the microporous breathable membrane dissipating the main wind pressure load, allows the inner sealing layer to operate in an environment with minimal pressure. This avoids fatigue deformation and premature aging of the sealing layer under repeated high-pressure impacts, greatly extending the maintenance cycle of the entire sealing system.

[0022] Thanks to its microporous breathable membrane design that spans and covers the seams, along with multiple redundant seals, this solution offers exceptional tolerance for minor on-site installation deviations (such as uneven window frames or inconsistent seam gaps). Even with slight play at the connection between the subframe and the window frame, the microporous breathable membrane still provides insulation. This robust tolerance significantly enhances the overall quality of the waterproofed finished product.

[0023] This invention, based on the principle of pressure balance, enables it to adapt to various complex climates, from coastal typhoon-prone high-pressure areas to areas with frequent changes in cold air pressure, thus giving building doors and windows the ability to cope with complex dynamic leakage.

[0024] 5) The building window waterproofing structure of the present invention, comprising a subframe embedded in the wall opening and a window frame fixedly connected to the subframe, establishes a dual-stable boundary. First, the subframe embedded in the wall serves as a mechanical transition layer between the main building structure and the fine components of the doors and windows. This structure effectively mitigates the destructive effect of building settlement and thermal expansion / contraction on stress concentration at the sealing points, ensuring that the subsequent sealing layer can function on a relatively stable and deformation-controlled base. Second, the fixed connection between the window frame and the subframe, through mechanical limiting and tightening, ensures controllable tolerance of the fit gap between them. This precise gap control is a prerequisite for the functioning of all subsequent sealing features. Through a stable frame system, the sealing layer can obtain uniform and durable compressive stress, preventing local sealing failure caused by frame shaking or twisting, thereby greatly improving the long-term reliability of the door and window system.

[0025] 6) The leak-proof structure for building windows of this invention features a layout where the sealing layers are arranged sequentially from the outside to the inside, achieving a gradient filtration of leakage risks. The outer sealing layer, as the first line of defense, bears the main responsibility for dynamic pressure barrier. The middle and inner sealing layers provide redundancy and fine adjustment. Because the three sealing layers employ a cascaded structure, a micro-buffer space is formed between each layer. This space can progressively reduce the kinetic energy of external airflow, resulting in a decrease in wind and water pressure reaching the interior. This multi-layered interception mechanism ensures that even under extreme weather conditions, when the outer barrier is subjected to instantaneous high-pressure impacts, the inner system maintains a high degree of water tightness and air tightness. Attached Figure Description

[0026] Figure 1 This is a schematic elevation view of the present invention; Figure 2 This is a partial structural diagram of the present invention, which uses a magnetic sheet and an adsorption element to clamp the microporous breathable membrane. Figure 3 This is a partial structural diagram of the present invention when using an arc-shaped elastic scraper to press the microporous breathable membrane; Figure 4 This is a process flow diagram of the construction method of the present invention; In all the accompanying drawings, the same reference numerals denote the same technical features, specifically: 1. Subframe; 2. Window frame; 3. Fixing plate; 4. Glass; 5. Polyurethane foam; 6. Outer sealing layer; 7. Middle sealing layer; 8. Inner sealing layer; 9. Sealing layer assembly; 10. Balance chamber; 11. Microporous breathable membrane; 12. Magnetic sheet; 13. Adsorption component; 14. Arc-shaped elastic scraper. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0028] Reference Figure 1 , Figure 2 The building window waterproofing structure includes a subframe 1 embedded in a wall opening and a window frame 2 fixedly connected to the subframe 1. Both the subframe 1 and the window frame 2 are rectangular frames. The subframe 1 is preferably installed in the wall opening by fixing pieces 3 and screws. The subframe 1 is preferably fixedly connected to the window frame 2 by connecting pieces and screws. A glass 4 is installed inside the window frame 2.

[0029] A sealing layer is provided between the window frame 2 and the subframe 1. The sealing layer is rectangular and fits onto the window frame 2. The window frame 2 and the subframe 1 cooperate to press the sealing layer. The subframe 1 is provided with a first rectangular cavity that opens toward the window frame 2. The window frame 2 is provided with a second rectangular cavity that opens toward the subframe 1 at a position corresponding to the first rectangular cavity. The first rectangular cavity and the second rectangular cavity together form a rectangular frame-shaped balancing chamber 10. The balancing chamber 10 and the sealing layer are arranged sequentially from the outside to the inside. The balancing chamber 10 is arranged around the window frame 2. A microporous breathable membrane 11 is fixedly installed on the inner wall of the balancing chamber 10 near the outside. The microporous breathable membrane 11 is rectangular frame-shaped and spans and covers the seam between the window frame 2 and the subframe 1.

[0030] This invention successfully constructs a low-stress, highly reliable door and window anti-leakage system with air pressure self-regulation function. It not only establishes multiple interception barriers, but also eliminates the pressure source driving leakage, which helps to achieve long-term waterproofing of building doors and windows.

[0031] Furthermore, both the subframe 1 and the window frame 2 are welded from multiple profiles, which facilitates the subsequent installation of the microporous breathable membrane 11 inside them; the microporous breathable membrane 11 can be assembled from multiple strip membranes using a split structure.

[0032] A magnetic sheet 12 is fixedly installed on the inner wall of the balance chamber 10 near the outside. Adsorption elements 13 are fixed to the inner and outer peripheries of the microporous breathable membrane 11 on the side away from the outside. The magnetic sheet 12 and the adsorption elements 13 cooperate to clamp the microporous breathable membrane 11, thereby fixing the microporous breathable membrane 11 to the inner wall of the balance chamber 10 near the outside. The adsorption element 13 is an iron foil or a soft magnetic strip. Since the microporous breathable membrane 11 is rectangular, adsorption elements 13 can be fixed to both its inner and outer peripheries. The adsorption elements 13 on the inner and outer peripheries are both rectangular.

[0033] By cooperating with the magnetic sheet 12 and the adsorption element 13 (iron foil or soft magnetic strip), a continuous and uniform clamping force can be formed along the periphery of the microporous breathable membrane 11. The peripherally distributed clamping force avoids wrinkles or tensile stress concentration that may occur with point fixation, ensuring that the microporous breathable membrane 11 is flatly attached to the inner wall of the balance chamber 10, thereby ensuring the tightness and consistency of the sealing effect.

[0034] The iron foil and soft magnetic strip have excellent flexibility, which can adapt to the deformation of the microporous breathable membrane 11 and the slight undulations of the inner wall of the balance chamber 10, ensuring the tight coupling of the magnetic circuit. Its extremely small thickness will not occupy too much space in the balance chamber 10, effectively ensuring the aerodynamic volume of the balance chamber 10 and maintaining the air pressure balance efficiency.

[0035] The soft magnetic material and iron foil have good anti-aging properties in the closed chamber and can provide a long-lasting and stable adsorption force, ensuring that the microporous breathable membrane 11 can still firmly seal the seams under long-term wind pressure fluctuations without displacement or falling off.

[0036] The adhesive application method creates continuous support and sealing force along the periphery of the microporous breathable membrane 11. The adhesive penetrates and fills the microscopic irregularities on the profile surface, ensuring a molecular-level seal between the edge of the microporous breathable membrane 11 and the inner wall of the balance chamber 10, thus preventing bypass leakage at the joint.

[0037] The outer edge of the microporous breathable membrane 11 can be pre-fixed (attached) to the subframe 1, so only the magnetic sheet 12 needs to be set on the window frame, and only the magnetic sheet 12 and the adsorption member 13 need to cooperate to clamp the inner edge of the microporous breathable membrane 11; or the inner edge of the microporous breathable membrane 11 can be pre-fixed to the window frame 2, so only the magnetic sheet 12 needs to be set on the subframe 1, and only the magnetic sheet 12 and the adsorption member 13 need to cooperate to clamp the outer edge of the microporous breathable membrane 11; or, magnetic sheets 10 can be set on both the subframe 1 and the window frame 2, and adsorption members 13 can be set on both the outer and inner periphery of the microporous breathable membrane 11.

[0038] Furthermore, refer to Figure 3 The present invention also includes an arc-shaped elastic scraper 14; Both the subframe 1 and the window frame 2 are welded from multiple profiles, which facilitates the subsequent installation of the microporous breathable membrane 11 inside them; the microporous breathable membrane 11 can be assembled from multiple strip membranes using a split structure.

[0039] The inner and outer peripheries of the microporous breathable membrane 11 are fixed to the inner wall of the balance chamber 10 near the outside by means of adhesive. Since the microporous breathable membrane 11 is a rectangular frame, its inner and outer peripheries can be attached to the inner wall of the balance chamber 10. At least one arc-shaped elastic scraper 14 is arranged on each side of the rectangular balance chamber 10. The end of the arc-shaped elastic scraper 14 furthest from the outside is fixedly installed on the balance chamber 10. The end of the arc-shaped elastic scraper 14 closest to the outside is a free end. The free end is used to press the microporous breathable membrane 11 onto the inner wall of the balance chamber 10 and move it on the microporous breathable membrane 11 when the arc-shaped elastic scraper 14 undergoes elastic deformation, thereby adhering the microporous breathable membrane 11 to the balance chamber 10. After the microporous breathable membrane 11 is installed in place, the free end presses the edge of the microporous breathable membrane 11 tightly.

[0040] If the outer edge of the microporous breathable membrane 11 is pre-fixed to the subframe 1, then the end of the arc-shaped elastic scraper 14 away from the outside is fixed to the subframe 1, and the free end presses against the microporous breathable membrane 11 and scrapes against it, so that the microporous breathable membrane 11 is attached to the window frame 2 and presses against the inner edge of the microporous breathable membrane 11; conversely, if the inner edge of the microporous breathable membrane 11 is pre-fixed to the window frame 2, then the end of the arc-shaped elastic scraper 14 away from the outside is fixed to the window frame 2, and the free end presses against the microporous breathable membrane 11 and scrapes against it, so that the microporous breathable membrane 11 is adhered to the subframe 1 and presses against the outer edge of the microporous breathable membrane 11.

[0041] The balancing chamber 10 is typically narrow and sealed, making it impossible for traditional tools and manpower to reach in for effective pressing. An arc-shaped elastic scraper 14 is fixedly mounted on the balancing chamber 10 at one end, with the other end being a free end near the outside. This design transforms external intervention into internal integration, utilizing the mechanical movement of the arc-shaped elastic scraper 14 itself to complete the installation task.

[0042] When the free end of the arc-shaped elastic scraper 14 undergoes elastic deformation, it generates a continuous and stable centripetal force, firmly pressing the microporous breathable membrane 11 against the inner wall of the balance chamber 10. This elastic pressure is adaptive and can compensate for minor unevenness on the profile surface, ensuring sufficient wetting and adhesion between the adhesive and the substrate.

[0043] The free end of the arc-shaped elastic scraper 14 can move on the microporous breathable membrane 11. This moving pressing technique is similar to the leveling operation of a manual scraper. During the movement, it can effectively remove air bubbles and excess adhesive between the microporous breathable membrane 11 and the profile, ensuring that the adhesive layer is flat and free of voids.

[0044] The curved elastic scraper 14 utilizes the mechanical displacement of the window frame 2 as it enters the subframe 1 as a driving force (the inner wall of the balance chamber 10 near the outside can compress the curved elastic scraper 14, causing it to elastically deform, pressing the microporous breathable membrane 11 and scraping it by moving along the membrane 11). When the window frame 2 is pushed into place, the curved elastic scraper 14 deforms under pressure and slides along the membrane surface, achieving an integrated effect of assembly and installation, and positioning and pasting, which greatly reduces the dependence on the operator's skills.

[0045] After the microporous breathable membrane 11 is installed in place, the free end presses against the edge of the microporous breathable membrane 11. The continuous extrusion force provided by the free end can counteract the tensile stress generated by wind pressure, preventing the edge of the microporous breathable membrane 11 from curling or peeling due to uneven force on the adhesive layer. Although the microporous breathable membrane 11 is mainly bonded with neutral silicone adhesive, the free end provides additional mechanical restraint, upgrading the bonding interface from simple chemical bonding to a dual stabilizing mechanism of mechanical pressing + chemical bonding. Under strong wind loads, the building structure will experience slight vibrations or displacements, and the joint width between the window frame 2 and the sub-frame 1 will also change accordingly. Due to the arc-shaped elastic scraper 14's arc-shaped elastic characteristics, its free end can generate a continuous and stable centripetal force. When the sub-frame 1 or window frame 2 experiences slight shaking, the arc-shaped elastic scraper 14 can compensate for the gap changes in real time through its own elastic deformation, ensuring that the pressure on the edge of the microporous breathable membrane 11 remains constant, preventing the microporous breathable membrane 11 from fatigue displacement due to the reciprocating motion of the sub-frame 1 or window frame 2.

[0046] Furthermore, the microporous breathable membrane 11 is adhered to the inner wall of the balance chamber 10 near the outside using neutral silicone adhesive, and the neutral silicone adhesive has a 100% tensile strength of 0.2 MPa to 0.35 MPa at 23°C. Neutral silicone adhesives such as Dow Corning (DOWSIL) 791 / 795 series and Oriental Yuhong (YS-109) can be used.

[0047] Neutral silicone sealant exhibits excellent adhesion to aluminum alloy, PVC, and other window frame profiles 2 and the polymer microporous breathable membrane 11, forming a continuous and high-strength sealing interface. This ensures that the microporous breathable membrane 11 can firmly span and cover the joint between the window frame 2 and the subframe 1, preventing detachment or edge leakage under extreme wind pressure conditions. Neutral silicone sealant also possesses excellent resistance to ultraviolet radiation, high and low temperatures, and moisture. Even under long-term exposure to complex external environments, the adhesive layer maintains stable performance without becoming brittle or softening, thus guaranteeing the overall design life of the leak-proof structure.

[0048] The window frame 2 and the subframe 1 may experience relative displacement due to thermal expansion and contraction caused by temperature differences or minor vibrations caused by gusts of wind. The low modulus of 0.2MPa to 0.35MPa ensures that the adhesive layer has extremely high flexibility and ductility, and can absorb these displacement stresses through its own elastic deformation without generating excessive tensile force.

[0049] The microporous breathable membrane 11 is typically extremely thin and has a specific microstructure. If the adhesive layer of the bonding neutral silicone sealant is too hard, the stress generated by displacement will directly act on the microporous breathable membrane 11, easily causing it to tear from the bonding edge. This solution, by precisely controlling the tensile strength of the sealant, allows the sealant layer to act as a stress buffer, uniformly distributing the stress and greatly reducing the risk of damage to the microporous breathable membrane 11, thus ensuring the continuity of the pressure balancing function.

[0050] The low modulus means that the neutral silicone adhesive exerts minimal reaction force on the bonding substrate when stretched. This ensures that the adhesive layer remains firmly adhered to the inner wall of the balance chamber 10 even when the frame undergoes a wide range of displacement, effectively preventing the neutral silicone adhesive from peeling off from the profile interface due to internal stress overload and maintaining the airtight integrity of the balance chamber 10.

[0051] The reliability of the adhesive layer is a prerequisite for the functioning of the balance chamber 10. Through the precise fixation of the low-modulus silicone sealant, the microporous breathable membrane 11 can always maintain a flat and tight sealing state, ensuring that air molecules can exchange through the micropores while liquid water cannot pass through the seams. This pressure balance mechanism, which makes the pressure inside the balance chamber tend to be balanced with the outside pressure, can be accurately achieved under various complex working conditions.

[0052] This quantified range of tensile strength provides a clear technical benchmark for industrialized construction. The selection of high-performance series such as Dow Corning 791 / 795, combined with precise mechanical parameter requirements, ensures a high degree of certainty and consistency in the sealing system after on-site installation, significantly improving the leak-proof quality of building windows throughout their entire lifespan.

[0053] Furthermore, the microporous breathable membrane 11 is made of expanded polytetrafluoroethylene, polypropylene, or polyethylene, with a pore size of 0.1 μm to 10 μm.

[0054] Because the diameter of air molecules is much smaller than the diameter of the micropores (approximately 0.0004 μm), air molecules can smoothly pass through the microporous breathable membrane 11 and enter the balance chamber 10. This allows the air pressure inside the balance chamber 10 to quickly and in real time match the outdoor wind pressure during strong winds and heavy rain. By maintaining the dynamic balance between the balance chamber 10 and the outdoor wind pressure through the microporous breathable membrane 11, the driving force for leakage—the pressure difference between the inside and outside—is eliminated, preventing waterproof rainwater from seeping from the outside to the inside through the joint between the subframe 1 and the window frame 2.

[0055] Even at the very small pore size limit (10 μm), the diameter of liquid water droplets is much larger than these micropores due to their surface tension. Water molecule clusters cannot penetrate the microporous breathable membrane 11, thus achieving a waterproof wall that is also breathable.

[0056] Expanded polytetrafluoroethylene (ePTFE) material has extremely low surface energy and exhibits strong hydrophobic properties. When liquid water comes into contact with the membrane surface, it forms a large contact angle and quickly forms water droplets that slide off, effectively preventing water accumulation or penetration on the membrane surface and further enhancing the leak-proof rating at the joints.

[0057] These polymer materials exhibit excellent stability within the internal environment of the balance chamber 10. They can resist chemical corrosion caused by residual acid rain, salt spray, or humid and hot environments at the window seams, ensuring the integrity of the microporous structure does not collapse or become blocked throughout its entire life cycle, thus maintaining a long-lasting pressure balance function.

[0058] The joint between the window frame 2 and the subframe 1 is prone to capillary water absorption. The microporous breathable membrane 11 crosses and covers this joint, and by utilizing the hydrophobic microporous structure of the material itself, the capillary path is completely cut off, preventing rainwater from entering the room through the crack due to capillary pressure.

[0059] The pore size range of 0.1μm to 10μm can effectively intercept most of the fine dust and particulate matter in the atmosphere from entering the balance chamber 10. This not only protects the subsequent middle sealing layer 7 and inner sealing layer 8 from the corrosion of pollutants, but also ensures the cleanliness of the internal environment of the balance chamber 10 and reduces the risk of drainage hole blockage.

[0060] Under various complex wind pressure conditions, the accuracy and response speed of the pressure balancing mechanism of the microporous breathable membrane 11 and the balance chamber 10 enable the stepped multi-seal system of the entire window to transform from passive leak sealing to active pressure regulation, which greatly improves the water tightness and safety redundancy of building windows under extreme climatic conditions.

[0061] Furthermore, there are three sealing layers, namely an outer sealing layer 6, a middle sealing layer 7, and an inner sealing layer 8, which together form a sealing layer group 9. Each sealing layer is rectangular in shape. The balance chamber 10, the outer sealing layer 6, the middle sealing layer 7, and the inner sealing layer 8 are arranged sequentially from the outside to the inside.

[0062] The subframe 1 and / or the window frame 2 are provided with an outer sealing layer 6 mounting groove, the subframe 1 and / or the window frame 2 are provided with a middle sealing layer 7 mounting groove, and the subframe 1 and / or the window frame 2 are provided with an inner sealing layer 8 mounting groove. The outer sealing layer 6, the middle sealing layer 7 and the inner sealing layer 8 are respectively installed in the outer sealing layer 6 mounting groove, the middle sealing layer 7 mounting groove and the inner sealing layer 8 mounting groove.

[0063] The three-layer sealing layer creates multiple barriers between the window frame 2 and the subframe 1. The outer sealing layer 6 initially intercepts external atmospheric pressure, eliminating most of the dynamic leakage force driven by wind pressure; the middle sealing layer 7, as the main seal, further enhances airtightness and watertightness under lower residual pressure; and the inner sealing layer 8, as the final airtight defense, ensures absolute sealing of the indoor environment. This stepped layout allows each layer of seal to perform optimally under a specific pressure gradient. Even if one line of defense is affected by local fluctuations, the other lines of defense can still provide sufficient redundancy protection, greatly improving the overall system robustness of the window.

[0064] The gaps formed by the three sealing layers and the frame profile actually create multiple independent buffer cavities. When external wind pressure fluctuates drastically, these buffer cavities can effectively attenuate the transmission of pressure waves and prevent external moisture or air from penetrating the sealing system through pulse effects, thus achieving a stable and efficient sealing effect.

[0065] The specialized mounting groove design provides precise positioning for each sealing layer. During the assembly of window frame 2 and subframe 1, the mounting groove ensures the accuracy of the sealing layer's position in the entire circumference, preventing skewing or displacement that may occur due to manual application, thereby ensuring uniform pressure on the sealing layer.

[0066] The sealing layer is installed within the slot, its root strongly mechanically restrained by the profile slot wall. Even under vibrations from prolonged window opening and closing or frame displacement caused by strong wind pressure, the sealing layer remains firmly in its predetermined position, without curling, detachment, or misalignment. This mechanical locking effect ensures the geometric integrity of the sealing barrier throughout its entire lifespan.

[0067] By designing a reasonable installation groove depth and sealing layer size, the pre-compression rate of each sealing layer can be precisely set. This scientific stress distribution avoids fatigue and permanent deformation of the sealing layer due to excessive compression, and also prevents poor sealing due to insufficient compression, thereby maintaining the material's long-term elastic resilience and sealing performance.

[0068] The outer sealing layer 6 not only blocks rainwater but also creates a protected microenvironment for the middle and inner sealing layers 8. Because the outer layer intercepts most of the dust, acid rain, and external pollution, the precision mounting groove and sealing layer on the inner side are not easily affected by corrosion or debris accumulation, thus maintaining the cleanliness and efficiency of the sealing interface and significantly extending the maintenance cycle of the entire sealing system.

[0069] Through the systematic integration of three layers of sealing and three mounting grooves, a qualitative leap has been achieved from a single seal to systemic defense. This solution not only ensures the stability and durability of the sealing interface at the micro level, but also constructs a high-tolerance, high-stability, and high-reliability window leak-proof underlying architecture at the macro level.

[0070] Furthermore, the outer sealing layer 6 is a water-swellable waterproofing strip, the middle sealing layer 7 is an EPDM foam composite strip, and the inner sealing layer 8 is a silicone sealing strip.

[0071] The outer sealing layer 6 uses a water-swellable sealing strip, which, together with the balance chamber 10, forms a redundant and synergistic system of air pressure regulation and physical sealing. Under normal operating conditions, the balance chamber 10 dissipates the main leakage dynamics; however, in cases of extreme and continuous rainfall or when the building structure undergoes minor displacement due to long-term use, leading to increased gaps, the outer sealing layer 6 can capture minute amounts of infiltrated water vapor or condensate and generate controlled expansion, actively filling the assembly gaps. This mechanism ensures that the system maintains a very high leak-proof safety factor even under dynamic stress environments, rather than relying solely on a single pressure balancing function.

[0072] The intermediate sealing layer 7 is an EPDM (ethylene propylene diene monomer) foam composite strip. EPDM foam material has extremely high elastic recovery and extremely low permanent deformation. Under the combined compression of the window frame 2 and the subframe 1, it can provide a long-lasting and stable sealing pressure. Even under long-term exposure to vibrations from opening and closing or minor displacements of the building structure, the closed-cell air bubbles inside its foam structure can provide continuous mechanical compensation like countless miniature springs, ensuring long-term stability of airtightness and watertightness. The foam composite structure gives the intermediate sealing layer 7 better flexibility, allowing it to perfectly conform to the surface of complex irregular profiles and eliminate leakage channels at the microscopic level.

[0073] The silicone material of the inner sealing layer 8 is renowned for its exceptional flexibility and resistance to compression deformation. As the last line of defense, it achieves a high degree of interfacial adhesion with minimal clamping force, thus establishing a near-absolute airtight barrier on the indoor side to prevent even minor leaks of indoor and outdoor air. Silicone possesses excellent aging and weather resistance, remaining soft and non-hardening even in environments with significant temperature differences between indoors and outdoors. This ensures that the inner sealing layer 8 maintains optimal working condition throughout its entire lifespan, forming a stable gradient protection system together with the outer and middle layers.

[0074] The differentiated material configuration of the outer sealing layer 6, the middle sealing layer 7, and the inner sealing layer 8 creates a complementary mechanical system. The outer sealing layer 6 utilizes expansion force for active leak sealing, the middle sealing layer 7 utilizes resilience to bear the main pressure, and the inner sealing layer 8 utilizes flexibility for precise sealing. This scientific combination of material properties gives the sealing system a strong environmental adaptability.

[0075] All three materials possess excellent weather resistance and each targets different threats. This combination not only ensures the sealing quality of every contact surface at a microscopic level, but also ensures that the entire window system has a high degree of safety redundancy when dealing with wind pressure impacts, rainwater infiltration, and building deformation at a macroscopic level.

[0076] Furthermore, polyurethane foam 5 is used to fill the space between the subframe 1 and the wall.

[0077] The polyurethane foam 5 exhibits strong expansion and penetration during construction, effectively filling the minute gaps between the subframe 1 and irregular wall openings. After curing, the polyurethane foam 5 forms a continuous and uniform support surface, evenly transferring the window system's weight and wind load to the main building structure. This circumferential fixing method avoids stress concentration issues that can occur with traditional mechanical fasteners, significantly improving the overall stability of the subframe 1 installation.

[0078] The polyurethane foam 5 not only serves as a filler, but its strong adhesion also forms a solid composite whole between the subframe 1 and the wall. Under severe external vibration or dynamic wind pressure, this interface provides the necessary mechanical tension to ensure that the subframe 1 does not shift, providing a solid reference for the subsequent precise alignment of the window frame 2 and the tightening of the sealing layer.

[0079] Furthermore, it also includes a polyurethane waterproof coating applied to the wall opening, wherein the polyurethane foam 5 is disposed on the polyurethane waterproof coating.

[0080] Polyurethane waterproof coatings are applied in liquid form to the surface of wall openings, utilizing their excellent wetting and penetrating properties to enter the capillary pores of concrete or masonry substrates. After curing, the polyurethane waterproof coating forms a dense, seamless, flexible waterproof membrane on the surface of the wall opening substrate.

[0081] The polyurethane foam 5, filled on top of the polyurethane waterproof coating, utilizes its expansion properties to solve the problem of filling large gaps between the subframe 1 and the wall. This combination of coating film and foam ensures that the installation nodes have both fine protection against the micropores of the substrate and a thick barrier against structural gaps, forming a systematic, stepped defense effect.

[0082] Because both the polyurethane waterproof coating and polyurethane foam 5 use polyurethane (PU) as their base material, this material consistency generates extremely strong chemical affinity. During the curing process, the isocyanate groups in polyurethane foam 5 can undergo a secondary reaction with the active groups on the surface of the underlying polyurethane waterproof coating. This chemical-level bonding effect allows the two materials to fuse together at the interface, eliminating the delamination phenomenon commonly seen between dissimilar materials. This homogeneous bonding interface greatly enhances the system's resistance to peeling. When the building structure is subjected to alternating stresses caused by vibration, wind pressure loads, or thermal expansion and contraction, the polyurethane waterproof coating and polyurethane foam 5 can deform synchronously as a composite unit, effectively preventing the formation of minute gaps at the deepest points of the installation joints, thereby ensuring the continuity and durability of the overall seal.

[0083] Reference Figure 4 According to another aspect of the present invention, a construction method for the aforementioned building window waterproofing structure is also provided, comprising the following steps: 1) The subframe 1 is pre-embedded in the wall opening, and polyurethane foam is filled between the subframe 1 and the wall for initial sealing and fixation; by pre-embedding the subframe 1 and filling it with polyurethane foam, a stable frame with a good sealing foundation is provided for the installation of subsequent components.

[0084] 2) Install the sealing layer in the pre-set sealing layer mounting groove on the subframe 1 and / or window frame 2; pre-set the sealing layer mounting groove and install the sealing layer before the subframe 1 or window frame 2 arrives on site. This process of mounting the groove first and then applying the sealant, which can be partially completed in the factory, ensures extremely precise geometric positioning of the outer, middle, and inner sealing barriers, avoiding the displacement or breakage of the sealing layer caused by the influence of ambient temperature and humidity during traditional on-site sealant application, and greatly improving the reliability and consistency of the multi-seal system.

[0085] 3) Before the window frame 2 enters the subframe 1, one edge of the microporous breathable membrane 11 is pre-attached and fixed to the inner wall of the first rectangular cavity or the second rectangular cavity near the outside. Pre-attaching is convenient and ensures a firm bond. The balance chamber 10 after the window is closed is extremely small, making it difficult to insert tools. By pre-fixing one edge, construction workers can complete the initial positioning and sealing of the microporous breathable membrane 11 in a spacious and clear environment. This step ensures sufficient flatness of the microporous breathable membrane 11 when crossing the joint between the window frame 2 and the subframe 1, providing necessary tension allowance for precise application of the side edge in subsequent step 4), and preventing air pressure leakage caused by wrinkles in the microporous breathable membrane 11 within the balance chamber 10.

[0086] 4) The window frame 2 is installed into the sub-frame 1, causing the sealing layer to be compressed to form a sealing barrier. Simultaneously, the first rectangular cavity and the second rectangular cavity are aligned to form a balanced chamber. The microporous breathable membrane 11 is fixed to the inner wall of the balanced chamber 10 near the outside by adhesive or magnetic attraction. When the window frame 2 is pushed into the sub-frame 1, the pre-installed outer sealing layer 6, middle sealing layer 7, and inner sealing layer 8 are automatically compressed under mechanical force to form multiple sealing barriers, achieving sealing upon assembly. This process requires no additional sealing operations, significantly reducing on-site installation time.

[0087] The microporous breathable membrane 11 is fixed to the inner wall of the balance chamber 10 near the outside by adhesive or magnetic attraction. This feature allows the microporous breathable membrane 11 to be finally positioned by magnetic attraction or the contact force of the pre-set adhesive layer at the moment the balance chamber 10 closes. This method uses the displacement of the frame to replace manual pressing, solving the technical pain point of being unable to operate manually due to the blockage of the balance chamber 10, and ensuring the immediate effectiveness of the air pressure balance function inside the balance chamber 10.

[0088] 5) Fix the window frame 2 to the subframe 1 together. After the window frame 2 and the subframe 1 are fixed, the microporous breathable membrane 11 has been firmly laid across the joint. This construction state ensures that air molecules can exchange through the micropores to balance the pressure inside the chamber with the outdoor pressure, while liquid water is blocked, thus eliminating the pressure source driving rainwater leakage from the very first moment of delivery.

[0089] The above construction method not only solves the installation problem under limited space in engineering practice, but also ensures that the sealing layer can accurately, efficiently and effectively perform its technical functions of waterproofing, airtightness and air pressure balance from the process level.

[0090] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A waterproof structure for building windows, characterized in that, This includes a subframe embedded in a wall opening and a window frame fixedly connected to the subframe, wherein: A sealing layer is provided between the window frame and the subframe. The sealing layer is rectangular and fits onto the window frame. The window frame and the subframe cooperate to press the sealing layer. The subframe has a first rectangular cavity opening towards the window frame, and the window frame has a second rectangular cavity opening towards the subframe at a position corresponding to the first rectangular cavity. The first and second rectangular cavities together form a rectangular frame-shaped balancing chamber. The balancing chamber and the sealing layer are arranged sequentially from the outside to the inside. The balancing chamber is arranged around the window frame. A microporous breathable membrane is fixedly installed on the inner wall of the balancing chamber near the outside. The microporous breathable membrane is rectangular frame-shaped and spans and covers the seam between the window frame and the subframe.

2. The building window waterproofing structure according to claim 1, characterized in that, Both the subframe and the window frame are welded together from multiple profiles. A magnetic sheet is fixedly installed on the inner wall of the balance chamber near the outside. Adsorption elements are fixed on the inner and outer peripheries of the microporous breathable membrane on the side away from the outside. The magnetic sheet and the adsorption elements cooperate to clamp the microporous breathable membrane, thereby fixing the microporous breathable membrane on the inner wall of the balance chamber near the outside. The adsorption element is an iron foil or a soft magnetic strip.

3. The building window waterproofing structure according to claim 1, characterized in that, It also includes an arc-shaped elastic scraper; Both the subframe and the window frame are welded together from multiple profiles. The inner and outer peripheries of the microporous breathable membrane are fixed to the inner wall of the balance chamber near the outside by means of adhesive bonding. The end of the arc-shaped elastic scraper furthest from the outside is fixedly installed on the balance chamber, and the end of the arc-shaped elastic scraper closest to the outside is a free end. The free end is used to press the microporous breathable membrane onto the inner wall of the balance chamber and move it on the microporous breathable membrane when the arc-shaped elastic scraper undergoes elastic deformation, thereby adhering the microporous breathable membrane to the balance chamber. After the microporous breathable membrane is installed in place, the free end presses the edge of the microporous breathable membrane tightly.

4. The building window waterproofing structure according to claim 3, characterized in that, The microporous breathable membrane is bonded to the inner wall of the balance chamber near the outside by neutral silicone adhesive, and the neutral silicone adhesive has a 100% tensile strength of 0.2MPa~0.35MPa at 23°C.

5. The building window waterproofing structure according to claim 1, characterized in that, The microporous breathable membrane is made of expanded polytetrafluoroethylene, polypropylene, or polyethylene, with a pore size of 0.1μm to 10μm.

6. The building window waterproofing structure according to claim 1, characterized in that, There are three sealing layers, which are, in order, an outer sealing layer, a middle sealing layer, and an inner sealing layer. The outer sealing layer, the middle sealing layer, and the inner sealing layer are arranged in sequence from the outside to the inside. An outer sealing layer mounting groove is provided on the subframe and / or the window frame, a middle sealing layer mounting groove is provided on the subframe and / or the window frame, and an inner sealing layer mounting groove is provided on the subframe and / or the window frame. The outer sealing layer, the middle sealing layer, and the inner sealing layer are respectively installed in the outer sealing layer mounting groove, the middle sealing layer mounting groove, and the inner sealing layer mounting groove.

7. The building window waterproofing structure according to claim 6, characterized in that, The outer sealing layer is a water-swellable waterproofing strip, the middle sealing layer is an EPDM foam composite strip, and the inner sealing layer is a silicone sealing strip.

8. The building window waterproofing structure according to claim 1, characterized in that, The space between the subframe and the wall is filled with polyurethane foam.

9. The building window waterproofing structure according to claim 8, characterized in that, It also includes a polyurethane waterproof coating applied to the opening in the wall, wherein the polyurethane foam is applied to the polyurethane waterproof coating.

10. A construction method for the building window waterproofing structure according to any one of claims 1 to 9, characterized in that, Includes the following steps: 1) The subframe is pre-embedded in the wall opening, and polyurethane foam is filled between the subframe and the wall for initial sealing and fixation; 2) Install the sealing layer in the pre-set sealing layer mounting groove on the subframe and / or window frame; 3) Before the window frame enters the subframe, one edge of the microporous breathable membrane is pre-attached and fixed to the inner wall of the first rectangular cavity or the second rectangular cavity near the outside. 4) The window frame is installed into the subframe, so that the sealing layer is compressed to form a sealing barrier. At the same time, the first rectangular cavity and the second rectangular cavity are connected to form a balanced chamber. The microporous breathable membrane is fixed to the inner wall of the balanced chamber near the outside by means of adhesive or magnetic attraction. 5) Fix the window frame and the subframe together.

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