Building firewall composite core material and recovery method thereof

Abstract

The invention discloses a fireproof and heat-insulating composite core material for buildings, which is formed by compounding a nano microporous heat-insulating plate (12-18mm) and a gypsum heat-absorbing layer (gt; 3mm) arranged on a cold surface, and through a synergistic heat-absorbing and heat-insulating mechanism, the temperature rise of an unexposed surface is less than or equal to 180 DEG C and the fire-resistant integrity is more than or equal to 120 minutes in a 950 DEG C fire surface test. Compared with a traditional scheme, the use amount of high-cost materials is reduced by 25% or above, the total thickness is reduced to 15-21 mm, and the functions of sound insulation, electromagnetic shielding and environment-friendly recycling are supported. According to the scheme, the cost is reduced by 30%-40%, and GB / T 9978 and EN 1634-1 certification is passed, so that the method is suitable for scenes such as fireproof doors and partition walls and has remarkable economic benefits and application prospects.

Description

Technical Field

[0001] The present invention relates to the technical field of building fireproof materials, and in particular to a building fireproof and heat-insulating composite core material and a recycling method thereof. Background Art

[0002] With the continuous improvement of building safety standards, the requirements for fireproofing and heat insulation performance of building components such as fire doors and fireproof partitions are becoming increasingly stringent, especially the need to meet the fire resistance integrity standard of 120 minutes or more. At present, the fireproofing and heat insulation materials widely used in the industry are mainly divided into two categories: Rockwool insulation solution: Rockwool with a thickness of approximately 50 mm was used as the insulation layer. While this material offered the advantage of low cost, its large size significantly increased the overall size of the fireproof components, making installation difficult and occupying excessive building space, making it difficult to meet the requirements of modern architecture for lightweight and compact design.

[0003] Nanoporous insulation board solution: Thermal insulation is achieved through nanoporous insulation boards with a thickness of 15-25 mm. While this material can effectively reduce the thickness of components, its high raw material cost and complex preparation process significantly increase overall costs, limiting its application in large-scale construction projects.

[0004] Furthermore, existing technologies often employ heat-absorbing materials (such as vermiculite or calcium silicate boards) on the hot side of the insulation layer to improve fire resistance. However, these materials are prone to rapid dehydration or structural failure in high-temperature environments (e.g., hot surface temperatures exceeding 1000°C in the early stages of a fire), resulting in a sharp drop in heat absorption efficiency and an inability to maintain stable performance throughout a fire.

[0005] The above technical solutions generally have the following problems: The contradiction between thickness and cost: the excessive thickness of rock wool and the high cost of nano-porous insulation board are difficult to balance; Efficiency decay of heat-absorbing materials: The heat-absorbing materials installed on the hot surface are unstable at high temperatures, and their fire-proof performance decreases significantly over time; Insufficient comprehensive performance: Existing single materials or simple composite structures cannot simultaneously meet the requirements of efficient thermal insulation, long-term heat absorption and economy.

[0006] Therefore, there is an urgent need to develop a new type of fireproof and heat-insulating composite core material that can significantly reduce material usage and production costs while ensuring fire resistance, and solve the problem of high-temperature failure of heat-absorbing materials through structural optimization to meet the comprehensive needs of modern buildings for safety, economy and space efficiency. Summary of the Invention

[0007] In order to overcome the above-mentioned defects of the prior art, an embodiment of the present invention provides a building fireproof and heat-insulating composite core material and a recycling method thereof.

[0008] To achieve the above objectives, the invention has the following innovative features: comprising a heat insulating layer and a heat absorbing layer; The thermal insulation layer is a nano-microporous insulation board with a thickness of 12mm to 18mm, a thermal conductivity of less than 0.020W / (m·K), and a density of 150kg / m³ to 350kg / m³; The heat-absorbing layer is a fire-proof gypsum board or gypsum fire-proof heat-absorbing coating with a thickness greater than 3mm, fixed on the cold side of the insulation layer; The cold side is the contact area of ​​the composite core material that is not exposed to fire in a fire, and its operating temperature range is 80℃ to 140℃; The heat absorption layer releases crystalline water at high temperature, so that the temperature rise curve of the back-fire surface remains flat within 120 minutes, the tail temperature does not exceed 180°C, and the tail temperature is reduced by 15% to 20% compared with the solution without a heat absorption layer.

[0009] Furthermore, the fireproof gypsum board is a composite of any one or more of paper-faced gypsum board, fiber-faced gypsum board, and cloth-faced gypsum board.

[0010] Furthermore, the content of aluminum sulfate dihydrate in the above-mentioned gypsum fire-retardant and heat-absorbing coating is greater than 70%.

[0011] Furthermore, the porosity of the nanoporous thermal insulation board is 85% to 92%, and the pore size distribution is 10nm to 50nm.

[0012] Furthermore, the total thickness of the above-mentioned composite core material is 15mm to 22mm, and in the wet heat cycle test, after 100 cycles under conditions of relative humidity of 95%, and in the freeze-thaw cycle test, after 50 cycles under conditions of a temperature range of -20°C to 50°C, the temperature rise of the back-fire surface still does not exceed 200°C, and the compressive strength decrease rate is less than 10%.

[0013] Furthermore, an optional functional layer is added between the heat absorption layer and the heat insulation layer. The thickness of the optional functional layer does not exceed 3 mm, and the total thickness of the composite core material is still 15-22 mm.

[0014] Furthermore, the optional functional layer is a sound insulation layer or an electromagnetic shielding layer.

[0015] Furthermore, when the composite core material is used in fire doors, its overall structure is certified by GB / T 9978 standard, with a fire resistance integrity of 120 minutes to 180 minutes, and the door body thickness does not exceed 50mm.

[0016] Furthermore, the surface of the nanoporous insulation board of the composite core material is coated with hydrophobic glass fiber cloth or an equivalent hydrophobic coating, with a contact angle greater than 120 degrees, and the thermal conductivity coefficient change rate is less than 5% after exposure to a salt spray test for 240 hours.

[0017] The present invention provides a method for recycling composite core materials: After the waste composite core material is crushed, the steel plate component is separated by magnetic separation, and the gypsum component and the nano-porous insulation board component are separated by flotation; The gypsum component is used for the preparation of recycled gypsum board, with a recovery rate of not less than 90%; The components of the nanoporous insulation board are crushed and used as lightweight aggregate for concrete or roadbed filler, with a recovery rate of not less than 85%.

[0018] The beneficial effects of the present invention are: 1. Fire resistance performance: passed the 950℃ hot surface test for 120 minutes, the back-fire surface temperature rise ≤180℃, and the fire resistance integrity ≥120 minutes; 2. Environmental adaptability: After humidity and heat cycle (RH ≥ 95%, 100 times) and freeze-thaw test (-20℃~50℃, 50 times), the temperature rise is still ≤ 200℃, and the compressive strength decrease rate is <10%; 3. Economical: Material costs are reduced by 30%-40%, and it is compatible with GB / T 9978 and EN 1634-1 international certifications, suitable for fire doors, partitions, containers and other scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of the composite core material structure of the present invention.

[0020] Figure 2 This is a schematic diagram of fire door application.

[0021] Figure 3 This is a comparison chart of the temperature rise curves of the 950℃ hot surface test.

[0022] Figure 4 This is the recycling process flow chart. DETAILED DESCRIPTION

[0023] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0024] like Figure 1 The basic structure of the fireproof and heat-insulating composite core material for buildings of the present invention is as follows: Insulation layer 1: nano-microporous insulation board with a thickness of 12-18 mm, a thermal conductivity coefficient of <0.020 W / (m·K), and a density of 150-350 kg / m³; Heat absorption layer 2: fireproof gypsum board or gypsum fire-retardant coating with a thickness of >3 mm, fixed to the cold side of the insulation layer (the non-fire contact area, with a temperature of 80-140°C); Function: The heat absorption layer absorbs heat by releasing crystalline water, so that the temperature rise curve of the back-fire surface remains flat within 120 minutes, and the tail temperature is ≤180℃, which is 15%-20% lower than that of the solution without a heat absorption layer.

[0025] Cold surface design: Breaking through the traditional technical bias of placing heat-absorbing materials on the hot side, the cold surface setting extends the heat absorption efficiency; Synergistic effect: The high thermal insulation of nanoporous insulation board combined with the heat absorption of gypsum significantly reduces the amount of material used.

[0026] In the present invention, as a preferred embodiment, the fireproof gypsum board can be a composite of one or more of paper-faced gypsum board, fiber-faced gypsum board, and cloth-faced gypsum board.

[0027] in: Paper-faced gypsum board: lightweight, easy to process, suitable for standardized production; Fiber gypsum board: Add glass fiber to enhance crack resistance; Cloth-faced gypsum board: the surface is covered with cloth to improve wear resistance; Composite use: Balance strength and cost through multi-layer composite (such as paper surface + fiber).

[0028] In the present invention, as a preferred embodiment, the content of aluminum sulfate dihydrate in the gypsum fire-retardant and heat-absorbing coating is greater than 70%.

[0029] effect: Endothermic mechanism: Aluminum sulfate dihydrate dehydrates and absorbs heat at high temperatures, absorbing about 300 J of heat per gram; Content optimization: Content > 70% ensures maximum heat absorption while avoiding excessively high coating viscosity that affects spraying.

[0030] In the present invention, as a preferred embodiment, the porosity of the nanoporous thermal insulation board is 85%-92%, and the pore size is 10-50 nm. Scientific basis: Porosity: >85% to ensure low thermal conductivity (<0.020W / (m·K)); Pore ​​size: Nanoscale pores of 10-50 nm can effectively suppress the heat conduction of gas molecules (Knudsen effect).

[0031] In the present invention, as a preferred embodiment, the total thickness of the composite core material is 15-22 mm. After passing the moisture-heat cycle (RH ≥ 95%, 100 times) and freeze-thaw test (20°C-50°C, 50 times), the temperature rise of the back-fired surface is ≤ 200°C, and the compressive strength decrease rate is <10%.

[0032] Test significance: Humidity and heat / freeze-thaw: simulate extreme environments such as high humidity, salt spray, and temperature differences to verify long-term stability; Temperature rise and strength: Ensure that the core material still meets fire protection and structural requirements under harsh conditions.

[0033] In the present invention, as a preferred embodiment, an optional functional layer 3 is added between the heat absorption layer and the heat insulation layer. The thickness of the optional functional layer is 1-2 mm, and the total thickness of the composite core material is still controlled within the range of 15-22 mm. The functional layer is a sound insulation layer (sound insulation ≥ 35 dB) or an electromagnetic shielding layer (shielding effectiveness ≥ 25 dB), wherein the sound insulation layer is 1-2 mm and the electromagnetic shielding layer is 0.5-1 mm.

[0034] Application value: Sound insulation layer: such as porous ceramic fiberboard, suitable for noise reduction scenarios such as hospitals and schools; Electromagnetic shielding layer: such as aluminized fiberglass cloth, suitable for special scenarios such as data centers and laboratories.

[0035] like Figure 2 The specific application structure of the composite core material of the present invention in the fire door is as follows: Composite core material 4: Located inside the fire door, it consists of a heat-insulating layer 1, a heat-absorbing layer 2, and an optional functional layer 3, with a total thickness of 15-21 mm; It is sandwiched between two layers of 1.2-1.5 mm thick steel plates 5 to form a "sandwich" structure.

[0036] Steel Plate 5: Material: galvanized steel plate or fire-resistant coated steel plate; Function: Provide structural strength, protect the core material from mechanical damage, and serve as the interface between the fire surface and the back fire surface.

[0037] Assembly details: The composite core material 4 and the steel plate 5 are fixed by a polyurethane adhesive or mechanical fasteners; The total thickness of the door body is ≤50mm, which is significantly thinner than traditional rock wool fire doors (thickness ≥70mm).

[0038] Technical significance: Through lightweight design, it solves the problem of bloated volume of traditional fire doors, while meeting the 120-minute fire resistance requirements of GB / T 9978 or EN 1634-1 certification. In the present invention, as a preferred embodiment, the surface of the nanoporous insulation board is coated with hydrophobic glass fiber cloth or an equivalent hydrophobic coating, with a contact angle of >120° and a thermal conductivity change rate of <5% after a salt spray test for 240 hours.

[0039] Technical effects: Hydrophobicity: Contact angle >120° prevents water penetration and avoids the increase of thermal conductivity in humid environments; Corrosion resistance: Salt spray testing verifies its durability in coastal or industrial environments.

[0040] like Figure 4 The recycling method of the composite core material of the present invention Technical features: Crushing: crush the waste core material into particles ≤10mm; Magnetic separation: separation of steel plate components (recovery rate ≥ 95%); Flotation: The crushed material is placed in an aqueous solution containing 0.5% sodium lauryl sulfate. Gypsum (density 1.2-1.5g / cm³) and nanoporous insulation board (density 0.15-0.35g / cm³) are separated by stirring and bubble adsorption. The gypsum sinks and the insulation board floats, separating the gypsum (recovery rate ≥90%) and the insulation board (recovery rate ≥85%). Recycling: Gypsum is used in recycled gypsum boards and insulation boards as lightweight aggregate.

[0041] Environmental value: Resource recycling: reducing construction waste and supporting green building certification (such as LEED); Economic benefits: The cost of recycled materials is 30%-50% lower than that of virgin materials. The layered structure of the composite core material.

[0042] Example 1 Fireproof Gypsum Board Composite Solution Step 1: Preparation of nanoporous insulation board Preparation basis: The preparation method disclosed in the applicant's authorized patent (patent number: CN202010180844.4) is adopted.

[0043] Key parameters: thickness 15mm, thermal conductivity 0.018W / (m·K), density 180kg / m³, porosity 90%, pore size 20-40nm.

[0044] Step 2: Prepare the fireproof gypsum board Formula: Gypsum powder: 80%, glass fiber: 3% (length 3-5mm), borate fire retardant additive: 8%, water: balance; Process: 1. After mixing, inject into the mold and allow to cure naturally for 24 hours; 2. Cut into 5mm thick plates, compressive strength 1.5MPa, water absorption 4%.

[0045] Step 3: Composite Core Assembly Fix the fireproof gypsum board to the cold side of the nanoporous insulation board, with a total thickness of 20mm; The core material of the fire door is made by compounding polyurethane adhesive with 1.5mm thick galvanized steel plate.

[0046] Step 4: Performance Testing Fire test: 950℃ hot surface continuously heated for 120 minutes, back-fire surface temperature rise 175℃, smoke density level 65, CO release 40mg / g; Environmental test: After humidity and heat cycle (RH ≥ 95%, 100 times), the temperature rise is ≤ 190℃ and the compressive strength decrease rate is 8%.

[0047] Example 2: Gypsum fire-retardant heat-absorbing coating composite solution Step 1: Preparation of nanoporous insulation board Preparation basis: Based on the applicant's authorized patent CN202010180844.4 method, the sintering parameters (temperature, time) were adjusted to obtain the required thickness of 17 mm, porosity of 88%, pore size of 30-50 nm, and density of 200 kg / m³.

[0048] Step 2: Preparation of gypsum fireproof heat-absorbing coating: Formula: Aluminum sulfate dihydrate: 75%, aluminum silicate fiber: 10%, expanded graphite: 5%, water-based acrylic resin: 10%; Process: Spray gypsum fireproof heat-absorbing coating onto the cold side of the nano-porous insulation board. After curing, the thickness is 4mm.

[0049] Step 3: Composite Core Assembly The coating layer is compounded with the nanoporous insulation board through a polyurethane adhesive, with a total thickness of 21mm (even if an optional functional layer of 1mm is added, it will not exceed 22mm); Salt spray test (5% NaCl, 35°C): The surface is coated with hydrophobic glass fiber cloth (contact angle 125°). After 240 hours of salt spray exposure, the thermal conductivity coefficient changes by 3.5%.

[0050] Step 4: Recovery Experiment Crushing: crush the waste core material into particles ≤10mm; Magnetic separation: Recover 95% of steel plate components; Flotation: gypsum recovery rate is 92%, insulation board recovery rate is 87%; Recycling: The compressive strength of recycled gypsum board is 1.2MPa, and the aggregate of insulation board is used as roadbed filler with a compressive strength ≥5MPa.

[0051] Recycling experiment: The gypsum recovery rate after crushing is 92%. The insulation board components are used as roadbed fillers, and the compressive strength meets the standards. Example

[0052] In fire door applications, a composite core material with a total thickness of 18mm (15mm insulation layer + 3mm heat absorption layer) is used, which has passed the GB / T 9978 standard test and has a fire resistance integrity of 180 minutes.

[0053] Comparative Example: Figure 3 This is a comparison chart of the temperature rise curve of the 950°C hot surface test of the present invention. Its purpose is to verify the performance advantages of the cold surface heat absorption design. The details are as follows: Horizontal axis: test time (0-120 minutes); Vertical axis: back-fire surface temperature (°C).

[0054] Curve comparison: Curve A (heat absorbing layer placed on the hot surface) Place a 5mm fireproof gypsum board on the hot side of the nanoporous insulation board; After testing at 950℃ for 120 minutes, the back-fire surface temperature rose by 210℃, and the tail temperature increased by 17% compared with the cold surface solution (175℃).

[0055] Note: The temperature rise is slow in the initial stage, and the tail temperature is ≤180℃ after 120 minutes; this is because the gypsum layer continuously releases crystallization water on the cold surface to absorb heat, delaying heat transfer.

[0056] Curve B (no heat absorption layer) Only 18mm nanoporous insulation board is used; The temperature of the back-fired surface rises by 225°C, and the material cost is 30% higher than that of the composite solution.

[0057] Note: The temperature rise rate is fast, and the tail temperature is ≥220℃ after 120 minutes; it only relies on the thermal insulation performance of the nano-microporous insulation board and has no active heat absorption mechanism.

[0058] Key Data Points: At 60 minutes: the temperature of curve A is about 120℃, and that of curve B is about 160℃; Performance difference: The tail temperature difference reaches 40°C, proving that the cold surface heat absorption solution improves performance by approximately 18%.

[0059] Technical significance: The effectiveness of the cold surface heat absorption design is intuitively demonstrated through experimental data, supporting the core innovation of "reducing the tail temperature rise by 15%-20%" in the claim.

[0060] Finally, a few points should be explained: First, in the description of this application, it should be noted that, unless otherwise specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense, and may refer to mechanical or electrical connections, internal communication between two components, or direct connection. "Up," "down," "left," and "right" are only used to indicate relative positional relationships. When the absolute positions of the objects being described change, the relative positional relationships may also change. Secondly: The drawings of the embodiments disclosed in the present invention only involve structures related to the embodiments disclosed in the present invention. Other structures may refer to conventional designs. The same embodiment and different embodiments of the present invention may be combined with each other without conflict. Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A building fireproof and heat-insulating composite core material, characterized in that: Including heat insulation layer and heat absorption layer; The thermal insulation layer is a nano-microporous insulation board with a thickness of 12 mm to 18 mm, a thermal conductivity coefficient of less than 0.020 W / (m·K), and a density of 150 kg / m³ to 350 kg / m³; The heat absorption layer is a fireproof gypsum board or gypsum fireproof heat absorption coating with a thickness greater than 3mm, fixed to the cold side of the insulation layer; The cold side is the contact area of ​​the composite core material facing away from the fire in a fire, and its operating temperature range is 80°C to 140°C; The heat absorption layer releases crystalline water at high temperature, so that the temperature rise curve of the back-fire surface remains flat within 120 minutes, the tail temperature does not exceed 180°C, and the tail temperature is reduced by 15% to 20% compared with the solution without a heat absorption layer.

2. A building fireproof and heat-insulating composite core material according to claim 1, characterized in that: The fireproof gypsum board is a composite of any one or more of paper-faced gypsum board, fiber-faced gypsum board and cloth-faced gypsum board.

3. A building fireproof and heat-insulating composite core material according to claim 1, characterized in that: The content of aluminum sulfate dihydrate in the gypsum fire-retardant and heat-absorbing coating is greater than 70%.

4. A building fireproof and heat-insulating composite core material according to claim 1, characterized in that: The porosity of the nanoporous thermal insulation board is 85% to 92%, and the pore size distribution is 10nm to 50nm.

5. The fireproof and heat-insulating composite core material for buildings according to claim 1, characterized in that: The total thickness of the composite core material is 15 mm to 22 mm, and in the wet heat cycle test, after 100 cycles under conditions of relative humidity of 95%, and in the freeze-thaw cycle test, after 50 cycles under conditions of a temperature range of -20°C to 50°C, the temperature rise of the back-fire surface still does not exceed 200°C, and the compressive strength decrease rate is less than 10%.

6. A building fireproof and heat-insulating composite core material according to claim 5, characterized in that: An optional functional layer is added between the heat absorption layer and the heat insulation layer. The thickness of the optional functional layer does not exceed 3 mm, and the total thickness of the composite core material is still 15-22 mm.

7. A building fireproof and heat-insulating composite core material according to claim 6, characterized in that: The optional functional layer is a sound insulation layer or an electromagnetic shielding layer.

8. The fireproof and heat-insulating composite core material for buildings according to claim 3, characterized in that: When the composite core material is applied to a fire door, its overall structure is certified according to GB / T 9978 standard, the fire resistance integrity is 120 minutes to 180 minutes, and the thickness of the door body does not exceed 50 mm.

9. The fireproof and heat-insulating composite core material for buildings according to claim 1, characterized in that: The surface of the nanoporous insulation board of the composite core material is coated with hydrophobic glass fiber cloth or an equivalent hydrophobic coating, with a contact angle greater than 120 degrees, and the thermal conductivity coefficient change rate is less than 5% after being exposed to a salt spray test for 240 hours.

10. A method for recycling a composite core material according to any one of claims 1 to 9, characterized in that: After the waste composite core material is crushed, the steel plate component is separated by magnetic separation, and the gypsum component and the nano-porous insulation board component are separated by flotation; The gypsum component is used for the preparation of recycled gypsum board, with a recovery rate of not less than 90%; The nanoporous thermal insulation board components are crushed and used as lightweight aggregate for concrete or roadbed filler, with a recovery rate of not less than 85%.

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