A method for producing and processing fireproof aluminum composite panels

Abstract

This invention relates to the field of fire-resistant aluminum composite panel technology and discloses a method for producing and processing fire-resistant aluminum composite panels, including the following steps: Step S1: Raw materials are fed into the hopper of a twin-screw extruder via a screw feeder and then into the twin-screw extruder. The twin-screw extruder melts and plasticizes the raw materials and extrudes them through a T-die. Step S2: The T-die sends the molten raw materials to a three-roll calender. The three-roll calender cools the molten raw materials and rolls and shapes them into a flame-retardant core board. Step S3: The two sides of the flame-retardant core board are bonded to the aluminum plate with a polymer adhesive film. After cooling and shaping, it becomes a fire-resistant aluminum composite panel blank and is placed in the cutting area for later use. Step S4: The fire-resistant aluminum composite panel blank is cut into the required dimensions according to production requirements. The aluminum plate scraps generated during cutting are separated from the flame-retardant core board. The aluminum plate is sold, and the flame-retardant core board is returned to the screw feeder for recycling. The production process is more environmentally friendly.

Description

Technical Field

[0001] This invention relates to the field of fire-resistant aluminum composite panel technology, and more specifically to a method for producing and processing fire-resistant aluminum composite panels. Background Technology

[0002] With the improvement of people's living standards and the strengthening of fire safety awareness, people have increasingly stringent requirements for fire resistance performance in many important building decoration occasions due to their need for safety protection for themselves and society. Therefore, a new type of fireproof decorative building material with unique advantages of fire resistance, environmental protection and resource conservation—fireproof aluminum composite panel—has emerged.

[0003] Fireproof aluminum composite panels are composed of multiple layers of materials. The upper and lower layers are high-purity aluminum alloy plates, and the middle layer is a non-toxic low-density polyethylene core board. A protective film is also pasted on the front. For outdoor use, the front of the aluminum composite panel is coated with fluorocarbon resin, while for indoor use, a non-fluorocarbon resin coating can be used. Because it is composed of two completely different materials, it retains the main characteristics of the original constituent materials while overcoming their shortcomings. It is corrosion-resistant, impact-resistant, fireproof, moisture-proof, soundproof, and earthquake-resistant, and therefore is widely used in various building decorations.

[0004] When fireproof aluminum composite panels are produced, the core of the panel is polyethylene. Due to its excellent properties, polyethylene is still widely used in film products and injection molded products, even though it is a type of white pollution. Therefore, the large-scale use of polyethylene will harm the environment and is inconsistent with the current green development concept. At present, at most, the polyethylene core of the damaged fireproof aluminum composite panels can be recycled, but the polyethylene products discarded by the outside world cannot be recycled.

[0005] Fire-resistant aluminum composite panels have limited tensile strength during production. When the size of the fire-resistant aluminum composite panel is large, it is heavy and its performance is generally poor, making it prone to breakage. The production of fire-resistant aluminum composite panels generates a lot of cutting waste, which is not currently properly processed. Fire-resistant aluminum composite panels are composed of aluminum sheets and polyethylene core boards, making them prone to separation. Summary of the Invention

[0006] In order to overcome the above-mentioned defects of the prior art, the embodiments of the present invention provide a method for producing and processing fireproof aluminum composite panels to solve the technical problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a method for producing and processing fireproof aluminum composite panels, comprising the following steps:

[0008] Step S1: The raw material enters the hopper of the twin-screw extruder through the screw feeder and enters the interior of the twin-screw extruder. The twin-screw extruder melts and plasticizes the raw material and extrudes it into the T-die opening.

[0009] Step S2: The T-shaped mold sends the molten raw material to the three-roll calender. The three-roll calender cools the molten raw material and rolls it to shape it into a flame-retardant core board.

[0010] Step S3: Bond the two sides of the flame-retardant core board to the aluminum plate with a polymer adhesive film. After cooling and shaping, it becomes a fireproof aluminum composite panel blank and is placed in the cutting area for later use.

[0011] Step S4: Cut the fireproof aluminum composite panel blank into the required size according to the production requirements. Separate the aluminum sheet and flame-retardant core board from the scrap aluminum sheet produced by cutting. Sell the aluminum sheet and send the flame-retardant core board back into the screw feeder for recycling.

[0012] In a preferred embodiment, the raw material composition consists of 100 parts of polyethylene sheet, 100 parts of flame retardant, 10 parts of coupling agent, and 10 parts of synergist. The flame retardant is aluminum hydroxide, zinc hydroxide, and zinc borate in a ratio of 23:23:4. The coupling agent is silane, titanate, and aluminate in a ratio of 2:3:4. The synergist is microencapsulated red phosphorus.

[0013] In a preferred embodiment, the polyethylene sheet is obtained from the recycling of agricultural film and greenhouse film. When recycling agricultural film and greenhouse film, the waste agricultural film and greenhouse film are first sorted out to remove large impurities. The sorted agricultural film and greenhouse film are then broken into fragments and cleaned. After cleaning, mud and dust impurities are removed, and the surface moisture is removed by a dewatering machine to become clean polyethylene sheet.

[0014] In a preferred embodiment, when preparing the raw materials, the flame retardant is first placed in a high-speed mixer to mix the aluminum hydroxide, zinc hydroxide, and zinc borate powder inside the flame retardant evenly. When the temperature is raised to 120°C, hollow glass microspheres and coupling agent are added, and after stirring and heating to 120°C, synergist and polyethylene sheet are added. After heating to 160°C, they are mixed for ten minutes to complete the production of the raw materials, which are soft block materials. The diameters of the flame retardant, coupling agent, and synergist are all 30nm-80nm.

[0015] In a preferred embodiment, a forced screw feeder is fixedly installed at the bottom of the hopper of the twin-screw extruder. After passing through the forced screw feeder, the raw material enters the interior of the twin-screw extruder and is extruded. The three-roll calender is arranged in a diagonal triangle, with the upper roll temperature at 120°C, the middle roll temperature at 100°C, and the lower roll temperature at 90°C.

[0016] In a preferred embodiment, when the flame-retardant core board is bonded to the aluminum plate, the flame-retardant core board is fixed on the laminating machine, and both the upper and lower surfaces of the flame-retardant core board are bonded to the polymer adhesive film. After bonding, the flame-retardant core board and the polymer adhesive film enter the high-temperature laminating machine for thermal bonding and lamination. One side of the polymer adhesive film is a polymer material and the other side is polyethylene, with the polyethylene side in contact with the flame-retardant core board.

[0017] In a preferred embodiment, the scraps generated during cutting are heated with steam to separate the flame-retardant core board from the aluminum plate. The aluminum plate is sold directly, while the flame-retardant core board is recycled. The powder generated during cutting is separated using an electrostatic separator. The aluminum powder is sold again, and the flame-retardant polyethylene powder is recycled together with the flame-retardant core board scraps.

[0018] In a preferred embodiment, the flame-retardant core board is compounded with LLDPE on both sides before contacting the polymer adhesive film, and then placed in a steam generator for eight hours. The steam generator is in a low-pressure environment with a pressure of 1.6 MPa, which causes the surface of the flame-retardant core board to undergo a cross-linking reaction and bond with the aluminum plate.

[0019] In a preferred embodiment, each screw of the twin-screw extruder has a diameter of 180 mm, a length-to-diameter ratio of 35:1, a compression section temperature of 260°C, two ends a temperature of 230°C, a die temperature of 200°C, and a rotational speed of 160 r / min.

[0020] The technical effects and advantages of this invention are as follows:

[0021] 1. The raw materials of this invention are polyethylene sheets, flame retardants, coupling agents and synergists. The polyethylene sheets are obtained from the recycling of agricultural film and greenhouse film. Waste agricultural film and greenhouse film are made of polyethylene. It takes more than 70 years for waste polyethylene film to completely decompose in the soil. Therefore, recycling waste agricultural film and greenhouse film can play an environmental protection role while reducing the production cost of fireproof aluminum composite panels.

[0022] 2. This invention produces flame-retardant core boards using polyethylene sheets, flame retardants, coupling agents, and synergists. When the flame retardant is above 200°C, it absorbs heat, decomposes, and dehydrates. This dilutes the combustion air, reduces the flame temperature, and the dehydrated oxides form a strong, dense, and expandable flame-retardant barrier on the material surface, providing thermal insulation and reducing the burning rate and heat release. The coupling agent itself is a mixture of silane, titanate, and aluminate, which increases the tensile strength of the board without affecting the oxygen index.

[0023] 3. This invention uses flame retardants and hollow glass microspheres to gradually add raw materials for mixing, resulting in a more uniform mixing effect. The addition of hollow glass microspheres to the raw materials increases the fluidity of the material during melting, and the final fireproof aluminum composite panel is lighter and has a sound insulation effect, making the fireproof aluminum composite panel perform better in use.

[0024] 4. This invention separates the flame-retardant core board from the aluminum plate by heating the scrap material generated during cutting with steam. The aluminum plate is sold directly, while the flame-retardant core board is recycled. The powder generated during cutting is separated using an electrostatic separator, and the aluminum powder is sold again. When the flame-retardant polyethylene powder and the scrap material are recycled together for production, this product does not generate useless waste and can save costs. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the overall production process of the present invention. Detailed Implementation

[0026] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. In addition, the forms of the various structures described in the following embodiments are merely illustrative. The fireproof aluminum composite panel production and processing method involved in the present invention is not limited to the structures described in the following embodiments. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] This invention provides a method for producing and processing fire-resistant aluminum composite panels, comprising the following steps:

[0028] Step S1: The raw material enters the hopper of the twin-screw extruder through the screw feeder and enters the interior of the twin-screw extruder. The twin-screw extruder melts and plasticizes the raw material and extrudes it into the T-die opening.

[0029] Step S2: The T-shaped mold sends the molten raw material to the three-roll calender. The three-roll calender cools the molten raw material and rolls it to shape it into a flame-retardant core board.

[0030] Step S3: Bond the two sides of the flame-retardant core board to the aluminum plate with a polymer adhesive film. After cooling and shaping, it becomes a fireproof aluminum composite panel blank and is placed in the cutting area for later use.

[0031] Step S4: Cut the fireproof aluminum composite panel blank into the required size according to the production requirements. Separate the aluminum sheet and flame-retardant core board from the scrap aluminum sheet produced by cutting. Sell the aluminum sheet and send the flame-retardant core board back into the screw feeder for recycling.

[0032] Furthermore, the polyethylene sheets are obtained from the recycling of agricultural film and greenhouse film. During the recycling process, the waste agricultural film and greenhouse film are first sorted to remove large impurities. The sorted agricultural film and greenhouse film are then crushed into fragments and cleaned. After cleaning, mud and dust impurities are removed, and the surface moisture is removed by a dewatering machine to become clean polyethylene sheets. The waste agricultural film and greenhouse film are then made of polyethylene. It takes more than 70 years for waste polyethylene film to completely decompose in the soil. Therefore, recycling waste agricultural film and greenhouse film can play an environmental protection role while reducing the production cost of fireproof aluminum composite panels.

[0033] Furthermore, during the raw material preparation, the flame retardant is first placed in a high-speed mixer to ensure uniform mixing of the aluminum hydroxide, zinc hydroxide, and zinc borate powders within the flame retardant. When the temperature reaches 120°C, hollow glass microspheres and a coupling agent are added, and the mixture is stirred and heated to 120°C. Then, a synergist and polyethylene sheet are added, and the mixture is heated to 160°C and mixed for ten minutes to complete the raw material production. This material is in soft, blocky form, with the flame retardant, coupling agent, and synergist having diameters of 30nm-80nm. The raw materials are mixed by gradually adding them, resulting in a more uniform mixing effect. The addition of hollow glass microspheres increases the fluidity of the material during melting, leading to a lighter final product: a fire-resistant aluminum composite panel with sound insulation properties. The fire-resistant aluminum composite panel exhibits better performance in use, with the flame retardant, coupling agent, and synergist having diameters of 30nm-80nm, resulting in optimal oxygen index and tensile properties for the finished product.

[0034] Furthermore, a forced screw feeder is fixedly installed at the bottom of the hopper of the twin-screw extruder. After passing through the forced screw feeder, the raw material enters the interior of the twin-screw extruder for extrusion processing. The three-roll calender is arranged in a diagonal triangle, with the upper roll temperature at 120°C, the middle roll temperature at 100°C, and the lower roll temperature at 90°C. Since soft lumps of material easily accumulate in the hopper and cannot fall freely into the extruder's feed inlet, the forced screw feeder installed at the bottom of the hopper can force the raw material into the twin-screw extruder's feed inlet, facilitating subsequent production. The temperature of the upper, middle, and lower rolls of the three-roll calender, arranged in a diagonal triangle, is strictly controlled, which can solve the problems of material sagging and surface breakage or cracks.

[0035] Furthermore, when bonding the flame-retardant core board to the aluminum plate, the flame-retardant core board is fixed on the laminating machine, and both the upper and lower sides of the flame-retardant core board are bonded to the polymer adhesive film. After bonding, the flame-retardant core board and the polymer adhesive film enter the high-temperature laminating machine for thermal bonding. One side of the polymer adhesive film is a polymer material and the other side is polyethylene, with the polyethylene side in contact with the flame-retardant core board. When the fireproof aluminum composite panel blank is cut, strips or blocks of scrap and powdery cutting materials are generated. These are separated and processed. The strips or blocks separate the aluminum plate from the core board, while the powdery waste is separated by an electrostatic separator. Both the aluminum plate and aluminum powder can be sold, while the strips, blocks, or powdery flame-retardant polyethylene materials can be put back into the extruder for remelting and reuse, reducing costs and making the production process more environmentally friendly.

[0036] Furthermore, the scraps generated during cutting are separated from the aluminum plate using steam heating. The aluminum plate is sold directly, while the flame-retardant core plate is recycled. The powder generated during shearing is separated using an electrostatic separator. The aluminum powder is sold again, while the flame-retardant polyethylene powder is recycled together with the flame-retardant core plate scraps.

[0037] In this embodiment, the two sides of the flame-retardant core board are compounded with LLDPE before contacting the polymer adhesive film, and then placed in a steam generator for eight hours. The steam generator is a low-pressure environment with a pressure of 1.6 MPa, which causes the surface of the flame-retardant core board to undergo a cross-linking reaction and bond with the aluminum plate. Since the materials of the flame-retardant core board and the aluminum plate are quite different, the polymer film alone cannot guarantee a tight bond between the flame-retardant core board and the aluminum plate. Compounding and cross-linking the surface of the flame-retardant core board can increase the mechanical properties of the flame-retardant core board and improve the glass strength between the flame-retardant core board and the aluminum plate, thus preventing them from peeling off.

[0038] Furthermore, each screw of the twin-screw extruder has a diameter of 180mm, a length-to-diameter ratio of 35:1, a compression section temperature of 260℃, and end temperatures of 230℃, a die temperature of 200℃, and a rotation speed of 160r / min. When melting and extruding raw materials using a twin-screw extruder, as the rotation speed increases, the shear rate increases, thereby increasing the extrusion volume. However, when the speed exceeds 160r / min, it will cause the entire twin-screw extruder to shake, thus affecting the quality of the base raw material. Therefore, setting the rotation speed to 160r / min can maximize the output. In addition, the dimensions of the twin-screw extruder itself and the temperature of each section are set to ensure that the viscosity of the molten material is low, thereby increasing the extrusion volume and accelerating the production speed.

[0039] Example 2

[0040] The raw material composition consists of 100 parts polyethylene sheet, 100 parts flame retardant, 10 parts coupling agent, and 10 parts synergist. The flame retardant is aluminum hydroxide, zinc hydroxide, and zinc borate in a ratio of 23:23:4. The coupling agent is silane, titanate, and aluminate in a ratio of 2:3:4. The synergist is microencapsulated red phosphorus.

[0041] In this embodiment, polyethylene sheets, flame retardants, coupling agents, and synergists are used to produce flame-retardant core boards. When the flame retardant is above 200°C, it absorbs heat, decomposes, and dehydrates. This dilutes the combustion air, reduces the flame temperature, and the dehydrated oxides form a strong, dense, and expandable flame-retardant barrier on the material surface, providing thermal insulation and reducing the burning rate and heat release. The coupling agent is a mixture of silane, titanate, and aluminate, which increases the tensile strength of the board without affecting the oxygen index, thus not affecting the flame retardancy. The synergist in this application can improve the flame retardant effect of the flame retardant, and microencapsulated red phosphorus is used as a synergist. It does not release ammonia gas during combustion, thus avoiding the generation of toxic gases in the event of a fire.

[0042] The coupling agents are silane, titanate, and aluminate, and the effect of their ratio on the material properties is shown in the table below:

[0043] silane titanate Aluminate Tensile strength Oxygen Index none none none 10.0 40.0 2.0 none 4.0 12.4 37.8 none 3.0 4.0 12.5 38.6 2.0 3.0 4.0 14.5 40.0 1.0 2.0 3.0 12.0 38.0

[0044] As can be seen from the table, when a coupling agent is added, the tensile strength of flame-retardant polyethylene will be improved, but its oxygen index will decrease. However, when the added coupling agents are silane, titanate and aluminate in a ratio of 2:3:4, the tensile strength will increase while the flame-retardant polyethylene will not decrease. Therefore, it can bring better mechanical properties to flame-retardant polyethylene.

[0045] The synergists were selected from metal oxides, phosphorus oxides, and silicon oxides. For metal oxides, zinc oxide and iron oxide were chosen; for phosphorus oxides, microencapsulated red phosphorus and phosphate esters were selected; and for silicon oxides, silica and hydroxyl silicone oil were chosen. Their combustion characteristics are shown in the table below:

[0046]

[0047] The red phosphorus in the table is microencapsulated red phosphorus. As can be seen from the table, when synergists are added, regardless of whether the added synergists are metal oxides, phosphorus oxides or silicon oxides, they can all play a flame-retardant role in polyethylene core boards. Therefore, adding synergists can increase the performance of polyethylene boards. When the added synergist is microencapsulated red phosphorus, the heating rate and total heat release of the polyethylene board are relatively low, and the combustion efficiency is also relatively low. Therefore, using it as a synergist can play a better flame-retardant role.

[0048] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0049] In conclusion, 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 within the protection scope of the present invention.

Claims

1. A method for producing and processing fireproof aluminum composite panels, characterized in that, Includes the following steps: Step S1: The raw material enters the hopper of the twin-screw extruder through the screw feeder and enters the interior of the twin-screw extruder. The twin-screw extruder melts and plasticizes the raw material and extrudes it into the T-die opening. Step S2: The T-shaped mold sends the molten raw material to the three-roll calender. The three-roll calender cools the molten raw material and rolls it to shape it into a flame-retardant core board. Step S3: The two sides of the flame-retardant core board are bonded to the aluminum plate with a polymer adhesive film. After cooling and shaping, it becomes a fireproof aluminum-plastic composite board blank and is placed in the cutting area for later use. Before the two sides of the flame-retardant core board come into contact with the polymer adhesive film, LLDPE is used for compounding and it is placed in a steam generator for eight hours. The steam generator is a low-pressure environment with a pressure of 1.6 MPa, which causes the surface of the flame-retardant core board to undergo a cross-linking reaction and then bond it to the aluminum plate. Step S4: Cut the fireproof aluminum composite panel blank into the required size according to the production requirements. Separate the aluminum sheet and flame-retardant core board from the scrap aluminum sheet produced by cutting. Sell the aluminum sheet and send the flame-retardant core board back into the screw feeder for recycling.

2. The method for producing and processing fireproof aluminum composite panels according to claim 1, characterized in that: The raw material composition is 100 parts polyethylene sheet, 100 parts flame retardant, 10 parts coupling agent, and 10 parts synergist. The flame retardant is aluminum hydroxide, zinc hydroxide, and zinc borate in a ratio of 23:23:

4. The coupling agent is silane, titanate, and aluminate in a ratio of 2:3:

4. The synergist is microencapsulated red phosphorus.

3. The method for producing and processing fireproof aluminum composite panels according to claim 2, characterized in that: The polyethylene sheet material is obtained from the recycling of agricultural film and greenhouse film. When recycling agricultural film and greenhouse film, the waste agricultural film and greenhouse film are first sorted out to remove large impurities. The sorted agricultural film and greenhouse film are then crushed into fragments and cleaned. After cleaning, mud and dust impurities are removed, and the surface moisture is removed by a dewatering machine to become clean polyethylene sheet material.

4. The method for producing and processing fireproof aluminum composite panels according to claim 1, characterized in that: When preparing the raw materials, the flame retardant is first placed in a high-speed mixer to mix the aluminum hydroxide, zinc hydroxide, and zinc borate powder inside the flame retardant evenly. When the temperature rises to 120°C, hollow glass microspheres and coupling agents are added, and the mixture is stirred and heated to 120°C. Then, synergists and polyethylene sheets are added, and the mixture is heated to 160°C and mixed for ten minutes to complete the production of the raw materials. The raw materials are in soft block form, and the diameters of the flame retardant, coupling agent, and synergist are all 30nm-80nm.

5. The method for producing and processing fireproof aluminum composite panels according to claim 1, characterized in that: A forced screw feeder is fixedly installed at the bottom of the hopper of the twin-screw extruder. After passing through the forced screw feeder, the raw material enters the interior of the twin-screw extruder and is extruded. The three-roll calender is arranged in a diagonal triangle, with the upper roll temperature at 120°C, the middle roll temperature at 100°C, and the lower roll temperature at 90°C.

6. The method for producing and processing fireproof aluminum composite panels according to claim 1, characterized in that: When the flame-retardant core board is bonded to the aluminum plate, the flame-retardant core board is fixed on the laminating machine. Both the upper and lower sides of the flame-retardant core board are bonded to the polymer adhesive film. After bonding, the flame-retardant core board and the polymer adhesive film enter the high-temperature laminating machine for thermal bonding. One side of the polymer adhesive film is a polymer material and the other side is polyethylene. The polyethylene side is in contact with the flame-retardant core board.

7. The method for producing and processing fireproof aluminum composite panels according to claim 1, characterized in that: The scraps generated during cutting are separated from the aluminum plate by steam heating. The aluminum plate is sold directly, while the flame-retardant core plate is recycled. The powder generated during cutting is separated by an electrostatic separator. The aluminum powder is sold again, and the flame-retardant core plate powder is recycled together with the scrap flame-retardant core plate.

8. The method for producing and processing fireproof aluminum composite panels according to claim 1, characterized in that: The twin-screw extruder has a screw diameter of 180 mm, a length-to-diameter ratio of 35:1, a compression section temperature of 260°C, two ends temperature of 230°C, a die temperature of 200°C, and a rotation speed of 160 r / min.

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