Aircraft-grade light flame-retardant composite interior trim panel

Abstract

The invention relates to the technical field of aeronautical materials, in particular to an aeronautical-grade light flame-retardant composite interior trim panel. In order to solve the problem that in the prior art, the flame retardant property and the material strength of a PPS composite material need to be further improved, the aviation-grade light flame-retardant composite interior trim panel comprises a surface layer and a core layer, and the surface layer and the core layer are connected through a bonding layer. The surface layer is prepared from the following components in parts by mass: 90 to 100 parts of PPS (polyphenylene sulfite) resin and 0 to 10 parts of nano montmorillonite; the core layer is prepared from the following components in parts by mass: 40 to 60 parts of glass fiber, 30 to 50 parts of PPS (polyphenylene sulfite) fiber and 5 to 10 parts of flame-retardant PC (polycarbonate) fiber. According to the invention, a multi-layer structural design taking the PPS material as a main component is adopted, the core layer is of a porous structure formed by interweaving the glass fibers and the PPS / PC fibers, the overall density can be reduced on the premise of maintaining high strength, and meanwhile, the PC material can capture free radicals in a gas phase after being modified by the phosphate flame retardant, so that the flame-retardant effect is synergistically enhanced.

Description

Technical Field

[0001] This invention relates to the field of aerospace materials technology, and in particular to an aerospace-grade lightweight flame-retardant composite interior panel. Background Technology

[0002] Traditional aerospace interior materials mostly use thermosetting resins, such as epoxy resin, in composite structures with honeycomb core materials. This results in problems such as long production cycles, difficulty in recycling, and high heat release. PPS materials, due to their high heat resistance, chemical corrosion resistance, and recyclability, are widely used in many fields. However, single resin systems cannot meet the stringent requirements of aerospace in terms of flame retardancy and material strength, limiting their application in the aerospace materials field.

[0003] In response to this problem, people have conducted exploratory research in long-term production and daily life practices. For example, a Chinese invention patent application discloses a nano-modified aerospace material of polyphenylene sulfide and styrene-butadiene copolymer [application number: 202410791435.6]. The invention application includes: 100 parts of polyphenylene sulfide, 10-30 parts of styrene-butadiene copolymer, 2-5 parts of carbon fiber, 0-60 parts of glass fiber, 2-5 parts of nanomaterials, and 1.6-4.4 parts of auxiliary materials.

[0004] This invention combines the advantages of PPS and TPE, and significantly improves the overall performance of the material through nano-modification, making it suitable for use in the aerospace field. However, its performance in terms of flame retardancy and material strength still needs further improvement. Summary of the Invention

[0005] The purpose of this invention is to address the above-mentioned problems by providing an aerospace-grade lightweight flame-retardant composite interior trim panel.

[0006] To achieve the above objectives, the present invention adopts the following technical solutions:

[0007] An aerospace-grade lightweight flame-retardant composite interior panel includes a surface layer and a core layer, which are connected by a bonding layer. The surface layer includes 90-100 parts by weight of PPS resin and 0-10 parts by weight of nano-montmorillonite. The core layer includes 40-60 parts by weight of glass fiber, 30-50 parts by weight of PPS fiber and 5-10 parts by weight of flame-retardant PC fiber.

[0008] In the aforementioned aerospace-grade lightweight flame-retardant composite interior trim panel, the thickness of the surface layer is 0.1-0.4 mm, and the thickness of the core layer is 2-10 mm.

[0009] In the aforementioned aerospace-grade lightweight flame-retardant composite interior trim panel, the surface layer is prepared by the following method:

[0010] PPS particles are vacuum dried to a moisture content of less than 0.03%, and then added to an extruder for extrusion to obtain the surface layer.

[0011] In the aforementioned aerospace-grade lightweight flame-retardant composite interior panel, the temperature of the extruder is 320-340℃, and the die pressure is 10-14MPa.

[0012] In the aforementioned aerospace-grade lightweight flame-retardant composite interior trim panel, the core layer is prepared by the following method:

[0013] Step 1: Vacuum dry PC particles at 120℃ for 5 hours, then add the dried PC particles and phosphate flame retardant to the extruder through the feeding pipe, and extrude to obtain flame retardant PC fibers.

[0014] Step 2: Vacuum dry the PPS particles at 130℃ for 5 hours, then add the dried PPS particles to the extruder through the feeding pipe and extrude to obtain PPS fibers;

[0015] Step 3: Add glass fiber, flame-retardant PC fiber obtained in Step 1 and PPS fiber obtained in Step 2 into a three-dimensional mixer in proportion and mix them. Under the conditions of wind speed of 9m / s and web laying speed of 1.8m / min, the airflow forms a web and cross-lays the web. The web thickness is 4.8-5.2mm to obtain the web.

[0016] Step 4: Feed the mesh obtained in Step 3 into the needle punching machine and pre-punch 180 needles / cm. 2 Initial shaping achieved, main needle count 250 needles / cm 2 The needle is inserted to a depth of 7-8mm, causing the fibers to entangle and forming the core layer.

[0017] In the aforementioned aerospace-grade lightweight flame-retardant composite interior panel, the glass fiber is pretreated by the following method before mixing:

[0018] Cut the glass fibers to a length of 50-52 mm and soak them in KH-550 coupling agent for 5-15 minutes.

[0019] In the aforementioned aerospace-grade lightweight flame-retardant composite interior panel, the bonding layer is formed by the following method:

[0020] Step A: Stack the top layer, fiberglass cloth and top layer in the order of top layer and put them into the double steel belt press. The hot roller presses the top layer to form a top layer prepreg on one side of the surface.

[0021] Step B: The prepreg, core layer and prepreg are stacked in the order of surface layer and core layer and placed into a double steel belt press for pre-pressing. After pre-pressing, the temperature is raised for final pressing. After final pressing, the layers are cooled under pressure holding conditions. At this time, a bonding layer for fixing and connecting the surface layer and core layer is formed between the surface layer and the core layer.

[0022] In the aforementioned aerospace-grade lightweight flame-retardant composite interior panel, the hot roller temperature in step A is 295℃, the pressure is 0.6MPa, the composite speed is 1.2m / min, and the areal density of the fiberglass cloth is 100-400g / m³. 2 .

[0023] In the aforementioned aerospace-grade lightweight flame-retardant composite interior panel, during the pre-compression process in step B, the surface temperature is 270-290℃, the core temperature is 250-270℃, the pressure is 0.8-1.2MPa, and the pre-compression time is 1-3min.

[0024] In the aforementioned aerospace-grade lightweight flame-retardant composite interior panel, during the final pressing process in step B, the surface temperature is 320-340℃, the core temperature is 290-310℃, the pressure is 4.0-6.0MPa, and the final pressing time is 2-4min; the cooling rate after final pressing in step B is 15℃ / s, and when the temperatures of both the surface and core layers drop below 100℃, a further cooling rate of 50℃ / min is adopted.

[0025] Compared with existing technologies, the advantages of this invention are:

[0026] 1. This invention adopts a multi-layer structure design with PPS material as the main component. The core layer is formed by interweaving glass fiber and PPS / PC fiber to form a porous structure, which can reduce the overall density by 20%-30% while maintaining high strength. At the same time, PPS material itself has good flame retardancy, and PC material modified with phosphate flame retardant can capture free radicals in the gas phase, which synergistically enhances the flame retardant effect.

[0027] 2. The bonding layer between the core layer and the surface layer of this invention is formed by hot pressing and melting, which ensures the bonding strength between the core layer and the surface layer and avoids the problems of delamination expansion or fragmentation and peeling under high temperature environment, thereby further enhancing the flame retardancy and low smoke characteristics of the entire composite material.

[0028] 3. In the cooling process of this invention, the high-temperature zone is first cooled at an extremely fast rate to ensure that the interface fuses and forms a mechanically interlocked interface, thus suppressing warping. In the low-temperature zone, the cooling rate is drastically reduced to a very slow rate to equalize the temperature and eliminate internal stress.

[0029] 4. This invention adopts a fully thermoplastic system, which supports hot pressing repair or remolding of parts, reducing aviation maintenance costs. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the structure of the present invention;

[0031] In the diagram: Surface layer 1, core layer 2, bonding layer 3. Detailed Implementation

[0032] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0033] Example 1

[0034] This embodiment provides an aerospace-grade lightweight flame-retardant composite interior trim panel, such as... Figure 1 As shown, it includes a surface layer 1 and a core layer 2. The thickness of the surface layer 1 is 0.4 mm, and the thickness of the core layer 2 is 2 mm. The surface layer 1 and the core layer 2 are connected by a bonding layer 3. The surface layer 1 includes 90 parts by weight of PPS resin and 10 parts by weight of nano-montmorillonite. The core layer 2 includes 40 parts by weight of glass fiber, 50 parts by weight of PPS fiber, and 10 parts by weight of flame-retardant PC fiber.

[0035] The surface layer 1 is prepared by the following method:

[0036] PPS particles are vacuum dried to a moisture content of less than 0.03%, then added to an extruder and extruded at 320°C with a die pressure of 10 MPa to obtain surface layer 1.

[0037] The core layer 2 is prepared by the following method:

[0038] Step 1: Vacuum dry PC particles at 120℃ for 5 hours, then add the dried PC particles and phosphate flame retardant to the extruder through the feeding pipe, and extrude to obtain flame retardant PC fibers.

[0039] Step 2: Vacuum dry the PPS particles at 130℃ for 5 hours, then add the dried PPS particles to the extruder through the feeding pipe and extrude to obtain PPS fibers;

[0040] Step 3: Cut the glass fiber to a length of 50mm and soak it in KH-550 coupling agent for 5 minutes;

[0041] Step 4: Add the glass fiber obtained in Step 3, the flame-retardant PC fiber obtained in Step 1, and the PPS fiber obtained in Step 2 into a three-dimensional mixer in proportion and mix them. Under the conditions of wind speed of 9m / s and web laying speed of 1.8m / min, the airflow forms a web and cross-lays the web. The web thickness is 4.8mm to obtain the web.

[0042] Step 5: Feed the mesh obtained in Step 4 into the needle punching machine and pre-punch 180 needles / cm. 2 Initial shaping achieved, main needle count 250 needles / cm 2 The needle is inserted to a depth of 7-8 mm, causing the fibers to entangle and resulting in core layer 1.

[0043] The bonding layer 3 is formed by the following method:

[0044] Step A: Layer 1, fiberglass cloth, and surface layer 1 are stacked in the order listed and placed into a double steel belt press. Hot rollers apply pressure to form a surface prepreg on one side of surface layer 1. The hot roller temperature is 295℃, the pressure is 0.6MPa, the lamination speed is 1.2m / min, and the areal density of the fiberglass cloth is 100g / m³. 2 ;

[0045] Step B: Stack the surface prepreg, core layer 2, and surface prepreg in the order of surface prepreg and place them in a double steel strip press for pre-pressing. During pre-pressing, control the temperature of surface layer 1 at 270℃, the temperature of core layer 2 at 250℃, the pressure at 0.8MPa, and the pre-pressing time at 1min. After pre-pressing, raise the temperature for final pressing. During final pressing, control the temperature of surface layer 1 at 320℃, the temperature of core layer 2 at 290℃, the pressure at 4.0MPa, and the final pressing time at 2min. After final pressing, cool under the condition of maintaining 4.0MPa at a cooling rate of 15℃ / s. When the temperature of both surface layer 1 and core layer 2 drops below 100℃, use a cooling rate of 50℃ / min. At this time, a bonding layer 3 is formed between surface layer 1 and core layer 2 to fix and connect them.

[0046] Example 2

[0047] This embodiment provides an aerospace-grade lightweight flame-retardant composite interior trim panel, such as... Figure 1 As shown, it includes a surface layer 1 and a core layer 2. The thickness of the surface layer 1 is 0.1 mm, and the thickness of the core layer 2 is 10 mm. The surface layer 1 and the core layer 2 are connected by a bonding layer 3. The surface layer 1 includes 100 parts by weight of PPS resin and 0 parts by weight of nano-montmorillonite. The core layer 2 includes 60 parts by weight of glass fiber, 30 parts by weight of PPS fiber, and 5 parts by weight of flame-retardant PC fiber.

[0048] The surface layer 1 is prepared by the following method:

[0049] PPS particles are vacuum dried to a moisture content of less than 0.03%, then added to an extruder and extruded at 340°C and a die pressure of 14 MPa to obtain surface layer 1.

[0050] The core layer 2 is prepared by the following method:

[0051] Step 1: Vacuum dry PC particles at 120℃ for 5 hours, then add the dried PC particles and phosphate flame retardant to the extruder through the feeding pipe, and extrude to obtain flame retardant PC fibers.

[0052] Step 2: Vacuum dry the PPS particles at 130℃ for 5 hours, then add the dried PPS particles to the extruder through the feeding pipe and extrude to obtain PPS fibers;

[0053] Step 3: Cut the glass fiber to a length of 52mm and soak it in KH-550 coupling agent for 15 minutes;

[0054] Step 4: Add the glass fiber obtained in Step 3, the flame-retardant PC fiber obtained in Step 1, and the PPS fiber obtained in Step 2 into a three-dimensional mixer in proportion and mix them. Under the conditions of wind speed of 9m / s and web laying speed of 1.8m / min, the airflow forms a web and cross-lays the web. The web thickness is 5.2mm to obtain the web.

[0055] Step 5: Feed the mesh obtained in Step 4 into the needle punching machine and pre-punch 180 needles / cm. 2 Initial shaping achieved, main needle count 250 needles / cm 2 The needle is inserted to a depth of 7-8 mm, causing the fibers to entangle and resulting in core layer 1.

[0056] The bonding layer 3 is formed by the following method:

[0057] Step A: Layer 1, fiberglass cloth, and surface layer 1 are stacked in the order listed and placed into a double steel belt press. Hot rollers apply pressure to form a surface prepreg on one side of surface layer 1. The hot roller temperature is 295℃, the pressure is 0.6MPa, the lamination speed is 1.2m / min, and the areal density of the fiberglass cloth is 400g / m². 2 ;

[0058] Step B: Stack the surface prepreg, core layer 2, and surface prepreg in the order of surface prepreg and place them in a double steel strip press for pre-pressing. During pre-pressing, control the temperature of surface layer 1 at 290℃, the temperature of core layer 2 at 270℃, the pressure at 1.2MPa, and the pre-pressing time at 3min. After pre-pressing, raise the temperature for final pressing. During final pressing, control the temperature of surface layer 1 at 340℃, the temperature of core layer 2 at 310℃, the pressure at 6.0MPa, and the final pressing time at 4min. After final pressing, cool under the condition of maintaining 6.0MPa at a cooling rate of 15℃ / s. When the temperature of both surface layer 1 and core layer 2 drops below 100℃, use a cooling rate of 50℃ / min. At this time, a bonding layer 3 is formed between surface layer 1 and core layer 2 to fix and connect them.

[0059] Example 3

[0060] This embodiment provides an aerospace-grade lightweight flame-retardant composite interior trim panel, such as... Figure 1As shown, it includes a surface layer 1 and a core layer 2. The thickness of the surface layer 1 is 0.2 mm, and the thickness of the core layer 2 is 5 mm. The surface layer 1 and the core layer 2 are connected by a bonding layer 3. The surface layer 1 includes 95 parts by weight of PPS resin and 5 parts by weight of nano-montmorillonite. The core layer 2 includes 50 parts by weight of glass fiber, 40 parts by weight of PPS fiber, and 8 parts by weight of flame-retardant PC fiber.

[0061] The surface layer 1 is prepared by the following method:

[0062] PPS particles are vacuum dried to a moisture content of less than 0.03%, then added to an extruder and extruded at 330°C and a die pressure of 12 MPa to obtain surface layer 1.

[0063] The core layer 2 is prepared by the following method:

[0064] Step 1: Vacuum dry PC particles at 120℃ for 5 hours, then add the dried PC particles and phosphate flame retardant to the extruder through the feeding pipe, and extrude to obtain flame retardant PC fibers.

[0065] Step 2: Vacuum dry the PPS particles at 130℃ for 5 hours, then add the dried PPS particles to the extruder through the feeding pipe and extrude to obtain PPS fibers;

[0066] Step 3: Cut the glass fiber to a length of 51mm and soak it in KH-550 coupling agent for 10 minutes;

[0067] Step 4: Add the glass fiber obtained in Step 3, the flame-retardant PC fiber obtained in Step 1, and the PPS fiber obtained in Step 2 into a three-dimensional mixer in proportion and mix them. Under the conditions of wind speed of 9m / s and web laying speed of 1.8m / min, the airflow forms a web and cross-lays the web. The web thickness is 5.0mm to obtain the web.

[0068] Step 5: Feed the mesh obtained in Step 4 into the needle punching machine and pre-punch 180 needles / cm. 2 Initial shaping achieved, main needle count 250 needles / cm 2 The needle is inserted to a depth of 7-8 mm, causing the fibers to entangle and resulting in core layer 1.

[0069] The bonding layer 3 is formed by the following method:

[0070] Step A: Layer 1, fiberglass cloth, and surface layer 1 are stacked in the order listed and placed into a double steel belt press. Hot rollers apply pressure to form a surface prepreg on one side of surface layer 1. The hot roller temperature is 295℃, the pressure is 0.6MPa, the lamination speed is 1.2m / min, and the areal density of the fiberglass cloth is 200g / m². 2 ;

[0071] Step B: Stack the surface prepreg, core layer 2, and surface prepreg in the order of surface prepreg and place them in a double steel strip press for pre-pressing. During pre-pressing, control the temperature of surface layer 1 at 280℃, the temperature of core layer 2 at 260℃, the pressure at 1.0MPa, and the pre-pressing time at 2min. After pre-pressing, raise the temperature for final pressing. During final pressing, control the temperature of surface layer 1 at 330℃, the temperature of core layer 2 at 300℃, the pressure at 5.0MPa, and the final pressing time at 3min. After final pressing, cool under the condition of maintaining 5.0MPa at a cooling rate of 15℃ / s. When the temperature of both surface layer 1 and core layer 2 drops below 100℃, use a cooling rate of 50℃ / min. At this time, a bonding layer 3 is formed between surface layer 1 and core layer 2 to fix and connect them.

[0072] Application Example 1

[0073] The tensile strength, limiting oxygen index, peak heat release, and smoke density of the interior trim panels prepared in Example 3 were measured. Tensile strength was measured according to GB / T 1040.2-2022 "Determination of tensile properties of plastics – Part 2: Test conditions for molded and extruded plastics"; limiting oxygen index was measured according to GB / T 2406.2-2009 "Determination of burning behavior of plastics by oxygen index method – Part 2: Test at room temperature"; peak heat release was measured according to GB / T16172-2007 "Test method for heat release rate of building materials"; and smoke density was measured according to AITM2-0007 "Determination of specific optical density". The results are shown in the table below:

[0074]

[0075] Results Analysis: The experimental data above show that the interior trim panels provided by this invention meet aviation standards and achieve the intended purpose of this invention.

[0076] The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

[0077] Although this document frequently uses terms such as surface layer 1, core layer 2, and bonding layer 3, the possibility of using other terms is not excluded. These terms are used merely for the convenience of describing and explaining the essence of the invention; interpreting them as any additional limitation would contradict the spirit of the invention.

Claims

1. An aerospace-grade lightweight flame-retardant composite interior trim panel, comprising a surface layer (1) and a core layer (2), wherein the surface layer (1) and the core layer (2) are connected by a bonding layer (3), characterized in that: The outer layer (1) comprises 90-100 parts by weight of PPS resin and 0-10 parts by weight of nano-montmorillonite; the core layer (2) comprises 40-60 parts by weight of glass fiber, 30-50 parts by weight of PPS fiber and 5-10 parts by weight of flame-retardant PC fiber.

2. The aerospace-grade lightweight flame-retardant composite interior trim panel as described in claim 1, characterized in that: The thickness of the surface layer (1) is 0.1-0.4 mm, and the thickness of the core layer (2) is 2-10 mm.

3. The aerospace-grade lightweight flame-retardant composite interior trim panel as described in claim 1, characterized in that: The surface layer (1) is prepared by the following method: PPS particles are vacuum dried to a moisture content of less than 0.03%, and then added to an extruder for extrusion to obtain the surface layer (1).

4. The aerospace-grade lightweight flame-retardant composite interior trim panel as described in claim 3, characterized in that: The temperature of the extruder is 320-340℃, and the die pressure is 10-14MPa.

5. The aerospace-grade lightweight flame-retardant composite interior trim panel as described in claim 1, characterized in that: The core layer (2) is prepared by the following method: Step 1: Vacuum dry PC particles at 120℃ for 5 hours, then add the dried PC particles and phosphate flame retardant to the extruder through the feeding pipe, and extrude to obtain flame retardant PC fibers. Step 2: Vacuum dry PPS particles at 130℃ for 5 hours, then add the dried PPS particles to the extruder through the feeding pipe to extrude PPS fibers. Step 3: Add glass fiber, flame-retardant PC fiber obtained in Step 1 and PPS fiber obtained in Step 2 into a three-dimensional mixer in proportion and mix them. Under the conditions of wind speed of 9m / s and web laying speed of 1.8m / min, the airflow forms a web and cross-lays the web. The web thickness is 4.8-5.2mm to obtain the web. Step 4: Feed the mesh obtained in Step 3 into the needle punching machine and pre-punch 180 needles / cm. 2 Initial shaping achieved, main needle count 250 needles / cm 2 The needle is pierced to a depth of 7-8 mm, which causes the fibers to entangle and obtain the core layer (1).

6. The aerospace-grade lightweight flame-retardant composite interior trim panel as described in claim 5, characterized in that: The glass fibers are pretreated by the following method before mixing: Cut the glass fibers to a length of 50-52 mm and soak them in KH-550 coupling agent for 5-15 minutes.

7. The aerospace-grade lightweight flame-retardant composite interior trim panel as described in claim 1, characterized in that: The bonding layer (3) is formed by the following method: Step A: Stack the top layer (1), fiberglass cloth and top layer (1) in the order of double steel belt press, and press the hot roller to form a top layer prepreg on one side of the top layer (1); Step B: The surface prepreg, core layer (2) and surface prepreg are stacked in the order of being placed in a double steel belt press for pre-pressing. After pre-pressing, the temperature is raised for final pressing. After final pressing, the material is cooled under pressure holding conditions. At this time, a bonding layer (3) is formed between the surface layer (1) and the core layer (2) to fix and connect the surface layer (1) and the core layer (2).

8. The aerospace-grade lightweight flame-retardant composite interior trim panel as described in claim 7, characterized in that: In step A, the temperature of the hot roller is 295℃, the pressure is 0.6MPa, the lamination speed is 1.2m / min, and the areal density of the fiberglass cloth is 100-400g / m². 2 .

9. The aerospace-grade lightweight flame-retardant composite interior trim panel as described in claim 7, characterized in that: In step B, the temperature of the surface layer (1) during the pre-compression process is 270-290℃, the temperature of the core layer (2) is 250-270℃, the pressure is 0.8-1.2MPa, and the pre-compression time is 1-3min.

10. The aerospace-grade lightweight flame-retardant composite interior trim panel as described in claim 7, characterized in that: In step B, the temperature of the surface layer (1) during the final pressurization process is 320-340℃, the temperature of the core layer (2) is 290-310℃, the pressure is 4.0-6.0MPa, and the final pressurization time is 2-4min. The cooling rate after final pressurization in step B is 15℃ / s. When the temperatures of the surface layer (1) and the core layer (2) drop below 100℃, a cooling rate of 50℃ / min is then adopted.

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