Flame-retardant / heat-insulating carbon fiber composite multilayer honeycomb and preparation method thereof

Abstract

The invention discloses a flame-retardant / heat-insulating carbon fiber composite multi-layer honeycomb and a preparation method, relates to the field of lightweight composite material functionalization, combines various flame-retardant and heat-insulating composite structure layers with a lightweight high-strength carbon fiber honeycomb structure, and can solve the problem of single performance of materials and structures. The multi-layer honeycomb comprises a carbon fiber panel, a carbon fiber laminated plate core and a flame-retardant heat-insulating composite structure layer; the carbon fiber panel consists of an upper carbon fiber panel and a lower carbon fiber panel; the upper carbon fiber panel is arranged at the upper part of the carbon fiber laminated plate core, and the lower carbon fiber panel is arranged at the lower part of the carbon fiber laminated plate core; the carbon fiber laminated plate core is formed by interlocking a plurality of carbon fiber laminated plate interlocking strips with the same thickness; the flame-retardant and heat-insulating composite structure layer is made of a flame-retardant and heat-insulating material and is arranged on the fire-facing surface of the honeycomb or two sides of the honeycomb. The composite material has the advantages of light weight, high strength, flame retardance, heat insulation, simplicity and convenience in assembly, and easiness in large-scale production and manufacturing.

Description

Technical Field

[0001] The invention belongs to the field of functionalization of lightweight composite materials, and specifically relates to a flame retardant / heat insulating carbon fiber composite honeycomb multilayer structure and a preparation method thereof. Background Art

[0002] In the process of renewal of aviation, aerospace and shipbuilding materials, composite materials have gradually become the standard choice in structural design, especially composite honeycomb structures, which have been widely used in various industries due to their light weight, excellent specific strength and specific stiffness, and excellent mechanical properties.

[0003] In the field of ships, the flame retardancy and thermal insulation performance of composite materials has always been one of the most concerned issues for designers. At the same time, the thermal insulation problem of thermal equipment is also a huge challenge. Traditional thermal insulation materials, such as rock wool and mineral wool, although they have certain thermal insulation properties, have limitations in weight and load-bearing. The application of these materials in bulkheads, ship steam pipes, boilers and other equipment is often attached to the original structure, and it is necessary to sacrifice the lightness of the material to obtain better thermal insulation effect, resulting in an increase in the overall weight of the ship, affecting energy efficiency and speed. In addition, when ships are in service for a long time at sea, they face a more severe environment and higher requirements for thermal insulation materials, which requires the materials to have not only good thermal insulation properties, but also excellent corrosion resistance and long-term stability.

[0004] CN108819358A, the invention titled "A unidirectional carbon fiber composite multi-level honeycomb structure and its preparation method" discloses that the honeycomb structure is composed of an upper panel, a multi-level honeycomb structure sandwich layer and a lower panel; the multi-level honeycomb structure sandwich layer is assembled by a plurality of multi-level honeycomb interlocking strips with grooves, the multi-level honeycomb interlocking strips with grooves are composed of an upper composite material plate, a middle high-rigidity foam plate and a lower composite material plate, and the composite material plate is a plate paved with two layers of unidirectional carbon fiber composite materials. The invention solves the problem that the low-density area of ​​the composite honeycomb structure has low flat compressive strength and the shear strength is not as good as the composite pyramid lattice structure, improves the anti-buckling ability of the composite honeycomb wall, and improves the flat compressive strength and shear strength of the carbon fiber composite honeycomb structure.

[0005] Although coating rock wool on composite materials can improve the flame retardant and heat insulating properties of the structure, its disadvantages include the need to use nails to fix the rock wool on the surface of the material, poor process compatibility with composite materials, and will destroy the heat insulating properties of the overall structure. At present, there are also studies that use expanded fireproof non-woven fabrics as surface layers or intermediate functional layers to integrate with composite materials, which can effectively improve the fireproof ability of composite materials. However, when the temperature exceeds the excitation temperature of the expanded fireproof non-woven fabric, the structure of the composite material will fail and cannot be used any more.

[0006] Based on the above, the shipbuilding industry urgently needs a new type of load-bearing and heat-insulating integrated material that can provide excellent load-bearing performance, flame retardancy and heat insulation performance, as well as good durability while maintaining light weight. Carbon fiber composite materials have light weight, high strength, corrosion resistance and good fatigue performance, and have good application prospects in the shipbuilding industry. The development of this material will help improve the energy efficiency of ships, reduce maintenance costs, and enhance overall safety performance. However, there is currently a lack of ideal solutions that can meet these comprehensive requirements on the market. Summary of the invention

[0007] In order to solve the above technical problems, the present invention provides a flame retardant / heat insulating carbon fiber composite multilayer honeycomb and a preparation method thereof. The present invention combines a plurality of flame retardant and heat insulating composite structural layers with a lightweight and high-strength carbon fiber honeycomb structure, which can solve the problem of single performance of materials and structures.

[0008] The flame retardant / heat insulating carbon fiber composite multilayer honeycomb of the present invention comprises a carbon fiber panel, a carbon fiber laminate core and a flame retardant and heat insulating composite structural layer;

[0009] The carbon fiber panel is composed of an upper carbon fiber panel and a lower carbon fiber panel; the upper carbon fiber panel is arranged on the upper part of the carbon fiber laminate core, and the lower carbon fiber panel is arranged on the lower part of the carbon fiber laminate core;

[0010] The carbon fiber laminate core is formed by a plurality of carbon fiber laminate interlocking strips of equal thickness interlocked with each other; the flame retardant heat insulating composite structure layer is composed of two or more flame retardant heat insulating materials, and the flame retardant heat insulating composite structure layer is arranged on the fire-facing surface of the honeycomb or on both sides of the honeycomb.

[0011] Furthermore, the flame retardant and heat insulating composite structure layer is obtained by alternately laying two or more flame retardant and heat insulating materials.

[0012] Furthermore, the flame retardant heat insulating material is one or more of flame retardant foam, aerogel, and expanded fireproof non-woven fabric.

[0013] Furthermore, the intumescent fireproof non-woven fabric is located at the outermost layer of the flame retardant and heat insulating composite structure layer.

[0014] Furthermore, the thickness of the flame retardant foam and aerogel is 0.5 mm to 3.5 mm, the thermal conductivity range is 0.01-0.035 W / (mK), and the thickness of the expanded fireproof non-woven fabric is 0.5 mm to 2 mm.

[0015] Furthermore, the carbon fiber panel has a thickness of 0.5 mm to 3 mm.

[0016] Furthermore, the carbon fiber laminate is one of carbon fiber, carbon fiber / PMI, and foam / carbon fiber, and the core thickness of the carbon fiber laminate is 0.3 to 3.5 mm.

[0017] Furthermore, the flame retardant and heat insulating composite structure layer is arranged on the upper carbon fiber panel.

[0018] A method for preparing a flame retardant / heat insulating carbon fiber composite multilayer honeycomb of the present invention, wherein the flame retardant / heat insulating carbon fiber composite multilayer honeycomb preparation method is as follows:

[0019] The carbon fiber laminate core is formed by a plurality of slotted grille locking strips of equal thickness that are interlocked and fixed to each other, and the interlocking and fixing parts are connected with adhesive film. The upper surface of the carbon fiber laminate core and the upper carbon fiber panel are bonded together with adhesive, and the lower surface of the carbon fiber laminate core and the lower carbon fiber panel are bonded together with adhesive film; the lower carbon fiber panel and the flame-retardant and heat-insulating composite structure layer are bonded together with adhesive film.

[0020] Furthermore, the flame retardant heat insulating material is one or more of flame retardant foam, aerogel, and expanded fireproof non-woven fabric.

[0021] The present invention has the following beneficial effects:

[0022] The present invention adopts a honeycomb grid structure made of flame retardant materials on the basis of the traditional honeycomb structure. After ensuring a certain compressive resistance, a certain enclosed space can be left in the core part of the carbon fiber honeycomb structure to allow air to be retained therein. Since the thermal conductivity of air is very small, such a special design can bring relatively excellent flame retardant and heat insulating properties to the honeycomb structure.

[0023] In addition, a flame retardant and heat-insulating composite structure layer is added to the fire-facing side or both sides of the carbon fiber panel. This composite layer is a specific material combination and structural combination, including flame retardant foam / aerogel and expanded fireproof non-woven fabric, in which the flame retardant foam / aerogel is in direct contact with the carbon fiber honeycomb structure, and the expanded fireproof non-woven fabric is in direct contact with the flame retardant foam / aerogel, not in direct contact with the carbon fiber grid structure, and is located on the outermost side of the structure. The advantages of this fireproof structure are mainly the following aspects:

[0024] First, the composite structure layer brings less weight and lighter load to the structure as a whole, while greatly preventing the transfer of heat and playing an excellent thermal insulation effect. Secondly, the outermost layer of the expanded fireproof non-woven fabric is based on graphite, fused with mineral fiber and glass fiber. When it exceeds the expansion excitation temperature, it will produce a greater expansion effect, which has the beneficial effect of flame retardancy and fire resistance. Compared with the integration of the expanded fireproof non-woven fabric and the composite material or the placement of the middle layer, the placement of the outermost layer has the least impact on the structural integrity. Thirdly, the thermal conductivity of the intermediate flame-retardant foam / aerogel functional layer is low, which can reduce the effect of heat transfer. Finally, beyond expectations, compared with the thermal insulation layer without the thermal insulation layer and the thermal insulation layer of the aerogel alone, the introduction of the composite structure layer greatly improves the temperature uniformity and stability of the grid structure backplane. The main reason is that the introduction of the expansion layer and the middle layer changes the heat flow path and the thermal field distribution, and has a regulating effect on the temperature change rate of the heating and cooling process. When the fireproof non-woven fabric expands, the three-layer composite structure forms macro / fine / micro gradient pores, which effectively improves the heat transfer path and thermal stress matching of the flame-retardant and thermal insulation honeycomb grid.

[0025] The present invention combines the two functions of flame retardancy and heat insulation and load bearing, and adopts the off-site design of the honeycomb grid structure and the flame retardancy and heat insulation composite functional layer. The expansion of the outermost fireproof non-woven fabric will not affect the integrity of the overall structure, and at the same time plays a role in regulating the thermal field and improving uniformity. The middle flame retardant foam / aerogel functional layer has a heat insulation effect. The overall structure can have better mechanical property retention and a smaller dimensional change rate. At the same time, in addition to meeting the requirements of light weight, high strength, flame retardancy, and heat insulation, it also has the advantages of simple and convenient assembly, and easy mass production and manufacturing. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the honeycomb structure of the present invention;

[0027] Figure 2 It is a schematic diagram of the locking strip of the carbon fiber laminate in the honeycomb structure of the present invention;

[0028] Figure 3 This is a schematic diagram of the carbon fiber laminate core of the present invention;

[0029] Figure 4 It is a schematic diagram of combining the carbon fiber upper panel of the honeycomb structure of the present invention with the aerogel or flame retardant foam;

[0030] Figure 5 It is a schematic diagram of combining the carbon fiber upper panel of the honeycomb structure of the present invention with the expanded fireproof non-woven fabric;

[0031] Figure 6 It is a schematic diagram of combining the carbon fiber upper panel of the honeycomb structure of the present invention with aerogel or flame retardant foam and expanded fireproof non-woven fabric;

[0032] Figure 7 The time-temperature curve diagram of the center point of the back plate of Example 1;

[0033] Figure 8 The time-temperature curve of the center point of the back plate of comparative example 1;

[0034] Fig. 9 The time-temperature curve of the center point of the back plate of comparative example 1;

[0035] Fig.10 The maximum, minimum and average time-temperature curves on the center line of the back plate of Example 1;

[0036] Fig.11 The highest, lowest and average time-temperature curves on the center line of the back plate of Comparative Example 1;

[0037] Fig.12 The highest, lowest and average time-temperature curves on the center line of the back plate of Comparative Example 2;

[0038] In the figure, 1 is a carbon fiber upper panel, 2 is a carbon fiber laminate core, 3 is a carbon fiber lower panel, 4 is a carbon fiber laminate locking strip, 5 is aerogel or foam, and 6 is an expanded fireproof non-woven fabric. DETAILED DESCRIPTION

[0039] In order to make the objectives, technical solutions and advantages of the embodiments of the present invention more clearly understood, the spirit of the contents disclosed by the present invention will be described in detail below. After understanding the embodiments of the contents of the present invention, any technician in the relevant technical field can change and modify them according to the techniques taught by the contents of the present invention without departing from the spirit and scope of the contents of the present invention.

[0040] The exemplary embodiments of the present invention and the description thereof are used to explain the present invention but are not intended to limit the present invention.

[0041] Embodiment 1

[0042] A lightweight carbon fiber honeycomb structure integrating flame retardancy, heat insulation and load bearing in this embodiment is composed of an upper panel 1, a carbon fiber laminate core 2, a lower panel 3, an aerogel 5 and an expanded fireproof non-woven fabric 6;

[0043] The carbon fiber laminate core 2 is formed by a plurality of slotted grid locking strips 4 of equal thickness interlocked and fixed to each other, and the interlocking and fixing parts are connected with adhesive film;

[0044] The upper surface of the carbon fiber laminate core 2 and the upper panel 1 are bonded together by adhesive, and the lower surface of the carbon fiber laminate core 2 and the lower panel 3 are bonded together by adhesive film.

[0045] The lower panel 3 and the aerogel 5 are bonded together with an adhesive film.

[0046] The lower aerogel 5 and the expanded fireproof nonwoven fabric 6 are bonded together with an adhesive film.

[0047] Embodiment 2

[0048] This embodiment is different from the first embodiment in that the aerogel is replaced by flame retardant foam. The rest is the same as the first embodiment.

[0049] Embodiment 3

[0050] The difference between this embodiment and the first embodiment is that the upper and lower honeycomb panels are both pasted with a flame retardant and heat insulating composite structure layer. The rest is the same as the first embodiment.

[0051] Comparative Example 1

[0052] The lightweight carbon fiber honeycomb structure of this comparative example is composed of an upper panel 1, a carbon fiber laminate core 2, and a lower panel 3;

[0053] The carbon fiber laminate core 2 is formed by a plurality of slotted grid locking strips 4 of equal thickness interlocked and fixed to each other, and the interlocking and fixing parts are connected with adhesive film;

[0054] The upper surface of the carbon fiber laminate core 2 and the upper panel 1 are bonded together by adhesive, and the lower surface of the carbon fiber laminate core 2 and the lower panel 3 are bonded together by adhesive film.

[0055] Comparative Example 2:

[0056] The difference between this comparative example and comparative example 1 is that the lower panel 3 and the aerogel 5 are bonded together with an adhesive film.

[0057] Test results: At room temperature, the honeycomb structure was heated by a butane torch (flame temperature of about 850°C). The maximum temperature at the center of the back panel of the honeycomb structure without any flame retardant and heat insulation composite structure layer was about 140.5°C as measured by an infrared thermal imager. The air layer inside gave it a certain flame retardant and heat insulation effect. The maximum temperature of the flame retardant and heat insulation composite structure layer with aerogel and expanded fireproof non-woven fabric pasted on one side was reduced to about 102.9°C, further improving the flame retardant and heat insulation effect. Figure 7-9 For Example 1, the time from the highest temperature of the back plate to the stable state from the ambient temperature is 14 minutes, while for Comparative Examples 1 and 2, the time from the highest temperature of the back plate to the stable state from the ambient temperature is 9.5 minutes and 13 minutes. The temperature at the center point of the back plate of Example 1 rises more slowly than that of Example 1. Under the same time, the temperature at the center point of the back plate of Example 1 is lower; in addition, the maximum temperature of the embodiment is lower than that of the comparative example, and the thermal insulation performance is better.

[0058] Maximum temperature Embodiment 1 ～102℃ Comparative Example 1 ～140℃ Comparative Example 2 ～113℃ Comparative Example 2 ～113℃

[0059] In addition, the maximum, minimum and average temperature curves of the center line of the backplane of Example 1, Comparative Example 1 and Comparative Example 2 were tested, and the maximum and minimum temperature differences were ~8°C, ~20°C and ~21°C, respectively. In general, Example 1 has the best temperature uniformity and stability, while the temperatures of Comparative Examples 1 and 2 are relatively poor. Although aerogel is added to Comparative Example 2 to give it a good thermal insulation effect, the temperature uniformity and stability of the entire backplane are poor. This is because aerogel is not a strictly isotropic material, and its defects lead to uneven heat flow conduction when the thickness is thin.

Claims

1. A flame retardant / heat insulating carbon fiber composite multilayer honeycomb, characterized in that It comprises a carbon fiber panel, a carbon fiber laminate core (2) and a flame retardant and heat insulating composite structural layer; The carbon fiber panel is composed of an upper carbon fiber panel (1) and a lower carbon fiber panel (3); the upper carbon fiber panel (1) is arranged on the upper part of the carbon fiber laminate core (2), and the lower carbon fiber panel (3) is arranged on the lower part of the carbon fiber laminate core (2); The carbon fiber laminate core (2) is formed by a plurality of carbon fiber laminate interlocking strips (4) of equal thickness interlocked with each other; the flame retardant heat insulating composite structure layer is composed of two or more flame retardant heat insulating materials, and the flame retardant heat insulating composite structure layer is arranged on the fire-facing surface of the honeycomb or on both sides of the honeycomb.

2. The flame retardant / heat insulating carbon fiber composite multilayer honeycomb according to claim 1, characterized in that The flame retardant and heat insulating composite structure layer is obtained by alternately laying two or more flame retardant and heat insulating materials.

3. A flame retardant / heat insulating carbon fiber composite multilayer honeycomb according to claim 1 or 2, characterized in that The flame retardant heat insulating material is one or more of flame retardant foam, aerogel, and expanded fireproof non-woven fabric.

4. The flame retardant / heat insulating carbon fiber composite multilayer honeycomb according to claim 3, characterized in that The expanded fireproof non-woven fabric is located at the outermost layer of the flame-retardant and heat-insulating composite structure layer.

5. The flame retardant / heat insulating carbon fiber composite multilayer honeycomb according to claim 1, characterized in that The thickness of the flame retardant foam and aerogel is 0.5 mm to 3.5 mm, the thermal conductivity range is 0.01-0.035 W / (mK), and the thickness of the expanded fireproof non-woven fabric is 0.5 mm to 2 mm.

6. The flame retardant / heat insulating carbon fiber composite multilayer honeycomb according to claim 1, characterized in that The thickness of the carbon fiber panel is 0.5 mm to 3 mm.

7. The flame retardant / heat insulating carbon fiber composite multilayer honeycomb according to claim 1, characterized in that The carbon fiber laminate is one of carbon fiber, carbon fiber / PMI, and foam / carbon fiber. The core thickness of the carbon fiber laminate is 0.3-3.5 mm.

8. The flame retardant / heat insulating carbon fiber composite multilayer honeycomb according to claim 1, characterized in that The flame retardant and heat insulating composite structural layer is arranged on the upper carbon fiber panel (1).

9. A method for preparing a flame retardant / heat insulating carbon fiber composite multilayer honeycomb according to claim 1, characterized in that The method for preparing the flame retardant / heat insulating carbon fiber composite multilayer honeycomb is as follows: The carbon fiber laminate core (2) is formed by a plurality of slotted grille interlocking strips (4) of equal thickness interlocked and fixed to each other, and the interlocking and fixing parts are connected by adhesive film. The upper surface of the carbon fiber laminate core (2) and the upper carbon fiber panel (1) are bonded together by adhesive, and the lower surface of the carbon fiber laminate core (2) and the lower carbon fiber panel (3) are bonded together by adhesive film; the lower carbon fiber panel (3) and the flame-retardant and heat-insulating composite structure layer are bonded together by adhesive film.

10. The method for preparing a flame retardant / heat insulating carbon fiber composite multilayer honeycomb according to claim 9, characterized in that The flame retardant heat insulating material is one or more of flame retardant foam, aerogel, and expanded fireproof non-woven fabric.

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