A preparation method and system of honeycomb three-dimensional fabric composite material

Abstract

The present invention provides a preparation method and system of a honeycomb three-dimensional fabric composite material, the preparation method comprising: inserting a core mold into a three-dimensional fabric to obtain a preformed body, sealing the preformed body, and injecting resin into the sealed preformed body for precuring molding to obtain a prefabricated honeycomb three-dimensional fabric composite material containing a core mold; wherein the core mold comprises a heat-expandable rubber core mold and a fusible core mold, and the melting temperature of the fusible core mold is lower than the glass transition temperature of the resin and higher than the precuring temperature of the resin; heating the prefabricated honeycomb three-dimensional fabric composite material to remove the fusible core mold and complete curing, and then taking out the heat-expandable rubber core mold to obtain a honeycomb three-dimensional fabric composite material. The preparation method provided by the present scheme realizes the demolding-free and recycling of part of the core mold, improves the molding quality of the honeycomb three-dimensional fabric composite material, and reduces the production cost.

Description

Technical Field

[0001] The invention relates to the technical field of composite materials, and in particular to a preparation method and system of a honeycomb three-dimensional fabric composite material. Background Art

[0002] Honeycomb fabric composite material is a hollow structural material with an integrated fiber reinforced structure, which is composed of three-dimensional honeycomb fabric as the reinforcement phase and resin, ceramics, etc. as the matrix. It has the advantages of high specific strength, good impact resistance, and strong designability.

[0003] The honeycomb core is the key to the design and preparation of honeycomb three-dimensional fabric composite materials. The molding methods of continuous honeycomb three-dimensional fabric composite materials currently adopt bonding, hot pressing based on thermoplastic resin, roll forming, sewing, folding after cutting with prepreg, bonding and interlocking. However, this method has a simple preparation process and cannot achieve the preparation of truly continuous honeycombs, resulting in poor integrity of the obtained honeycomb three-dimensional fabric composite materials, low interlayer strength, and easy cracking at the bonding point.

[0004] Although the three-dimensional woven integrated honeycomb three-dimensional fabric composite material can change the shortcomings of poor interlayer performance of traditional bonding and interlocking methods, and also has the advantages of fast weaving speed and low cost, this type of method usually relies on the shaping of the core mold, and the process of wearing and demolding the core mold is very easy to damage the fibers and destroy the shape of the honeycomb. The Chinese patent with application number 2021108114000 discloses a three-dimensional woven fiber reinforced honeycomb preparation device and method based on a thermal expansion flexible core mold. A small number of rigid core molds are used in conjunction with thermal expansion silicone rubber core molds to reduce the damage to the three-dimensional woven fiber reinforced honeycomb caused by partial wearing and demolding. However, the device is complex and the processing accuracy requirements of the base of the device are high, which increases the production cost; and it is not considered that when the thermal expansion silicone rubber is completely cured and cooled, it will be constrained by the bonding force between the resin and the heat expansion silicone rubber, which will damage the quality of the inner wall of the honeycomb when shrinking. Summary of the invention

[0005] The invention provides a preparation method and system of a honeycomb three-dimensional fabric composite material. The preparation method realizes the demoulding-free and recycling of part of the core mold, improves the molding quality of the honeycomb three-dimensional fabric composite material, and reduces the production cost.

[0006] In a first aspect, the present invention provides a method for preparing a honeycomb three-dimensional fabric composite material, the preparation method comprising:

[0007] Inserting a core mold into the three-dimensional fabric to obtain a preform, sealing the preform, and injecting resin into the sealed preform for precuring molding to obtain a prefabricated honeycomb three-dimensional fabric composite material containing the core mold; wherein the core mold includes a thermal expansion rubber core mold and a meltable core mold, and the melting temperature of the meltable core mold is lower than the glass transition temperature of the resin and higher than the precuring temperature of the resin;

[0008] The prefabricated honeycomb three-dimensional fabric composite material is subjected to a heating treatment to remove the fusible core mold and complete solidification, and then the heat expansion rubber core mold is taken out to obtain the honeycomb three-dimensional fabric composite material.

[0009] Preferably, before the pre-curing molding, the cross-section of the heat-expandable rubber core mold is smaller than the cross-section of the honeycomb holes of the honeycomb three-dimensional fabric composite material.

[0010] Preferably, the temperature of the heat treatment is higher than the melting temperature and lower than the glass transition temperature of the resin.

[0011] Preferably, the number of the meltable core molds is greater than the number of the heat-expandable rubber core molds.

[0012] Preferably, the heat expandable rubber core molds are evenly spaced and distributed in the meltable core mold.

[0013] Preferably, the heat-expandable rubber core mold and the meltable core mold are arranged in an axisymmetric distribution.

[0014] More preferably, the number of the continuously adjacent heat-expandable rubber core dies located on the same straight line does not exceed 2.

[0015] Preferably, the honeycomb pore structure of the honeycomb three-dimensional fabric composite material is at least one of a regular hexagon, a triangle, a square, a rhombus, and a circle.

[0016] Preferably, the length of the core mold is greater than the height of the three-dimensional fabric.

[0017] More preferably, the length of the core mold is 5 to 20 mm higher than the height of the three-dimensional fabric.

[0018] Preferably, the viscosity of the resin injected into the sealed preform is not greater than 300 mPa·s.

[0019] Preferably, the three-dimensional fabric is at least one of alkali-free glass fiber fabric, carbon fiber fabric, ceramic fiber fabric, quartz fiber fabric, and aramid fiber fabric;

[0020] The resin is at least one of phenolic resin, epoxy resin, unsaturated polyester resin, bismaleimide resin, polyimide resin, cyanate resin, and silicon-containing aromatic acetylene resin.

[0021] Preferably, before inserting the core mold into the three-dimensional fabric, the method further comprises:

[0022] A release agent is coated on the surface of the core mold.

[0023] Preferably, before injecting the resin into the sealed preform, the method further comprises:

[0024] The resin is subjected to a degassing treatment.

[0025] In a second aspect, the present invention provides a system for preparing a honeycomb three-dimensional fabric composite material for implementing the preparation method described in the first aspect, the preparation system comprising: a resin guide device, a preform, and a heating device;

[0026] The preform is a three-dimensional fabric with a core mold inserted;

[0027] The core mold includes a heat expansion rubber core mold and a meltable core mold;

[0028] The preform is placed on the heating device; the resin guide device is connected to the preform;

[0029] The resin guide device is used to inject resin into the sealed preform; wherein the melting temperature of the meltable core mold is lower than the glass transition temperature of the resin and higher than the pre-curing temperature of the resin;

[0030] The heating device is used to pre-cure the preformed body injected with the resin to obtain a prefabricated honeycomb three-dimensional fabric composite material containing the core mold; and is used to heat the prefabricated honeycomb three-dimensional fabric composite material to remove the fusible core mold and complete curing.

[0031] Preferably, the preparation system further comprises: a core mold recovery preparation device;

[0032] The core mold recovery and preparation device is connected to the prefabricated honeycomb three-dimensional fabric composite material including the core mold;

[0033] The core mold recovery and preparation device is used to recover the meltable core mold after the heating treatment;

[0034] The core mold recovery and preparation device is also used to prepare the fusible core mold according to the structural size of the preset honeycomb holes of the honeycomb three-dimensional fabric composite material.

[0035] More preferably, the core mold recovery and preparation device includes a core mold preparation mechanism, a liquid control mechanism and a core mold recovery mechanism; wherein, the core mold preparation mechanism is used to prepare the meltable core mold through the liquid control mechanism, and the core mold recovery mechanism is used to recover the meltable core mold after the heating treatment.

[0036] Preferably, the preparation system further comprises: a core mold recovery preparation device;

[0037] After the precuring and forming and before the heating treatment, the core mold recovery and preparation device is connected to the prefabricated honeycomb three-dimensional fabric composite material containing the core mold, and the core mold recovery and preparation device and the prefabricated honeycomb three-dimensional fabric composite material containing the core mold are arranged side by side on a horizontally placed platform in the heating device;

[0038] During the heating treatment, the platform is adjusted to be placed vertically, and the core mold recovery and preparation device is located below the prefabricated honeycomb three-dimensional fabric composite material containing the core mold, so that the meltable core mold can be recovered into the core mold recovery and preparation device.

[0039] Preferably, the preparation system further comprises:

[0040] The core mold material and the core mold recovery and preparation device are determined according to the structural dimensions of the preset honeycomb holes of the honeycomb three-dimensional fabric composite material; wherein the cross-sections and dimensions of the meltable core molds prepared by different core mold recovery and preparation devices are different;

[0041] The core mold material is processed and formed by utilizing the core mold recovery and preparation device to prepare the meltable core mold.

[0042] Preferably, the resin flow guide device includes a flow valve and a flow guide tube; wherein the flow guide tube is used to transport the resin, and the number of the flow guide tubes is determined according to the structural size of the preset honeycomb holes of the honeycomb three-dimensional fabric composite material; the flow valve is used to control the flow rate of the resin in real time.

[0043] Preferably, the preparation system further comprises: a resin stirring and degassing device for stirring and mixing the resin and removing bubbles from the resin, and the resin stirring and degassing device is connected to the resin flow guiding device.

[0044] Compared with the prior art, the present invention has at least the following beneficial effects:

[0045] The embodiment of the present invention provides a method for preparing a honeycomb three-dimensional fabric composite material, which adopts a heat-expandable rubber core mold and a meltable core mold. The meltable core mold is used as a rigid core mold to cooperate with the flexible heat-expandable rubber core mold. The heat-expandable rubber core mold reduces the difficulty of inserting the core mold. Since the melting temperature of the meltable core mold is lower than the glass transition temperature of the resin and higher than the pre-curing temperature of the resin, the preliminary shaping of the honeycomb pore structure can be achieved after pre-curing. Then, the meltable core mold can be removed from the mold and recycled by heating, and the resin can be completely cured. Moreover, since the meltable core mold does not need to be demolded, the molding quality of the honeycomb three-dimensional fabric composite material is improved, the production cost is reduced, and the production efficiency is improved.

[0046] In the present invention, at room temperature, the cross-section of the heat-expandable rubber core mold is smaller than the cross-section of the honeycomb hole of the honeycomb three-dimensional fabric composite material. Therefore, a small amount of heat-expandable rubber core molds are cross-inserted into the fusible core mold to avoid the fibers being too tight to be inserted into all the core molds, thereby reducing the difficulty of inserting the core molds and even avoiding excessive pulling of the fibers. The heat-expandable rubber core mold is reduced in volume after pre-curing, heating, and cooling, and is reduced to a state where the cross-section is smaller than the cross-section of the honeycomb hole, which is convenient for demolding and avoids damage to the honeycomb hole wall caused by forced demolding. At the same time, the number of fusible core molds used in the present invention is greater than the number of heat-expandable rubber core molds, which reduces the influence of the bonding force between the heat-expandable rubber core mold and the resin after cooling on the quality of the inner wall of the honeycomb hole.

[0047] In the present invention, the preparation system adopts a resin flow guide device, and the number of flow guide tubes can be determined according to the structural size of the preset honeycomb holes of the honeycomb three-dimensional fabric composite material, which is conducive to promoting the uniform infusion of resin into the three-dimensional fabric, making the three-dimensional fabric evenly impregnated with resin, improving the uniformity of the resin in the honeycomb three-dimensional fabric composite material, and optimizing the molding quality of the composite material. At the same time, the resin stirring and degassing device can evenly mix the single component or different components of resin, and further remove the bubbles in the resin before infusion, further improve the impregnation uniformity, reduce the generation of bubbles, and improve the molding quality of the honeycomb three-dimensional fabric composite material.

[0048] In the present invention, a matching core mold recovery and preparation device can be selected according to the preset structural size of the honeycomb hole, and honeycomb three-dimensional fabric composite materials with various honeycomb hole sizes can be flexibly prepared to improve production efficiency.

[0049] The preparation system provided by the present invention can rely on gravity to achieve automatic recovery of the fusible core mold during the heating process by controlling the placement direction of the platform during the pre-curing molding process and the heating process, thereby simplifying the manual operation process and improving the preparation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1It is a schematic diagram of an arrangement of a heat-expandable rubber core mold and a meltable core mold provided by one embodiment of the present invention;

[0051] Figure 2 It is a schematic diagram of another arrangement of a heat-expandable rubber core mold and a meltable core mold provided by one embodiment of the present invention;

[0052] Figure 3 It is a structural diagram of a system for preparing a honeycomb three-dimensional fabric composite material provided by one embodiment of the present invention;

[0053] Figure 4 It is a structural schematic diagram of a core mold recovery and preparation device provided by one embodiment of the present invention;

[0054] Figure 5 It is a schematic diagram of the connection of a prefabricated honeycomb three-dimensional fabric composite material including a core mold, a core mold recovery and preparation device, a platform angle adjustment component and a platform provided by one embodiment of the present invention;

[0055] Figure 6 It is a schematic diagram of another prefabricated honeycomb three-dimensional fabric composite material including a core mold, a core mold recovery and preparation device, a platform angle adjustment component and a connection of the platform provided by one embodiment of the present invention;

[0056] Figure 7 It is a three-dimensional structural diagram of another system for preparing a honeycomb three-dimensional fabric composite material provided by one embodiment of the present invention. DETAILED DESCRIPTION

[0057] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0058] An embodiment of the present invention provides a method for preparing a honeycomb three-dimensional fabric composite material, the preparation method comprising:

[0059] Inserting the core mold into the three-dimensional fabric to obtain a preform, sealing the preform, and injecting resin into the sealed preform for precuring molding to obtain a prefabricated honeycomb three-dimensional fabric composite material containing the core mold; wherein the core mold includes a thermal expansion rubber core mold and a meltable core mold, and the melting temperature of the meltable core mold is lower than the glass transition temperature of the resin and higher than the precuring temperature of the resin;

[0060] The prefabricated honeycomb three-dimensional fabric composite material is subjected to a heating treatment to remove the fusible core mold and complete solidification, and then the heat expansion rubber core mold is taken out to obtain the honeycomb three-dimensional fabric composite material.

[0061] It should be noted that the heating treatment includes a first heating treatment and a second heating treatment, wherein the first heating treatment is used to remove the meltable core mold and the second heating treatment is used to complete the curing of the resin. The curing of the resin in the present invention preferably adopts a gradient heating curing method.

[0062] The preparation method of the present invention adopts a heat-expandable rubber core mold and a meltable core mold. The meltable core mold is used as a rigid core mold to cooperate with the flexible heat-expandable rubber core mold. The heat-expandable rubber core mold reduces the difficulty of inserting the core mold. Since the melting temperature of the meltable core mold is lower than the glass transition temperature of the resin and higher than the pre-curing temperature of the resin, the preliminary shaping of the honeycomb pore structure can be achieved after pre-curing. Then, the meltable core mold can be free of demoulding and recycled by heating treatment, and the resin can be completely cured. Moreover, since the meltable core mold does not need to be demoulded, the molding quality of the honeycomb three-dimensional fabric composite material is improved, the production cost is reduced, and the production efficiency is improved.

[0063] It should be noted that the meltable core mold includes but is not limited to materials such as paraffin wax, PLA plastic, and meltable foam. Sealing is achieved by laying a vacuum bag on the preform.

[0064] According to some preferred embodiments, before pre-curing and molding, the cross-section of the heat-expandable rubber core mold is smaller than the cross-section of the honeycomb holes of the honeycomb three-dimensional fabric composite material.

[0065] It should be noted that before pre-curing molding, that is, at room temperature (for example, 20°C to 30°C), the cross-section of the heat expansion rubber core mold is smaller than the cross-section of the honeycomb holes of the honeycomb three-dimensional fabric composite material. As the temperature gradually increases, the heat expansion rubber core mold expands in volume. However, before the pre-curing molding temperature, the expansion of the heat expansion rubber core mold reaches stability. At this time, the cross-section of the heat expansion rubber core mold is the same as the cross-section of the honeycomb holes of the honeycomb three-dimensional fabric composite material, and is also the same as the cross-section of the meltable core mold.

[0066] According to some preferred embodiments, the temperature of the heating treatment is higher than the melting temperature and lower than the glass transition temperature of the resin.

[0067] It should be noted that the heat-expandable rubber core mold includes but is not limited to heat-expandable silicone rubber.

[0068] In the present invention, the heat-expandable rubber core mold expands in volume after being heated. Since the cross-section of the heat-expandable rubber core mold is smaller than the cross-section of the honeycomb hole of the honeycomb three-dimensional fabric composite material at room temperature, a small amount of heat-expandable rubber core molds are cross-inserted into the fusible core mold to avoid the fibers being too tight to be inserted, reduce the difficulty of inserting the core mold, and even avoid excessive pulling of the fibers. During the curing and molding process, the cross-section of the expanded heat-expandable rubber core mold is the same as the cross-section of the honeycomb hole, so that the honeycomb three-dimensional fabric composite material can still obtain regular honeycomb holes based on the heat-expandable rubber core mold and the fusible core mold. In addition, the heat-expandable rubber core mold shrinks in volume after being heated and then cooled, and the cross-section after shrinkage is restored to a state smaller than the cross-section of the honeycomb hole, which is convenient for demoulding and avoids damage to the honeycomb hole wall caused by forced demoulding.

[0069] According to some preferred embodiments, the number of the meltable core molds is greater than the number of the heat-expandable rubber core molds; and the heat-expandable rubber core molds are evenly spaced and distributed in the meltable core molds.

[0070] The number of fusible core molds used in the present invention is greater than the number of heat-expandable rubber core molds, and the heat-expandable rubber core molds are evenly spaced in the fusible core molds and are arranged at periodic intervals. This not only reduces the influence of the bonding force between the heat-expandable rubber core mold and the resin on the quality of the inner wall of the honeycomb hole after cooling, but also reduces the difficulty of inserting the rigid fusible core mold with the help of the flexible heat-expandable rubber core mold.

[0071] According to some more preferred embodiments, the heat-expandable rubber core mold and the meltable core mold are arranged in an axisymmetric distribution.

[0072] According to some more preferred embodiments, the number of consecutively adjacent heat-expandable rubber core molds located on the same straight line does not exceed 2 (for example, it may be 2 or 1).

[0073] In a specific embodiment, Figure 1 and Figure 2 As shown, for the regular hexagonal honeycomb holes, each regular hexagon is a honeycomb grid, the fusible core mold adopts a paraffin core mold, and the heat expansion rubber core mold adopts a heat expansion silicone rubber core mold. Figure 1 In the figure, 7 honeycomb cells are regarded as a group, which consists of a regular hexagon located in the center and 6 regular hexagons located at the periphery thereof. The 6 honeycomb cells located at the periphery are inserted into the paraffin core mold, and the 1 honeycomb cell in the center is inserted into the heat expansion silicone rubber core mold. Figure 2In the embodiment, 19 honeycomb cells are regarded as a group, which consists of a regular hexagon located in the center, 6 regular hexagons located in the second outer layer surrounding the center, and 12 regular hexagons located in the outermost layer; wherein, the central honeycomb cell is inserted into the fusible core mold, the 6 honeycomb cells in the second outer layer are inserted into the heat-expandable silicone rubber core mold, and the 12 honeycomb cells in the outermost layer are inserted into the fusible core mold. It should be noted that the arrangement of the heat-expandable rubber core mold and the fusible core mold of the present invention is not limited to Figure 1 and Figure 2 Two combination rules.

[0074] According to some preferred embodiments, the honeycomb pore structure of the honeycomb three-dimensional fabric composite material is at least one of a regular hexagon, a triangle, a square, a rhombus, and a circle.

[0075] It should be noted that at least one is any one or a mixture of any several in any proportion.

[0076] According to some preferred embodiments, the length of the core mold is greater than the height of the three-dimensional fabric.

[0077] In the present invention, the height of the core mold is higher than the height of the three-dimensional fabric, so that the core mold can pass through the three-dimensional fabric, thereby better maintaining the structure of the honeycomb holes.

[0078] According to some more preferred embodiments, the length of the core mold is 5 to 20 mm higher than the height of the three-dimensional fabric (for example, it can be 5 mm, 5.5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, 19 mm or 20 mm).

[0079] According to some preferred embodiments, the viscosity of the resin injected into the sealed preform is not greater than 300 mPa·s (for example, it may be 300 mPa·s, 280 mPa·s, 260 mPa·s, 250 mPa·s, 240 mPa·s, 220 mPa·s, 200 mPa·s, 180 mPa·s, 160 mPa·s, 150 mPa·s, 140 mPa·s, 120 mPa·s or 100 mPa·s, etc.).

[0080] According to some preferred embodiments, before injecting resin into the sealed preform, the method further comprises:

[0081] Degas the resin.

[0082] Specifically, after determining the amount of resin according to the structural dimensions of the preset honeycomb holes and the quality of the three-dimensional fabric, set the appropriate resin stirring time and speed with reference to the resin characteristics and actual operation experience, heat and stir the fixed amount of resin, and after sufficient stirring, set the appropriate vacuum time and pressure to degas the resin. After the resin degassing treatment is completed, turn on the vacuum pump to vacuum the sealed preform, and then use the vacuum pressure to introduce the resin into the three-dimensional fabric. During the diversion, the flow valve is used to adjust the resin flow rate, flow rate and other parameters in real time to ensure that the resin and the honeycomb are completely infiltrated and the resin is well uniform.

[0083] In the present invention, the viscosity of the resin poured into the sealed preform is controlled to be no more than 300 mPa·s, so that the resin can fully infiltrate the three-dimensional fabric while ensuring the fluidity of the resin.

[0084] According to some preferred embodiments, the three-dimensional fabric is at least one of an alkali-free glass fiber fabric, a carbon fiber fabric, a ceramic fiber fabric, a quartz fiber fabric, and an aramid fiber fabric;

[0085] The resin is at least one of phenolic resin, epoxy resin, unsaturated polyester resin, bismaleimide resin, polyimide resin, cyanate resin, and silicon-containing aromatic acetylene resin.

[0086] It should be noted that the three-dimensional fabric includes but is not limited to the above-mentioned fiber fabric types, and the three-dimensional fabric is obtained by using but is not limited to weaving, knitting, sewing and other technologies. The resin includes but is not limited to the above-mentioned resin. In addition, a curing agent is added to the resin to complete the curing and molding, and a diluent, accelerator, initiator and filler can also be added to the resin as needed.

[0087] According to some preferred embodiments, before inserting the core mold into the three-dimensional fabric, the method further includes:

[0088] Apply a release agent to the surface of the core mold.

[0089] The present invention also provides a system for preparing a honeycomb three-dimensional fabric composite material, which is used to implement any of the above-mentioned preparation methods, such as Figure 3 As shown, the preparation system includes: a resin guiding device 301, a preform 302 and a heating device 303;

[0090] The preform 302 is a three-dimensional fabric 305 with a core mold 304 inserted;

[0091] The core mold 304 includes a heat-expandable rubber core mold 3041 and a meltable core mold 3042;

[0092] The preform 302 is placed on the heating device 303; the resin guide device 301 is connected to the preform 302;

[0093] The resin guide device 301 is used to inject resin into the sealed preform 302; wherein the melting temperature of the fusible core mold 3042 is lower than the glass transition temperature of the resin and higher than the pre-curing temperature of the resin;

[0094] The heating device 303 is used to pre-cure the preformed body 302 injected with resin to obtain a prefabricated honeycomb three-dimensional fabric composite material including a core mold 304; and to heat the prefabricated honeycomb three-dimensional fabric composite material to remove the fusible core mold and complete the curing.

[0095] According to some preferred embodiments, after the curing is completed, the step further includes taking out the heat-expandable rubber core mold.

[0096] According to some preferred embodiments, the preparation system further comprises: a core mold recovery preparation device;

[0097] The core mold recovery and preparation device is connected to the prefabricated honeycomb three-dimensional fabric composite material including the core mold;

[0098] The core mold recovery and preparation device is used to recover the meltable core mold after the heating treatment;

[0099] The core mold recovery and preparation device is also used to prepare a fusible core mold according to the structural size of the preset honeycomb holes of the honeycomb three-dimensional fabric composite material.

[0100] According to some more preferred embodiments, the core mold recovery and preparation device includes a core mold preparation mechanism, a liquid control mechanism and a core mold recovery mechanism; wherein the core mold preparation mechanism is used to prepare a meltable core mold through the liquid control mechanism, and the core mold recovery mechanism is used to recover the meltable core mold after heat treatment.

[0101] More importantly, the core mold preparation mechanism includes a plurality of core molds. When determining the number of heat-expandable rubber core molds and meltable core molds, the number of meltable core molds prepared by the core mold recovery and preparation device can be selected as needed.

[0102] In a specific embodiment, Figure 4 As shown, for the regular hexagonal honeycomb holes, the core mold recovery and preparation device includes a core mold preparation mechanism 401, a liquid control mechanism 402 and a core mold recovery mechanism 403. The core mold preparation mechanism 401 includes 24 core mold molds, and the liquid control mechanism 402 is used to control the flow rate, flow rate and other parameters of the material of the fusible core mold flowing into the core mold preparation mechanism 401, and control part or all of the core mold molds to obtain the required number of fusible core molds.

[0103] According to some preferred embodiments, the preparation system further comprises: a core mold recovery preparation device;

[0104] After pre-curing and before heating, the core mold recovery and preparation device is connected to the prefabricated honeycomb three-dimensional fabric composite material containing the core mold, and the core mold recovery and preparation device and the prefabricated honeycomb three-dimensional fabric composite material containing the core mold are arranged side by side on a horizontally placed platform in the heating device;

[0105] During the heating treatment, the platform is adjusted to be placed vertically, and the core mold recovery and preparation device is located below the prefabricated honeycomb three-dimensional fabric composite material containing the core mold, so that the fusible core mold can be recovered into the core mold recovery and preparation device.

[0106] It should be noted that the core mold recovery preparation device and the prefabricated honeycomb three-dimensional fabric composite material containing the core mold are both fixed on the platform through a detachable connection. When the resin is injected into the preform, the core mold recovery preparation device is not placed on the platform of the heating device; after the precuring molding is completed, before the heating treatment, the core mold recovery preparation device is placed on the platform and connected to the prefabricated honeycomb three-dimensional fabric composite material containing the core mold.

[0107] The preparation system provided by the present invention can rely on gravity to achieve automatic recovery of the fusible core mold during the heating process by controlling the placement direction of the platform during the curing molding process and the heating process. This not only simplifies the manual operation process and improves the preparation efficiency, but also does not require a high-precision device positioning base.

[0108] In a specific embodiment, Figure 5 and Figure 6 As shown, Figure 5 The figure shows that when the platform D is placed horizontally, the prefabricated honeycomb three-dimensional fabric composite material I including the core mold is located on the left side of the core mold recovery and preparation device E; the platform angle adjustment member F is used to adjust the platform D to be placed horizontally or vertically. When the platform is flipped 90° by the platform angle adjustment member F, as shown in FIG. Figure 6 As shown, the prefabricated honeycomb three-dimensional fabric composite material I including the core mold is located above the core mold recovery and preparation device E.

[0109] According to some preferred embodiments, the preparation system further comprises:

[0110] The core mold material and the core mold recovery and preparation device are determined according to the structural dimensions of the preset honeycomb holes of the honeycomb three-dimensional fabric composite material; wherein the cross-sections and dimensions of the fusible core molds prepared by different core mold recovery and preparation devices are different;

[0111] The core mold material is processed and formed by utilizing the core mold recovery and preparation device to prepare a fusible core mold.

[0112] In the present invention, a matching core mold recovery and preparation device can be selected according to the preset structural size of the honeycomb hole, and honeycomb three-dimensional fabric composite materials with various honeycomb hole sizes can be flexibly prepared to improve production efficiency.

[0113] According to some preferred embodiments, the resin guide device includes a flow valve and a guide tube; wherein the guide tube is used to transport the resin, and the number of the guide tubes is determined according to the structural size of the preset honeycomb holes of the honeycomb three-dimensional fabric composite material; the flow valve is used to control the flow rate of the resin in real time.

[0114] In the present invention, the preparation system determines the number of inlets and outlets of the resin guide device according to the size of the honeycomb holes, and connects a corresponding number of guide tubes (for example, 1, 2, 3, 4 or 5, etc.). This is conducive to promoting the uniform infusion of resin into the three-dimensional fabric, making the three-dimensional fabric evenly impregnated with resin, improving the uniformity of the resin in the honeycomb three-dimensional fabric composite material, especially the resin uniformity of the honeycomb wall, and optimizing the molding quality of the composite material.

[0115] According to some preferred embodiments, the preparation system further comprises: a resin stirring and degassing device for stirring and mixing the resin and removing bubbles from the resin, and the resin stirring and degassing device is connected to the resin guiding device.

[0116] The resin stirring and degassing device used in the present invention can evenly mix single-component or different-component resins, and can further remove bubbles in the resin before infusion, further improve impregnation uniformity, reduce bubble generation, and improve the molding quality of the honeycomb three-dimensional fabric composite material.

[0117] In order to more clearly illustrate the technical solution and advantages of the present invention, a preparation method and system of a honeycomb three-dimensional fabric composite material are described in detail below through several embodiments.

[0118] In the following embodiments, the Figure 7 The preparation system shown is used to prepare a honeycomb three-dimensional fabric composite material. Figure 7 As shown, the preparation system includes: a resin stirring and degassing device 701, a resin flow guiding device 702, a vacuum heating device, a platform D, a platform angle adjustment component F, a vacuum pump G and a preform I; wherein, the resin stirring and degassing device 701 includes a feed port A, and is provided with a plurality of sub-ports (for example, three sub-ports A1, A2, and A3) to adapt to different types of resins, a stirring component B, and a degassing device C. It should be noted that before pre-curing, I is the pre-form; after pre-curing, I is the prefabricated honeycomb three-dimensional fabric composite material including the core mold.

[0119] Specifically, the core mold recovery preparation device E used in Examples 1 and 2 is as follows: Figure 4As shown, the arrangement and distribution of the heat-expandable silicone rubber core mold and the paraffin core mold inserted into the three-dimensional fabric in the preform of Example 1 is as follows: Figure 1 The arrangement of the heat-expandable silicone rubber core mold and the PLA core mold inserted into the three-dimensional fabric in the preform of Example 2 is shown in FIG. Figure 2 The periodic arrangement shown.

[0120] It should be noted that the stirring component B includes but is not limited to a stirring container, a stirring mechanism, a temperature control mechanism, a resin concentration detection mechanism, etc., and can adjust parameters such as stirring speed, stirring force, stirring temperature, etc. according to different resin types. Figure 7 The connection relationship between the various devices in the resin stirring and degassing-resin diversion-precuring molding process is shown in FIG. It should be noted that after the resin infusion is completed, the resin diversion device is turned off and the vacuum pump is kept running for 1 to 2 minutes.

[0121] Example 1

[0122] A method for preparing a honeycomb three-dimensional fabric composite material comprises the following steps:

[0123] (1) Epoxy resin is selected as the resin, and the curing temperature curve is 40°C*1h+70°C*6h. Paraffin is selected as the meltable core mold according to the curing temperature curve of epoxy resin;

[0124] (2) The three-dimensional fabric selects a carbon fiber braid with an overall size of 250*100*150mm, and the preset honeycomb grid has a cross-section of a regular hexagon with a side length of 6.8mm and a length of 150mm. Select a matching core mold recovery and preparation device E to prepare the paraffin into a regular hexagonal prism core mold with a cross-section of 6.8mm and a length of 155mm (that is, a molten paraffin core mold). After spraying the release agent on the surface of the paraffin core mold several times, stretch the three-dimensional fabric to open the honeycomb grid, and then insert the paraffin core mold into the honeycomb grid of the three-dimensional fabric; there will still be a certain degree of difficulty in interlacing, so a small amount of heat-expandable silicone rubber core molds need to be periodically cross-inserted (at this time, the cross-section of the heat-expandable silicone rubber core mold is a regular hexagon with a side length of less than 6.8mm and a length of 155mm; during the curing and molding process, its cross-section expands to a regular hexagon with a side length of 6.8mm), such as Figure 1 As shown, the three-dimensional fabric with the core mold inserted is the preform.

[0125] (3) The preform is fixed on the platform D of the heating device through a detachable connection, and the preform on the platform D is covered with a guide net and a vacuum bag in turn for sealing, and a resin guide tube is connected to the preform by a resin guide device. Since the molding requirements of the honeycomb three-dimensional fabric are relatively high, secondary sealing is generally performed.

[0126] (4) According to the preset honeycomb grid and the three-dimensional fabric in step (2), the amount of epoxy resin is determined to be 3 kg, and the epoxy resin component A and component B are added from the feed ports A1 and A2 of the resin stirring and degassing device according to the proportion and amount. The resin stirring time is set to 10 min and the stirring speed is set to 200 r / min. After sufficient stirring, the resin is degassed and degassed at 10 to 20 kPa for 10 min.

[0127] (5) After the resin degassing treatment is completed, turn on the vacuum pump G to evacuate the three-dimensional fabric for 5 minutes.

[0128] (6) Open the resin guide device 702 and start the guide; according to the honeycomb guide effect, adjust the resin flow rate in real time on the guide control device to ensure that the resin and the three-dimensional fabric are completely infiltrated and the resin is well uniform.

[0129] (7) Turn off the resin guide device 702, adjust the temperature setting of the heating device, and raise the temperature to 40°C to allow the three-dimensional fabric impregnated with resin to begin to solidify. After 0.5 hours of the resin pre-curing stage, remove the vacuum bag, guide net, and guide tube. Fix the core mold recovery preparation device E on the platform D through a detachable connection (such as Figure 5 As shown), E is connected to the prefabricated honeycomb three-dimensional fabric composite material I including the core mold obtained after pre-curing and molding, so as to completely cover the three-dimensional fabric. Among them, the size of the core mold recovery preparation device E is slightly larger than the size of 250*100mm.

[0130] (8) Rotate platform D 90° so that the platform is perpendicular to the ground (e.g. Figure 6 As shown), the prefabricated honeycomb three-dimensional fabric composite material I including the core mold is connected to the core mold recovery and preparation device E, and the temperature is continued to rise to the melting temperature of the paraffin core mold of 60°C. The paraffin core mold begins to melt, and the molten paraffin flows into the core mold recovery and preparation device E below.

[0131] (9) After the wax core mold is completely melted, the core mold is removed and recycled to the preparation device E, and the recycled wax liquid can be remade into a wax core mold in this device.

[0132] (10) Continue to raise the temperature to 70°C according to the curing curve, and cure the pre-cured three-dimensional fabric for 6 hours. After the curing is completed, cool naturally, take out the thermal expansion silicone rubber core mold, and obtain a high-quality honeycomb three-dimensional fabric composite material.

[0133] Example 2

[0134] A method for preparing a honeycomb three-dimensional fabric composite material comprises the following steps:

[0135] (1) The resin is selected as cyanate resin, and the curing temperature curve is 130℃*1h+140℃*1h+160℃*2h+180℃*2h+200℃*2h+220℃*2h. PLA plastic is selected as the meltable core mold according to the curing temperature curve of cyanate resin;

[0136] (2) The three-dimensional fabric selects a glass fiber woven fabric with an overall size of 500*150*300mm, and the preset cross-section of the honeycomb grid is a regular hexagon with a side length of 15.7mm and a length of 300mm. Select a matching core mold recovery and preparation device E to prepare the PLA plastic into a regular hexagonal prism core mold with a cross-section of 15.7mm and a length of 310mm (that is, a fusible PLA core mold). After spraying the release agent on the surface of the PLA core mold several times, stretch the three-dimensional fabric to open the honeycomb grid, and then insert the PLA core mold into the honeycomb grid of the three-dimensional fabric; there will still be a certain degree of difficulty in interlacing, so a small amount of heat-expandable silicone rubber core molds need to be periodically cross-inserted (at this time, the cross-section of the heat-expandable silicone rubber core mold is a regular hexagon with a side length of less than 6.8mm and a length of 155mm; during the curing process, its cross-section expands to a regular hexagon with a side length of 6.8mm), such as Figure 2 As shown, the three-dimensional fabric with the core mold inserted is the preform.

[0137] (3) The preform is fixed on the platform D of the heating device through a detachable connection, and the preform on the platform D is covered with a guide net and a vacuum bag in turn for sealing, and two resin guide tubes are connected to the preform by a resin guide device. Since the molding requirements of the honeycomb three-dimensional fabric are relatively high, secondary sealing is generally performed.

[0138] (4) According to the preset honeycomb grid and the three-dimensional fabric in step (2), the amount of cyanate resin is determined to be 7 kg, and the cyanate resin is added from the feed port A1 of the resin stirring and degassing device. Since the cyanate resin is solid at room temperature, it needs to be heated and melted into a liquid at a heating temperature of 100°C, and then stirred. Set the resin stirring time to 10 minutes and the stirring speed to 100 r / min. After sufficient stirring, the resin is degassed, and the degassing time is 20 minutes at 10-20 kPa.

[0139] (5) After the resin degassing treatment is completed, turn on the vacuum pump G to evacuate the three-dimensional fabric of the preform I for 10 minutes.

[0140] (6) Open the resin guide device 702, output the resin from the two guide pipes and start the guide; according to the honeycomb guide effect, adjust the resin flow rate in real time on the guide control device to ensure that the resin and the three-dimensional fabric are completely infiltrated and the resin is well uniform.

[0141] (7) Turn off the resin guide device 702, adjust the temperature setting of the vacuum heating device, and raise the temperature to 130°C to allow the three-dimensional fabric impregnated with resin to begin to solidify. After the resin begins to pre-cure for 1 hour, remove the vacuum bag, guide net, and guide tube. Fix the core mold recovery preparation device E on the platform D through a detachable connection (such as Figure 5 As shown), E is connected to the prefabricated honeycomb three-dimensional fabric composite material I including the core mold obtained after pre-curing and molding, so as to completely cover the three-dimensional fabric. Among them, the size of the core mold recovery preparation device E is slightly larger than the size of 500*150mm.

[0142] (8) Rotate platform D 90° so that the platform is perpendicular to the ground (e.g. Figure 6 As shown), the prefabricated honeycomb three-dimensional fabric composite material I including the core mold is connected to the core mold recovery and preparation device E, and the temperature is continued to be increased to the melting temperature of the PLA core mold of 150°C, the PLA core mold begins to melt, and the molten PLA flows into the core mold recovery and preparation device E below.

[0143] (9) After the PLA core mold is completely melted, the core mold is removed and recycled to the preparation device E, and the recycled PLA can be remade into a PLA core mold in this device.

[0144] (10) Continue to raise the temperature according to the curing curve to complete the subsequent curing. After the curing is completed, cool naturally and take out the thermal expansion silicone rubber core mold to obtain a high-quality honeycomb three-dimensional fabric composite material.

[0145] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention. The parts not described in detail in the present invention are well-known technologies of those skilled in the art.

Claims

1. A method for preparing a honeycomb three-dimensional fabric composite material, characterized in that: The preparation method comprises: Inserting a core mold into the three-dimensional fabric to obtain a preform, sealing the preform, and injecting resin into the sealed preform for precuring molding to obtain a prefabricated honeycomb three-dimensional fabric composite material containing the core mold; wherein the core mold includes a thermal expansion rubber core mold and a meltable core mold, and the melting temperature of the meltable core mold is lower than the glass transition temperature of the resin and higher than the precuring temperature of the resin; The prefabricated honeycomb three-dimensional fabric composite material is subjected to a first heating treatment to remove the fusible core mold, and a second heating treatment is performed to complete curing, and then the thermal expansion rubber core mold is taken out to obtain the honeycomb three-dimensional fabric composite material; the curing adopts a gradient heating temperature rising curing method; Before the pre-curing molding, the cross section of the heat-expandable rubber core mold is smaller than the cross section of the honeycomb hole of the honeycomb three-dimensional fabric composite material; during the curing molding process, the cross section of the heat-expandable rubber core mold after expansion is the same as the cross section of the honeycomb hole, and the heat-expandable rubber core mold is reduced in volume after being heated and then cooled, and the cross section after reduction is restored to a state smaller than the cross section of the honeycomb hole; The number of the meltable core molds is greater than the number of the heat-expandable rubber core molds; the heat-expandable rubber core molds are evenly spaced and distributed in the meltable core molds in a periodic arrangement.

2. The preparation method according to claim 1, characterized in that: The heat-expandable rubber core mold and the meltable core mold are arranged in an axisymmetric distribution.

3. The preparation method according to claim 2, characterized in that: The number of the continuously adjacent heat expansion rubber core molds located on the same straight line does not exceed 2.

4. The preparation method according to claim 1, characterized in that: The honeycomb pore structure of the honeycomb three-dimensional fabric composite material is at least one of a regular hexagon, a triangle, a square, a rhombus, and a circle.

5. The preparation method according to claim 1, characterized in that: The length of the core mold is greater than the height of the three-dimensional fabric.

6. The preparation method according to claim 5, characterized in that: The length of the core mold is 5 to 20 mm higher than the height of the three-dimensional fabric.

7. The preparation method according to claim 1, characterized in that: The viscosity of the resin injected into the sealed preform is not greater than 300 mPa·s.

8. The preparation method according to claim 1, characterized in that: The three-dimensional fabric is at least one of alkali-free glass fiber fabric, carbon fiber fabric, ceramic fiber fabric, quartz fiber fabric, and aramid fiber fabric; The resin is at least one of phenolic resin, epoxy resin, unsaturated polyester resin, bismaleimide resin, polyimide resin, cyanate resin and silicon-containing aromatic acetylene resin.

9. The preparation method according to any one of claims 1 to 8, characterized in that: Before inserting the core mold into the three-dimensional fabric, the method further comprises: A release agent is coated on the surface of the core mold.

10. The preparation method according to any one of claims 1 to 8, characterized in that: Before injecting the resin into the sealed preform, the method further comprises: The resin is subjected to a degassing treatment.

11. A system for preparing a honeycomb three-dimensional fabric composite material, used to implement the preparation method as claimed in any one of claims 1 to 10, characterized in that: The preparation system comprises: a resin guiding device, a preform and a heating device; The preform is a three-dimensional fabric with a core mold inserted; The core mold includes a heat expansion rubber core mold and a meltable core mold; The preform is placed on the heating device; the resin guide device is connected to the preform; The resin guide device is used to inject resin into the sealed preform; wherein the melting temperature of the meltable core mold is lower than the glass transition temperature of the resin and higher than the pre-curing temperature of the resin; The heating device is used to pre-cure the preformed body injected with the resin to obtain a prefabricated honeycomb three-dimensional fabric composite material containing the core mold; and is used to heat the prefabricated honeycomb three-dimensional fabric composite material to remove the fusible core mold and complete curing.

12. The preparation system according to claim 11, characterized in that: Also includes: Core mold recovery and preparation device; The core mold recovery and preparation device is connected to the prefabricated honeycomb three-dimensional fabric composite material including the core mold; The core mold recovery and preparation device is used to recover the meltable core mold after the heating treatment; The core mold recovery and preparation device is also used to prepare the meltable core mold according to the structural size of the preset honeycomb holes of the honeycomb three-dimensional fabric composite material; The core mold recovery and preparation device includes a core mold preparation mechanism, a liquid control mechanism and a core mold recovery mechanism; wherein the core mold preparation mechanism is used to prepare the meltable core mold through the liquid control mechanism, and the core mold recovery mechanism is used to recover the meltable core mold after the heating treatment.

13. The preparation system according to claim 12, characterized in that: After the precuring and forming and before the heating treatment, the core mold recovery and preparation device is connected to the prefabricated honeycomb three-dimensional fabric composite material containing the core mold, and the core mold recovery and preparation device and the prefabricated honeycomb three-dimensional fabric composite material containing the core mold are arranged side by side on a horizontally placed platform in the heating device; During the heating treatment, the platform is adjusted to be placed vertically, and the core mold recovery and preparation device is located below the prefabricated honeycomb three-dimensional fabric composite material containing the core mold, so that the meltable core mold can be recovered into the core mold recovery and preparation device.

14. The preparation system according to any one of claims 12 to 13, characterized in that: Also includes: The core mold material and the core mold recovery and preparation device are determined according to the structural dimensions of the preset honeycomb holes of the honeycomb three-dimensional fabric composite material; wherein the cross-sections and dimensions of the meltable core molds prepared by different core mold recovery and preparation devices are different; The core mold material is processed and formed by utilizing the core mold recovery and preparation device to prepare the meltable core mold.

15. The preparation system according to any one of claims 11 to 13, characterized in that: Also includes: The resin flow guide device includes a flow valve and a flow guide tube; wherein the flow guide tube is used to transport the resin, and the number of the flow guide tubes is determined according to the structural size of the preset honeycomb holes of the honeycomb three-dimensional fabric composite material; the flow valve is used to control the flow rate of the resin in real time.

16. The preparation system according to any one of claims 11 to 13, characterized in that: Also includes: A resin stirring and degassing device is used for stirring and mixing the resin and removing bubbles from the resin, and the resin stirring and degassing device is connected to the resin guiding device.

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