A warp-resistant high-strength continuous fiber-reinforced thermoplastic composite material and a method for producing the same

Abstract

The application belongs to the field of polymer composites and molding technology, and particularly relates to a warpage-resistant high-strength continuous fiber reinforced thermoplastic composite material and a preparation method thereof. The warpage-resistant high-strength continuous fiber reinforced thermoplastic composite material comprises a continuous fiber reinforced layer and a warpage-resistant layer, the continuous fiber reinforced layer and the warpage-resistant layer are stacked, the continuous fiber reinforced layer is prepared from continuous fibers and a thermoplastic resin, and the warpage-resistant layer is prepared from a warpage-resistant filler and a resin matrix. The warpage-resistant layer is independently prepared and does not interfere with the continuous fiber impregnation molding process. The position, number of layers and thickness of the warpage-resistant film interlayer can be flexibly regulated and controlled, the residual internal stress of the layer is offset, the warpage degree of the material can be greatly reduced while the high mechanical properties of the composite material are retained, the material structure design freedom is high, the adaptability is strong, and the material can be widely applied to the preparation field of high-precision lightweight parts of automobiles, rail transit and low-altitude aircraft.

Description

Technical Field

[0001] This invention belongs to the field of polymer composite materials and molding technology, specifically relating to a warp-resistant, high-strength continuous fiber reinforced thermoplastic composite material and its preparation method. Background Technology

[0002] Continuous fiber reinforced thermoplastic composites, as a class of lightweight and high-strength materials, derive their strength primarily from the high-strength characteristics of the continuous fibers. Although continuous fiber reinforced thermoplastic composites offer advantages over metals, such as lower density and easier processing, the one-dimensional nature of the fibers results in significant anisotropy. Therefore, during processing, continuous fiber reinforced thermoplastic composites often exhibit different internal stresses along the fiber direction and those deviating from it, leading to dimensional instability phenomena such as warping.

[0003] Currently, common anti-warping methods mainly involve obtaining quasi-isotropic continuous fiber reinforced composites by laying continuous fibers in different directions. However, this method is inefficient and leads to complex mechanical properties due to interlayer coupling and other effects, sometimes failing to address both part performance and interlayer strength and orientation barriers. Alternatively, anti-warping fillers can be added to the resin to achieve anti-warping properties. While these methods can achieve a certain degree of anti-warping performance, they result in significant strength loss in continuous fiber reinforced thermoplastic composites and are also costly.

[0004] While some existing patents attempt to address these issues, they still have shortcomings. For example, publication number CN121893623A discloses a type of asymmetric laminated thermoplastic composite material, which obtains a thermoplastic composite material with a certain degree of anti-warping effect by inserting a pure resin compensation layer into the center face of a continuous fiber-reinforced thermoplastic reinforcing layer. However, this method suffers from the difficulty in adjusting the anti-warping effect of a single pure resin compensation layer, and it is also difficult to obtain a more universal anti-warping effect when continuous fibers are laid at complex angles.

[0005] Patent US4291084 discloses a type of anti-warping thermoplastic fiber sheet, which improves the surface appearance and smoothness by applying a mica resin layer to the outer surface of the fiber reinforcement layer. The linear expansion coefficient of the material is adjusted by adjusting the ratio of mica in the surface resin to glass fiber in the reinforcement layer. Although a certain anti-warping effect is achieved, the internal stress distribution cannot be precisely controlled by the intercalation position.

[0006] Based on the shortcomings of existing technologies, there is an urgent need to develop a continuous fiber-reinforced thermoplastic composite material that can independently control the anti-warping structure, does not damage the mechanical properties of fiber reinforcement, and is compatible with multi-layer layup processes, in order to solve the problem of mass production application of high-precision lightweight components in the industry. Summary of the Invention

[0007] Based on the above technical background, the main objective of this invention is to provide a high-strength, anti-warping continuous fiber reinforced thermoplastic composite material and its preparation method, so as to overcome the shortcomings of the prior art, such as the inability to independently control the anti-warping structure and the reduction of the mechanical properties of the composite material while reducing the anti-warping rate.

[0008] To achieve the aforementioned objectives, the technical solution adopted by this invention includes:

[0009] The first aspect of the present invention is to provide a high-strength, anti-warping, continuous fiber-reinforced thermoplastic composite material, the high-strength, anti-warping, continuous fiber-reinforced thermoplastic composite material comprising a continuous fiber reinforcement layer and an anti-warping layer, wherein the continuous fiber reinforcement layer and the anti-warping layer are stacked.

[0010] Preferably, the continuous fiber reinforcement layers are stacked sequentially at a set angle, and the anti-warping layer is disposed between adjacent continuous fiber reinforcement layers; The set angles are 0° and 90° respectively.

[0011] In this invention, the angles set above are based on the fiber axis of the bottom continuous fiber reinforcement layer in the anti-warping high-strength continuous fiber reinforced thermoplastic composite material, with 0° along the fiber axis of the bottom continuous fiber reinforcement layer and 90° perpendicular to the fiber axis of the bottom continuous fiber reinforcement layer.

[0012] The continuous fiber reinforcement layer is a continuous fiber reinforced thermoplastic unidirectional tape. The continuous fiber reinforced thermoplastic unidirectional tape is a composite material made of continuous fibers and polypropylene through a special process, in which the fibers are unidirectional. The thermoplastic unidirectional tape has the advantages of light weight, high modulus and corrosion resistance.

[0013] The continuous fiber reinforcement layer is made by impregnating and calendering continuous fibers with thermoplastic resin, while the anti-warping layer is made by extrusion calendering, casting, or blown film processing of anti-warping plastic. Furthermore, the anti-warping layer is inserted between adjacent continuous fiber reinforcement layers at specific locations, making the anti-warping component in the anti-warping layer far more effective than when directly added inside the continuous fiber reinforcement layer. Moreover, the anti-warping layer of this invention is an independent layered design, with adjustable thickness and number of layers, allowing material designers to design anti-warping capability and interlayer strength according to the actual working conditions of the part. The anti-warping composite material of this invention possesses excellent design flexibility.

[0014] The thickness of the anti-warping high-strength continuous fiber reinforced thermoplastic composite material is 1.0 to 10.0 mm.

[0015] The continuous fiber reinforcement layer is made of continuous fibers and thermoplastic resin. Based on the total weight of the continuous fiber reinforcement layer as 100%, the continuous fibers account for 50-80% of the total weight of the continuous fiber reinforcement layer, and the thermoplastic resin accounts for the remainder.

[0016] Preferably, based on the total weight of the continuous fiber reinforcement layer as 100%, the continuous fiber accounts for 65% of the total weight of the continuous fiber reinforcement layer, and the thermoplastic resin accounts for the remainder.

[0017] The continuous fiber is selected from one or more of carbon fiber, glass fiber, basalt fiber, aramid fiber, polyester fiber and polyimide fiber.

[0018] Preferably, the continuous fiber is glass fiber.

[0019] The thermoplastic resin is selected from one or more of polyolefins, polyamides, polyimides, polycarbonates, and polyesters.

[0020] Preferably, the thermoplastic resin is polyethylene or polyamide.

[0021] The anti-warping layer is made of anti-warping filler and resin matrix. Based on the total weight of the anti-warping layer as 100%, the anti-warping filler accounts for 20-60% of the total weight of the anti-warping layer, and the resin matrix accounts for the remainder.

[0022] Preferably, based on the total weight of the anti-warping layer being 100%, the anti-warping filler accounts for 40% of the total weight of the anti-warping layer, and the resin matrix accounts for the remainder.

[0023] The anti-warping filler is a layered silicate mineral selected from one or more of talc powder, mica powder, montmorillonite, kaolin, and halloysite.

[0024] Preferably, the anti-warping filler is selected from one or more of talc powder, mica powder, and montmorillonite.

[0025] More preferably, the anti-warping filler is obtained by mixing mica powder and talc powder in a mass ratio of (1.2-2):1.

[0026] For example, the anti-warping filler is obtained by mixing mica powder and talc powder in a mass ratio of 1.5:1.

[0027] Mica has a high aspect ratio, which can constrain large planar deformations. Talc can regulate the uniformity of melt flow and is compatible with polyolefin matrix resins, which can reduce lateral residual shrinkage stress.

[0028] More preferably, the anti-warping filler is obtained by mixing montmorillonite and mica powder in a mass ratio of 1:(1.5-2.5).

[0029] For example, the anti-warping filler is obtained by mixing montmorillonite and mica powder in a mass ratio of 1:2.0.

[0030] The nano-montmorillonite in this composite filler can achieve micro-pore filling and shrinkage, while the mica powder can regulate macro-planar deformation. This composite filler is compatible with polar resin matrices such as polyamide and polyester, and has better interfacial compatibility.

[0031] More preferably, the anti-warping filler is obtained by mixing talc powder, mica powder and montmorillonite in a mass ratio of 1:(1-2):(0.5-1).

[0032] For example, the anti-warping filler is obtained by mixing talc powder, mica powder and montmorillonite in a mass ratio of 1:1.5:0.8.

[0033] The above three fillers are mixed and arranged in a three-dimensional layered staggered pattern, which can offset the bidirectional internal stress of 0° / 90° layup in all directions. It is suitable for all types of thermoplastic resin matrices and has the best anti-warping effect. Compared with single anti-warping filler, this composite anti-warping filler can further reduce warping deformation by more than 15%, while taking into account film-forming properties and interlayer thermal fusion bonding strength.

[0034] The resin matrix is ​​selected from one or more of polyolefins, polyamides, polyimides, polycarbonates, and polyesters.

[0035] Preferably, the resin matrix is ​​polyethylene or polyamide.

[0036] The thickness of each continuous fiber reinforcement layer is 0.1–0.4 mm, and the thickness of each anti-warping layer is 50–400 μm. Setting the thicknesses of the continuous fiber reinforcement layer and the anti-warping layer within the above ranges provides sufficient structural strength while achieving a lightweight design.

[0037] Preferably, the thickness of each continuous fiber reinforcement layer is 0.2 mm, and the thickness of each anti-warping layer is 100 μm.

[0038] The ratio of the total thickness of the anti-warping layer to the total thickness of the continuous fiber reinforcement layer is 0.22 to 2.0. If the thickness of the anti-warping layer is too low, the anti-warping performance will be poor, making it difficult to meet the application requirements. Conversely, if the total thickness of the anti-warping layer is too high, although it can improve the anti-warping effect, it will correspondingly reduce the overall mechanical properties of the composite material, which contradicts the original intention of pursuing lightweighting when using continuous fiber reinforced thermoplastic composites.

[0039] Preferably, the ratio of the total thickness of the anti-warping layer to the total thickness of the continuous fiber reinforcement layer is 0.5.

[0040] A second aspect of the present invention is to provide a method for preparing the anti-warping high-strength continuous fiber reinforced thermoplastic composite material described in the first aspect of the present invention, the method comprising the following steps: S1. Mix the anti-warping filler and resin matrix evenly to obtain the anti-warping layer; S2. The continuous fibers are made into a continuous fiber unidirectional fabric, the continuous fiber unidirectional fabric is added to a thermoplastic resin for impregnation and rolling, and then water-cooled for shaping to obtain a continuous fiber reinforced layer. S3. The continuous fiber reinforcement layer and the anti-warping layer are stacked, and the resulting layer is hot-pressed and fused together, and then cooled to obtain an anti-warping high-strength continuous fiber reinforced thermoplastic composite material.

[0041] The steps described above are described in detail below.

[0042] In step S1, the anti-warping filler and resin matrix are mixed evenly, and the anti-warping layer is obtained by extrusion calendering, casting or blown film process.

[0043] Preferably, the anti-warping filler and resin matrix are mixed evenly, and the anti-warping layer is obtained by blown film process.

[0044] In step S2, the continuous fiber unidirectional fabric is added to the thermoplastic resin and impregnated and rolled at 120-270°C for 0.2-0.8 min.

[0045] Preferably, the continuous fiber unidirectional fabric is added to the thermoplastic resin and impregnated and rolled at 150°C for 0.4 min.

[0046] After impregnation and roller pressing, the product is water-cooled and shaped at 45–55°C for 0.1–0.9 min.

[0047] Preferably, after impregnation and roller pressing, the material is water-cooled and shaped at 50°C for 0.5 min.

[0048] In step S3, the continuous fiber reinforcement layers are stacked sequentially at a set angle, and the anti-warping layer is placed between adjacent continuous fiber reinforcement layers. The set angles are 0° and 90° respectively.

[0049] The present invention incorporates an anti-warping layer intercalation stack between continuous fiber reinforcement layers. This design can minimize the warping defects caused by the large internal stress in the non-orthogonal angle direction due to the 0° and 90° angle lay-ups of the continuous fiber reinforcement layers. As a result, the manufactured continuous fiber reinforced thermoplastic composite material can achieve good anti-warping effect in all directions.

[0050] The resulting layered material was hot-pressed and fused at a temperature of 100–250°C and a pressure of 1–3 MPa for 1–2 min.

[0051] Preferably, the obtained layered material is hot-pressed and fused at a temperature of 120°C and a pressure of 2 MPa for 1.5 min.

[0052] The hot-pressed fused layered material is cooled for 0.5 to 2 minutes at a temperature of 50–70°C and a pressure of 0.1–0.3 MPa.

[0053] Preferably, the hot-pressed fused layered material is cooled for 1 min at a temperature of 60°C and a pressure of 0.2 MPa.

[0054] The continuous fiber reinforcement layer and the anti-warping layer are fused together by hot pressing under heating. This arrangement ensures that the continuous fiber reinforcement layer and the anti-warping layer are effectively and firmly fused together under heating to form a continuous integral structure, which helps to reduce the warping rate and improve the mechanical properties of the composite material.

[0055] The beneficial effects of this invention are as follows: The anti-warping high-strength continuous fiber reinforced thermoplastic composite material of the present invention is obtained by hot pressing after laminating a continuous fiber reinforcement layer and an anti-warping layer. The anti-warping layer and the continuous fiber reinforcement layer are set and prepared independently, avoiding the influence of the anti-warping filler on the continuous fiber impregnation process. Therefore, the fiber content can be unlimited in the preparation process of the continuous fiber reinforcement layer, making full use of the high strength characteristics of the continuous fiber reinforcement layer plate. This not only does not reduce the mechanical properties of the composite material, but also helps to improve the mechanical properties of the composite material.

[0056] The anti-warping layer of this invention is prepared by calendering, casting, or blown film processes, which is convenient. The layered silicate mineral filler in the anti-warping layer is orderly oriented in a two-dimensional plane within the anti-warping layer, thereby allowing independent adjustment of the proportion and orientation morphology of the layered silicate minerals in the anti-warping layer. The unique aspect ratio of the layered silicate minerals enables the anti-warping layer to effectively resist the warping of the fiber reinforcement layer, thereby maximizing the in-plane anti-warping properties of the composite material. This gives the composite material of this invention both excellent mechanical properties and anti-warping properties.

[0057] The number of anti-warping layers and the specific positions of the intercalations in the continuous fiber reinforced thermoplastic composite of this invention allow the anti-warping layer to eliminate the internal stress caused by fiber orientation in the adjacent continuous fiber reinforcement layer, thereby endowing the continuous fiber reinforced thermoplastic composite of this invention with excellent interlaminar strength and anti-warping properties. Since the anti-warping layer and the continuous fiber reinforcement layer are both independently configured, this provides material users with a variety of choices and design redundancy.

[0058] The anti-warping high-strength continuous fiber reinforced thermoplastic composite material of the present invention can be widely used in the manufacturing technology of automotive, rail transportation, low-altitude aircraft and other parts to meet the needs of different application scenarios. Attached Figure Description

[0059] Figure 1 A schematic diagram of a high-strength, warp-resistant, continuous fiber-reinforced thermoplastic composite material is shown. Figure 2 This diagram shows a composite material with a continuous fiber reinforcement layer and an anti-warping layer stacked together.

[0060] Explanation of icon numbers 1-Anti-warping high-strength continuous fiber reinforced thermoplastic composite material; 2-Continuous fiber reinforcement layer; 3-Anti-warping layer; 4-Anti-warping filler. Detailed Implementation

[0061] The present invention will now be described in detail, and its features and advantages will become clearer and more apparent from these descriptions.

[0062] This invention provides a high-strength, anti-warping, continuous fiber-reinforced thermoplastic composite material 1. The composite material includes an anti-warping layer 3 and a continuous fiber reinforcement layer 2. The continuous fiber reinforcement layer 2 is a continuous fiber-reinforced thermoplastic unidirectional tape. The continuous fiber reinforcement layers are stacked sequentially at predetermined angles. The anti-warping layer 3 is disposed between adjacent continuous fiber reinforcement layers 2, with predetermined angles of 0° and 90°, respectively. Figure 1 and Figure 2 As shown. The continuous fiber reinforcement layer 2 is made of thermoplastic resin and continuous fibers. Based on the total weight of the continuous fiber reinforcement layer (100%), the continuous fibers account for 65% of the total weight of the continuous fiber reinforcement layer 2, and the thermoplastic resin accounts for 35%. The anti-warping layer 3 is made of a resin matrix and anti-warping filler 4. Based on the total weight of the anti-warping layer 3 (100%), the anti-warping filler 4 accounts for 40% of the total weight, and the resin matrix accounts for 60%. The thickness of each continuous fiber layer 2 is 0.20 mm, and the thickness of each anti-warping layer 3 is 100 μm. The ratio of the total thickness of the anti-warping layer 3 to the total thickness of the continuous fiber reinforcement layer 2 is 0.444.

[0063] The resin matrix is ​​polyethylene or polyamide; The anti-warping filler is selected from one or more of talc powder, mica powder, and montmorillonite. The continuous fiber is glass fiber; The thermoplastic resin is polyethylene or polyamide.

[0064] A method for preparing the above-mentioned anti-warping high-strength continuous fiber reinforced thermoplastic composite material, the method comprising the following steps: S1. The anti-warping filler and resin matrix are mixed evenly, and an anti-warping layer with a single layer thickness of 100μm is obtained by blown film process. In the anti-warping layer, the anti-warping filler accounts for 40% of the total weight of the anti-warping layer.

[0065] S2. The continuous fibers are made into a continuous fiber unidirectional fabric. The continuous fiber unidirectional fabric is added to polyethylene and impregnated and rolled at 120-270℃ for 0.2-0.8 min. After impregnation and rolling, it is water-cooled and set at 45-55℃ for 0.1-0.9 min. A continuous fiber reinforcement layer with a single layer thickness of 0.20 mm is obtained, wherein the continuous fibers account for 65% of the total weight of the continuous fiber reinforcement layer.

[0066] S3. Continuous fiber reinforcement layers are stacked sequentially at a set angle, and anti-warping layers are placed between adjacent continuous fiber reinforcement layers at angles of 0° and 90° respectively, resulting in a layered structure containing an anti-warping layer with angles of: 0° continuous fiber reinforcement layer / anti-warping layer / 90° continuous fiber reinforcement layer / anti-warping layer / 0° continuous fiber reinforcement layer / anti-warping layer / 90° continuous fiber reinforcement layer / anti-warping layer / 0° continuous fiber reinforcement layer / anti-warping layer / 90° continuous fiber reinforcement layer / anti-warping layer / 0° continuous fiber reinforcement layer / anti-warping layer / 90° continuous fiber reinforcement layer / anti-warping layer / 0° continuous fiber reinforcement layer / anti-warping layer / 0° continuous fiber reinforcement layer / anti-warping layer / 0° continuous fiber reinforcement layer / 0° continuous fiber reinforcement layer / 0° continuous fiber reinforcement layer. The resulting layered structure is hot-pressed and fused at a temperature of 100–250°C and a pressure of 1–3 MPa for 1–2 min, followed by cooling at a temperature of 50–70°C and a pressure of 0.1–0.3 MPa for 0.5–2 min. The material is trimmed and cut to obtain a high-strength, continuous fiber-reinforced thermoplastic composite material with a thickness of 2.60 mm, which is resistant to warping.

[0067] Example The present invention is further illustrated below with specific examples. These embodiments are merely illustrative and not intended to limit the scope of the invention. All raw materials used in the embodiments of the present invention are commercially available.

[0068] Example 1 A high-strength, anti-warping, continuous fiber-reinforced thermoplastic composite material, comprising an anti-warping layer and a continuous fiber reinforcement layer, wherein the continuous fiber reinforcement layer is a continuous fiber-reinforced thermoplastic unidirectional tape, the continuous fiber reinforcement layers are sequentially stacked at predetermined angles, and the anti-warping layer is disposed between adjacent continuous fiber reinforcement layers, the predetermined angles being 0° and 90° sequentially. Figure 1 and Figure 2As shown. The continuous fiber reinforcement layer is made of polyethylene and continuous fiber glass fiber. Based on the total weight of the continuous fiber reinforcement layer (100%), the glass fiber accounts for 65% of the total weight, and the thermoplastic resin polyethylene accounts for 35%. The anti-warping layer is made of resin matrix polyethylene and anti-warping filler talc. Based on the total weight of the anti-warping layer (100%), the anti-warping filler talc accounts for 40% of the total weight, and the resin matrix polyethylene accounts for 60%. The thickness of each continuous fiber layer is 0.20 mm, the thickness of each anti-warping layer is 100 μm, and the ratio of the total thickness of the anti-warping layer to the total thickness of the continuous fiber reinforcement layer is 0.444.

[0069] A method for preparing the above-mentioned anti-warping high-strength continuous fiber reinforced thermoplastic composite material, the method comprising the following steps: S1. The anti-warping filler talc powder and the resin matrix polyethylene are mixed evenly, and an anti-warping layer with a single layer thickness of 100μm is obtained by blown film process. In the anti-warping layer, talc powder accounts for 40% of the total weight of the anti-warping layer.

[0070] S2. Glass fiber is made into a continuous unidirectional fiber fabric. The continuous unidirectional fiber fabric is added to polyethylene and impregnated and rolled at 150°C for 0.4 min. After impregnation and rolling, it is water-cooled and set at 50°C for 0.5 min. A continuous fiber reinforcement layer with a single layer thickness of 0.20 mm is obtained, wherein glass fiber accounts for 65% of the total weight of the continuous fiber reinforcement layer.

[0071] S3. Continuous fiber reinforcement layers are stacked sequentially at a set angle, and anti-warping layers are placed between adjacent continuous fiber reinforcement layers at angles of 0° and 90° respectively, resulting in a layered structure containing an anti-warping layer with angles of: 0° continuous fiber reinforcement layer / anti-warping layer / 90° continuous fiber reinforcement layer / anti-warping layer / 0° continuous fiber reinforcement layer / anti-warping layer / 90° continuous fiber reinforcement layer / anti-warping layer / 0° continuous fiber reinforcement layer / anti-warping layer / 90° continuous fiber reinforcement layer / anti-warping layer / 0° continuous fiber reinforcement layer / anti-warping layer / 0° continuous fiber reinforcement layer / anti-warping layer / 0° continuous fiber reinforcement layer / anti-warping layer / 0° continuous fiber reinforcement layer / 0° continuous fiber reinforcement layer. The resulting layered structure is hot-pressed and fused at 120°C and 2 MPa for 1.5 min, then cooled at 60°C and 0.2 MPa for 1 min, and trimmed to obtain a high-strength, anti-warping, continuous fiber reinforced thermoplastic composite material with a thickness of 2.60 mm.

[0072] Example 2 A high-strength, anti-warping, continuous fiber-reinforced thermoplastic composite material, comprising an anti-warping layer and a continuous fiber reinforcement layer, wherein the continuous fiber reinforcement layer is a continuous fiber-reinforced thermoplastic unidirectional tape, the continuous fiber reinforcement layers are sequentially stacked at predetermined angles, and the anti-warping layer is disposed between adjacent continuous fiber reinforcement layers, the predetermined angles being 0° and 90° sequentially. Figure 1 and Figure 2 As shown. The continuous fiber reinforcement layer is made of polyethylene and glass fiber. Based on the total weight of the continuous fiber reinforcement layer (100%), the glass fiber accounts for 65% of the total weight, and the polyethylene accounts for 35%. The anti-warping layer is made of polyethylene and anti-warping filler talc. Based on the total weight of the anti-warping layer (100%), the talc accounts for 40% of the total weight, and the polyethylene accounts for 60%. The thickness of each continuous fiber layer is 0.20 mm, the thickness of each anti-warping layer is 100 μm, and the ratio of the total thickness of the anti-warping layer to the total thickness of the continuous fiber reinforcement layer is 0.222.

[0073] The high-strength, anti-warping continuous fiber reinforced thermoplastic composite material was prepared in a manner similar to that in Example 1, with the only difference being: In step S3, continuous fiber reinforcement layers are stacked sequentially at a set angle, and anti-warping layers are placed between adjacent continuous fiber reinforcement layers at angles of 0° and 90°, respectively, to obtain a layered material containing an anti-warping layer with angles of: 0° continuous fiber reinforcement layer / 90° continuous fiber reinforcement layer / 0° continuous fiber reinforcement layer / anti-warping layer / 90° continuous fiber reinforcement layer / anti-warping layer / 0° continuous fiber reinforcement layer / 90° continuous fiber reinforcement layer / 90° continuous fiber reinforcement layer / 0° continuous fiber reinforcement layer. The resulting layered material is hot-pressed and fused at 120°C and 2MPa for 1.5 min, then cooled at 60°C and 0.2MPa for 1 min, and trimmed to obtain a high-strength, anti-warping, continuous fiber reinforced thermoplastic composite material with a thickness of 2.20 mm.

[0074] Example 3 The high-strength, continuous fiber-reinforced thermoplastic composite material with anti-warping properties was prepared in a manner similar to that in Example 1, except that the anti-warping filler talc was replaced with a mixture of talc and mica powder, wherein the anti-warping filler was obtained by mixing mica powder and talc powder in a mass ratio of 1.5:1.

[0075] Example 4 The high-strength, continuous fiber-reinforced thermoplastic composite material with anti-warping properties was prepared in a manner similar to that in Example 1, except that: the anti-warping filler talc was replaced with a mixture of montmorillonite and mica powder, wherein the anti-warping filler was obtained by mixing montmorillonite and mica powder in a mass ratio of 1:2.0; and the resin matrix and thermoplastic resin polyethylene were replaced with polyamide.

[0076] Example 5 The high-strength, continuous fiber-reinforced thermoplastic composite material with anti-warping properties was prepared in a manner similar to that in Example 1, except that the anti-warping filler talc was replaced with a mixture of talc, mica, and montmorillonite, wherein the anti-warping filler was obtained by mixing talc, mica, and montmorillonite in a mass ratio of 1:1.5:0.8.

[0077] Comparative Example Comparative Example 1 The high-strength, continuous fiber-reinforced thermoplastic composite material with anti-warping properties was prepared in a manner similar to that in Example 1, except that the anti-warping filler talc was not added to the anti-warping layer, which was made of polyethylene.

[0078] Comparative Example 2 The high-strength, continuous fiber-reinforced thermoplastic composite material with anti-warping properties was prepared in a manner similar to that in Example 1, except that: the anti-warping layer was not prepared, and the anti-warping filler talc powder from the anti-warping layer was added to the continuous fiber reinforcement layer. The fiber reinforcement layer was made of talc powder, polyethylene, and glass fiber, and the mass ratio of talc powder, polyethylene, and glass fiber was 40:35:65.

[0079] A method for preparing the above-mentioned anti-warping high-strength continuous fiber reinforced thermoplastic composite material, the method comprising the following steps: S2. Glass fiber is made into a continuous unidirectional fiber fabric. The continuous unidirectional fiber fabric is added to polyethylene and impregnated and rolled at 150°C for 0.4 min. After impregnation and rolling, it is water-cooled and set at 50°C for 0.5 min. A continuous fiber reinforcement layer with a single layer thickness of 0.20 mm is obtained, wherein glass fiber accounts for 65% of the total weight of the continuous fiber reinforcement layer.

[0080] S3. The continuous fiber reinforcement layers are stacked sequentially at a set angle of 0° and 90°, resulting in a layered structure with the following angles: 0° continuous fiber reinforcement layer / 90° continuous fiber reinforcement layer / 0° continuous fiber reinforcement layer / 90° continuous fiber reinforcement layer / 90° continuous fiber reinforcement layer / 90° continuous fiber reinforcement layer / 0° continuous fiber reinforcement layer / 0° continuous fiber reinforcement layer. The resulting layered structure is hot-pressed and fused at 120°C and 2 MPa for 1.5 min, then cooled at 60°C and 0.2 MPa for 1 min. After trimming and cutting, a high-strength, warp-resistant, continuous fiber reinforced thermoplastic composite material with a thickness of 2.60 mm is obtained.

[0081] Comparative Example 3 The high-strength, anti-warping continuous fiber reinforced thermoplastic composite material was prepared in a manner similar to that in Example 1, except that: the anti-warping layer was not prepared, and the resin matrix polyethylene in the anti-warping layer was added to the continuous fiber reinforcement layer, which was made of polyethylene and glass fiber with a mass ratio of 95:65.

[0082] A method for preparing the above-mentioned anti-warping high-strength continuous fiber reinforced thermoplastic composite material, the method comprising the following steps: S2. Glass fiber is made into a continuous unidirectional fiber fabric. The continuous unidirectional fiber fabric is added to polyethylene and impregnated and rolled at 150°C for 0.4 min. After impregnation and rolling, it is water-cooled and set at 50°C for 0.5 min. A continuous fiber reinforcement layer with a single layer thickness of 0.20 mm is obtained, wherein glass fiber accounts for 40.6% of the total weight of the continuous fiber reinforcement layer.

[0083] S3. Continuous fiber reinforcement layers are stacked sequentially at set angles of 0° and 90°, resulting in a layered structure with the following angles: 0° continuous fiber reinforcement layer / 90° continuous fiber reinforcement layer / 0° continuous fiber reinforcement layer / 90° continuous fiber reinforcement layer / 90° continuous fiber reinforcement layer / 90° continuous fiber reinforcement layer / 0° continuous fiber reinforcement layer / 0° continuous fiber reinforcement layer. The resulting layered structure is hot-pressed and fused at 120°C and 2 MPa for 1.5 min, then cooled at 60°C and 0.2 MPa for 1 min. After trimming and cutting, a high-strength, warp-resistant, continuous fiber reinforced thermoplastic composite material with a thickness of 2.60 mm is obtained.

[0084] Experimental Example Experimental Example 1: Mechanical Properties and Warp Resistance Test Tensile strength, flexural strength, impact strength, and resistance to warping were tested on Examples 1-5 and Comparative Examples 1-3, respectively. Tensile strength was tested according to standard ISO 527, flexural strength according to standard ISO 178, impact strength according to standard ISO 179-1, and warping was tested according to standard IPC-6012 (referring to the IPC-TM-6502.4.22 test method, placing the test sample plate on a horizontal platform, measuring the maximum arch height in the diagonal direction, and calculating the percentage). The test results are shown in Table 1.

[0085] Table 1

[0086] As can be seen from Table 1, the composite materials prepared in Examples 1 and 2 have a tensile strength of 215 MPa or higher, a flexural strength of 293 MPa or higher, and an impact strength of 102 kJ / m. 2 The warpage was below 0.28%. The composite materials prepared in Comparative Examples 1-3 had tensile strengths below 225 MPa, flexural strengths below 284 MPa, and impact strengths below 98 kJ / m². 2 For samples with a warpage of 1.07% or less, the tensile strength of the composite materials prepared in Examples 1-2 is not significantly different from that in Comparative Examples 1-3. The flexural strength and impact strength of the composite materials prepared in Examples 1-2 are higher than those in Comparative Examples 1-3, and the warpage is much lower. These results indicate that the composite materials prepared by the method described in this invention possess excellent tensile strength, flexural strength, impact strength, and anti-warpage properties.

[0087] Examples 3 through 5 modify the anti-warping filler by using a mixture of two or three types. In Example 3, the talc filler was replaced with a mixture of talc and mica powder. After the replacement, the tensile strength, flexural strength, impact strength, and warpage of Example 3 were not significantly different from those of Example 1. These results indicate that replacing talc with a mixture of talc and mica powder has little effect on tensile strength, flexural strength, impact strength, and warpage.

[0088] In Example 4, the anti-warping filler talc was replaced with a mixture of montmorillonite and mica powder. The tensile strength, flexural strength, and bending strength of Example 4 were significantly improved, and the warping degree was increased. The above results indicate that replacing the warping filler with a mixture of montmorillonite and mica powder helps to improve the tensile strength, flexural strength, and bending strength of the composite material, but reduces the anti-warping performance of the composite material.

[0089] In Example 5, the anti-warping filler talc was replaced with a mixture of talc, mica powder, and montmorillonite. The tensile strength, flexural strength, flexural strength, and warpage of Example 5 were not significantly different from those of Example 1. These results indicate that replacing talc with a mixture of talc, mica powder, and montmorillonite has little effect on tensile strength, flexural strength, impact strength, and warpage.

[0090] Compared with Example 1, Comparative Example 1 did not add anti-warping filler to the anti-warping layer. Its anti-warping layer was made of polyethylene. The tensile strength of the composite material prepared in Comparative Example 1 was similar to that of Example 1, while its flexural strength and impact strength were slightly lower than those of Example 1. Its warping degree was much higher than that of Example 1. The above results show that adding anti-warping filler to the composite material helps to significantly improve the anti-warping performance of the composite material, and has little impact on the mechanical properties of the composite material.

[0091] Compared with Example 1, Comparative Example 2 did not separately set up and prepare the anti-warping layer. In Comparative Example 2, the anti-warping filler talc powder was added to the continuous fiber reinforcement layer. The tensile strength, flexural strength and impact strength of the composite material obtained by Comparative Example 2 were much lower than those of Example 1, and its warping degree was higher than that of Example 1. The above results show that setting up the anti-warping layer separately helps to improve the tensile strength, flexural strength, impact strength and anti-warping performance of the composite material.

[0092] Compared with Example 1, Comparative Example 3 did not separately set or prepare an anti-warping layer, nor did it add anti-warping filler. The tensile strength, flexural strength, and impact strength of the composite material obtained in Comparative Example 3 were much lower than those in Example 1, while its warping degree was much higher than that in Example 1. The above results indicate that adding anti-warping filler to the composite material and separately setting an anti-warping layer is more helpful in improving the tensile strength, flexural strength, impact strength, and anti-warping performance of the composite material.

[0093] The present invention has been described in detail above with reference to specific embodiments and exemplary examples; however, these descriptions should not be construed as limiting the present invention. Those skilled in the art will understand that various equivalent substitutions, modifications, or improvements can be made to the technical solutions and embodiments of the present invention without departing from the spirit and scope of the invention, and all such modifications and improvements fall within the scope of the present invention. The scope of protection of the present invention is defined by the appended claims.

Claims

1. A high-strength, warp-resistant, continuous fiber-reinforced thermoplastic composite material, characterized in that, The anti-warping high-strength continuous fiber reinforced thermoplastic composite material includes a continuous fiber reinforcement layer and an anti-warping layer, wherein the continuous fiber reinforcement layer and the anti-warping layer are stacked. The continuous fiber reinforcement layer is made of continuous fibers and thermoplastic resin; The anti-warping layer is made of anti-warping filler and resin matrix; The ratio of the total thickness of the anti-warping layer to the total thickness of the continuous fiber reinforcement layer is 0.22 to 2.

0.

2. The anti-warping high-strength continuous fiber reinforced thermoplastic composite material according to claim 1, characterized in that, The continuous fiber reinforcement layers are stacked sequentially at a set angle, and the anti-warping layer is disposed between adjacent continuous fiber reinforcement layers; The set angles are 0° and 90° respectively.

3. The anti-warping high-strength continuous fiber reinforced thermoplastic composite material according to claim 1, characterized in that, With the total weight of the continuous fiber reinforcement layer being 100%, the continuous fibers account for 50-80% of the total weight of the continuous fiber reinforcement layer.

4. The anti-warping high-strength continuous fiber reinforced thermoplastic composite material according to claim 1, characterized in that, The continuous fiber is selected from one or more of carbon fiber, glass fiber, basalt fiber, aramid fiber, polyester fiber and polyimide fiber; The thermoplastic resin is selected from one or more of polyolefins, polyamides, polyimides, polycarbonates, and polyesters.

5. The anti-warping high-strength continuous fiber reinforced thermoplastic composite material according to claim 1, characterized in that, Based on the total weight of the anti-warping layer being 100%, the anti-warping filler accounts for 20-60% of the total weight of the anti-warping layer.

6. The anti-warping high-strength continuous fiber reinforced thermoplastic composite material according to claim 1, characterized in that, The anti-warping filler is selected from one or more of talc powder, mica powder, montmorillonite, kaolin, and halloysite; The resin matrix is ​​selected from one or more of polyolefins, polyamides, polyimides, polycarbonates, and polyesters.

7. The anti-warping high-strength continuous fiber reinforced thermoplastic composite material according to claim 1, characterized in that, The thickness of each continuous fiber reinforcement layer is 0.1–0.4 mm, and the thickness of each anti-warping layer is 50–400 μm.

8. A method for preparing a high-strength, anti-warping, continuous fiber-reinforced thermoplastic composite material according to any one of claims 1 to 7, characterized in that, The preparation method includes the following steps: S1. Mix the anti-warping filler and resin matrix evenly to obtain the anti-warping layer; S2. The continuous fibers are made into a continuous fiber unidirectional fabric, the continuous fiber unidirectional fabric is added to a thermoplastic resin for impregnation and rolling, and then water-cooled for shaping to obtain a continuous fiber reinforced layer. S3. The continuous fiber reinforcement layer and the anti-warping layer are stacked, and the resulting layer is hot-pressed and fused together, and then cooled to obtain an anti-warping high-strength continuous fiber reinforced thermoplastic composite material.

9. The preparation method according to claim 8, characterized in that, In step S2, Continuous fiber unidirectional fabric is added to thermoplastic resin and impregnated and rolled at 120–270°C for 0.2–0.8 min. After impregnation and roller pressing, the product is water-cooled and shaped at 45–55°C for 0.1–0.9 min.

10. The preparation method according to claim 8, characterized in that, In step S3, The resulting layered material was hot-pressed and fused together at a temperature of 100–250°C and a pressure of 1–3 MPa for 1–2 min. The hot-pressed fused layered material is cooled for 0.5 to 2 minutes at a temperature of 50–70°C and a pressure of 0.1–0.3 MPa.

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