A kind of blended yarn integrated weaving grid reinforcing rib composite material and preparation method

Abstract

The application discloses a kind of mixed yarn integration weaving grid reinforcing rib composite materials and preparation method, belong to textile technical field.The application utilizes natural fiber and resin fiber according to certain proportion to carry out blending, and the obtained mixed yarn is woven to obtain grid reinforcing rib by integration, the fiber of the intersection of warp and weft of the reinforcing rib passes through the pore generated from twisting process, so that the intersection of warp and weft of the reinforcing rib does not exist node, and the reinforcing rib woven by this kind of mixed fiber integration is placed in the interlayer of natural fiber woven cloth and fiber felt material to lay, and is prepared into composite material laminated board by hot mould pressing, and simultaneously plays the effect of self-adhesion and structural enhancement.The reinforcing rib has better mechanical property compared with non-woven fabric, and compared with the reinforcing rib prepared by traditional weaving method, the reinforcing rib can also be like non-woven fabric without node.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of textiles, and particularly relates to a kind of mixed fiber integrated woven grid reinforcement composite material and preparation method. BACKGROUND

[0002] The grid reinforcement in sheet form is widely used in improving the performance of composite laminates. Environmentally friendly, energy saving and other terms have become the slogan of the times. The use of environmentally friendly and high-yield natural fibers can replace metal to prepare grid reinforcement in some application scenarios. Natural fibers have environmentally friendly, high-yield and other characteristics that meet the characteristics of the times. Some composite material reinforcement structures prepared from natural fibers can ensure performance while having the excellent properties of natural fibers, and have become an important part of future material development.

[0003] Most grid reinforcements are made of metal materials, which have good mechanical properties but are heavy and difficult to meet the requirements of lightweight products. The grid reinforcement structure prepared by the traditional weaving method will produce nodes at the intersection of the warp and weft lines, which will cause stress concentration problems in the subsequent use of the reinforcement structure. The grid reinforcement prepared by the present application uses weaving means. The traditional weaving method will inevitably produce nodes on the surface of the woven fabric, which will cause stress concentration in the subsequent preparation of composite materials, affecting the performance of the product. Unlike non-woven fabric, the present application uses weaving means to eliminate the influence of nodes.

[0004] The grid reinforcement in sheet form is a common means of reinforcing composite boards as a sandwich. The principle used by the present application is that the fibers passing through the intersection of the warp and weft lines of the reinforcement are the pores produced during the twisting process of the mixed fiber. Compared with non-woven fabric and traditional weaving methods, the new weaving method is used to eliminate the influence of nodes; in order to achieve different reinforcement effects, different proportions and types of natural fibers and resin fibers are mixed to obtain mixed yarns. This kind of mixed yarn not only has the reinforcement effect of natural fiber but also has the self-adhesion of resin fiber; the weaving method of the present application eliminates the stress concentration problem caused by the nodes produced by the traditional weaving method; then the grid reinforcement is placed in the sandwich between the woven fabric and the fiber mat to lay up the preform, and the preform is molded into a composite laminate by hot molding. Finally, the effect of reinforcing the structure of the composite laminate is achieved. SUMMARY

[0005] In order to solve the problems of surface nodes produced by traditional weaving method and poor mechanical properties of composite materials, the present application proposes a kind of mixed fiber integrated woven grid reinforcement composite material and preparation method. The technical scheme adopted by the present application is as follows:

[0006] A kind of mixed fiber integrated woven grid reinforcement composite material and preparation method, the specific steps of the method are:

[0007] (1) Pretreatment: the natural continuous fibers are subjected to mechanical degumming treatment under room temperature conditions; the specific method is to put the natural continuous fibers into boiling water at 100 DEG C for 1-3h; the natural continuous fibers are one or more combinations of flax fibers, jute fibers, and hemp fibers;

[0008] (2) The natural continuous fibers treated in step (1) are mixed with resin fibers according to a ratio of 4-7 strands: 6-3 strands to obtain mixed yarns; the resin fibers are continuous fibers;

[0009] (3) The prepared mixed yarns are woven to obtain sheet-shaped grid reinforcing bars; the weaving method is to place the natural / resin fiber mixed yarns on a workbench, take another mixed yarn, cross them according to the orthogonal method, and make the latter pass through the gap generated by the twisting of the former, so as to form a stable sheet-shaped grid reinforcing bar through the interlaced weaving, i.e., the mixed fiber integrated woven grid reinforcing bar composite material; the twisting degree of the mixed yarns is 30-80 twists per meter.

[0010] Preferably, the fineness of the natural fibers is 0.5 dtex; the fineness of the resin fibers is 0.5 dtex.

[0011] Preferably, the mixing method in step (2) is longitudinal mixing or wrapping mixing.

[0012] The application also provides a mixed fiber integrated woven grid reinforcing bar composite material prepared by the above method.

[0013] The application also provides a preparation method for preparing a composite laminated board based on the mixed fiber integrated woven grid reinforcing bar composite material, and the steps of the method are as follows:

[0014] (1) Pretreatment: the natural continuous fibers are subjected to mechanical degumming treatment under room temperature conditions; the specific method is to put the natural continuous fibers into boiling water at 100 DEG C for 1-3h; the natural continuous fibers are one or more combinations of flax fibers, jute fibers, and hemp fibers;

[0015] (2) The natural continuous fibers treated in step (1) are mixed with resin fibers according to a ratio of 4-7 strands: 6-3 strands to obtain mixed yarns; the resin fibers are continuous fibers;

[0016] (3) The prepared mixed yarns in step (2) are placed into a weaving machine to weave into a woven fabric; the woven fabric form is one or more combinations of non-woven fabric, warp and weft fabric, and three-dimensional fabric;

[0017] (4) The mixed yarns prepared in step (2) are made into a fiber felt;

[0018] (5) the grid reinforcement and the woven fabric, fiber mat are alternately layered to obtain a preform; the woven fabric, the grid reinforcement and the woven fabric are consistent in fiber composition and ratio; if the grid reinforcement is composed of 60wt% natural fiber and 40wt% resin fiber, the woven fabric and the resin fiber mat also contain the same type of natural fiber and resin fiber, and the ratio is also 60wt% natural fiber and 40wt% resin fiber.

[0019] (6) the preform is placed into a mold pressing machine, and a natural fiber in-situ reinforced composite laminate is prepared by hot mold pressing under heating conditions.

[0020] Preferably, the layering mode of the grid reinforcement and the woven fabric, resin fiber mat adopts a sandwich structure.

[0021] Preferably, the weaving method in step (3) is manual weaving or mechanical weaving by a weaving machine.

[0022] Preferably, the temperature of the hot pressing process in step (6) is 150-230℃, and the pressure is 1-10MPa.

[0023] Preferably, the hot pressing process in step (6) adopts one-stage mold pressing or multi-stage mold pressing.

[0024] Preferably, after the hot pressing in step (6) is completed, the prepared blended yarn woven fabric in-situ reinforced fiber reinforced composite plate is cooled by mechanical cooling or air cooling.

[0025] The beneficial effects of the present application are as follows:

[0026] The present application utilizes natural fiber and resin fiber to be integrated woven into blended fiber grid reinforcement according to a certain ratio, the fiber at the intersection of the warp and weft of the reinforcement passes through the pores generated from the twisting process, so that there is no node at the intersection of the warp and weft of the reinforcement, the integrated woven reinforcement is placed in the interlayer of the natural fiber woven fabric and the fiber mat material for layering, and a composite laminate is prepared by hot mold pressing, which has the effects of self-adhesion and structural reinforcement. The reinforcement has better mechanical properties compared with non-woven fabric, and can also be free of nodes like non-woven fabric prepared by traditional weaving method. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 is the preparation flow chart of the grid reinforcement and the woven fabric in the present application;

[0028] Figure 2 is the preparation flow chart of the composite laminate in the present application;

[0029] Figure 3 is the structure schematic diagram of the woven node of the grid reinforcement in the present application.

[0030] Figure 4 A process flow chart of a preparation method of a mixed fiber integrated woven grid reinforcement composite material.

[0031] Wherein: 1-natural fiber and resin fiber; 2-spinning machine; 3-mixed yarn; 4-weaving machine; 5-woven cloth; 6-grid reinforcement; 7-fiber mat; 5-woven cloth; 6-grid reinforcement; 8-molding machine; 9-composite material laminated plate. DETAILED DESCRIPTION

[0032] The technical solutions of the present application are further explained and described by specific examples in combination with the accompanying drawings.

[0033] Example 1

[0034] The raw materials of this example use hemp fibers and polypropylene fibers, and the specific implementation method includes the following steps:

[0035] (1) Pretreatment: The hemp fibers are mechanically degummed at room temperature. Mechanical degumming can remove impurities on the surface of the hemp fibers and remove pectin, hemicellulose and lignin and other gums, thereby improving their softness and spinnability. Then put it in boiling water for 1 hour to further enhance the spinnability of the hemp fibers and improve the spinning effect of the hemp fibers and polypropylene fibers and improve the overall performance of the blended yarn.

[0036] (2) The hemp fibers and polypropylene fibers obtained after step (1) are blended according to the proportion to obtain a blended yarn; the proportion of natural fibers to resin fibers is 4 strands to 6 strands;

[0037] (3) The prepared blended yarn is placed in the weaving machine by using plain weave method to weave into woven cloth.

[0038] (4) The prepared blended yarn is integrated woven by using the method of hand weaving to obtain a sheet-shaped grid reinforcement. The weaving method is to place the hemp / polypropylene fiber blended yarn vertically on the workbench, labeled as 6-1; take another blended yarn, labeled as 6-2, and cross between them according to the orthogonal method, pass through the gap inside the longitudinal blended yarn 6-1 in the transverse direction, and form a stable sheet-shaped grid reinforcement by this interlaced weaving; the twisting degree of the blended yarn is 30-80 twists per meter.

[0039] (5) The woven cloth woven in step (3) and the grid reinforcement woven in step (4) and the resin fiber felt (made of 40wt% hemp fiber and 60wt% polypropylene fiber) are laminated to obtain a sandwich structure of the preform. The lamination method is one layer of woven cloth, one layer of grid reinforcement and one layer of resin fiber felt, which are alternately laminated. The preform is composed of two layers of woven cloth and two layers of grid reinforcement and one layer of resin fiber felt, wherein both ends of the preform are woven cloth.

[0040] (6) The preform is placed in the mold, and the mold is placed in the molding machine. Under the condition of heating, the molding machine is heated to 180℃, and the preform is molded under the pressure of 2Mpa for 3 minutes. After molding, the mold is taken out and placed in room temperature for air cooling to obtain the target laminate.

[0041] Example 2

[0042] The raw materials of this embodiment use hemp fiber and ABS resin fiber, and the specific implementation method includes the following steps:

[0043] (1) Pretreatment: The hemp fiber is mechanically degummed at room temperature. Through mechanical degumming, the impurities on the surface of the hemp fiber can be removed, and the pectin, hemicellulose and lignin in the hemp fiber can be removed, so as to improve the softness and spinnability of the hemp fiber. Then it is boiled in boiling water for 1 hour to further enhance the spinnability of the hemp fiber and improve the spinning effect of the hemp fiber and ABS resin fiber and the overall performance of the blended yarn.

[0044] (2) The hemp fiber and ABS resin fiber obtained after step (1) are blended according to the proportion to obtain blended yarn, wherein the proportion of natural fiber and resin fiber is 5 ends:5 ends.

[0045] (3) The prepared blended yarn is put into the weaving machine by plain weave method to weave into woven cloth.

[0046] (4) The prepared blended yarn is integrated woven into a sheet-shaped grid reinforcement by hand weaving method; the twist degree of the blended yarn is 30~80 twists per meter.

[0047] (5) The woven cloth woven in step (3) and the grid reinforcement woven in step (4) and the resin fiber felt (made of 40wt% hemp fiber and 60wt% polypropylene fiber) are laminated to obtain a sandwich structure of the preform. The lamination method is one layer of woven cloth, one layer of grid reinforcement and one layer of resin fiber felt, which are alternately laminated. The preform is composed of two layers of woven cloth and two layers of grid reinforcement and one layer of resin fiber felt, wherein both ends of the preform are woven cloth.

[0048] (6) Put the preform into the mold, and put the mold into the molding press. Under the condition of heating, the molding press is heated to 210°C. The preform is subjected to molding treatment under the pressure of 3Mpa, and the duration is 3 minutes. After the molding is completed, the mold is taken out and placed in room temperature for air cooling to obtain the target laminate.

[0049] Example 3

[0050] In this embodiment, jute fibers and nylon fibers are used as synthetic fibers. The specific implementation method includes the following steps:

[0051] (1) Pretreatment: The jute fibers are subjected to mechanical degumming treatment at room temperature. Through mechanical degumming, the impurities on the surface of the jute fibers can be removed, and the pectin, hemicellulose and lignin and other gums in the jute fibers can be removed, so as to improve the softness and spinnability of the jute fibers. Then, the jute fibers are boiled in boiling water for 1 hour to further enhance the spinnability of the jute fibers, improve the spinning effect of the jute fibers and nylon fibers, and improve the overall performance of the blended yarn.

[0052] (2) The jute fibers and nylon fibers obtained after step (1) are blended according to the proportion to obtain a blended yarn, wherein the proportion of natural fibers to resin fibers is 7 strands to 3 strands.

[0053] (3) The prepared blended yarn is woven into woven fabric by using plain weave method.

[0054] (4) The prepared blended yarn is integrated woven by using hand weaving method to obtain a sheet-like grid reinforcement. The twisting degree of the blended yarn is 30-80 twists per meter.

[0055] (5) The woven fabric woven in step (3) and the grid reinforcement woven in step (4) are laid with a resin fiber felt (made of 60wt% jute fibers and 40wt% nylon fibers) to obtain a preform with a sandwich structure. The laying method is to alternately lay one layer of woven fabric, one layer of grid reinforcement and one layer of resin fiber felt. The preform is composed of two layers of woven fabric, two layers of grid reinforcement and one layer of resin fiber felt. The two ends of the preform are woven fabric.

[0056] (6) Put the preform into the mold, and put the mold into the molding press. Under the condition of heating, the molding press is heated to 220°C. The preform is subjected to molding treatment under the pressure of 2Mpa, and the duration is 3 minutes. After the molding is completed, the mold is taken out and placed in room temperature for air cooling to obtain the target laminate.

[0057] Example 4

[0058] In this embodiment, the woven fabric, fiber felt and raw materials used are the same as those in Example 1. The specific implementation method includes the following steps:

[0059] (1) Flax fibers and polypropylene fibers are blended at a ratio of 4 strands: 6 strands to obtain blended yarns; the obtained blended yarns are woven using a traditional weaving method to obtain woven cloth with a structure similar to that of a grid reinforcing rib;

[0060] (2) The woven cloth and a resin fiber felt (made of 40wt% hemp fibers and 60wt% polypropylene fibers) are layered to obtain a sandwich-structured preform. The layering method is to alternately layer one layer of woven cloth and one layer of resin fiber felt, and the preform is composed of two layers of woven cloth and one layer of resin fiber felt, wherein both ends of the preform are woven cloth.

[0061] (3) The preform is placed in a mold and put into a molding machine. The molding machine is heated to 180℃, and the preform is subjected to 3 minutes of molding treatment under a pressure of 2Mpa. After molding is completed, the mold is taken out and allowed to air cool at room temperature to obtain a composite board.

[0062] It should be noted that the weaving method of the present application is different from the traditional weaving method in which yarns are alternately woven in the longitudinal direction and the transverse direction. Two strands of blended yarns are interwoven at the nodes to enable the nodes to tightly connect the two strands of blended yarns together.

[0063] The weaving method will be described in detail below taking the weaving method of 4-strand blended yarns and 4-strand blended yarns as an example. As shown in FIG. 6, the first blended yarn 6-1 and the second blended yarn 6-2 are each composed of 4 strands of yarn; wherein the first blended yarn 6-1 is composed of No. 1 first blended yarn 6-1-1, No. 2 first blended yarn 6-1-2, No. 3 first blended yarn 6-1-3 and No. 4 first blended yarn 6-1-4, and the second blended yarn 6-2 is composed of No. 1 second blended yarn 6-2-1, No. 2 second blended yarn 6-2-2, No. 3 second blended yarn 6-2-3 and No. 4 second blended yarn 6-2-4. Figure 3 The No. 1 first blended yarn 6-1-1 is located at the uppermost position, the No. 2 first blended yarn 6-1-2 passes from below the No. 4 second blended yarn 6-2-4 and above the No. 2 second blended yarn 6-2-2 and the No. 3 second blended yarn 6-2-3, the No. 3 first blended yarn 6-1-3 passes from below the No. 1 second blended yarn 6-2-1, the No. 3 second blended yarn 6-2-3 and the No. 4 second blended yarn 6-2-4 and above the No. 2 second blended yarn 6-2-2, and the No. 4 first blended yarn 6-1-4 passes from below the No. 1 second blended yarn 6-2-1 and above the No. 3 second blended yarn 6-2-3 and the No. 4 second blended yarn 6-2-4.

[0064]

[0065] ​The No. 1 second blended yarn 6-2-1 passes between the No. 1 first blended yarn 6-1-1 and the No. 4 first blended yarn 6-1-4, the No. 2 second blended yarn 6-2-2 is at the bottom, the No. 3 second blended yarn 6-2-3 passes between the No. 3 first blended yarn 6-1-3 and the No. 2 first blended yarn 6-1-2, and the No. 4 second blended yarn 6-2-4 passes between the No. 1 first blended yarn 6-1-1 and the No. 2 first blended yarn 6-1-2.

[0066] The tensile strength, shear strength and impact strength of the composite board reinforced by the integrated woven grid reinforcement of the hybrid fiber obtained in Examples 1 to 4 were tested, and the results are shown in Table 1. The test results show that the hybrid fiber sheet structure grid reinforcement composite board of the present application has superior mechanical properties, and has better performance than the ordinary laminate without in-situ reinforcement by the woven fabric in Example 4.

[0067] Table 1

[0068]

[0069] The above discloses the basic principles, key technologies and main advantages of the present application. It should be understood by those skilled in the art that the provided examples are intended to illustrate the core concept of the present application and do not limit its application. The present application allows various adjustments and improvements as long as they are within the spirit and scope of the present application. All these changes and improvements, as long as they are within the scope of protection of the present application, should be considered as part of the present application. Any changes within or equivalent to the scope of protection should be considered as the scope of coverage of the present application.

Claims

1. A method of making a hybrid fiber integrated woven grid reinforced composite material, characterized by, The specific steps of the method are: (1) Pretreatment: mechanical degumming treatment of natural continuous fibers at room temperature; the specific method is to put the natural continuous fibers into boiling water at 100°C and cook for 1-3h; the natural continuous fibers are one or a combination of more than one of flax fiber, jute fiber, and hemp fiber; (2) Mix the natural continuous fibers treated in step (1) and resin fibers according to a ratio of 4-7 strands: 6-3 strands to obtain a blended yarn; the resin fibers are continuous fibers; (3) Weave the prepared blended yarn to obtain a laminar mesh reinforcement, the weaving method is to place the first blended yarn on the workbench, take the second blended yarn, cross between the two according to the orthogonal method, and make the yarn of the second blended yarn pass through the gap generated by the twisting of the first blended yarn, and form a stable laminar mesh reinforcement through this interlaced weaving, that is, the blended fiber integrated woven mesh reinforcement composite material; the twisting degree of the blended yarn is 30-80 twists per meter.

2. The method of claim 1, wherein the method further comprises the step of: The fineness of the natural fiber is 0.5dtex; the fineness of the resin fiber is 0.5dtex. ​ 3. The method of claim 1, wherein the method further comprises the step of: 3-1) forming a plurality of the fiber-integrated woven grid-reinforced composite materials by the method of claim 1. The blending method in step (2) is longitudinal blending or wrapping blending.

4. A blended fiber integrated woven mesh reinforcement composite material prepared by the method of any one of claims 1-3.

5. A method of making a composite laminate from the integrated woven grid reinforced composite of claim 4, wherein, The steps of the method are: (1) Pretreatment: mechanical degumming treatment of natural continuous fibers at room temperature; the specific method is to put the natural continuous fibers into boiling water at 100°C and cook for 1-3h; the natural continuous fibers are one or a combination of more than one of flax fiber, jute fiber, and hemp fiber; (2) Mix the natural continuous fibers treated in step (1) and resin fibers according to a ratio of 4-7 strands: 6-3 strands to obtain a blended yarn; the resin fibers are continuous fibers; (3) Put the blended yarn prepared in step (2) into a weaving machine to weave into a woven fabric; (4) Make the blended yarn prepared in step (2) into a fiber felt; (5) Alternate the fiber felt, mesh reinforcement, and woven fabric to obtain a preform; the fiber composition and ratio of the fiber felt, mesh reinforcement, and woven fabric are consistent; (6) Put the preform into a molding machine, and prepare a natural fiber in-situ reinforced composite laminate under heating conditions by using a hot molding process.

6. The method of claim 5, wherein the composite laminate is prepared by the steps of: The layering method of the mesh reinforcement, woven fabric, and fiber felt adopts a sandwich structure.

7. The method for preparing the composite laminate according to claim 5, characterized in that, The weaving method in step (3) is hand weaving or mechanical weaving by a weaving machine.

8. The method for preparing the composite laminate according to claim 5, characterized in that, The temperature of the hot pressing process in step (6) is 150-230°C, and the pressure is 1-10MPa.

9. The method for preparing the composite laminate according to claim 5, characterized in that, The hot pressing process in step (6) adopts one-stage molding or multi-stage molding.

10. The method of claim 5, wherein the method further comprises the step of applying a layer of adhesive to the surface of the core layer prior to the step of applying the first layer of composite material to the surface of the core layer. After the hot pressing in step (6) is completed, the blended yarn woven fabric in-situ reinforced fiber reinforced composite board is cooled by mechanical cooling or air cooling.

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