Needle-punching method for preforms
By dividing the precast body into cells and generating needle-punch points on the cross-sectional profile, the problem of uneven fiber density was solved, thereby improving the structural strength and finished product quality of the precast body.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHINA ACADEMY OF MACHINERY SCIENCE & TECHNOLOGY
- Filing Date
- 2023-12-04
- Publication Date
- 2026-05-26
AI Technical Summary
In existing needle punching forming methods, the fiber density of the preform is uneven, which leads to a decrease in the quality of the finished product.
By dividing the cross-sectional profile of the precast body into multiple cells and generating the same number of needle points in each cell, the precast body is needled according to the position of the needle points to ensure that the same number of introduced fibers are formed in each cell, thereby improving the uniformity of fiber density.
This achieves uniform fiber density within the precast structure, improving its structural strength and finished product quality.
Smart Images
Figure CN117661200B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the technical field of composite material preparation, and specifically to a needle-punching method for preforms. Background Technology
[0002] Needle punching technology enables low-cost weaving of three-dimensional fabrics and is widely used in clothing linings, geotextiles, filter materials, carpets, blankets and tar paper base fabrics.
[0003] Needle punching technology refers to the repeated puncturing of fiber webs or nonwoven fabrics with needles to obtain Z-axis fiber clusters, which results in fiber entanglement between the unit layers of the final preform, forming a composite material with a certain thickness and strength.
[0004] In the needle punching forming method of related technologies, needles are evenly arranged on a needle plate, and the needles are moved by the movement of the needle plate, thereby achieving repeated puncture of the fiber web or nonwoven fabric. However, the needle plate usually moves in a single direction and is limited by the density of the needles on the needle plate, which often results in uneven fiber density in the final preform, thus reducing the quality of the finished preform. Summary of the Invention
[0005] In view of this, the present invention provides a needle punching method for preforms to solve the problem of uneven fiber density in preforms obtained by needle punching.
[0006] This invention provides a method for needle forming a preform, which specifically includes the following steps: obtaining the cross-sectional contour information of the preform; dividing the cross-sectional contour into multiple cells; generating multiple needle points in each cell; and needle-punching the preform according to the positions of the multiple needle points.
[0007] Beneficial Effects: In the needle-punching forming method of the precast body in this scheme, the purpose of needle-punching the precast body is to form introduced fibers along the needle-punching direction within the precast body. These introduced fibers can improve the structural strength and performance of the precast body. This scheme divides the precast body into multiple cells according to its cross-sectional contour, and generates the same number of needle-punching points within each cell. The precast body is needle-punched according to the location of these needle-punching points to ensure that the same number of introduced fibers are formed in each cell after needle-punching, thereby improving the uniformity of fiber density within the precast body.
[0008] In one alternative embodiment, the needle-punching method for the preform described above uses needles on a needle plate to needle the preform. In the step of dividing the cross-sectional profile into multiple cells, the size of each cell is the minimum unit size for the needle arrangement on the needle plate.
[0009] Beneficial effects: The cell size is set to correspond to the minimum unit size of the needle arrangement on the needle plate, ensuring that the cell size is small enough to maximize the uniformity of fibers within the preform. Furthermore, in practical applications, each cell can correspond to a needle on the needle plate, allowing multiple needles on the needle plate to simultaneously puncture multiple cells, further ensuring uniform fiber introduction within the preform and resulting in high preform production efficiency.
[0010] In one optional embodiment, the needle forming method for the preform further includes the steps of: dividing the preform into multiple unit layers along the thickness direction of the preform; determining the number of needle punches n for each unit layer; wherein the value of n is obtained based on the ratio of the target value of the needle punch density of the preform to the needle density of the needle plate.
[0011] Beneficial effects: By determining the number of times each unit layer is needled based on the target value of the preform's needled density and the needle density of the needle plate, the expected fiber density of the preform can be accurately achieved, ensuring the quality of the finished preform. Specifically, the number of times n is needled in each unit layer is the rounded-up ratio of the target value of the preform's needled density to the needle density of the needle plate.
[0012] In one optional implementation, in the step of generating multiple needle points in each cell, the number of needle points in each cell is n; where n is the number of times each cell layer is needled.
[0013] Beneficial effects: Each cell contains n needled points, allowing each unit layer to be needled n times, achieving the target needled density of the preform. This scheme ensures that each cell within each unit layer of the preform has n needled points, resulting in uniform fiber introduction in each layer after needled treatment, thus achieving uniformity of interlayer properties in the preform.
[0014] In one optional implementation, the step of generating multiple needle points in each cell includes the following steps: selecting n needle points Pi, where 1≤i≤n; forming a needle point set {P1,P2,…,Pn} based on the needle points Pi.
[0015] Beneficial effects: Selected needle points Pi are arranged in sequence to form a needle point set, which makes it easier for the needle plate to accurately obtain the position of the needle points during the needle-punching process, improves the accuracy of needle-punching, and thus ensures the uniformity of needle-punching density of the preform.
[0016] In one optional implementation, the step of acupuncturing the preform according to the positions of multiple acupuncture points includes repeating the acupuncture step in the order of the acupuncture point set. The acupuncture step includes: laying a unit layer; adjusting the position of the acupuncture plate so that the needles of the acupuncture plate are aligned with the acupuncture points Pi in each unit cell; and completing the acupuncture of the acupuncture points Pi.
[0017] Beneficial effects: In this scheme, according to the order of the needle point set, each unit layer is laid and one needle point Pi is needled, which reduces the number of needles, reduces fiber damage in the preform, and improves the finished product efficiency of the preform.
[0018] In one alternative implementation, the step of selecting n needle-punching points Pi includes: determining the origin of the coordinate system for each cell; and selecting n coordinate points Pi(Xi,Yi) within each cell based on the origin, where 1≤i≤n.
[0019] Beneficial effects: Facilitates digital control and improves the automation level of the implementation process.
[0020] In one optional implementation, in the step of puncturing the preform according to the positions of multiple puncture points, the depth to which the needle penetrates the preform each time is h, and the puncture depth h satisfies: h = s * n; where s is the thickness of each unit layer.
[0021] Beneficial effects: Setting the insertion depth of the needle to the product of the thickness of the unit layer and the number of times each unit layer is punctured ensures that the needle can penetrate n unit layers during puncture. This allows each unit layer to be punctured n times cumulatively during repeated puncture steps, ensuring consistent cumulative puncture density in each unit layer of the precast body and further improving the uniformity of the interlayer properties of the precast body.
[0022] In one alternative implementation, in the step of dividing the cross-sectional profile into multiple cells, the cells are constructed as triangles or as quadrilaterals.
[0023] Beneficial effects: The shape of the cell can be determined based on the needle arrangement of the needle plate. When the needle plate has triangular units, the cell can be constructed as a triangle; when the needle plate has quadrilateral units, the cell can be constructed as a quadrilateral. Thus, in practical applications, the number of needles on the corresponding needle plate in each cell is consistent, ensuring the consistency of needle density in each cell.
[0024] In one alternative implementation, in the step of generating multiple needle points in each cell, the multiple needle points are evenly distributed within the cell.
[0025] Beneficial effects: The uniform distribution of multiple needled points within each cell can further improve the uniformity of needled density in the preform, ensure the uniformity of fiber density within the preform, and thus improve the finished product performance of the preform. Attached Figure Description
[0026] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0027] Figure 1 This is a flowchart of a needle-punching forming method for a preform according to an embodiment of the present invention;
[0028] Figure 2 This is a schematic diagram of the distribution structure of cell and needle point in a needle-punching forming method for a preform according to an embodiment of the present invention;
[0029] Figure 3 This is a schematic diagram of a needle-punching forming method for a preform according to an embodiment of the present invention.
[0030] Explanation of reference numerals in the attached figures:
[0031] 1. Cell; 2. Needle plate; 21. Needle; 3. Cell layer; 4. Introducing fiber. Detailed Implementation
[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0033] Needle punching technology enables low-cost weaving of three-dimensional fabrics and is widely used in clothing linings, geotextiles, filter materials, carpets, blankets and tar paper base fabrics.
[0034] Needle punching technology refers to the repeated puncturing of fiber webs or nonwoven fabrics with needles to obtain Z-axis fiber clusters, which results in fiber entanglement between the unit layers of the final preform, forming a composite material with a certain thickness and strength.
[0035] In the needle punching forming method of related technologies, needles are evenly arranged on a needle plate, and the needles are moved by the movement of the needle plate, thereby achieving repeated puncture of the fiber web or nonwoven fabric. However, the needle plate usually moves in a single direction and is limited by the density of the needles on the needle plate, which often results in uneven fiber density in the final preform, thus reducing the quality of the finished preform.
[0036] Based on this, the present invention provides a needle punching method and a needle punching machine for forming a preform, so as to improve the uniformity of fiber density in the preform.
[0037] The following is combined with Figures 1 to 3 The following describes embodiments of the present invention.
[0038] According to an embodiment of the present invention, in one aspect, see... Figure 1 A method for needle-punching a preform is provided, which specifically includes the following steps:
[0039] S10: Obtain the cross-sectional contour information of the precast body;
[0040] S20: Divide the cross-sectional profile into multiple cells 1;
[0041] S30: Generate multiple needle prick points in each cell 1;
[0042] S40: The preform is needled according to the location of multiple needle points.
[0043] like Figure 3 As shown, the purpose of needle punching the preform is to form introduced fibers 4 along the needle punching direction within the preform. These introduced fibers 4 shape the preform into a monolithic structure and improve its structural strength and performance. In this embodiment, multiple cell sections 1 are divided according to the cross-sectional contour of the preform, and the same number of needle punches are generated within each cell section 1. The preform is needle punched according to the positions of these needle punches to ensure that after needle punching, the same number of introduced fibers 4 are formed within each cell section 1, improving the uniformity of fiber density within the preform and thus improving the finished quality of the preform.
[0044] Specifically, in step S10, the cross-sectional profile information of the preform refers to the cross-sectional profile formed by the preform on the plane to be punctured.
[0045] Furthermore, the needle-punching method for preforms in this application utilizes needles 21 on the needle plate 2 to needle the preform. Figure 1 As shown in the example, the needle plate 2 is arranged parallel to the preform, and the needles 21 on the needle plate 2 are perpendicular to the upper surface of the preform. It can be understood that the needle plate 2 and the preform can also be arranged at an angle, as long as the needle-punching of the preform can be achieved, and this application does not make specific limitations in this regard.
[0046] In some embodiments, in step S20, the size of each cell 1 is the smallest unit size of the needle arrangement on the needle plate 2, making the size of the cell 1 small enough to maximize the uniformity of the fibers in the preform. Furthermore, in practical applications, each cell 1 can correspond to a needle 21 on the needle plate 2, allowing multiple needles 21 on the needle plate 2 to simultaneously puncture multiple cells 1, further ensuring the formation of uniformly introduced fibers 4 within the preform, and resulting in a high preform production efficiency.
[0047] Furthermore, the specific shape of cell 1 can be determined based on the needle arrangement of the needle plate 2. For example, when the needle arrangement on the needle plate 2 is triangular, cell 1 can be constructed as a triangle. For example, when the needle arrangement on the needle plate 2 is quadrilateral, cell 1 can be constructed as a quadrilateral. Thus, in practical applications, the number of needles 21 on the corresponding needle plate 2 within each cell 1 is consistent, ensuring the consistency of needle density within each cell 1. For example, cell 1 can be constructed as a triangle. For example, cell 1 can also be constructed as a quadrilateral. It is understood that cell 1 can also be constructed as other shapes, such as circles or polygons, as long as they match the needle arrangement on the needle plate 2.
[0048] In some embodiments, in step S30, the generated multiple needled points are evenly distributed within cell 1 to further improve the uniformity of the needled density of the preform, ensure the uniformity of the fiber density within the preform, and thereby improve the finished product performance of the preform.
[0049] Furthermore, in some embodiments, the needle-punching method for the preform further includes the step of:
[0050] S50: Divide the precast body into multiple unit layers 3 along the thickness direction of the precast body;
[0051] S60: Determine the number of times n is needled in each unit layer 3; where the value of n is obtained based on the ratio of the target value of the needle density of the preform to the needle density of the needle plate 2.
[0052] The number of times n is needled in each unit layer 3 is determined based on the target value of the needle density of the preform and the needle density of the needle plate 2. This ensures that the fiber density expected to be achieved in the preform is accurately reached, thus guaranteeing the quality of the finished preform.
[0053] Specifically, steps S50 and S60 can be implemented at any step before step S40, preferably before step S10.
[0054] In step S50, the precast body can be divided into N unit layers 3 with a thickness of s along the thickness direction of the precast body, according to the target size and performance requirements of the precast body. Where N≥1.
[0055] For example, with Figure 3 Taking the example shown, the prefabricated body can be divided into 8 unit layers, where N is 8. It can be understood that N can be any integer greater than or equal to 1. The value of s can be obtained based on the thickness of the materials composing the prefabricated body.
[0056] Specifically, in step S60, the value of the number of times n is needled in each unit layer 3 is the rounded-up value of the ratio of the target value of the needle density of the preform to the value of the needle density of the needle plate 2.
[0057] Furthermore, in some embodiments, in step S30, the number of needle puncture points in each cell 1 is n. Here, n is the number of times each unit layer 3 is needled, that is, the number of times each unit layer 3 needs to be needled according to the target needle density of the preform, which is the same as the number of needle puncture points in each cell 1. This facilitates ensuring that each unit layer 3 can be needled n times, achieving the target needle density value of the preform.
[0058] In this embodiment, the prefabricated body can achieve n needle-punching points in each cell 1 within each unit layer 3, thereby obtaining uniformly introduced fibers 4 in each layer after needle-punching, achieving uniformity of interlayer performance in the prefabricated body. For example, using... Figure 2 As shown in the example, the number of punctures required for each unit layer 3 is calculated to be 9 according to the target needle density of the prefabricated body. Accordingly, each cell 1 can have 9 needle puncture points.
[0059] In some embodiments, step S30 further includes the following steps:
[0060] S31: Select n needle puncture points Pi, where 1≤i≤n;
[0061] S32: Form a set of acupuncture points {P1, P2, ..., Pn} based on the acupuncture point Pi.
[0062] In this embodiment, the selected needle points Pi are arranged in sequence to form a needle point set, which makes it easier for the needle plate 2 to accurately obtain the position of the needle points during the needle-punching process, improve the accuracy of needle-punching, and thus ensure the uniformity of the needle-punching density of the preform.
[0063] Specifically, in step S31, the needle-punching point Pi can be selected according to the coordinates to facilitate digital control and improve the automation level of the implementation process. Step S31 specifically includes the following steps:
[0064] S31a: Determine the origin of the coordinates for each cell 1; for example, using... Figure 2 As shown in the example, the bottom right corner of each cell 1 can be used as the origin of the coordinate system for each cell 1.
[0065] S31b: Based on the origin, select n coordinate points Pi(Xi,Yi) in each cell 1, where 1≤i≤n, to generate the needle point Pi. In this step, the values of X and Y in the coordinate point Pi(Xi,Yi) can be random.
[0066] In step S31b, the specific steps for selecting the coordinate points within each cell 1 are as follows:
[0067] Select the random coordinate point P1(X1,Y1) in cell 1 that is closest to the origin as the first needle point P1;
[0068] Then select the random coordinate point P2(X2,Y2) in cell 1 that is closest to point P1 as the second needle point P2; where the random coordinate point P2(X2,Y2) is a coordinate point other than the origin and point P1.
[0069] Repeat the above steps until a random needle prick point Pn is found.
[0070] In step S31, the acupuncture point set {P1, P2, ..., Pn} is formed according to the above-mentioned order of selecting acupuncture points.
[0071] Furthermore, in some embodiments, step S40 specifically includes repeating the acupuncture steps according to the order of the acupuncture point set. This acupuncture step includes:
[0072] S41: Lay out one unit layer 3;
[0073] S42: Adjust the position of the needle plate 2 so that the needles 21 of the needle plate 2 are directly aligned with the needle points Pi in each cell 1;
[0074] S43: Complete the needling of point Pi.
[0075] In this embodiment, following the order of the needle point set, each time a unit layer 3 is laid, one of the needle points Pi is needled to reduce the number of needle punctures, reduce fiber damage in the preform, and improve the finished product efficiency of the preform.
[0076] In some embodiments, in step S40, the depth to which the needle 21 penetrates the preform each time is h, and the penetration depth h satisfies: h = s * n; where s is the thickness of each unit layer 3. Setting the penetration depth of the needle 21 to the product of the thickness of the unit layer 3 and the number of times each unit layer 3 is punctured ensures that the needle 21 can penetrate n unit layers 3 during puncture, so that each unit layer 3 can be punctured n times cumulatively when the puncture step is repeated, ensuring that the cumulative puncture density of each unit layer 3 of the preform is consistent, and further improving the uniformity of the interlayer performance of the preform.
[0077] More specifically, when performing the above acupuncture procedure for the first time, the acupuncture procedure is as follows:
[0078] S41a: Lay out the first unit layer 3;
[0079] S42a: Adjust the initial height of the needle plate 2 and its corresponding position with the unit layer 3; wherein, adjust the initial height of the needle plate 2 so that when the needle 21 moves downward, it can just penetrate the n-layer unit layer 3; adjust the corresponding position of the needle plate 2 and the unit layer 3 so that the needle 21 is set relative to the needle puncture point P1.
[0080] S43a: After the needling of point P1 is completed, the height of the needle plate 2 is raised by s.
[0081] When performing the above acupuncture steps again, the acupuncture steps are as follows:
[0082] S41b: Lay out the (jn+i)th layer of unit cell 3; where j≥0;
[0083] S42b: Adjust the corresponding position of the needle plate 2 and the unit layer 3 so that the needle 21 is set relative to the needle point Pi;
[0084] S43b: After the needling of point Pi is completed, the height of the needle plate 2 is raised by s.
[0085] Repeat the above acupuncture steps until all unit layers 3 are acupunctured, and obtain a preform with uniform acupuncture density within unit layer 3.
[0086] Specifically, the value of j depends on the number of layers n that the needle 21 can penetrate in unit layer 3, so that... Figure 3 As shown in the example, each unit layer 3 is punctured 5 times (n), and the corresponding number of times the needle 21 can penetrate unit layer 3 (n) is also 5. When laying the first to fifth unit layers 3, j takes a value of 0; when laying the sixth to tenth unit layers 3, j takes a value of 1, and so on. This will not be elaborated further here.
[0087] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.
Claims
1. A method for needle-punching a preform, characterized in that, Includes the following steps: Obtain the cross-sectional contour information of the preform, divide the cross-sectional contour into multiple cells (1), the size of the cell (1) is the smallest unit size of the needle arrangement on the needle plate (2), and each cell (1) corresponds to a needle (21) on the needle plate (2); Along the thickness direction of the preform, the preform is divided into multiple unit layers (3), each layer having a thickness of s; The number of times n is needled in each unit layer (3) is determined based on the ratio of the target value of the needle density of the preform to the needle density of the needle plate (2); n needle puncture points are generated sequentially in each of the aforementioned cells (1); Calculate and adjust the depth of the needle (21) inserted into the preform each time: h = s * n; The preform is needled according to the needle puncture points and depths described above.
2. The needle-punching forming method for the preform according to claim 1, characterized in that, The step of generating n needle puncture points in each cell (1) includes the following steps: Select n acupuncture points P i Where 1≤i≤n; According to the acupuncture point P i Form a set of acupuncture points {P1, P2, ..., P} n } 3. The needle-punching forming method for the preform according to claim 2, characterized in that, The step of acupuncturing the preform according to the positions of the n acupuncture points includes repeating the acupuncture step in the order of the acupuncture point set, wherein the acupuncture step includes: Lay out one layer of the aforementioned unit layer (3); Adjust the position of the needle plate (2) so that the needles (21) of the needle plate (2) are respectively aligned with the acupuncture points P in each of the cells (1). i Right in front; Complete the needling at point P i Acupuncture.
4. The needle-punching forming method for the preform according to claim 2, characterized in that, The selection of n acupuncture points P i The steps include: Determine the origin of the coordinates for each of the cells (1); Based on the origin of the coordinate system, n coordinate points Pi(X) are selected within each cell (1). i ,Y i ), 1≤i≤n.
5. The needle-punching method for preforms according to claim 1, characterized in that, In the step of dividing the cross-sectional profile into multiple cells (1), the cell (1) is constructed as a triangle or as a quadrilateral.
6. The needle-punching forming method for the preform according to claim 1, characterized in that, In the step of generating n needle points in each of the cells (1), the needle points are evenly distributed in the cells (1).