A method of shaping a pre-stretched fabric with 3d printing and a 3d printed fabric product

Abstract

The application discloses a shaping method for pre-stretching fabric by 3D printing and 3D printed fabric. The shaping method is to classify the surface area of the expected shape according to the Gaussian curvature value of each point on the surface of the expected shape, and to plan the corresponding three-dimensional printing path according to the classification. The three-dimensional printing path is flattened into a two-dimensional plane path, and the 3D printing entity is obtained by processing in a three-dimensional modeling software. The application provides a shaping method for pre-stretching fabric by 3D printing, which has good shaping function and flexibility, and the production is fast. The shaping method combines the flexibility of the fabric and the structural property of the hard material, realizes complex and diverse shape design, improves the design and manufacturing level of the 3D printed fabric product, effectively integrates the geometric analysis and the manufacturing process, improves the production efficiency and the printing quality, and optimizes the material use and the product performance.

Description

Technical Field

[0001] This invention relates to functional fabric shaping technology, and particularly to a shaping method for pre-stretched fabrics using 3D printing and 3D printed fabric products. Background Technology

[0002] Since its inception, 3D printing technology has been widely applied in various fields, from manufacturing and healthcare to architecture and fashion design. Traditional 3D printing typically employs methods such as Fused Deposition Modeling (FDM), Stereolithography (SLA), and Selective Laser Sintering (SLS), primarily for manufacturing three-dimensional objects from rigid materials. These technologies excel in prototyping, custom parts, and small-batch production due to their high precision and flexibility. However, the application of 3D printing technology in flexible materials, especially fabrics, is relatively limited.

[0003] Existing 3D printing fabric technologies typically construct objects through direct layer-by-layer deposition, such as via fused deposition modeling (FDM™), as described in Chinese patent CN202311150780.3. This method achieves decorative and functional fabrics by printing rigid sheets onto a flexible fabric substrate. While popular for its simplicity, this approach suffers from several drawbacks, such as the inability to shape and control the fabric's form, relying solely on surface decoration. The combination of fabric flexibility and rigid 3D printing materials (PLA plastic) can produce a rich variety of forms and functions, particularly suitable for the design and manufacture of footwear, apparel, and other products requiring structurally shaped fabrics.

[0004] The following is an example of existing technology: (1) Shape memory polymer (SMP) technology: Method: Shape memory polymers (SMPs) are used as printing materials, and external stimuli (such as temperature, light, and humidity) induce morphological changes in the material. After printing, the SMP material can be programmed into a specific shape and will return to its original shape upon encountering a stimulus.

[0005] (2) Shape memory alloy (SMA) technology: Method: Shape memory alloys (such as nickel-titanium alloys) are used as printing materials, and temperature changes induce morphological changes in the alloy. SMA materials can be deformed at low temperatures and will return to their preset shape after being heated to a specific temperature.

[0006] (3) Hydrogel material technology: Method: Using hydrogel materials with water-absorbing properties, the absorption or loss of water induces expansion or contraction of the material, resulting in specific morphological changes. The morphological changes of hydrogel materials can be controlled by adjusting their water content.

[0007] (4) Dual-material printing technology: Method: Printing is performed using two materials with different properties. The difference in the coefficient of thermal expansion or other physical properties of the different materials induces morphological changes in the printed object under external stimuli. Typical methods include embedding one material into another to achieve controllable morphological changes.

[0008] (5) Bioprinting technology: Methods: Bioprinting utilizes biomaterials and cells for printing, enabling the self-assembly and morphological changes of biological structures through cell growth and tissue reorganization. Bioprinting technology can simulate the natural growth process of organisms, realizing complex biological structures.

[0009] (6) Temperature-responsive materials technology: Method: Using temperature-responsive materials, morphological changes in the material are induced by temperature variations. For example, thermochromic polymer materials soften or harden at specific temperatures to achieve adaptive structural deformation.

[0010] (7) Hollow pipe rope threading technology: Method: A structure with hollow tubes is manufactured using 3D printing technology, with tension ropes or other controllable materials pre-embedded during the printing process. After printing, the structure's shape can be changed by pulling or controlling these pre-embedded materials.

[0011] The following are some of the drawbacks of existing printing technologies: (1) Shape control precision: Many 4D printing technologies have certain limitations in terms of the precision and repeatability of shape changes, making it difficult to achieve high-precision control.

[0012] (2) Material property limitations: Existing smart materials have certain limitations in terms of mechanical strength, durability and response speed, which affect the performance of 4D printed objects.

[0013] (3) Process complexity: 4D printing technology usually requires complex equipment and processes, which are costly and not suitable for large-scale production.

[0014] (4) External stimuli: Many 4D printing technologies require specific external stimuli (such as temperature, humidity, and light), which limits their practical application.

[0015] (5) Structural design complexity: Hollow pipe rope threading technology and dual material printing technology require precise control in the structural design and manufacturing process, which increases the complexity of design and manufacturing.

[0016] Therefore, there is a need for a simpler and faster method that can combine the flexibility of fabrics with the structural integrity of rigid materials to achieve complex and diverse shape designs; improve the design and manufacturing level of 3D printed fabric products, and be applicable to the design and manufacturing of footwear, clothing and other products that require structural shaping. Summary of the Invention

[0017] Purpose of the invention: The purpose of this invention is to provide a rapid shaping method for pre-stretched fabrics using 3D printing, and 3D printed fabric products, which have good shaping function and flexibility.

[0018] Technical solution: The present invention provides a shaping method for pre-stretched fabric using 3D printing. Based on the Gaussian curvature values ​​of each point on the surface of the product's expected shape, the surface area of ​​the expected shape is classified according to curvature, and a corresponding three-dimensional printing path is planned accordingly. The three-dimensional printing path is flattened into a two-dimensional planar path, and the 3D printed entity is obtained by processing in three-dimensional modeling software.

[0019] Furthermore, it includes the following steps: (1) Gaussian curvature analysis: First, Gaussian curvature analysis of the model surface is performed to calculate the Gaussian curvature value at each point on the model surface; (2) Curvature classification: The curvature value is compared with the preset threshold ε and divided into positive curvature surface, negative curvature surface and zero curvature surface; (3) Printing path planning: Obtain the 3D printing path; (4) Two-dimensional flattening: Flatten the three-dimensional printing path into a two-dimensional planar path, and process it in three-dimensional modeling software to obtain the 3D printing entity; (5) Actual printing: The pre-stretched fabric is loaded onto the printing table using a fixture, the printing parameters are adjusted and PLA printing material is used for manufacturing; (6) Shaping: After printing, the product is shaped by cutting and the natural shrinkage of the fabric.

[0020] Furthermore, the printing path planning method in step (3) is as follows: A: Negative curvature surface: Draw a curve along the principal curvature direction at the point where the Gaussian curvature value is the largest, and generate a printing path; B: Positive curvature surface, using two methods: A hexagonal pattern centered at the point of maximum Gaussian curvature, with a radius varying according to the curvature value. The curve along the direction of curvature is broken and short lines of different lengths are arranged alternately. C: Zero curvature surface: Draw a free curve or leave it as a blank area according to design requirements.

[0021] Furthermore, the positive curvature surface is defined as follows: a region where the Gaussian curvature value at each point is greater than the positive threshold ε is called a positive curvature surface.

[0022] Furthermore, the negative curvature surface is defined as follows: a region where the Gaussian curvature value at each point is less than the negative threshold -ε is called a negative curvature surface.

[0023] Furthermore, the zero curvature surface is defined as follows: the Gaussian curvature values ​​at each point in the region that are between -ε and ε are called zero curvature surfaces.

[0024] Furthermore, this applies to 3D models of footwear and free-expression 3D models.

[0025] Furthermore, when dealing with 3D models of footwear, 3D printing path planning is performed for surfaces with positive curvature, negative curvature, and zero curvature, respectively.

[0026] Furthermore, when dealing with 3D models of footwear, 3D printing path planning is performed for both positive and negative curvature.

[0027] Another aspect of the present invention provides 3D printed fabric products prepared by the method.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. Rapid production: the entire process from calculation to actual production can be completed within 2 hours; 2. The materials are environmentally friendly, requiring only fabric + 6mm PLA printing path to form the shape; 3. Combining the flexibility of fabrics with the structural integrity of rigid materials, complex and diverse form designs can be achieved; 4. Improve the design and manufacturing level of 3D printed fabric products, suitable for footwear, clothing and other products that require structural shaping; 5. Effectively integrate geometric analysis and manufacturing processes to improve production efficiency and printing quality, and optimize material use and product performance. Attached Figure Description

[0029] Figure 1 This is a schematic diagram illustrating the different types of curvature surface splitting of the expected shape in Example 1; Figure 2 This is a schematic diagram of path division for negative curvature surface 1; Figure 3 This is a schematic diagram of the planar path for 3D printing on a pre-stretched fabric in Example 1; Figure 4 This is a schematic diagram of the shape after the fabric constraint is removed from the printed product in Example 1; Figure 5 This is a schematic diagram of the shape after the fabric constraint is removed from the printed product in Example 1; Figure 6 This is a schematic diagram illustrating the path division of the negative curvature surface 6 and the positive curvature surface 7. Figure 7 This is a schematic diagram of the planar path for 3D printing on a pre-stretched fabric in Example 2; Figure 8 This is a schematic diagram of the shape after the fabric constraint is removed from the printed form in Example 2; Figure 9 This is a technical system diagram. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the present invention will be further described below.

[0031] The technical system diagram of this embodiment is as follows: Figure 9 The technical approach is as follows: First, the target model is 3D scanned to obtain the initial model. Then, curvature analysis is performed. Based on the curvature analysis, the resulting surfaces are flattened, and different paths are distributed according to different curvature surfaces. On the zero-curvature surface, the designer combines their own creativity with the original database of different patterns. On the positive and negative curvature surfaces, wiring is performed according to the principles of this invention to obtain the final pattern. Finally, the final product is obtained by 3D printing.

[0032] The specific implementation process is illustrated below:

[0033] Example 1 For the illustrated 3D model of footwear, the first step is to perform an overall Gaussian curvature analysis of the surface, calculating the Gaussian curvature value at each point on the model's surface. The calculated Gaussian curvature values ​​are then categorized into three predefined classes to divide the model's surface. For example... Figure 1 As shown, the division is based on the following criteria: a region where the Gaussian curvature value at each point is greater than the positive threshold ε is called a positive curvature surface, such as positive curvature surface 4; a region where the Gaussian curvature value at each point is less than the negative threshold -ε is called a negative curvature surface, such as negative curvature surface 1, negative curvature surface 2, and negative curvature surface 3; and a region where the Gaussian curvature value at each point is between -ε and ε is called a zero curvature surface, such as zero curvature surface 5.

[0034] Wherein, ε is a control coefficient in Rhino's curvature analysis, and in this invention, ε ranges from 0.00x to -0.00y, where x and y are integer values ​​between 0 and 9. The flattening algorithm is an algorithm in Rhino.

[0035] Next, based on the division results, separate 3D printing path planning is performed for surfaces with different curvatures. For example... Figure 2As shown, for negative curvature surface 1, select the point a0 with the largest Gaussian curvature value. Develop and draw two curves l1 and l2 on the surface, terminating at the surface boundary, along the positive and negative directions of its principal curvatures k1 and k2, respectively. Each point on these curves advances along the corresponding principal curvature direction on the surface. Since the principal curvature k1 is greater than the principal curvature k2, divide l1 equally to obtain points a1, a2, and a3. From each point, develop curves n1, n2, and n3 on the surface along the corresponding principal curvature direction, terminating at the boundary, in the same manner as l2. Simultaneously, draw closed curves along the surface boundary. For negative curvature surface 1, its printing path consists of the surface boundary curves, l2, n1, n2, and n3. For negative curvature surfaces 2 and 3, the corresponding printing paths can be drawn using the same method as for negative curvature surface 1 described above.

[0036] For positive curvature, the point 'a' with the largest Gaussian curvature value is first marked using curvature analysis. Then, hexagons with decreasing radii are arranged outwards from this point to draw the printing path. A hexagon with the largest radius is placed at point 'a', and hexagons are arranged outwards from this center with their radii decreasing as the curvature value decreases. This ensures that the size of each hexagon is proportional to the Gaussian curvature value of its center point, thus forming a continuous pattern of hexagons of varying sizes across the entire surface, constituting the printing path for the positive curvature surface 4.

[0037] For the zero curvature surface 5, you can draw a free curve on it, or you can choose not to draw a path.

[0038] After drawing the 3D printing path for all curved surfaces, the overall 3D printing path based on the original footwear model is obtained, as shown in the figure.

[0039] The 3D printing path based on the original footwear model is flattened in 2D using a boundary-first flattening algorithm. The resulting planar curve is then processed in 3D modeling software to obtain a 3D printable entity, such as... Figure 3 Figure 4 As shown.

[0040] In actual printing production, a pre-stretched fabric with four-way elasticity can be loaded onto the printing table using a fixture. Appropriate printing parameters are adjusted, and PLA printing material is used for printing. After printing, the desired portion is trimmed along the edge, and the product is shaped as the fabric shrinks.

[0041] Example 2

[0042] For freely expressive 3D models, the first step is to perform an overall Gaussian curvature analysis of the surface, calculating the Gaussian curvature value at each point on the model's surface. For example... Figure 5As shown, the calculated Gaussian curvature values ​​are classified into three predefined categories to divide the model surface. The classification criteria are as follows: a region where the Gaussian curvature value at all points is greater than the positive threshold ε is called a positive curvature surface, such as positive curvature surface 7; a region where the Gaussian curvature value at all points is less than the negative threshold -ε is called a negative curvature surface, such as negative curvature surface 6; and a region where the Gaussian curvature value at all points is between -ε and ε is called a zero curvature surface, which does not appear here.

[0043] Next, based on the division results, separate 3D printing path planning is performed for surfaces with different curvatures. For example... Figure 6 As shown, for the positive curvature surface 7, alternating short lines are arranged parallel to each other along the longitudinal curvature direction, with the overlapping part accounting for about 1 / 3 of the total length. For the negative curvature surface 6, the point b0 with the largest Gaussian curvature value is selected, and two curves l3 and l4 are drawn on the surface terminating at the surface boundary along the positive and negative directions of its principal curvature k1 and k2, respectively. Each point on the two curves progresses along the corresponding principal curvature direction on the surface. Since the principal curvature k1 is greater than the principal curvature k2, l3 is divided equally to obtain points b1, b2, and b3. From each point, curves m1, m2, and m3 are drawn on the surface terminating at the boundary along the corresponding principal curvature direction in the same way as l4. Simultaneously, closed curves are drawn along the surface boundary. This 3D printing path based on the free expression class model is then flattened in 2D using a boundary-first flattening algorithm. The resulting planar curves are then processed in 3D modeling software to obtain a 3D printable entity, such as... Figure 7 Figure 8 As shown.

[0044] In actual printing production, a pre-stretched fabric with four-way elasticity can be loaded onto the printing table using a fixture. Appropriate printing parameters are adjusted, and PLA printing material is used for printing. After printing, the desired portion is trimmed along the edge, and the product is shaped as the fabric shrinks.

[0045] The above are merely preferred embodiments of the present invention and do not constitute any limitation on the present invention. Any equivalent substitutions or modifications made by those skilled in the art to the technical solutions and content disclosed in the present invention without departing from the scope of the present invention shall be deemed to have remained within the protection scope of the present invention.

Claims

1. A method for shaping pre-stretched fabric using 3D printing, characterized in that, Based on the Gaussian curvature values ​​of each point on the expected product shape surface, the surface area of ​​the expected shape is classified according to curvature, and the corresponding 3D printing path is planned accordingly. The 3D printing path is flattened into a 2D planar path and processed in 3D modeling software to obtain the 3D printed entity. The method for shaping pre-stretched fabric using 3D printing includes the following steps: (1) Gaussian curvature analysis: First, Gaussian curvature analysis of the model surface is performed to calculate the Gaussian curvature value at each point on the model surface; (2) Curvature classification: The curvature value is compared with the preset threshold ε and divided into positive curvature surface, negative curvature surface and zero curvature surface; (3) Printing path planning: Obtain the 3D printing path; (4) Two-dimensional flattening: Flatten the three-dimensional printing path into a two-dimensional planar path, and process it in three-dimensional modeling software to obtain the 3D printing entity; (5) Actual printing: The pre-stretched fabric is loaded onto the printing table using a fixture, the printing parameters are adjusted and PLA printing material is used for manufacturing; (6) Shaping: After printing, the product is shaped by cutting and the natural shrinkage of the fabric; The printing path planning method in step (3) is as follows: A: Negative curvature surface: Draw a curve along the principal curvature direction at the point where the Gaussian curvature value is the largest, and generate a printing path; B: Positive curvature surface, using one of the following two methods: A hexagonal pattern centered at the point of maximum Gaussian curvature, with a radius varying according to the curvature value. The curve along the direction of curvature is broken and short lines of different lengths are arranged alternately. C: Zero curvature surface: Draw a free curve or leave it as a blank area according to design requirements.

2. The shaping method for pre-stretched fabric using 3D printing according to claim 1, characterized in that, The positive curvature surface is defined as follows: a region where the Gaussian curvature value at each point is greater than the positive threshold ε is called a positive curvature surface.

3. The shaping method for pre-stretched fabric using 3D printing according to claim 1, characterized in that, The negative curvature surface is defined as follows: a region where the Gaussian curvature value at each point is less than the negative threshold -ε is called a negative curvature surface.

4. The shaping method for pre-stretched fabric using 3D printing according to claim 1, characterized in that, The zero curvature surface is defined as follows: the Gaussian curvature values ​​at each point in the region that are between -ε and ε are called zero curvature surfaces.

5. The shaping method for pre-stretched fabric using 3D printing according to claim 1, characterized in that, When dealing with 3D models of footwear, 3D printing path planning is performed for surfaces with positive curvature, negative curvature, and zero curvature.

6. The shaping method for pre-stretched fabric using 3D printing according to claim 1, characterized in that, When dealing with 3D models of footwear, 3D printing path planning is performed for both positive and negative curvature.

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