A 3D printing based glass fiber web and method of making the same
Patent Information
- Application Number
- CN202611497026.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-09-24
- Publication Date
- 2026-11-03
AI Technical Summary
Existing sandwich structures have limited core material properties, making it difficult to bond with the skin and resulting in insufficient strength. Traditional honeycomb or foam core materials are also difficult to achieve complex configurations and stress matching, and are costly.
Glass fiber cloth was used as the skin, and polylactic acid carbon fiber filaments were used to prepare a core material with a three-period minimal curved porous structure. The core material was formed by fused deposition modeling 3D printing technology, and a coupling agent was used between the skin and the core material to improve the bonding strength.
It achieves a lightweight, high-toughness, and low-cost sandwich structure with a flat compressive strength of 22 MPa, a flat compressive modulus of 1.5 GPa, and a three-point bending strength of 95 MPa. It significantly improves bending strength and avoids the interface delamination between the skin and the core material, making it suitable for cost-sensitive large wind turbine blade applications.
Smart Images
Figure CN123025541A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of composite materials and additive manufacturing technology, specifically to a glass fiber web sandwich structure and its preparation method, and particularly to a lightweight, high-strength sandwich structure using a three-period minimal surface (TPMS) porous structure as the core layer. Background Technology
[0002] With the rapid development of aerospace, rail transportation, and high-performance sports equipment, increasingly stringent requirements are being placed on the lightweight, high-strength, and multifunctional integration of structural materials. Sandwich structures, as a typical lightweight and high-strength structural form, typically consist of two layers of high-strength thin panels (skin) and a lightweight, thick core material, and are widely used in various load-bearing components. Currently, traditional sandwich structures mostly use foam plastics (such as PVC and PET foam), aluminum honeycomb, or balsa wood as core materials. However, these traditional core materials have inherent drawbacks: foam core materials have low strength and modulus, and their closed-cell structure makes it difficult to effectively expel moisture; honeycomb core materials are prone to peeling from the panels to the core material under out-of-plane impact, and their anisotropic characteristics lead to uneven stress distribution. Furthermore, the structural forms of these traditional core materials are relatively simple, making it difficult to perform topology optimization for complex stress fields, thus limiting further improvements in structural efficiency.
[0003] To address the aforementioned issues, existing technologies attempt to combine composite materials with additive manufacturing, employing lower-cost glass fiber as the skin material. However, designing a matching high-performance core material and achieving a robust bond between the glass fiber skin and the core remains a significant technical challenge. While conventional 3D-printed polymer core materials can be manufactured into complex shapes, their inherent strength often fails to meet the requirements of high-load conditions. Furthermore, traditional straight-hole or simple lattice structures are prone to stress concentration under load, leading to premature localized failure of the core material and failing to fully leverage the performance advantages of the glass fiber skin. Therefore, developing a sandwich structure that combines lightweight design with high toughness and controllable cost, along with its efficient fabrication method, is of significant practical importance. Summary of the Invention
[0004] In view of the shortcomings of existing sandwich structures, such as the single performance of core materials, insufficient bonding strength with the skin, and the difficulty of achieving complex configurations and stress matching with traditional honeycomb or foam core materials, this invention provides a glass fiber web sandwich structure and its preparation method that is lightweight, high toughness, low cost, and has a strong bond between the skin and the core material.
[0005] This invention provides a glass fiber web sandwich structure, comprising an upper skin, a lower skin, and a core material located between them. Both the upper and lower skins are made of woven glass fiber fabric. This glass fiber fabric is pre-treated with a coupling agent to improve its wettability and bonding strength with the resin matrix. Compared to carbon fiber, glass fiber offers lower cost and better insulation properties, making it suitable for cost-sensitive structural components or those without special electromagnetic shielding requirements.
[0006] The core material is made of polylactic acid carbon fiber (PLACF) filaments, with a carbon fiber mass fraction of 15%-30% and a filament diameter of 1.75 mm. The core material has a Gyroid surface porous structure in a three-period minimal surface, and is formed by fused deposition modeling 3D printing technology.
[0007] Beneficial effects
[0008] The fiberglass web sandwich structure prepared by this invention fully utilizes the advantages of low cost and good insulation of fiberglass, while achieving structural toughening through a porous TPMS core material. Testing showed that the structure achieved a flat compressive strength of 22 MPa, a flat compressive modulus of 1.5 GPa, and a three-point bending strength of 95 MPa. Compared to a PVC foam sandwich structure of the same density, the bending strength is increased by more than 250%, and no skin-core interface delamination phenomenon was observed. Compared to carbon fiber skin solutions, this solution significantly reduces material costs while maintaining good mechanical properties, making it more suitable for large-scale applications of cost-sensitive wind turbine blades. Attached Figure Description
[0009] Figure 1 This is a glass fiber web sandwich structure based on 3D printing.
[0010] In the figure, 1. Two layers of glass fiber skin; 2. TPMS structure of PLA+CF material. Detailed Implementation
[0011] The embodiments of the present invention are described in detail below. These embodiments are implemented based on the technical solution of the present invention, and provide detailed implementation methods and specific operation processes. However, the scope of protection of the present invention is not limited to the following embodiments.
[0012] This embodiment also provides a method for preparing the above-mentioned glass fiber web sandwich structure, including the following steps:
[0013] (1) Core material preparation: The three-dimensional digital model was imported into the 3D printer. Polylactic acid carbon fiber filaments were used for printing to obtain the core material preform. After printing, it was dried for 2 hours to remove moisture;
[0014] (2) Skin pretreatment: Cut the fiberglass cloth into square sheets, two sheets in total. Immerse the cut fiberglass cloth in epoxy resin solution, with a resin to fiberglass mass ratio of 1:1, then remove and drain, and set aside.
[0015] (3) Layer-by-layer assembly: On a flat mold coated with a release agent, the first layer of fiberglass cloth (lower skin), the prepared TPMS porous core material, and the second layer of fiberglass cloth (upper skin) are sequentially laid to form a "sandwich" preform. Ensure that each layer is aligned and there is no misalignment.
[0016] (4) Curing and molding: Place the prepared mold in a hot press, close the mold and apply pressure. Curing and then allow it to cool naturally to room temperature;
[0017] (5) Post-processing: After demolding, cut off the overflowing resin flash and excess glass fiber cloth edges around the perimeter, and polish the surface to obtain the final glass fiber web sandwich structure.
Claims
1. A glass fiber web based on 3D printing and its preparation method, characterized in that: It includes skin (1) and core material (2).
2. The 3D-printed glass fiber web according to claim 1, characterized in that, The web has a sandwich structure.
3. The glass fiber web based on 3D printing according to claim 1, characterized in that, The skin is composed of two layers of fiberglass cloth.
4. The glass fiber web based on 3D printing according to claim 1, characterized in that, The core material is a three-period minimal curved surface porous structure printed using 3D printing technology.
5. The 3D-printed fiberglass web according to claim 1, characterized in that, The core material is polylactic acid carbon fiber.
6. The preparation method according to claim 1, characterized in that, Includes the following steps: (1) A three-dimensional model of a porous structure was constructed based on the three-period minimal surface (TPMS) algorithm. Polylactic acid carbon fiber (PLA+CF) filaments were used for 3D printing to obtain a core material with a TPMS porous structure. The surface was then cleaned and dried. (2) Glass fiber cloth is used as the upper and lower skins and is laid on the upper and lower surfaces of the TPMS porous core material to form a "sandwich" core structure preform. (3) The assembled preform is placed in a mold, and the skin material and the core material are cured together under certain temperature and pressure conditions by vacuum-assisted resin infusion (VARI) process. (4) Demolding, trimming the flash and surface treatment of the cured glass fiber web sandwich structure to obtain the finished product.