What is the Principle of Digital Mold Technology for Double-Curved GRC Shapes? Analysis and Application Practice of Digital Mold Technology

Double-curved GRC forms, with their complex surfaces and high precision requirements, are difficult to produce using traditional mold technology. Digital mold technology, through parametric design and automated machining, enables the precise realization of complex double-curved forms and has become the core technical support for high-end GRC projects. Drawing on its practice in double-curved projects such as the Guangxi New Media Center, Qinglong explains the principles and key application points of digital mold technology.

1. Core Principle Framework of Digital Mold Technology

Digital mold technology centers on 3D data, running through the entire process of design, machining, and verification. 3D data modeling: Based on parametric design software such as Rhino and Grasshopper, a precise 3D model of the double-curved GRC form is constructed, with surface curvature optimized through algorithms to ensure a smooth form that is feasible for production; Qinglong uses BIM technology to achieve data coordination among architectural, structural, and mold design. Parametric decomposition of molds: The overall double-curved surface is decomposed into several machinable unit modules, with the surface parameters, dimensions, and jointing relationships of each module calculated; module division must balance machining efficiency with jointing precision, and complex double-curved forms are usually decomposed into unit modules of 1-3㎡. CNC machining drive: The decomposed module data is imported into CNC machining equipment, driving the equipment to machine the mold substrate according to preset parameters, achieving precise digital replication to replace traditional manual lofting.

2. Principles and Implementation of Key Technical Steps

Precise control of core technical steps is key to ensuring mold accuracy. Surface fitting algorithm: NURBS surface fitting technology is adopted, with control point adjustments achieving smooth transitions of complex double-curved surfaces; fitting errors are controlled within 0.5mm to ensure the mold surface matches the designed form. CNC machining technology: Commonly used equipment includes CNC engraving machines and 3D printers; CNC engraving machines are suitable for mold substrates such as foam and wood, with machining accuracy up to ±0.1mm, while 3D printers can directly print resin molds, suited to small-batch complex forms. In the Shanghai Astronomy Museum project, Qinglong used CNC engraving machines to machine double-curved molds, ensuring form accuracy. Mold surface treatment: The machined mold surface needs to be sanded and coated, with a special release agent and resin coating applied to ensure a smooth GRC surface after forming and easy demolding; coating thickness is controlled at 0.3-0.5mm.

3. Core Advantages of Digital Mold Technology

Compared with traditional mold technology, digital mold technology offers significant advantages. Improved precision: Digital machining errors can be controlled within ±0.5mm, far better than the ±3mm of traditional manual molds; Qinglong's double-curved GRC molds achieve jointing accuracy of ±0.2mm, ensuring the smoothness of the overall form. Improved efficiency: Mold design and machining cycles are shortened by 30%-50%; for complex double-curved projects, the mold cycle can be reduced from the traditional 30 days to within 15 days, with parallel machining of multiple modules possible. Cost optimization: For complex double-curved forms, digital molds can reduce mold modification and rework costs, and cost dilution is more evident in mass production; in the Hainan Poly Peninsula No. 1 project, Qinglong reduced mold costs by 20% through digital molds. Strong repeatability: 3D data can be stored long-term and directly reused or modified for subsequent similar projects, improving technology reuse rates.

4. Application Practice and Precautions of Digital Mold Technology

Standardized application processes ensure effective technology implementation. Application process: 3D model design → surface decomposition and optimization → mold substrate machining → surface treatment → mold assembly and verification → trial production validation → mass production; Qinglong sets up quality inspection checkpoints at each step to ensure mold qualification. Substrate selection: Based on project scale and precision requirements, substrates such as foam, wood, and resin are selected; large-volume projects prioritize wood molds, balancing cost and durability. Precautions: During mold assembly, positioning pins must be used for precise positioning to ensure module jointing errors meet requirements; during trial production, the forming effect of GRC components must be tested, and mold parameters fine-tuned according to actual conditions to avoid risks in mass production. Through trial production validation, Qinglong ensures that the first-pass forming qualification rate of double-curved GRC forms exceeds 99%.