my country is a major producer of packaging machinery, but its level still lags significantly behind advanced international standards. To improve my country's packaging machinery technology, advanced methods must be adopted in product design, development, and manufacturing. The rapid development of computer and network technologies provides strong support for achieving this goal, giving rise to many new concepts and perspectives, among which virtual design is one. Virtual design technology is based on computer simulation and product lifecycle modeling, integrating computer graphics, artificial intelligence, concurrent engineering, network technology, multimedia technology, and virtual reality technology. It allows for the conceptualization, design, manufacturing, testing, and analysis of products under virtual conditions. Its significant feature is the use of digital models—virtual products—to replace physical models for simulation analysis, thereby providing decision-making levels for products across multiple objectives such as time, quality, cost, service, and environment, achieving global optimization and one-time development success. User-oriented virtual product design is an effective means to adapt to diverse product needs, and scholars both domestically and internationally have conducted research in this area. For example, J. Bernhard et al. researched and implemented a virtual design service system based on Java3D technology; Zhou Jun et al. of Shandong University conducted a detailed study on the design principles, basic characteristics, system architecture, design content, and design process of virtual design for production lines. Combined with application examples, they established a virtual model of the production line, visually simulating its operating status, quickly diagnosing bottleneck processes, and effectively integrating the functions of production line design, simulation, analysis, diagnosis, optimization, and reorganization; Gao Guangda et al. of Tianjin University researched the macro-planning, module creation design, and interface design of modular virtual design systems, as well as rapid virtual creation technology and scheme evaluation technology for modular products, and developed a virtual modular design platform for CNC machine tools. Applying virtual design technology to the field of packaging machinery design allows for product design, manufacturing, performance prediction, and manufacturability assessment on computers. This enables packaging machinery design, development, and manufacturing technologies to evolve from traditional methods to a new stage, allowing enterprises to respond quickly and agilely to changes in market demand, make timely and reasonable adjustments and replanning of their production, and develop suitable packaging machinery systems or products at the most economical cost and in the shortest development cycle. 1. Development Environment for Virtual Design of Packaging Machinery The implementation of virtual design for packaging machinery requires a suitable product development environment. It enables parallel design, evaluation, and product modification within the development team, bridging different stages of product development through virtual prototypes in a shared product database. This environment can be built using existing CAD, CAE, CAM tools, engineering knowledge bases, and model libraries. It uses computer technology to virtually generate conceptual prototypes of the product, allowing for interactive simulation to evaluate the virtual product and simulate and optimize its key manufacturing processes and costs. In concurrent engineering, product data flows dynamically across various design units. Without a Product Data Management (PDM) system, multiple backups of geometric models, calculation results, input data, and analysis data would be created, potentially leading to the use of outdated data, wasting time and money. Therefore, a virtual product development environment should have a PDM subsystem, along with virtual design and simulation analysis subsystems. The PDM subsystem is the core of virtual product development, primarily managing 3D CAD model data and the product development process. The virtual design subsystem defines and solves design problems, feeding back information generated during prototyping, simulation, and evaluation phases to designers to support design decisions. The simulation analysis subsystem, by defining appropriate product, process, and activity models, integrates prototyping and manufacturing activities to directly generate design decisions and simulates the entire assembly process. Machine operating time and costs can also be calculated using enterprise standards. During product development, once the design concept is determined, the basic design model is represented as a 3D solid model, i.e., a virtual prototype, which can be implemented using CAD software. The model and related information are stored in the PDM system. Using the solid model, analytical models, such as process models and activity models, can be created to achieve process design, assembly simulation, virtual testing, and structural, kinematic, and dynamic analyses. 2. Modeling Process for Virtual Design of Packaging Machinery Establishing the 3D model of the packaging machinery is the most labor-intensive part of the system. To ensure that all components maintain correct geometric dimensions and constraints when overall parameters change, 3D parametric technology must be used. Pro/E, a parametric CAD/CAM design software, is a widely used 3D modeling tool. It is extensively applied in mechanical design, mold design, manufacturing, and mechanism analysis in industries such as machinery, automobiles, and home appliances. It features functions such as part design, engineering drawing, and product assembly. Pro/E's design modules are interconnected; any modification during the design process can be extended to the entire design, automatically updating all engineering documents, assembly and design drawings, and manufacturing data. Therefore, Pro/E can be used as the primary supporting software to establish a library of instances for all components of packaging machinery. Based on the geometric shapes and constraints of the components, parametric relationships can be established, ensuring that the components maintain correct relative positions and assembly relationships throughout the design process. To enable ordinary technicians to use this powerful CAD/CAM design software, 352Pro/TOOLKIT technology can be used to call Pro/E's functional modules, integrating the application with Pro/E to form a specific architecture and design menu for packaging machinery design, allowing technicians to quickly master the software. The basic parameter input, finite element analysis, and 3D parametric design modules for packaging machinery are all integrated into the Pro/E runtime environment. Design users can modify the parameters and dimensions of any structure within the packaging machinery at any time and call the finite element analysis module for strength and stiffness verification. Besides calling the Pro/E application, the system's design process, data input, and output functions are all implemented using VC programming. 3. Product Prototype in a Virtual Development Environment To perform interference checks on part assembly in a virtual environment, promptly identify design errors, and improve design efficiency, we do not manufacture physical prototypes but instead use virtual prototyping technology to construct virtual product prototypes. Virtual prototyping technology is a fully digital design method based on a computer simulation model of the product. The virtual prototyping environment can combine development models from different engineering fields, enabling designers to conduct effective and verifiable design work before physical prototypes are produced, improving communication within product development projects. Virtual prototyping allows developers to communicate with customers about the product in a natural way early on, meeting customer requirements. Virtual prototyping creates a visual digital model on the computer that resembles a real prototype. Virtual prototyping uses a "reference" method. It doesn't physically import all components into the assembly model; instead, it memorizes the positions of parts within the model and loads them only when needed. This significantly saves hard drive and memory space. Furthermore, the assembly model automatically updates when parts are modified, reducing workload considerably. Additionally, the components referenced by the assembly model can be stored on individual users' computers, a central server, or anywhere connected via a network, providing a technological foundation for concurrent engineering and enabling collaborative teamwork. Virtual assembly has two forms: top-down and bottom-up. For machinery with complex structures and shapes, where the dimensions and shapes of internal components largely depend on the product's external form, a top-down approach is suitable. In a virtual assembly environment, the overall machine shape is designed first. After determining the shape, the "control components" are distributed to their respective related parts, and then detailed designs are performed on the parts. For a design process that starts with the detailed design of each individual part and ends with the assembly of the parts, a bottom-up approach can be used. During component assembly, three methods—fitting, alignment, and orientation—can be used to constrain mating parts. Even if a part is modified, this constraint relationship remains. This assembly mode is suitable for products with complex transmission mechanisms, compact structures, diverse forms, high risk of interference between parts, and high requirements for reliability and accuracy. 4. Conclusion Virtual design replaces physical prototypes with product models. Through simulation testing of the model, product evaluation can be conducted, achieving high design quality at a lower cost and significantly improving flexibility and agility in new product development. Applying virtual design technology to packaging machinery design will enhance the design capabilities of packaging machinery products and promote the development of China's packaging machinery industry.