1. Importance of Molds
1. Cost
The industrialization of residential construction has shifted the traditional cast-in-place method to an assembly approach using prefabricated components produced in specialized factories and assembled on-site. Data indicates that in industrialized construction using assembly methods, the cost ratio between prefabricated component production and installation is roughly 7:3. Within the cost structure of prefabricated components, mold amortization accounts for approximately 5% to 10%, assuming excellent mold design. This highlights the significant impact that mold costs have on the overall expenses of industrialized construction.
2. Efficiency
Production efficiency is a critical factor directly influencing the manufacturing cost of prefabricated components. Higher production efficiency lowers component costs, while inefficiencies increase them. Among the many factors affecting efficiency, mold design plays a key role. For example, exterior wall panels, which have the most complex manufacturing process among prefabricated components, are heavily influenced by mold-related processes such as mold removal, mold assembly, and installation of embedded parts. Currently, automated exterior wall panel production lines in China operate with a design cycle time of 15-20 minutes. If mold removal and assembly cannot be completed within this time frame, the entire production line comes to a halt.
3. Quality
One of the major advantages of industrialized building methods over traditional cast-in-place construction is improved accuracy. Since concrete is a plastic material shaped entirely by molds, the dimensional accuracy of prefabricated components depends completely on the molds’ precision. Both the upcoming national industry standard “Technical Regulations for Prefabricated Concrete Structures” and various regional standards impose very high dimensional accuracy requirements. Therefore, mold design quality directly affects the dimensional accuracy of prefabricated components, and this impact becomes more pronounced with increased mold reuse.
In summary, whether considering cost, production efficiency, or component quality, mold design is a crucial factor that determines the success of industrialized construction projects.
2. Mold Design Concepts
Given the importance of mold design, addressing related challenges requires thoughtful strategies by designers. Based on past experience, the following key design concepts are recommended:
1. Service Life
The mold’s service life directly influences the manufacturing cost of components. Therefore, mold design must ensure adequate stiffness and durability to maximize the number of production cycles. This approach prevents the need for additional molds or increased maintenance costs due to insufficient stiffness during a project.
2. Universality
Designers should also aim for mold universality to increase reuse rates. Component factories typically do not charge clients the full mold cost upfront but deduct a residual value, usually 25% to 30%, from the total production cost. This residual value reflects the expected scrap metal price of the mold after project completion. Since molds cost many times more than scrap iron, selling molds as scrap represents a significant loss for both the factory and the client. Therefore, designers should prioritize mold universality from the start to maximize reuse and minimize waste.
3. Production Convenience
Molds ultimately serve the production needs of component factories. Without a deep understanding of the production process, even the most skilled mechanical manufacturers cannot design effective molds. Mold stiffness and size alone are insufficient if the mold design does not align with production workflows. Mold assembly and disassembly significantly impact production efficiency. Thus, designers must minimize assembly time while maintaining mold precision. Additionally, molds should be designed to allow workers to disassemble them without damaging components—for instance, by optimizing the demolding angle without compromising the structural stress of the prefabricated element. Achieving this requires thorough knowledge of component production processes.
4. Transportation Convenience
Transportation here refers to moving molds within the workshop along the automated production line. Molds must follow the production sequence, so their design should facilitate easy transportation. This involves reducing mold weight through structural calculations, while maintaining rigidity and durability. Ideally, molds should be light enough to be transported by just two workers without the need for cranes.
5. Use of 3D Design Software
Due to the complex shapes of prefabricated component molds—especially sandwich exterior wall panels with tongue-and-groove edges, grouting sleeve openings, and numerous exposed reinforcing bars—3D design software is essential. It makes the mold design process more intuitive and precise, significantly reducing mental workload. The 3D model allows direct comparison with component designs for inspection and error correction, streamlining the entire design workflow.
In conclusion, excellent mold design requires a comprehensive balance of cost, production efficiency, and quality considerations. Each of these factors is indispensable in creating molds that contribute to the success of industrialized construction.
Must log in before commenting!
Sign Up