What Percentage of Total Cost Do Molds Account for in Hollow-Out UHPC Shapes? Economic Analysis and Qinglong Group's Cost Optimization Strategies

The mold cost of openwork UHPC forms accounts for a significantly higher share of the total cost than solid forms, typically fluctuating between 20%-40%, with the exact proportion determined by four major variables: "openwork complexity, mold reuse rate, component output, and mold material." Cost analysis by Qinglong Group based on numerous artistic openwork projects (such as the artistic screens for the Shenzhen Yirui Biotechnology Building) shows that for openwork panels with regular patterns and many repeating units, mold costs can be controlled within 20%-25%, while for artistic one-off pieces with complex, non-repeating patterns and high precision requirements, mold costs may reach as high as 35%-40%. In the "Woven" facade project of the Dongguan Women and Children's Activity Center, we optimized the pattern through parametric design into 5 standardized, assemblable "woven units," reducing mold types from over a hundred to just 5 and successfully cutting the mold cost share from an estimated 38% to 22%. Controlling mold costs is the key to making openwork art widely accessible.

Openwork Pattern Complexity Is the Core Cost Driver

Mold cost is inversely correlated with the "feature size" of the openwork pattern. The smaller the feature size (e.g., rib width <10mm, aperture <20mm), the requirements for mold machining precision (requiring smaller cutters and slower speeds) and demolding processes rise exponentially, leading to a surge in machining time, difficulty, and rejection rates. Complex curved-surface openwork (such as gradient openings on double-curved surfaces) requires five-axis CNC machining, with costs far higher than flat openwork.

Mold Reuse Rate Is Key to Amortizing Costs

Mold fees are a typical one-time investment: the larger the output, the lower the cost allocated per piece. If one mold can produce 100 panels, its cost share may be only 10%; if it produces only 5, the share may exceed 50%. Therefore, maximizing the repetition rate of openwork patterns and component standardization at the design stage is the most effective means of controlling costs. We encourage architects to adopt "modular" design thinking.

Trade-Offs Between Mold Materials and Processes

For small batches (<50 pieces) or trial production, lower-cost resin or silicone molds can be used, but they have short service lives, and in the long run the per-use cost may be higher. For large volumes, investment in long-life steel molds is a must. We offer a "mold scheme comparison" service, calculating the full life-cycle costs for clients under different mold strategies.

Innovative Processes Reduce Mold Dependency

For ultra-small batches or prototyping, we are exploring moldless forming technologies, such as 3D-printing sand molds and then casting UHPC, or directly using concrete 3D printing to build openwork forms, which can completely eliminate traditional mold costs, though these have not yet become widespread for large-size components with high surface quality. In addition, adopting a "standard base panel + post-cutting/engraving" process can also partially reduce mold complexity and cost.

In the face of high mold costs, transparent communication and joint optimization are essential. Qinglong Group engages in in-depth communication with clients and designers early in the project, providing "design-cost" linkage analysis to explore the optimal balance between artistic effect, structural performance, and manufacturing cost, so that stunning openwork concepts can be realized at a reasonable cost.