What Are the Common Mold Materials for UHPC Components and Their Advantages? Mold Selection and Qinglong Group's 28 Years of Process Optimization Practice

The choice of mold material for UHPC components directly affects product precision, surface quality, and production efficiency. High-quality molds must feature high wear resistance, high precision, easy demolding, and long service life. As an industry leader with 28 years of deep expertise in UHPC, Qinglong Group has drawn on hands-on experience from national landmark projects such as the double-curved curtain wall of the Wuhan Hanxiu Theater and the wave roof of the Hainan International Convention and Exhibition Center to summarize the applicable scenarios and advantages of four major mold types: steel molds, aluminum molds, resin molds, and wood-substitute molds. Among them, steel molds offer the longest service life (over 1,000 uses), aluminum molds are lightweight and suited to complex shapes, resin molds excel at replicating details, and wood-substitute molds are economical and quick to machine. At our Nanning production base, we manufacture molds with five-axis CNC machining centers, controlling surface profile errors within ±0.1mm to ensure UHPC components achieve high fidelity to the designed shapes.

Advantages and Application Scenarios of Steel Molds

Steel molds are made of 45# steel or die steel with a hardness of HRC50-55, offering excellent wear resistance and suitability for mass production. In the Shenzhen Yirui Biotechnology Building project, Qinglong Group used steel molds to produce 3,000 square meters of standard panels, achieving a mold life of over 800 uses and panel dimensional deviation of ≤±1mm. Their drawbacks are heavy weight and high cost, making them suitable for projects with output exceeding 500 pieces. Through surface chrome plating, we reduced demolding resistance by 30% and extended mold life by 20%.

Lightweight and Precision Characteristics of Aluminum Molds

Aluminum molds weigh only one-third as much as steel molds and are suitable for complex curved surfaces and large components. In the “Red Lantern” double-curved panel project of the Wuhan Hanxiu Theater, Qinglong Group adopted 7075 aerospace aluminum molds processed by five-axis CNC machining to achieve fine shapes with curvature radii of ≤300mm. Aluminum molds offer good thermal conductivity, ensuring uniform temperatures during steam curing, but their wear resistance is relatively poor, with a service life of about 300-500 uses. Through hard anodizing, we increased surface hardness to HV400, extending the service cycle.

Economy and Detail Expression of Resin Molds

Epoxy resin molds are low-cost and quick to machine, suitable for small batches or components with complex textures. In the Hainan Changying Universal 100 Park project, we used resin molds to replicate coral textures with a fidelity of over 95%. However, their low strength and short life (about 100 uses) require reinforced support structures. Qinglong Group improved stiffness by adding aluminum powder, extending resin mold life to 150 uses.

Rapid Prototyping Capability of Wood-Substitute Molds

Wood substitutes (such as machinable wood) are suitable for prototyping and small-batch trial production. Qinglong Group uses wood-substitute molds during new product development, completing mold fabrication within 3 days at only one-fifth the cost of steel molds. However, wood substitutes have poor wear resistance, with a life of about 50 uses, so they are suited to short-term projects. Through penetration curing treatment, we extended the life to 80 uses.

Mold selection requires comprehensive consideration of output, shape complexity, cost, and other factors. Qinglong Group has established a mold database to customize the optimal solution for each project, ensuring a balance between quality and efficiency.