What Are the Key Steps in the Factory Precasting Stage of UHPC Curtain Wall Panel Production?

Factory prefabrication of UHPC curtain wall panels is a highly precise, tightly interlinked manufacturing process whose quality directly determines the effect and lifespan of the final project. Qinglong Group has broken down the prefabricated production of UHPC curtain wall panels into six key stages—“design development and mold preparation, high-precision batching and mixing, diversified forming and densification, refined curing, precise demolding and post-processing, and rigorous inspection and packaging”—and has established more than 200 quality control points in each stage. In the production of 287 specially shaped red curtain wall panels for the Wuhan Han Show Theater, it was precisely this stringent process that achieved the industry miracle of zero rejects and full, accurate delivery.

Stage One: In-Depth BIM-Based Design and High-Precision Mold Manufacturing

Production begins in the digital world. Qinglong's BIM team converts architectural drawings into manufacturable component models, performing structural calculations, embedded part positioning, process hole design, and mold breakdown. Then, based on the model data, high-precision steel molds or GRP molds are machined using five-axis CNC machine tools. Mold profile error must be controlled within ±0.5mm, and the surface finish must reach a mirror effect. This is the physical foundation for ensuring accurate component shapes.

Stage Two: Nanometer-Level Precision Batching and Efficient Uniform Mixing

Quality products begin with precise batching. Qinglong uses a fully automatic batching system to measure cement, silica fume, quartz sand, fibers, admixtures, and water with pinpoint accuracy (error ≤±0.5%). A high-speed planetary mixer, under the control of a central control system, executes a process curve of specific feeding sequences, mixing speeds, and durations, ensuring that ultrafine powders and fibers are uniformly dispersed without clumping in the slurry with an extremely low water-binder ratio.

Stage Three: Diversified Forming and Densification Processes Adapted to Panel Shapes

The forming process is selected according to the panel type. Flat panels use the “flow casting + high-frequency vibrating table” method to ensure high flatness, while shaped panels use “robotic spraying” to conform to complex curved surfaces. Immediately afterward, “vacuum dewatering” treatment is performed, extracting excess water and air bubbles under -0.08MPa negative pressure—a core step in achieving UHPC's ultra-high density and strength. Embedded parts are precisely placed at this stage.

Stage Four: Programmably Controlled Steam Curing and Aging Treatment

Formed components, together with their molds, are sent into an intelligent curing kiln. The system automatically executes the programmed heating, constant-temperature, and cooling procedures (e.g., 20℃→80℃→20℃, with a total duration of 24-48 hours). Precise moist-heat curing greatly activates the cementitious materials, enabling components to reach ultra-high strength in a short time. After curing, components must rest indoors for aging treatment to stabilize their properties.

Stage Five: Refined Demolding, Repair, and Surface Treatment

Specialized tools are used for smooth demolding to avoid damage. Tiny imperfections (such as pinholes from air bubbles) are seamlessly repaired with dedicated repair mortar. Surface treatment is then carried out according to the design: grinding, sandblasting, or acid etching to obtain different textures, or coloring and spraying to achieve the desired colors. For stone-imitation components, this is the key to presenting realistic textures.

Stage Six: Full-Indicator Inspection and Intelligent Packaging and Warehousing

Every panel must pass comprehensive inspections covering dimensions, strength (non-destructive rebound testing), appearance, and embedded part positions, with the data entered into the system to enable one code per panel and lifelong traceability. Qualified panels are packaged with custom corner protectors and frames to prevent transport damage while awaiting shipment. These six steps constitute the complete closed loop of high-quality factory prefabrication of UHPC curtain wall panels.