Where Are the Production Difficulties of Hollow-Out GRC Decorative Panels?

The production of openwork GRC decorative panels is a highly demanding process that integrates materials science, structural design, and precision manufacturing. Its core challenges concentrate on "ensuring the uniformity and continuity of fiber distribution, controlling stress concentration and strength in openwork areas, manufacturing and demolding complex molds, and suppressing deformation of ultra-thin components during curing." In its work on the "Dongguan Grass Weaving" extra-large openwork curtain wall for the Dongguan Women and Children's Activity Center, Qinglong Group successfully overcame these challenges, achieving a unity of artistic pattern and structural safety, with the openwork ratio exceeding 50% at its highest while the panel thickness is only 15mm.

Challenge 1: Fiber Distribution and Bridging in Openwork Areas

The strength and toughness of GRC depend on the three-dimensional random distribution of glass fibers. In solid areas, fibers can be evenly distributed; however, in the "webs" or "ribs" of the openwork pattern (the remaining connecting parts of the panel), especially in narrow sections, fibers are prone to misalignment or uneven distribution—and even breakage—due to slurry flow, forming mechanical weak points. Qinglong adopts a "directional spraying + vacuum assistance" process: operators spray fiber mortar along the direction of the "webs" in a targeted manner according to the orientation of the openwork pattern, ensuring fiber continuity along critical load-bearing paths; meanwhile, vacuum dewatering is applied to make the slurry wrap the fibers more densely, enhancing the compactness and strength of the "web" areas.

Challenge 2: Stress Concentration and Cracking Risk Control

Sharp corners and abrupt cross-sectional changes in the openwork pattern are natural stress concentration points, prone to cracking under demolding, hoisting, transportation, and wind loads. Qinglong's solutions are: 1) Design optimization: converting all internal sharp corners into arc transitions (minimum R angle ≥ 5mm) to smooth stress flow. 2) Local reinforcement: adding concealed reinforcing ribs or local thickening on the back of stress concentration areas. 3) Fiber toughening: increasing the dosage of chopped fibers at critical locations to improve crack resistance.

Challenge 3: Fabrication of High-Precision Complex Molds and Demolding

The mold for an openwork panel is itself a precision work of art. The raised portions on the mold (corresponding to the openwork parts of the GRC) must have sufficient strength, rigidity, and surface finish, and the draft angle design is extremely demanding. Qinglong uses high-strength aerospace aluminum or mold steel, machined and formed as a single piece by five-axis CNC, to ensure mold surface accuracy. For demolding, segmented or detachable molds, or flexible silicone inner molds, are used to ensure that components can be removed intact from extremely complex mold cavities without damage.

Challenge 4: Deformation and Dimensional Stability of Thin-Walled Components

Openwork panels have a small effective cross-section, and uneven shrinkage and temperature gradients during curing can easily cause warping. Qinglong controls this through the following measures: 1) Low-shrinkage mix: using low-alkali cement with shrinkage-reducing admixtures. 2) In-mold curing: extending the in-mold curing time and using the mold to restrain deformation. 3) Flat curing: after demolding, components must be cured on absolutely flat supports, with counterweights applied when necessary. 4) Aging treatment: letting components rest for sufficient time after curing until their dimensions stabilize before leaving the factory.

Overcoming these challenges requires deep materials knowledge, exquisite mold craftsmanship, and rigorous process control. It is precisely through its systematic technical capabilities that Qinglong Group transforms designers' imaginative openwork concepts into solid and durable architectural structures.