Why Can't Free-Form Curved GRC Panels Use Traditional Wooden Molds?

In the field of GRC curved panel manufacturing, the limitations of traditional wooden molds are particularly pronounced when dealing with complex curved surfaces. As the Qinglong Group with 28 years of deep expertise in the GRC field, we have drawn on our experience in major projects such as the "Chinese Red Lantern" double-curved panels for the Wuhan Han Show Theatre and the wave-shaped roof of the Hainan International Convention and Exhibition Center, and found that traditional wooden molds have fundamental defects in three areas—precision retention, durability, and production efficiency—and cannot meet the high standards that modern architecture demands for curved GRC panels.

Precision retention is the primary challenge for wooden molds. Wood undergoes dimensional changes of 0.1-0.3% due to temperature and humidity variations. For double-curved panels with a radius of curvature smaller than 2m, such deformation can cause panel joint errors exceeding 5mm. Qinglong Group conducted comparative tests in the Nanning New Media Center project: after 20 consecutive production runs, the pine wood mold showed profile errors of ±3mm, while the epoxy resin mold kept errors within ±1mm after 200 production runs. Especially for mega projects such as the 120,000-square-meter wave-shaped roof of the Hainan International Convention and Exhibition Center, the mismatch between the thermal expansion coefficient of wooden molds (3-5×10⁻⁶/℃ along the grain) and that of GRC material (8-10×10⁻⁶/℃) leads to demolding difficulties and surface defects.

Insufficient durability restricts mass production. High-quality pine molds have a service life of about 50 uses, while complex curved shapes require more precise molds. In the Shenzhen Yirui Biotech Building project, Qinglong Group found that relief molds made of beech wood showed edge wear after only 30 uses, severely affecting product consistency in mass production. In contrast, GRP molds can be used more than 200 times, making them particularly suitable for large projects producing over 10,000 pieces annually. Frequent mold replacement not only increases costs but also causes dimensional variations between batches, affecting on-site installation accuracy.

Low production efficiency affects project schedules. Wooden molds take 5-7 days to fabricate and depend on the craftsmanship of highly skilled carpenters. Qinglong Group's measured data shows that producing a set of 3m×6m double-curved wooden molds requires 240 man-hours, while CNC-machined epoxy resin molds take only 72 man-hours. In the Algeria hotel project, adopting digital mold technology shortened mold preparation time by 60%, greatly improving overall project efficiency. As a result, modern GRC curved panel production has widely adopted advanced mold materials such as GRP and epoxy resin.