What Are the Mold Parting Principles for Complex GRC Shapes?

The parting (mold splitting) of complex GRC shapes is a key link connecting creative design and manufacturable production. Scientific parting principles aim to balance multiple objectives such as "artistic effect, structural soundness, production feasibility, and economic cost." When tackling extremely complex GRC projects such as the "Dongguan grass weaving" design at the Dongguan Women and Children's Activity Center, Qinglong Group has developed a set of parting principles centered on "function first, easy demolding, fewer welded seams, and convenient installation," ensuring that every complex unit can be produced and assembled efficiently and to a high standard.

The primary principle of mold parting is to preserve the integrity of the decorative effect. Parting lines should, wherever possible, be placed at the natural transitions of a shape, within shadow joints, or where materials change, so that they are visually minimized or even hidden. For example, in relief sculptures, parting lines can be placed deep within the grooves of the pattern; in streamlined forms, they can follow the contour lines. Parting lines should absolutely be avoided on large flat surfaces or at visual focal points. Qinglong's detailed design engineers communicate closely with architects, treating the parting strategy as an integral part of the overall design.

Demolding feasibility is a hard constraint of mold parting. Parting must ensure that components can be smoothly removed from the mold without producing "undercuts" or "negative angles." For shapes with undercuts, more complex mold processes such as "mother-child molds" or "flexible molds" are usually required. At the same time, the stiffness and durability of the mold itself must be considered, as overly slender molds are prone to deformation through repeated use. Qinglong's experience is that the weight of a single component should ideally be kept within 1.5 tons, with dimensions not exceeding transport limits (e.g., 6 m long x 2.5 m wide), to ensure safe and convenient production, transportation, and hoisting.

Economy and installation convenience are important considerations in mold parting. Where the visual effect allows, "standard modular" segmentation should be adopted as much as possible to reduce the variety of molds and thereby significantly lower costs. For example, repeating units can be designed as universal modules. Parting must also take into account the placement of hoisting points for on-site installation, the accessibility of connection nodes, and the installation sequence. Qinglong uses BIM technology for virtual disassembly and installation simulations to optimize parting schemes, striving to achieve the most complex shapes with the fewest modules and the most rational interfaces, thereby attaining a perfect unity of art and engineering.