Introduction
In the slip-casting process of sanitaryware ceramics, mold design determines product quality, production efficiency, and cost control. A scientifically sound and well-designed mold is the prerequisite for ensuring uniform blank shape, precise dimensions, and controllable defects. However, in practice, many issues often stem from hidden flaws embedded during the design phase: from uneven blank thickness, cracking, and deformation, to excessive dimensional deviations, difficult demolding, and accelerated mold wear—these production pain points, when traced back to their root causes, are largely directly related to the maturity of the mold design. This in-depth analysis explores how mold design ultimately impacts forming quality by controlling critical factors such as slurry flow paths, drainage efficiency, and stress distribution.
The impact of mold design on molding quality is primarily reflected in the following aspects:
Determining the Uniformity and Structural Defects of the Green Body Key Points: Uniformity of Slurry Absorption, Structural Stress Impact Explanation: The design of the mold cavity, particularly the thickness ratios and curvature transitions across different sections, directly determines whether slurry dehydrates and settles uniformly under capillary action. Improper design leads to uneven thickness in different areas of the green body, causing critical defects like cracking and deformation during drying and firing due to inconsistent shrinkage. Smooth inner walls minimize friction between powder and mold, enabling smoother flow and filling during compaction. This enhances the green body's density and uniformity. Simultaneously, effective venting design prevents gas accumulation within the green body, avoiding bubbles or defects and ensuring consistent quality. |  |
Controlling Dimensional Accuracy and Shrinkage Rate Key Points: Dimensional Tolerances, Shrinkage Prediction Impact Explanation: Mold dimensions are precisely scaled up after accounting for the shrinkage rate of the slip (drying shrinkage + firing shrinkage). Design must be supported by precise data on the shrinkage characteristics of the clay body used. Inaccurate shrinkage rate calculations will directly result in post-firing dimensional deviations that fail to meet installation requirements, particularly for products requiring precise fitment like one-piece toilets. For example, improperly designed drain pipe dimensions in a toilet bowl may cause drainage blockages or ball jams. |  |
影响脱模难度与模具寿命
Factors Affecting Demolding Difficulty and Mold Life
Key Points: Draft Angle, Parting Line Design
Impact Explanation:
Draft Angle: An appropriate draft angle is crucial for ensuring smooth removal of the blank from the mold without damage. An insufficient draft angle leads to difficult demolding, potentially causing blank tearing or mold wear; an excessive draft angle alters the product's designed shape.
Parting Line Design: The positioning of the parting line (where mold halves meet) is critical. Effective design hides the parting line on non-visible surfaces, preserving aesthetics. Simultaneously, the precision of parting line alignment directly impacts mold closure tightness, preventing slurry leakage (mud seeping through gaps) that causes flash and increases post-molding cleanup. Mold design impacts the smoothness of the demolding process. Complex mold structures or rough inner surfaces may cause excessive stretching or friction during part removal, leading to defects like cracks or breakage. Furthermore, poorly designed parting lines can increase demolding difficulty or even prevent complete part extraction.
Concerning Production Efficiency and Costs Key Points: Mold Filling Speed, Drainage Efficiency Impact Explanation: The drainage performance of a mold directly impacts mold filling speed, i.e., the molding cycle. Optimizing the mold's drainage channels and venting system can significantly reduce filling time, increase daily output, and lower unit production costs. Proper mold design enhances production efficiency. Additionally, the durability and stability of the mold affect its service life; frequent mold replacements increase production costs. |  |
Mold design serves as the bridge connecting product design and mass production, acting as a critical factor influencing molding quality. A successful mold design must not only meet the product's aesthetic and functional requirements but also balance production feasibility, efficiency, and cost-effectiveness. Any minor flaw in the design will be magnified during large-scale production, ultimately directly impacting the product's yield rate and quality.