Rice cooker inner liners endure frequent drastic temperature changes in daily use, requiring excellent surface finish, uniform wall thickness and stable dimensional precision. The cooling system dominates product deformation control, molding cycle shortening and defect prevention. Combined with the circular curved shape and deep cavity characteristics of liners, the cooling system design is completed following overall principles, pipeline layout, parameter matching, sealing protection and test optimization.
1. Basic Design Principles of Cooling SystemsThe design focuses on uniform heat dissipation, efficient heat exchange and reasonable mold strength. Synchronized cooling of cavity and core avoids large internal and external temperature difference which causes oval distortion and side wall twisting. Cooling pipelines fit closely with product outlines, keeping consistent heat dissipation speed on all forming surfaces. Safe wall thickness is reserved between pipelines and molding surfaces to prevent mold cracking and material leakage under high injection pressure. Temperature settings adapt to common food-grade plastic forming requirements, realizing stable continuous cooling and improved production efficiency.
2. Cooling Pipeline Layout on Cavity SideCircular surrounding pipelines are adopted matching the rotary liner structure. Multi-layer annular pipelines are arranged separately at bottom arc area, straight side wall and thickened rim position to achieve regional temperature control. The distance from pipeline center to molding surface and spacing between adjacent pipelines maintain unified specifications for balanced heat dissipation. Concentric circular pipelines accelerate heat emission at thick bottom parts to prevent sink marks. Spiral pipelines follow side wall radian to eliminate heat dissipation blind zones. Dense auxiliary pipelines are added at thick assembly edges to balance local heat accumulation. Inlet and outlet ports are arranged diagonally for smooth circulating water flow.
3. Cooling Pipeline Structure on Core SideThe core part adopts combined cooling structure with central straight pipelines and water wells. Vertical main pipelines extend to the deepest liner bottom and connect horizontal annular pipelines, forming three-dimensional circulating loops. Partition water well structures wrap inner molding surfaces fully, solving slow heat dissipation problems of deep cavity molds. Pipeline aperture suits narrow internal installation space while guaranteeing core rigidity against injection pressure impact. Water well depth adjusts according to inner curved shapes to avoid whitening and stress cracks on liner inner walls.
4. Matching of Pipeline Size, Flow Velocity and Temperature ParametersStandard pipeline diameters are selected based on liner volume size. Normal-temperature soft industrial water serves as cooling medium with stable flow velocity to ensure sufficient heat exchange effect. Mold temperature stays within reasonable range according to plastic types. Temperature gap between cavity and core is limited within 5℃ to avoid uneven shrinkage, eccentric shape and assembly deviation. Cooling duration matches product wall thickness to balance molding quality and production efficiency.
5. Pipeline Sealing, Connector and Mold Protection DesignStandard quick-install copper joints are equipped for convenient assembly and reliable sealing against water leakage. Arc transition design at pipeline corners reduces flow resistance and dirt deposition. High-temperature resistant sealing rings are installed at pipeline penetrating positions to prevent aging failure. External pipelines are protected with baffles from collision damage. Residual water inside pipelines is drained thoroughly during mold storage to avoid rust and scale buildup. Regular circulating cleaning removes scale deposits and keeps stable pipeline flow capacity.
6. Cooling System Debugging and Defect OptimizationPipeline smoothness and sealing performance are inspected strictly during trial molding. Corresponding cooling measures are adjusted aiming at different molding defects. Dense pipelines and lower water temperature are applied to eliminate sink marks. Balanced internal and external mold temperature corrects edge warping deformation. Water flow direction is modified to improve circular distortion issues. Cooling time is optimized properly under qualified forming conditions to raise output. Mold surface temperature is monitored regularly to fix optimal cooling parameters. Daily maintenance maintains long-term stable operation of cooling systems.
