Measures to Improve Pattern Forming and Processing Quality of Lost Foam Casting

In mass production of castings, lost foam casting adopts molding machines to produce patterns. Pattern quality depends on the type and quality of EPS and STMMA foam beads, mold machining accuracy, mold service condition, and operating parameters of pattern forming machines. The pattern quality can be significantly improved by pressure feeding forming process.

1. Common Forming Machines for Lost Foam Casting

(1) CX Series Forming Machine(2) DJQCX Series Hydraulic Forming Machine

2. Operation Precautions of Lost Foam Casting Forming Machine

(1) Before startup, conduct a comprehensive inspection on all directions to check potential safety hazards and unobstructed passages.(2) Ensure smooth water circuits, oil circuits, air circuits, electrical circuits and feeding pipelines, and check for leakage.(3) Verify integrity of switches, valves, electrical control systems, displays and buttons.(4) Ensure flexible and smooth operation of transmission parts including lead screws, turbines and guide columns.(5) Check normal clamping and opening of molds.(6) Operate in strict accordance with pattern production procedures: mold closing, feeding, mold opening and pattern taking.(7) Inspect and clean patterns after taking them out.

3. Pressure Forming Process for Lost Foam Patterns

Some foundries suffer unstable casting quality and poor pattern surface finish. Problems such as excessive gas evolution, slag inclusion, impurity inclusion frequently occur. Casting deformation often appears especially in slender and thin-walled workpieces.According to comparative analysis and summary, the density of lost foam patterns is generally controlled at 18–24 kg/m³ to obtain smooth pattern surfaces.Optimal feeding pressure, feeding speed, feeding duration and feeding parameters vary for different castings.In general, patterns manufactured by pressure feeding process fully meet technical requirements of lost foam casting.