Selecting the right injection molding machine is a crucial step to ensure efficient production, prevent common defects like burn marks and sink marks, and improve overall product quality. Below, we break down how to match your mold to the machine across key dimensions to support precision injection molding.
- Tie Bar Spacing (also called tie-bar clearance or platen spacing between tie bars): The machine’s tie bar spacing must be larger than the mold’s width and height to allow easy installation. If too small, the mold cannot be properly secured, affecting stability. Recommendation: Measure your mold dimensions and choose a machine with spacing at least 10% larger.
- Mold Thickness (or mold height): Verify the machine’s minimum and maximum mold thickness (daylight/opening) range. Your mold thickness must fall within this range to avoid insufficient or excessive opening stroke. A good match reduces cycle time and boosts output.
- Injection Pressure: Select sufficient injection pressure (typically 1000–2000 bar) based on cavity complexity and material viscosity. Insufficient pressure often causes incomplete filling and impacts product precision.
- Shot Size (or injection capacity/melt volume): The machine’s shot size should cover the product weight plus 1.2–1.5 times the sprue and runner losses. Too large wastes material; too small leads to short shots.
Optimizing across these dimensions significantly reduces scrap rates and achieves better cost control.