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Calcimator

Extrusion Die Swell Calculator

Calculate die swell ratio from material elasticity, L/D ratio, shear rate, and melt temperature. Determine required die dimensions to achieve target extrudate size.

Inputs

Results

Die swell ratio (B)

2.5

Required die diameter (mm)

12

Diameter swell (%)150
Predicted extrudate OD (mm)62.5
Area swell ratio6.25
Area swell (%)525
Size error if uncompensated (mm)32.5
Size error (%)108.3
L/D ratio2
Recommended L/D10.3
How to Use This Calculator
  1. Enter Die opening diameter (mm), Target extrudate OD (mm), and Die land length (mm).
  2. Set Apparent wall shear rate (1/s), Material elasticity (1-5), and Melt temperature (°C).
  3. Adjust Reference temperature (°C) as needed.
  4. Review Die swell ratio (B) and Required die diameter (mm).
  5. Use Diameter swell (%) and Predicted extrudate OD (mm) to inform your decision.
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