WLF Equation

Parameter Set

Calibration of the coefficients depends on having accurate frequency sweeps from a precision spectrometer. While using the wlf equation, researchers shift multiple data points to form a single continuous curve that describes the material across several decades of time. These parameters identify how sensitive a specific resin is to temperature shifts near its operating limit.

Scaling Standard

Accuracy is maintained by using the standard universal constants until more specific measurements for a proprietary blend are available. Within the context of the wlf equation, small deviations in the recorded glass transition temperature will lead to massive errors in the shifted shift values. Testing laboratories verify these shifts using dynamic mechanical thermal analysis instruments every month.

Use Boundary

Validity stops abruptly once the temperature falls below the glass transition point and the material becomes a rigid solid. Because the wlf equation describes a probability of molecular movement based on free volume, it cannot handle the brittle fracture logic of crystals. The final calculation predicts how fast a plastic part will sag under its own weight over a year.