A METHOD FOR DETERMINING THE THERMAL CONDUCTIVITY OF ANISOTROPIC PLASTIC FILMS AND ITS USAGE

摘要

The invention relates to a method for determining the thermal conductivity of anisotropic plastic films. A focused and modulated heating beam (11) is directed to a plastic film sample (10), whereby a thermal profile (13) is obtained for the plastic film sample (10) and a medium surrounding it. The thermal profile (13) is inspected by means of a measuring beam (12), whereby a phase and magnitude information (Ζn, Ζt) is obtained for the thermal profile (13) as a function of a transversal offset (14) both for vertical and horizontal deviations. The vertical and horizontal deviation signals of the phase and magnitude information (Ζn, Ζt) are analyzed by means of a projection method, such as a method of partial least squares regression PLS, whereby said thermic wave represents in the analysis a certain matrix (X) and the thermic diffusivity (α) of the plastic film sample (10) is contained as one factor in another matrix (Y). By using known samples or a simulated training set, a PLS model (predictive model) is formed, by means of which the thermic diffusivity (α) of unknown plastic film samples and the thermal conductivity (K) on the basis of the formulas (1): α = K / (ςC) and (2): K = α . ςC are determined.