Gloss, quantitative measurement

The quantitative measurement of gloss of extruded sheet is described by Michael [26]. In this study, a goniophotometer was used to measure both the gloss height (maximum intensity of the reflected light beam) and the gloss sharpness expressed as the reciprocal width of the gloss distribution curve the width is measured in... 

The appearance of the article is one of the obvious criteria in evaluating the quality, of processing, measurements of gloss, clarity, etc., may help to quantify the assessment. But while appearance is an important aspect, it does not give us sufficient quantitative information about processing. Sometimes a better appearance may even mean less good mechanical properties ... 

Typical results for the natural exposure of an epoxy-polyamine coating, a particularly poor coating with respect to UV durability, are shown in Figure 14.17. Even after several days of namral exposure, in a northern European climate, oxidation products are clearly visible in the top 2-3 pm layer. It should be pointed out that quantitative assessment of these changes is possible well before any measurable gloss loss can be recorded [Davies, 1993]. 

In order to quantitatively evaluate the smoothness of a surfaee, which has considerable influence on the total gloss appearance of the sample, it is necessary to objectively measure this phenomena. The measurement of specular gloss and reflection haze does not take into account the visual impression of orange peel. Also the measurement of image clarity correlates poorly with the visual ranking of orange peel. 

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