جستجوی مقالات مرتبط با کلیدواژه « پوست پرتقالی » در نشریات گروه « مهندسی شیمی، نفت و پلیمر »

One crucial aspect of object quality control involves assessing their visual properties. Objects possess three key properties that significantly contribute to their quality, beauty, and impressiveness. These properties can be primarily categorized into colorimetric characteristics and geometrical properties. Among these attributes, the gloss factor stands out as one of the most significant geometrical properties of surfaces. It profoundly impacts how people perceive an object's appearance, creating the impression of a bright and shiny surface. The evaluation of the gloss parameter holds great importance in quality control across various industries, including textiles, automotive, printing, packaging, and more. Numerous research studies have been conducted to harmonize the definition of the gloss concept, bridging the gap between instrumental measurement and human visual perception. The ultimate objective of these studies is to develop descriptive models that accurately quantify gloss and align with the results of human visual perception. This paper provides a comprehensive description and definition of the various perceptual aspects of gloss, highlighting its significance in diverse industries. Additionally, it reviews research carried out in the field, focusing on different evaluation methods and the quantification of gloss.

Illumination/observation geometries have an effective role in visual assessments of geometric attributes such as gloss, distinctness of image, orange peel of automotive paints. In this research, gloss, distinctness of image and orange peel of an automotive paint were investigated under three different illumination/observation conditions namely, directional, diffuse and combination of the two(i.e. directional plus diffuse) usually achieved in a standard light cabinet. For each condition, the visual assessments were carried out at various viewing geometries. For this purpose, three scales, i.e. specular gloss, distinctness of image and orange peel were prepared for a black automotive finish. These scales were separately evaluated visually under various illumination/viewing conditions by a panel of 8 observers. The statistical parameters showed that the visual perception of gloss under directional lighting/viewing geometry of 38º/7 º along with visual perception of distinctness of image and orange peel observed in a standard light cabinet with a 45º /0º geometry gave the most reasonable results as the performance of observers in such set ups induced average stress values of less than 8%. J. Color Sci. Tech. 7(2014), 323-330©. Institute for Color Science and Technology.

Assessment of the total appearance of an automotive coating using standard methods would have a great impact in the automotive industry. These methods should have a good correlation with visual assessments. In this research, the correlation between visual assessments and the wave scan DOI results were investigated for white, metallic grey and metallic black automotive samples. The visual assessments were carried out by a panel of 14 observers, including 6 males and 8 females under a light source simulating D65 in a light cabinet with a viewing geometry of 45/0. The visual assessment method used was one of paired comparison. Such quality rankings were then converted to quantitative equivalents by the aid of the Thurston scale and the results were compared with each of the wave scan output parameters. Statistical and error estimation parameters (i.e. R 2 and stress) illustrated that amongst all wave scan parameters, only Wd, Wc, LW and in that order strongly correlated with human evaluations of geometric attributes for these achromatic paint samples. Investigation of structure spectrum showed that Wb is another important parameter indirectly influencing on the surface appearance and in fact the value of Wb is greater than Wd and Wc in the acceptable region. Therefore, there seems to be a complex relationship between these parameters which represent the short and the long waves which is of utmost importance in assessing perceived total appearance. J. Color Sci. Tech. 7(2013), 123-131©. Institute for Color Science and Technology