Titania pigments are used in molding compounds as a means to improve opacity by increasing the scattering efficiency of the medium and to develop new applications such as liquid crystal displays (LCD) and light emitting diodes (LED). The characteristics of the injection molded products are a function of molding parameters such as gate location and shear rate. In this study, quantitative measures of the particle distribution of titania pigments in polymer composites have been experimentally determined, including area fraction, average diameter, and diameter volume. A 2 × 3 × 3 ANOVA test has been conducted to assess the statistical significance of these parameters. This study deals with the size and spatial distribution of the particles. The important parameters calculated based on the Feret’s diameter are diameter-volume (dv), diameter-number (dn), and area fraction (AF). The term diameter-volume (dv) has been used to give greater significance to the large particles and thus ‘large’ indicates more and/or larger particles. The parameters have been calculated by using Image-J image processing software. MINITAB has been used to assess the statistical significance of these parameters. The results show that titania particles are not uniformly distributed within the final molded parts and they vary along the molding (longitudinal) and transverse directions of plastic flow. The difference of pigment area fraction and diameter volume at different locations within a final molded part has a significant effect on the percentage reflectance of the surface.

This content is only available via PDF.
You do not currently have access to this content.