Determination of Opaque (PC) Grade Through Data Mining, Modeling, Simulation, and Optimization: Influence of Material Processing Temperature on Pigment Dispersion and Rheological Properties

This research study will provide methodical scientific explanations for color-mismatches in compounded plastics and identify the dispersion characteristics of the pigments used. Related issues will also be addressed to develop better formulations that enhance color coordination, color stability, and the uniformity of compounded plastic materials, while minimizing waste. In previous research, the focus was on transparent grades, whereas in this paper, opaque polycarbonate (PC) grades were the focus, with data collected through data mining of archived records from an industrial plant. Also, data mining methods were used to identify relationships between particular processing factors and color variations. In addition, Grade B was considered due to its identical pigmentation but different polycarbonate resin percentages, with R1/R2 equal to 90/10% which yields 101 associated color adjustments in total. The number of lots without adjustment is 60, and 41 with adjustment. Interactions among three parameters of the processing (PPs) in order to maintain the same color mixture under various conditions were studied using both experimental and numerical methods. Using General Trends (GT) methods, PPs were controlled at five different levels independently, while keeping all other variables constant. Moreover, the impact effects of PPs on color output and the effect of tristimulus color (l*, a*,b*, L*, and dE*) were also analyzed. From the above and from an engineering perspective, it is crucial to understand how these parameters affect color consistency. A comparison, using a spectrophotometer, between standard target values (CIE L* - 63.36, a* - -0.34, b* - 0.20) and the measured color values was conducted, identifying the significant PPs that contribute to the minimum color deviation. The distribution of the particle (PSD) size (2 µm) is dominated by small particles at all temperatures (T). Similar peak percentages (60–63%) are shown when Temp reaches 230 °C and 280 °C, and slightly lower percentages (60%) when Temp reaches 255 °C. This suggests is rising in temperature (from 230 to 280 degrees Celsius) slightly shifts the distribution toward smaller particles, but a more balanced mix of small and medium particles appears at 255°C, suggesting Temp, which influences particle breakage and agglomeration behavior. When most particles stay in the range of 1-3 µm for all Temps, consistent fine dispersion is demonstrated. Using Design of Experiments (DOE), impending research will expand GT analysis to include interactions between several parameters. Furthermore, processing temperature will be the subject of an ANOVA to determine its statistical significance, with the results being confirmed at a confidence level of p < 0.05. In order to back up the creation of prediction models for industrial-scale applications, the study will also evaluate the diagnostic procedure's robustness across different polymer grades and colorants. The improved color matching performance for opaque grades was a direct outcome of the high-quality mixing that occurred during the polycarbonate compounding process, which also minimized color streaking and guaranteed uniform distribution of pigments. By means of a particle size analyzer on the Microtrac S3500, it examined the distribution of primary particle sizes for four different colors. Black channel (13-20 µm), red iron oxide (0.8-1.6 µm), titanium dioxide (1.7-8.0 µm), and organic yellow (0.8-1.8 µm)were the ranges of measurements. Improved dispersion and less aggregation were achieved by employing increased ultrasonic power and duration. Similar to the reference pigment, the main pigment displays ranging from 1 to 2 µm in size. Mean particle size and particle count are positively correlated; rising temperatures result in smaller pigments and more particles, which affect colour response. Particle sizes were nearly identical when PSA and SEM were compared to PSD. The improved color matching performance for opaque grades was a direct outcome of the high-quality mixing that occurred during the polycarbonate compounding process, which also minimized color streaking and guaranteed uniform pigment dispersion.To finish, the influence of processing temperature on viscosity, dispersion of pigment size at three different temperatures, and color superiority was investigated by analyzing the effects of viscosity, Digital Optical Microscopy (DOM),Scanning Electron Microscopy(SEM) ,and pigment size distribution(PSA) at various processing levels. The samples were characterized for viscosity, DOM, and Particle size distribution at (230°C, 255°C, and 280 °C) temperatures. The overall mixing of PC compounding ingredients ensures uniform pigment dispersion, minimizes color-mismatching and results in minimal color difference (dE*), which improves color-matching significantly.