Automotive interiors are comprised of a variety of materials and produced by several companies. To achieve a uniform appearance, automotive companies have tight quality control (QC) tolerances. Color tolerances are typically ±0.5 for ΔL*, Δa*, Δb* and gloss tolerances are typically ±0.3 to 0.5 gloss units (GU).
As a starting point, a master plaque is supplied by the automotive company. The parts supplier develops production parts for visual acceptance to the master plaque. Once the production parts are visually approved, they become the working standards. Because of the tight tolerances, it is very difficult to QC production parts by visual assessment alone. The tighter tolerances have also pushed the performance limits of the current color and gloss instrumentation. BYK-Gardner developed a special line of gloss (micro-TRI-gloss – S and micro-gloss 60º – S) and color instruments (spectro-guide sphere or 45/0 gloss – S) to provide highly repeatable measurements. The “S” family instruments have a gloss repeatability of ±0.1 GU and a reproducibility performance of ±0.2 GU. The reproducibility specification is particularly important if a plant is using more than one instrument. The spectro-guide sphere or 45/0 gloss –S can measure color and 60º gloss in one instrument saving time and money.
How tight are your tolerances? Can your instrument handle them?