Another useful tool for plastics manufacturers to enhance aesthetics in plastic products are optical brighteners. They are designed to brighten colors or mask yellowing in plastics. They work via a fluorescent mechanism, absorbing light in the UV spectrum and emitting it in the blue range of the visible spectrum, resulting in a brighter, fresher appearance.
These products are particularly useful to mask the yellowness sometimes observed in plastics and fibers after high-temperature processing operations or incorporation of recycled materials. They are also used in formulations containing pigments or dyes to make colors appear more brilliant.
Key applications include film and sheet, fibers, and molded thermoplastic products. Optical brighteners can also be used to enhance polylactic acid (PLA) and recycled materials like polyethylene terephthalate (PET) regrind which both have a yellow tint. Specialty packaging such as tumblers/cups and novelty items also benefit from optical brighteners, enabling them to jump off the shelf and enhance consumer appeal. Optical brighteners also find use in engineering plastics like polyolefins, home- and copolymers, and styrenes among others.
Optical brighteners are colorless or slightly colored organic compounds that, in solution or applied to a substrate, absorb ultraviolet light and re-emit most of it at between 400 and 500 nm as visible violet-to-blue fluorescent light.
Unlike dyes, optical brighteners offset the yellowish cast and at the same time improve lightness, because their bluing effect is not based on subtracting yellow-green light, but rather on adding blue light.
Plastics Color Corp. is a highly experienced supplier of colorants, compounds, and additive masterbatches. We can custom formulate a functional additive package to meet the requirements of your application. We offer optical brighteners in an additive masterbatch or as part of your optical package. Need help? Send us your questions at Info@PlasticsColor.com.