EDISON, NJ—A new line of high strength, transparent and opaque liquid colorants for PET stretch blow molding provides uniform coloration at letdowns to 1000:1, according to Thomas Loschiavo, national sales manager, here.

Designated Series 99, the concentrated colorants are comprised of a liquid vehicle, which is totally compatible with all PET resin formulations, and up to 80 percent of pigment by weight. Proprietary processing techniques break down pigment agglomerates into individual particles, which are wet-out in suspension, preventing reagglomeration and increasing the tinctorial strength and uniformity of the original pigment by 50 to 80 percent.

The colorants are injected through the feed throat of molding machines using a peristaltic metering pump. Color changeovers can be accomplished in 10 minutes by switching tubes on the pump head. Natural resin in the hopper never requires emptying, eliminating the shutdown time required to dry hygroscopic color compounds and pre-colored resins. Colorant storage space is also minimized, says the manufacturer.

The new colorants are said to promote rapid and complete distribution of color into PET resins, allowing uniform coloration of opaque and transparent bottles, even in thin wall sections, at letdowns from 100:1 to 1000:1.

Series 99 colorants are FDA compliant and are available as multi-functional packages containing UV stabilizers, antioxidants, and other additives.