Nucleating and clarifying agents for PP & HDPE enables processors to shorten cycle times

A new family of nucleating and clarifying agents from Riverdale Global enables processors of PP and HDPE to shorten cycle times while obtaining the cost and accuracy advantages of liquid additives over pellet concentrates. +Speed™ additives are effective at minimal use levels. Letdown ratios range from only 0.1 to 0.5% for three grades of nucleating agent and 0.2 to 1.0% for a fourth grade that serves as a nucleating and clarifying agent. All four products comply with California Proposition 65 and are FDA approved for food-contact applications. The new additives are available in pails or drums, in custom blends with liquid colors, or as one of the GlobalPlus™ range of liquid additives. In the GlobalPlus system, each additive is supplied in a drum with a built-in pump that stay sealed throughout shipping, handling, and processing. The +Speed product range includes: ? NUC-138 nucleating agent for PP. It induces a higher crystallization temperature in the resin, which enables the molten polymer to harden at a higher temperature. This in turn decreases the necessary cooling time and shortens molding cycles. ? NUC-139 nucleating agent and acid neutralizer. It reduces molding cycles for HDPE by adjusting the orientation of the polymer crystals to optimize shrinkage properties and avoid the long mold residence time needed to withstand the internal stresses that cause part deformation. The additive also functions as a neutralizer of acid residues from the catalysts used to polymerize PP. Such residues can cause polymer degradation and warpage of the molded part. ? NUC-140 nucleating agent for use with PP and HDPE can shorten cycle times by increasing crystallization temperatures and optimizing shrinkage properties. ? NUC-141A is a nucleating and clarifying agent for PP that increases the rate of polymer crystallization in the melt phase at lower processing temperatures, enhancing clarity while reducing cycle time and energy consumption. “New +Speed nucleating agents provide a range of process and product enhancements plus the economic and quality benefits of liquid additives,” said Charles B. Irish, vice president of product development for Riverdale Global. “While liquid additives cost more per pound than pellet concentrates, they contain higher loadings of active ingredient and thus can be used at lower addition levels. This translates into a lower cost per part. In addition, liquids can be metered into the process with more precision, exhibit greater heat stability because they are produced without melt compounding, and take up a fraction of the space needed to store pellets.” Global Plus sealed additives are single-additive liquid dispersions supplied in a container that stays sealed from the moment it arrives at the processor’s loading dock, through storage, handling, and metering into the process, and during return to Riverdale Global for replenishment. Sealed additives are designed for processors who run clear or natural resins or who need to supplement the additive packages in pre-compounded or masterbatch materials.