German compounder and distributor Lehmann & Voss (LuV, Hamburg; www.lehvoss.de/eng) has developed two processing aids that are claimed to greatly simplify and optimise the processing of barrier materials PA and EVOH. “Luvobatch” PA PPA 9659 is based on highly viscous PA carrier and is suitable for use with many PAs. “Luvobatch” EVOH PPA 5157 is based on an EVOH with 32 mol% ethylene content and is suitable for use in all standard EVOH qualities with ethylene contents of 2 mol% up to 44 mol%.

Processing of PA and EVOH can be carried out without surface effects, pinholes and gel particles through use of the aids, LuV said. The additives often represent only fraction of the layer thickness of the semi-finished product (film, tube or sheet), but in terms of cost can be significant. Additionally, defects in the barrier layers of multi-layer systems can lead to increased scrap, which can only be expensively reprocessed.

The company said initial trials with film, sheet and tube manufacturers has shown the anticipated effects and a noticeable product and/or process optimisation was possible for customers. This, in turn, has led to a boost in productivity for the products in the trials and consequently to cost reductions.