Mineral masterbatches are not used so often in production of injected parts. Their main use is in automotive where we can often find out talk-filled products with the aim to reinforce critical parts of the product.
However we also solved the customer’s requirement to reinforce the injected boxes. In this particular case it was about improving the dimensional stability. The products were boxes made from HDPE and PP and the walls of the boxes were deformed due to the residual shrinkage of the polymer. Customer tried to solve or limited the problem by prolonging the cooling time but this change was not sufficient and economical.
Our solution for both cases was to use Granic® material based on calcium carbonate with LLDPE carrier. Calcium carbonate has naturally reinforcing properties which eliminate wall deformation, and at the same time we were able to reduce the cycle time by 10 % (thanks to the higher thermal conductivity of the mineral). We produced a product that had the required dimensional stability with lower production costs.