Improving processing and end-use properties of polyolefin compounds
At K2016 ExxonMobil Chemical has introduced new low viscosity Vistamaxx polymers. These materials can be used to maintain or improve cycle times of injection moulded or extruded applications. Vistamaxx 8880 improves the flow and processing of polyolefin compounds which contain Vistamaxx 6202 or 6502, or are heavily filled.
For compounders, adding Vistamaxx 8880 to a formulation enhances the moulding process by reducing injection pressure due to its low viscosity and cooling efficiency. The company said that with controlled cooling temperature, cycle times can be achieved that are comparable to SEBS compounds used for soft TPE components such as grips and other soft-touch overmoulding TPE applications,
Because Vistamaxx 8880 reduces compound viscosity it can enhance polyolefin blend properties to deliver better flexibility, increased impact resistance and improved aesthetics. Reduced unit costs are possible due to the enhanced processing efficiency provided by Vistamaxx 8880 for compounding, injection molding and extrusion processes. Its enhanced flow can facilitate higher production rates leading to cost efficiencies during processing. Meanwhile, Vistamaxx 6202 and 6502 allow increased filler loadings for lower costs.
End-users can benefit from improved products, like non-slippery TPE grips or stay-flat carpet tiles. In TPE grips, Vistamaxx 6202 or 6502 can help to improve surface quality by enabling soft-touch and a non-slippery feel due to oil-free compounds. Stress whitening can also be minimised. Costs can be reduced by up to 20 % because filler loadings of up to 30 % are possible. By adding Vistamaxx 8880 in the same formulation, comparable cycle times and higher flow are possible with the same tool.
In carpet tiles, Vistamaxx can be used to design a highly filled polyolefin solution as secondary backing, providing dimensional stability and flexibility to the end-use carpet. Lower costs are possible due to high filler loading capability, lower polymer density and recycling of scrap during manufacturing. The addition of Vistamaxx 8880 to a compound based on Vistamaxx 6202 or 6502 allows filler loadings to be increased further. It also enables very good extrusion processability due to a high flow rate.
“Vistamaxx polymers are used for compound modification at dosage levels of five to 15 % to enhance properties such as impact strength and clarity, while reducing stress whitening,” said Gertrud Masure, Vistamaxx market development manager, ExxonMobil. “For applications such as grips, however, dosage levels have to be much higher to achieve the required performance improvements which can result in longer cycle times. Compounders can now tailor processing and end-use product performance even more by using Vistamaxx 8880 to modify viscosity. They can achieve product improvements by including Vistamaxx 6202 and 6502 in their formulations, while processing performance can be maintained or enhanced by using low viscosity Vistamaxx 8880 in the same formulations.”