Viscosity
The viscosity of all thermoplastic melts is non-Newtonian, i.e., the viscosity is a function of the shear rate at which it is tested. For a given polyethylene resin, the relationship between its measured viscosity and the applied shear rate depends on its molecular characteristics. All polyethylene resins are shear thinning. The general characteristics of the relationship of viscosity to shear rate are shown in left-hand figure. Both viscosity and shear rate are plotted on logarithmic scales, reflecting the wide range of values encountered in commercial processes. The response of the various types of polyethylene resins to increasing shear is a function of their degree of long-chain branching and molecular weight distribution. Lucofin® 1400HN and Lucofin® 1400MN with their high degree of long-chain branching and broad molecular weight distribution show a shear thinning effect close to that of conventional LDPE. This guarantees a superior processability. Opposite to that finding LLDPEs -including plastomers- with their rather linear structure and narrower molecular weight distribution show a shear thinning effect to a much lesser degree. As a result, plastomers only have small processing windows prone to instabilities, such as melt fracture and shark skin. This means that Lucofin® resins will run smoothly during blown and cast film extrusion.

Melting point and vicat temperature
Right-hand figure shows the melting points and the vicat temperatures of Lucofin® 1400HN compared to an EVA with similar comonomer content and MFI and compared to a plastomer with similar MFI. Both the melting points and the vicat temperatures show the highest values for Lucofin® 1400HN. This is a clear indication for the excellent maximum service temperature during end-usage of Lucofin® 1400 HN based compounds compared to competition grade based compounds. All film testing procedures involving elevated temperatures are therefore likely to be passed by formulations based on Lucofin® resins.