MELT TENSION

Figure 5 High melt tension LLDPEs from supported metallocenes. (From Ref. 2.)...

PA-6/PMP/PMP-g-MA Melt kneaded in biaxial extruder/mechanical properties/melt tension Enna et al. 2013... 

Increased long chain branching More chain entanglement Increased melt tension Increased shear sensitivity Increased bubble stability Less draw resonance Less torque increase Less die pressure increase... 

Another area of current research deals with combining the earlier work on production of polymer blends in the elastic melt extruder and the observation of the maximm in melt elasticity as a fimction of composition as fo md in the orthogonal rheometer studies on blends. It would be expected that as the melt elasticity increased the forces required for melt orientation would also increase. This has been confirmed in current studies of melt tension in fiber spinning experiments. The important point is that the composition of the blend can be used to control the molecular orientation. 

Fig. 2.2 Temperature dependence of apparent melt viscosity and melt tension of HP-LCP...

The tensile and flexural properties of pure HP-LCP were superior to those of pure LCP-E. The tensile strength of pure HP-LCP is nearly 15 % and the flexural strength is 45 % higher than those of pure LCP-E. Although the improvement of the mechanical performance was not the main focus of this development, these properties could be substantially enhanced due to the high melt tension of HP-LCP. 

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