Sliding interface, melting

In this chapter the physical properties of resins related to processing will be described. The chapter and Appendix A4 include physical properties for many resins. These properties include bulk density and compaction, lateral stress ratio, stress at a sliding interface, melting flux, heat capacity, thermal conductivity, and melt density. Some of these properties are easy to measure by many laboratories while others such as the melting flux and stress at a sliding interface can be measured in only a few places using highly specialized equipment. 

Appendix A4 Shear Stress at a Sliding Interface and Melting Fluxes for Select Resins... 

Figure A4.4 Shear stress at a sliding interface for a PC/ABS resin blend with an MFR of 1.7 dg/min (260 °C, 3.8 kg) as a function of temperature and sliding velocity at a pressure of 0.7 MPa. The melting flux for this resin is shown in Fig. 4.13...

Shear stresses at a sliding interface and the melting fluxes for LDPE, ABS, HIPS, and LLDPE were reported at a pressure of 0.7 MPa and as a function of temperature and velocity. These data contribute to the better understanding of the solids conveying and melting processes in single-screw, plasticating extruders. 

Fig. 20 Chain sliding diffusion model of primary nucleation. Polymer chains are rearranged from Gaussian shape within the melt into a nucleus through chain sliding diffusion within the nucleus and disentanglement within the interface. Bottom graph indicates change in free energy of the nucleus against N...

As shown in Fig. 1, chain sliding diffusion becomes difficult due to pinning effect within the interface between a nucleus and the melt. Since Jo is proportional to the topological diffusion constant D, D is related to ve from Eq. 62,... 

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