Rheological behavior of coextruded multilayer architectures

摘要

Utilizing a thermoplastic extrusion process, a multilayered architecture was fabricated. Thermoplastic blends of 55 vol% X7R dielectric and 50 vol% nickel powder were prepared by high shear mixing. Sheets pressed from this material were cut, stacked, and laminated to produce multilayered blocks. The blocks were extruded through a slotted spinneret to reduce layer thickness. The relation between viscosity and shear rate is relatively well understood for two- or three-layered polymer coextrusion. This behavior has not been studied for heavily loaded multi-component systems, such as might be used for MLCCs and other multilayered devices. A correlation was observed between the flow behavior during extrusion and that observed during mixing. Results show how control of the rheological behavior of highly loaded systems can control extrusion defects.