Effect of processing conditions on the development of morphology in clay nanoparticle filled Nylon 6 fibers

The effect of melt temperature on the phase behavior and preferential orientation development in Nylon 6/montmorillonite nanocomposites were investigated at melt spinning temperatures ranging from 230degrees to 250degreesC. The fibers were found to exhibit mostly gamma crystalline form that is typical of Nylon 6 filled with montmorillonite nanoparticles. At higher take-up speeds alpha-crystals begin to appear in the crystalline phase. The presence of nanoparticles was found to impart substantial chain orientation levels even at low to moderate take up speeds reaching a plateau at moderate take up speeds. This was attributed to the increased spin line stress in the presence of nanoparticles that increase the overall viscosity due to their large contact areas with the polymer chains. This increased spinline tension was found to cause fiber breakup at moderate speeds. Increasing melt temperature from 230degreesC to 250degreesC alleviated this problem.