Processing of Short Fiber Reinforced Thermoplastics: I Influence of Processing Conditions on the Morphology of Extruded Filaments

BARBOSA, SILVIA ELENA; KENNY, JOSÉ M

POLYMER ENGINEERING AND SCIENCE

Wiley

Lugar: Brookfield; Año: 2000 vol. 40 p. 11 - 22

0032-3888

An experimental investigation of the processing of glass fiber reinforced polypropylene is presented. Final fiber orientation distribution, fiber distribution in filament sections, rheological properties, final fiber length distribution and surface morphology are analyzed. This analysis was done taking into account the quantity of fibers and its interaction and correlated with flow conditions. Final fiber orientation distribution increases when shear rate increases and fiber concentration decreases. Filament sections density variation increases with concentrations of fibers decreases. Density profile shows a significant variation with fiber concentration but is not dependent of the shear rate applied.  The viscosity shows a linear dependence with shear rate and increases with fiber concentration. The average fiber length and the breadth of this distribution decreases with the increase of the fiber concentration and extrusion rate. The extruded filament surface shows a minor roughness when the shear rate increases or when fiber concentration decreases The results of this experimental characterization give a useful information to determine the influence of the processing variables on the final properties of short fiber reinforced polypropylene and constitutes the first part of a more ambitious project including also the development of a modeling strategy of the processing behavior of short fiber composites.