Processing of short-fiber reinforced polypropylene. I. Influence of processing conditions on the morphology of extruded filaments

Citation
Se. Barbosa et Jm. Kenny, Processing of short-fiber reinforced polypropylene. I. Influence of processing conditions on the morphology of extruded filaments, POLYM ENG S, 40(1), 2000, pp. 11-22
Citations number
21
Categorie Soggetti
Material Science & Engineering
Journal title
POLYMER ENGINEERING AND SCIENCE
ISSN journal
00323888 → ACNP
Volume
40
Issue
1
Year of publication
2000
Pages
11 - 22
Database
ISI
SICI code
0032-3888(200001)40:1<11:POSRPI>2.0.ZU;2-N
Abstract
An experimental investigation of the processing of glass fiber reinforced p olypropylene is presented. Final fiber orientation distribution, fiber dist ribution in filament sections, rheological properties, final fiber length d istribution and surface morphology were analyzed. This analysis was done ta king into account the quantity of fibers and their interactions and now con ditions. The final fiber orientation increased when shear rate increased an d fiber concentration decreased. Moreover, inhomogeneities in fiber distrib ution increased as the concentration of fibers decreased. The density profi le showed a significant variation with fiber concentration, but it was not dependent on the shear rate applied. The viscosity showed a linear dependen ce with shear rate. The average fiber length and the breadth of this distri bution decreased with the increasing fiber concentration and extrusion rate . The extruded filament surface showed minor roughness when the shear rate increased or when the fiber concentration decreased. The results of this ex perimental characterization give useful information to determine the influe nce of the processing variables on the final properties of short-fiber rein forced polypropylene and constitutes the first part of a more ambitious pro ject that also includes the development of a modeling strategy of the proce ssing behavior for short-fiber composites.