Experimental study of fiber breakage during injection molding of polypropylene/short glass fiber composites

MARÌA P. RUIZ; LEANDRO N. LUDUEÑA; ANTONIO J. PONTES

Mar del Plata

Simposio; XVI Latin-American Polymer Symposium (SLAP 2018), XIV Iberoamerican Polymer Congress (CIP 2018); 2018

Instituto de Investigaciones en Ciencia y Tecnología de Materiales (INTEMA)

Short fiber thermoplastic composites (SFTC) have been developed in the last years looking for higher mechanical performance. Injection molding is a processing technique used to produce high performance SFTC parts with complex geometries at high production rates. The main issue of these materials is to prevent fiber breakage during processing. In this work, a novel experimental setup is proposed which is able to isolate the main parameters causing fiber breakage during mold filling of injection molded polymer composites1. A capillary rheometer was designed to be attached to the clamping unit of an injection molding machine. The use of a capillary rheometer of 4mm diameter made possible the quantification of fiber breakage at constant shear rate (SR) in the injection molding SR range avoiding fiber / capillary wall contacts. The motivation for the design of such capillary rheometer is that conventional ones with capillaries of 4mm in diameter could reach maximum SR at wall of 600s-1, which is a low value considering that mold filling stage in injection molding can reach SR values as high as 100000s-1.