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Injection molding of long fiber‐reinforced thermoplastics: A comparison of extruded and pultruded materials with direct addition of roving strands
Author(s) -
Truckenmüller F.,
Fritz H.G.
Publication year - 1991
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.760311806
Subject(s) - materials science , composite material , fiber , molding (decorative) , pultrusion , glass fiber , polymer , reciprocating motion , compression molding , pellets , fineness , composite number , mold , mechanical engineering , engineering , gas compressor
An injection molding process is proposed whereby roving strands are directly incorporated into the polymer melt by using a reciprocating‐screw‐plasticating unit. The direct incorporation of continuous fibers (DIF) offers the possibility to substitute the relatively expensive and limited pultrusion process currently used to produce long fiber pellets. In this preliminary study experimental investigations on glass fiber‐reinforced polyamide‐6,6 are carried out, starting with short and long fiber pellets in comparison to the direct incorporation of roving strands into the polymer melt. Some special aspects of the processing of long fiber‐reinforced thermoplastics are discussed. The results of fundamental mechanical and physical property investigations are presented, including fiber length distribution, fiber concentration, fiber bundling/clustering and fiber orientation. The influence of fiber diameter and fineness of strands (tex) on the feed‐in behavior and the resulting property profile is also discussed.