Premium
Manipulation of the Microstructure of Injection Moldings in a Special Mold and Their Mechanical Behavior
Author(s) -
Silva Cristina A.,
Viana Júlio C.,
Cunha António M.
Publication year - 2006
Publication title -
macromolecular materials and engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.913
H-Index - 96
eISSN - 1439-2054
pISSN - 1438-7492
DOI - 10.1002/mame.200600193
Subject(s) - microstructure , materials science , mold , molding (decorative) , composite material , rotation (mathematics) , ultimate tensile strength , rotational speed , mechanical engineering , geometry , mathematics , engineering
Summary: In this work, the relationships between the microstructure and the mechanical properties of injection moldings using a special mold for manipulation of their microstructure are studied. Distinct molding microstructures were obtained by superimposing a mold surface rotation action in different rotation modes during the filling stage of a center‐gated disk. For this, disks were injected in the special molding tool—the RCE mold—with distinct filling sequences (stationary, continuous, stepped, and pulsed rotation modes) for two different thicknesses (1.5 and 2.5 mm) in a propylene homopolymer. This enables the development of a wide range of microstructures, which were characterized by polarized light microscopy. The mechanical behavior of the moldings was assessed by tensile and impact testing. The results are presented in terms of the relationships between the developed microstructure and the assessed mechanical properties. The imposition of a rotation action of the molds wall influences the development of the microstructure, and hence the mechanical properties of the moldings.Effect of the rotating mode: stationary, continuous (R), stepped (RS), and pulsed modes (RC), at 150 rpm on the microstructure at position P2 (cuts to transversal flow direction). Thickness: 1.50 mm.