Molecular Orientation in Injection-Molded Polypropylene Copolymers with Ethylene
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M. Fujiyama
Abstract
The molecular orientation process in injection molding of polypropylene copolymers with ethylene was theoretically analyzed from a view point of growth of melt orientation (recoverable shear strain) at the gate and its relaxation in the mold cavity. Regardless of the characteristics of raw resin (copolymerization type and ethylene content) and molding conditions (cylinder temperature), there exist unitary correlations between calculated degree of molecular orientation and experimentally measured degrees of molecular orientation such as the thickness of skin layer and crystalline c-axis orientation function. According to this analysis, the fact that molecular orientation is decreased by copolymerization with ethylene is due to decrease in melt orientation (recoverable shear strain), decrease in the relaxation time and reduction of crystallization temperature.
© 1992, Carl Hanser Verlag, Munich
Artikel in diesem Heft
- Contents
- Contents
- Continuous Mixing and Compounds
- Starve-fed Flow in Co-Rotating Twin Screw Extruders
- Process for Improvement in Toughness of Unsaturated Polyester with Elastomer
- Mechanical Properties of Thermoplastic Polyurethane Blends and Copolymers of Styrene and Acrylonitrile
- Extrusion
- Mixing on Melting in Single Screw Extrusion
- Numerical Study of Slip at the Walls in the Extruder
- Elimination of Sag in Plastic Pipe Extrusion
- Fibers and Film
- Issues Concerning the Rate of Heat Transfer from a Spinline
- Skew Stretched Polycarbonate Films
- Molding
- Molecular Orientation in Injection-Molded Polypropylene Copolymers with Ethylene
- Melt-recrystallization of Talc-filled Polypropylene Injection Moldings
- Processing Characteristics of Thermoplastic Sheet Composites
- Rapid Communication of Recent Advances
- The Face-relief Strategy for Design of Profile Dies
Artikel in diesem Heft
- Contents
- Contents
- Continuous Mixing and Compounds
- Starve-fed Flow in Co-Rotating Twin Screw Extruders
- Process for Improvement in Toughness of Unsaturated Polyester with Elastomer
- Mechanical Properties of Thermoplastic Polyurethane Blends and Copolymers of Styrene and Acrylonitrile
- Extrusion
- Mixing on Melting in Single Screw Extrusion
- Numerical Study of Slip at the Walls in the Extruder
- Elimination of Sag in Plastic Pipe Extrusion
- Fibers and Film
- Issues Concerning the Rate of Heat Transfer from a Spinline
- Skew Stretched Polycarbonate Films
- Molding
- Molecular Orientation in Injection-Molded Polypropylene Copolymers with Ethylene
- Melt-recrystallization of Talc-filled Polypropylene Injection Moldings
- Processing Characteristics of Thermoplastic Sheet Composites
- Rapid Communication of Recent Advances
- The Face-relief Strategy for Design of Profile Dies
