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Structure Development in Injection Molding of Isotactic Polypropylene, its Blends, Compounds and Dynamic Vulcanizates

  • Y. Yu and J. L. White
Published/Copyright: June 3, 2013
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International Polymer Processing
From the journal International Polymer Processing Volume 18 Issue 4

Abstract

We make a comparative study of structure development in injection molding of isotactic polypropylene, polypropylene blends/compounds and dynamically vulcanized polypropylene thermoplastic elastomers (TPVs) WAXS 2θ scans were used to determine crystalline forms and the distribution of relative amounts of crystalline forms through the cross-section of injection molded parts. WAXS film patterns, polarized optical light micrographs and birefringence were used to qualitatively indicate polymer chain orientation variation through the cross-section. We also used WAXS pole figures to investigate polymer crystalline orientation and filler orientation in different layers of the injection molded parts.

It was found that a low or modest orientation layer exists on the part surface. There is an intermediate highly oriented layer in the parts of isotactic polypropylene and most polypropylene blends/compounds. The interior of the parts was spherulitic and increasingly isotropic as one moved to the center. The thickness of the surface layer increases as the injection pressure decreases. The layer was not observed in parts of dynamically vulcanized polypropylene thermoplastic elastomers. This would seem to be associated with the TPVs possessing a yield stress and not exhibiting substantial fountain flow in mold filling.

* Mail address: J. L. White, Institute of Polymer Engineering, University of Akron, Akron, Ohio, 44325-0301, USA
Received: 2003-1-20
Accepted: 2003-9-3
Published Online: 2013-06-03
Published in Print: 2003-12-01

© 2003, Carl Hanser Verlag, Munich

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  1. Contents
  2. Contents
  3. Editorial
  4. Fourth of a Series: Pioneering Polymer Industry Developments: The First Continuous Kneading Machines
  5. Screw Extrusion
  6. Prediction of Residence Time Distribution in EZ and KE Element of a Ko-Kneader by using CFD Method
  7. Computational Study of Velocity Field in the KE Element of a Modular Ko-Kneader with CFD Method
  8. Optimization of Sweet Bread Dough Processing Conditions by Twin Screw Extrusion
  9. Experimental Development of Processing Technology for Yuba-like Films Using Twin Screw Extrusion
  10. Die Extrusion
  11. Flow Analyses in a Spiral Mandrel Die Assuming Wall Slip
  12. Effect of Elongational Viscosity on the Flow in a Flat Die
  13. Measuring Polymer Melt Density and Viscosity in Real-time during Extrusion Processes using Ultrasound Sensors Fusion
  14. Film
  15. Scale-up Rule for Double Bubble Tubular Process of PA6 Film
  16. Molding
  17. Analysis of the Morphological Development of PBT/ABS Blends during the Twin Screw Extrusion and Injection Molding Processes
  18. Investigation of the Mechanical Properties and Chemical Resistance of PC/PBT/Impact Modifier Blends
  19. Structure Development in Injection Molding of Isotactic Polypropylene, its Blends, Compounds and Dynamic Vulcanizates
  20. The Flow Behavior of Core Material and Breakthrough Phenomenon in Sandwich Injection Molding
  21. The Flow Behavior of Core Material and Breakthrough Phenomenon in Sandwich Injection Molding
  22. PPS News
  23. PPS News
https://doi.org/10.3139/217.1786

Articles in the same Issue

  1. Contents
  2. Contents
  3. Editorial
  4. Fourth of a Series: Pioneering Polymer Industry Developments: The First Continuous Kneading Machines
  5. Screw Extrusion
  6. Prediction of Residence Time Distribution in EZ and KE Element of a Ko-Kneader by using CFD Method
  7. Computational Study of Velocity Field in the KE Element of a Modular Ko-Kneader with CFD Method
  8. Optimization of Sweet Bread Dough Processing Conditions by Twin Screw Extrusion
  9. Experimental Development of Processing Technology for Yuba-like Films Using Twin Screw Extrusion
  10. Die Extrusion
  11. Flow Analyses in a Spiral Mandrel Die Assuming Wall Slip
  12. Effect of Elongational Viscosity on the Flow in a Flat Die
  13. Measuring Polymer Melt Density and Viscosity in Real-time during Extrusion Processes using Ultrasound Sensors Fusion
  14. Film
  15. Scale-up Rule for Double Bubble Tubular Process of PA6 Film
  16. Molding
  17. Analysis of the Morphological Development of PBT/ABS Blends during the Twin Screw Extrusion and Injection Molding Processes
  18. Investigation of the Mechanical Properties and Chemical Resistance of PC/PBT/Impact Modifier Blends
  19. Structure Development in Injection Molding of Isotactic Polypropylene, its Blends, Compounds and Dynamic Vulcanizates
  20. The Flow Behavior of Core Material and Breakthrough Phenomenon in Sandwich Injection Molding
  21. The Flow Behavior of Core Material and Breakthrough Phenomenon in Sandwich Injection Molding
  22. PPS News
  23. PPS News
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