Titre : |
Use of the fast-cool pVT data for shrinkage analysis in injection molding |
Type de document : |
texte imprimé |
Auteurs : |
S. Han, Auteur ; K. K. Wang, Auteur |
Année de publication : |
2002 |
Article en page(s) : |
p. 67-75 |
Note générale : |
Bibliogr. |
Langues : |
Anglais (eng) |
Index. décimale : |
668.9 Polymères |
Résumé : |
The prediction of shrinkage and warpage of crystalline polymers is quite difficult. This is because of the complications of the crystallization process and associated material property changes. Particularly, the pVT behaviour is dependent on the cooling rate during injection molding. Traditionally, the pVT data were measured in a device where the cooling rate is very slow compared to that in the actual injection molding process. This cooling-rate dependent pVT data is considered to affect the shrinkage and warpage calculation significantly. In the present study, a method has been developed to obtain pVT behaviour at the same cooling rate as in the actual injection molding process. Obtaining other material data such as viscosity, thermal conductivity and heat capacity at the cooling rate of the actual injection molding process has also been considered. Injection-molding experiments have been conducted to measure the shrinkage of a part using semi-crystalline polymers. The polymers used in this study are polyamide 66 (PA 66) and polybutylene terephthalate (PBT).
Simulation has been done to calculate the shrinkage using the cooling-rate dependent material properties. Using the fast-cool pVT behaviour, the agreement between the simulation and the experiment improved significantly compared to the traditional approach. |
Note de contenu : |
- A procedure to obtain fast-cool PVT behavior : Crystallization kinetics - Crystallization kinetics model - Measurement example - PVT curves of amorphous and semi-crystalline states - Slowly-crystallizing polymer - Fast-crystallizing with glas-transition temperature above room temperature - Fast-crystallizing with glas-transition temperature below room temperature - Cooling history - Final stage in obtaining fast-cool pVT
- Other material properties : Viscosity - Heat capacity and thermal conductivity
- Simulation and comparison of results with experiment |
DOI : |
10.3139/217.1674 |
En ligne : |
https://drive.google.com/file/d/1-B6H8Red7ej0izHo6Utv6RBP5DwPldRo/view?usp=drive [...] |
Format de la ressource électronique : |
Pdf |
Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=15988 |
in INTERNATIONAL POLYMER PROCESSING > Vol. XVII, N° 1 (03/2002) . - p. 67-75