Titre : |
The effects of processing parameters on the residual wall thickness distribution at the sharp angle corner of water assisted injection molded parts |
Type de document : |
texte imprimé |
Auteurs : |
T. Pudpong, Auteur ; P. Buahom, Auteur ; I. Satoh, Auteur ; T. Saito, Auteur |
Année de publication : |
2013 |
Article en page(s) : |
p. 528-540 |
Note générale : |
Bibliogr. |
Langues : |
Anglais (eng) |
Catégories : |
Epaisseur -- Mesure Matières plastiques -- Moulage par injection Matières plastiques -- Moulage par injection assistée par eau Polypropylène Simulation par ordinateur Tubes
|
Index. décimale : |
668.4 Plastiques, vinyles |
Résumé : |
Water-assisted injection molding (WAIM) has been widely used for tubular plastic parts due to its advantages of relatively low cost and fast cycling time. However, the non-uniform distribution of the wall thickness, especially at the sharp corner, is still a basic problem in the WAIM process. This work presents the effects of sharp corner angles on wall thickness distribution in sections near corners for various processing conditions of the WAIM process, including melt temperature, mold temperature, water delay time, water holding time, and holding pressure. Three grades of polypropylene (PP) resins with different melt flow indices were studied using seven mold geometries that varied the angle of the sharp corner section. The wall thickness distribution at the corner sections were characterized in terms of inner and outer residual wall thicknesses, hollow core ratio, and the percentage of difference between the inner and outer wall thicknesses. In addition, computational fluid dynamic simulations with Moldflow Plastics Insight version 4.1 were performed for each sharp corner angle. It was found that the wall thickness distribution of the straight tube was more uniform than those of the curve tubes. Water injection delay time and water pressure were the major parameters that had a significant impact on the hollowed core ratios, while the percent difference between inner and outer wall thicknesses was mainly influenced by melt temperature. |
Note de contenu : |
- EXPERIMENTAL PROCEDURE : Materials - Injection molding machine and mold - Process parameters - Characterization - Simulation
- RESULTS AND DISCUSSION : Relationship between shear rate and inner residual wall thickness - Effect of MFI on residual wall thickness distribution - Effect of melt temperatures on residual wall thickness distribution - Effect of mold temperature on residual wall thickness distribution - The effect of water delay time on residual wall thickness distribution - The effect of water pressure on residual wall thickness distribution - The effect of water holding time on residual wall thickness distribution - Stifness - Inner surface roughness - Switchover mark - Microscopic observation |
DOI : |
10.3139/217.2792 |
En ligne : |
https://drive.google.com/file/d/1fjKjyjWOGlo3-G8uXFzpKHhITn1nsyA2/view?usp=drive [...] |
Format de la ressource électronique : |
Pdf |
Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=19899 |
in INTERNATIONAL POLYMER PROCESSING > Vol. XXVIII, N° 5 (11/2013) . - p. 528-540