| Titre : |
Injection molding is getting more continuous : "Back flow compensation" combines passively blocking screw head geometry with machine operation at speed |
| Type de document : |
texte imprimé |
| Auteurs : |
Stefan Kruppa, Auteur ; Johannes Wortberg, Auteur ; Reinhard Schiffers, Auteur |
| Année de publication : |
2016 |
| Article en page(s) : |
p. 81-84 |
| Langues : |
Anglais (eng) |
| Catégories : |
Matières plastiques -- Moulage par injection -- Appareils et matériel
|
| Index. décimale : |
668.4 Plastiques, vinyles |
| Résumé : |
Within the scope of a joint research project, machine maker KraussMaffei and the Duisburg-Essen University developed an injection molding concept without movable backflow valve. Hereby, the decisive elements are a newly designed screw head and continued rotation during the injection phase. |
| Note de contenu : |
- The backflow valve : diva-like behavior
- The alternative : innovative screw heads plus rotation
- Geometric layout and modeling
- Process-related investigation of weight constancy
- Energetic considerations
- FIGURES : 1. Signal curves for consecutive injection cycles in a process with a 3-flight BFV. Partial filling with PA6 (type: Durethan B 30 5 ; manufacturer: Lanxess Deutschland GmbH) is achieved without holding pressure. The curves show an unstable process due to the non-reproducible closing behavior of the ring backflow valve - 2. CAD model of backflow compensation - 3. Seconds 3 to 9 show the holding pressure phase, in which pressure and the residual melt cushion can be maintained also with BFC (top). During the holding pressure phase, screw speed can be lower than during plastification - here, it is 75 rpm (center). Bottom: With the 3-F-BFV, torque during injection is generated by the mass flow - 4. Constant shot weight for partial (top) and complete filling (bottom) with holding pressure for 3-F-BFV, ASOV-BFV, and BFC-BFV. The backflow-compen¬sated version (BFC) gives the best results - 5. Mean electric power consumption for drives Pdrv, and heaters Pheat in kW for various resulting screw speeds Nscr . Due to additional dissipation in the injection phase, less heating energy is required, so that the duty cycle of the barrel heaters is reduced |
| En ligne : |
https://drive.google.com/file/d/1etbkRvRKe1NFvN6hcgW-s-nXs9pv03M9/view?usp=drive [...] |
| Format de la ressource électronique : |
Pdf |
| Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=27778 |
in KUNSTSTOFFE INTERNATIONAL > Vol. 106, N° 9 (09/2016) . - p. 81-84
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Injection molding is getting more continuous in KUNSTSTOFFE INTERNATIONAL, Vol. 106, N° 9 (09/2016)
