Titre : |
Better part properties thanks to fewer fiber breakage : Plastification system optimized for processing long glass fiber materials |
Type de document : |
texte imprimé |
Auteurs : |
Thomas Köpplmayr, Auteur ; Georg Steinbichler, Auteur |
Année de publication : |
2019 |
Article en page(s) : |
p. 20-22 |
Langues : |
Anglais (eng) |
Catégories : |
Composites à fibres de verre Composites à fibres longues Matières plastiques -- Moulage par injection Matières plastiques dans les automobiles Plastification PolyamidesUn polyamide est un polymère contenant des fonctions amides -C(=O)-NH- résultant d'une réaction de polycondensation entre les fonctions acide carboxylique et amine.
Selon la composition de leur chaîne squelettique, les polyamides sont classés en aliphatiques, semi-aromatiques et aromatiques. Selon le type d'unités répétitives, les polyamides peuvent être des homopolymères ou des copolymères. Polypropylène
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Index. décimale : |
668.4 Plastiques, vinyles |
Résumé : |
Long glass-fiber-reinforced polypropylene and polyamide are used in automotive lightweight construction especially where high impact toughness, very good crash behavior and low weight are required. However, care must be taken during injection molding, since not every screw is suitable for these materials. To maintain the fiber length reliably and obtain a uniform distribution of the fibers, Engel has developed a new plastification system especially for processing long glass-fiber-reinforced materials. |
Note de contenu : |
- A screw for different materials
- Comparison of the different screw concepts
- Loading of the fibers in the melt
- Figure : The greater channel depth in the feed zone prevents feeding problems with the rod-shaped pellets
- Fig. 1 : With the standard screw without LGF mixing head, the average fiber length is greatest, however with a low back pressure of 10 bar, fiber bundles are clearly visible. With the new LFS and 10 bar back pressure, the measured fiber lengths are somewhat higher than with the standard screw and 100 bar. Note: the distribution curve is a distribution of different fiber lengths and not a spot measurement
- Fig. 2 : High flowability (low viscosity) results in lower fiber length reduction (less friction). The standard screw with LGF mixing head and the new LFS yield comparable fiber lengths. All trials were performed at 10 bar holding pressure
- Fig. 3 : The plastification performances are greatest with the newly developed LFS. For the same cycle time, it offers the advantage of a lower rotational speed and therefore also less fiber size reduction. The trials were performed with screws with a diameter of 90 mm in each case |
En ligne : |
https://drive.google.com/file/d/1yRcDDgZWP6io1n856yicnT9GbimaFirm/view?usp=drive [...] |
Format de la ressource électronique : |
Pdf |
Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=31811 |
in KUNSTSTOFFE INTERNATIONAL > Vol. 109, N° 1-2 (01-02/2019) . - p. 20-22