[article]
| Titre : |
Quantified surface improvement using temperature cycle injection moulding : Production of glossy weldline-free parts including in foamed and filled resins |
| Type de document : |
texte imprimé |
| Année de publication : |
2011 |
| Article en page(s) : |
p. 323-330 |
| Note générale : |
Bibliogr. |
| Langues : |
Anglais (eng) |
| Catégories : |
Composites à fibres de verre
Copolymères
Mousses plastiques
Polyméthacrylate de méthyleLe poly(méthacrylate de méthyle) (souvent abrégé en PMMA, de l'anglais Poly(methyl methacrylate)) est un polymère thermoplastique transparent obtenu par polyaddition dont le monomère est le méthacrylate de méthyle (MMA). Ce polymère est plus connu sous son premier nom commercial de Plexiglas (nom déposé), même si le leader global du PMMA est Altuglas International9 du groupe Arkema, sous le nom commercial Altuglas. Il est également vendu sous les noms commerciaux Lucite, Crystalite, Perspex ou Nudec.
Polypropylène
Talc
Terpolymère acrylonitrile butadiène styrène
Thermoplastiques -- Moulage par injection
|
| Index. décimale : |
668.4 Plastiques, vinyles |
| Résumé : |
In temperature cycle injection moulding (TCIM) of thermoplastics, the mould cavity surface is heated rapidly to a temperature close to the glass transition or crystalline melting point of the resin before melt injection, and then cooled after injection is complete. A range of important benefits of the process are listed, among which is surface improvement, and results are presented that quantify in detail the improvements achhieved. Weldline dimensions and surface roughness are determined using white light inteferometry, with a scale of inspection below 5 nm. For a qualitative comparison of the surface finish, photography and stereomicroscopy are used. Weld lines on conventional ABS/PMMA parts are up to 17 μm deep and 70 μm wide, hence clearly visible, whereas they are not detectable on TCIM parts. Surface roughness, Ra, on these parts is found to be 37 nm for conventional parts, reducing to 20 nm using TCIM. Surface roughness is compared for conventional and TCIM mouldings in chemically foamed ABS, foamed PP with and without talc, and long-fibre-glass filled PP. For the conventionally produced foamed parts, Ra is approximately 1 500 nm. Using TCIM, Ra reduces to 30 nm for ABS, 70 nm for unfilled PP and 130 nm for PP with talc. Visually, this corresponds to a change from a heavily patterned, striated appearance to a uniform glossy surface. The parts in long-fibre (11 mm) filled PP show a reduction in Ra from 1 600 nm to 150 nm using TCIM. The conventionally moulded parts have a rough, pitted surface; the TCIM parts are smooth and glossy. |
| DOI : |
10.3139/217.2454 |
| En ligne : |
https://drive.google.com/file/d/1_KHh2V-tW877kgY-HIhfxezDMWRW57Z5/view?usp=drive [...] |
| Format de la ressource électronique : |
Pdf |
| Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=12421 |
in INTERNATIONAL POLYMER PROCESSING > Vol. XXVI, N° 3 (07/2011) . - p. 323-330
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Quantified surface improvement using temperature cycle injection moulding in INTERNATIONAL POLYMER PROCESSING, Vol. XXVI, N° 3 (07/2011)
