Influence of processing parameters on the fiber length and impact properties of injection molded long glass fiber reinforced polypropylene / M. Rohde in INTERNATIONAL POLYMER PROCESSING, Vol. XXVI, N° 3 (07/2011)  

[article]  inINTERNATIONAL POLYMER PROCESSING > Vol. XXVI, N° 3 (07/2011) . - p. 292-303 Titre : Influence of processing parameters on the fiber length and impact properties of injection molded long glass fiber reinforced polypropylene Type de document : texte imprimé Auteurs : M. Rohde, Auteur ; A. Ebel, Auteur ; Felipe Wolff Fabris, Auteur ; Volker Altstädt, Auteur Année de publication : 2011 Article en page(s) : p. 292-303 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Composites à fibres de verre -- Moulage par injection Composites thermoplastiques -- Moulage par injection Polypropylène Tags : 'Composites  fibres  verre'  Polypropylene  'Analyse  paramètre  moulage'  'Etude  impact'  'Longueur  fibre' Index. décimale : 668.4 Plastiques, vinyles Résumé : Injection molding of long fiber-reinforced thermoplastics is a well-established method in automotive industry to produce high quality structural parts in mass production without the need of further finishing, where the performance is strongly dependent on the fiber length. It is known that the processing parameters have to be carefully chosen as they directly influence the final fiber length and can therefore have a negative effect on the resulting mechanical properties of the part. Particularly in terms of impact behavior, the fiber length is seen as a key factor. The aim of the present work is to quantify the effects of the injection molding parameters on the impact behavior of long fiber reinforced compounds. In a first step the resulting fiber length of injection molded glass fiber reinforced polypropylene is analyzed as a function of the injection velocity, holding pressure, revolution speed and back pressure. The single steps of fiber length analysis are carefully investigated in terms of feasibility and accuracy, in order to assure that a reproducible and reliable test method is employed. Subsequently, the impact behavior of the PP-GF compounds is quantified by falling dart experiments, and the results are then correlated to the fiber length and the processing parameters to establish a fundamental processing-structure-property relationship. The investigation of the fiber length analysis shows that a high pyrolysis temperature leads to embrittlement of the glass fibers and a decrease of tensile strength of the single fibers. This may consequently lead to incorrect characterization of the fiber length due to fiber breakage. The results of the statistical investigation of the processing parameters indicate a significant influence of the back pressure on both impact energy and fiber length. Note de contenu : - EXPERIMENTAL : Materials - Fiber length - Single fiber tensile testing - Injection molding - Mechanical characterization - Characterization of morphology - RESULTS AND DISCUSSION : Fiber length analysis - Impact properties and fiber length DOI : 10.3139/217.2442 En ligne : https://drive.google.com/file/d/1T2PBcVKE0DAN6yOLE16GbpGa8joFaFbv/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=12408 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
013159	-	Périodique	Bibliothèque principale	Documentaires	Disponible

Micro replication by injection-compression molding / M. Rohde in INTERNATIONAL POLYMER PROCESSING, Vol. XXIV, N° 3 (07/2009)  

[article]  inINTERNATIONAL POLYMER PROCESSING > Vol. XXIV, N° 3 (07/2009) . - p. 288-297 Titre : Micro replication by injection-compression molding Type de document : texte imprimé Auteurs : M. Rohde, Auteur ; A. Derdouri, Auteur ; Musa R. Kamal, Auteur Année de publication : 2009 Article en page(s) : p. 288-297 Note générale : Bibliogr. Langues : Anglais (eng) Index. décimale : 668.9 Polymères Résumé : The replication of polymeric microstructures on a flat surface is not easily achieved by conventional injection molding, because of the required micro-dimensional control and the stringent tolerances of most applications. Moreover, the flow behaviour of melts in micro cavities remains not well understood and challenging. On the other hand, injection-compression molding is an established process for the manufacturing of optical storage media, like compact discs (CD) or digital versatile discs (DVD), with grooves and pits at the micro-scale. The difficulties arise mainly from two sources: lack of adequate filling because of premature freezing of features with very small thicknesses and excessive deformation during ejection due to high friction at the polymer-metal interface. In this work, a study is carried out to investigate the effect of process parameters on the replication of various microstructures on a flat disk using microinjection-compression molding. A commercial microinjection molding machine has been used in the study. Two optical grade polymers poly(methyl methacrylate) (PMMA) and cyclic olefin polymer (COP) were used in conjunction with various mold inserts to reproduce the embedded microstructures. The dimensions of the microstructures on the inserts and molded parts were measured with a confocal profiler. A transcription ratio was defined to assess the quality of the replication. The design of experiment (DOE) method was used to obtain correlations between the process parameters and the development of the microstructure during injection-compression molding. DOI : 10.3139/217.2264 En ligne : https://drive.google.com/file/d/1BovX7_ewXmMt3K3Zi8JPa9csMPSVfFPx/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=5933 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
011432	-	Périodique	Bibliothèque principale	Documentaires	Disponible

---

1 (1 - 2 / 2)