Barrier screw compounding and mechanical properties of EAA copolymer and cellulose fiber composite / Ruth Ariño in INTERNATIONAL POLYMER PROCESSING, Vol. XXVIII, N° 4 (08/2013)  

[article]  inINTERNATIONAL POLYMER PROCESSING > Vol. XXVIII, N° 4 (08/2013) . - p. 421-428 Titre : Barrier screw compounding and mechanical properties of EAA copolymer and cellulose fiber composite Type de document : texte imprimé Auteurs : Ruth Ariño, Auteur ; A. Boldizar, Auteur Année de publication : 2013 Article en page(s) : p. 421-428 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Composites à fibres végétales -- Extrusion Composites à fibres végétales -- Moulage par injection Composites à fibres végétales -- Propriétés mécaniques Copolymère éthylène acide acrylique Distribution et orientation des fibres Fibres cellulosiques Vis barrière Index. décimale : 668.4 Plastiques, vinyles Résumé : The difficulty of feeding cellulose fibers and thermoplastics into the extruder or injection molding machine is addressed, this being a serious problem in the production of cellulose fiber composites for industrial applications. Agglomerates consisting in cellulose fibers and ethylene-acrylic acid copolymer (EAA) with different cellulose contents and different fiber lengths were processed with two different screws in order to better understand how the dispersion of the fibers can be improved by melt extrusion. A conventional screw with a compression ratio of 4:1 and a screw with barrier flights were used at different screw rotation speeds. The fiber length and fiber content were measured and microscopic analyses were performed in order to estimate the number and size of the cellulose fiber aggregates in the final composites. It was concluded that the barrier screw was more effective than the conventional screw in breaking up the fiber aggregates and dispersing the fibers. More but smaller cellulose aggregates were observed when the barrier screw was used, and the reduction of length was significantly greater for long than for short fibers. In contrast to that was expected, the samples containing the shorter fibers had better mechanical properties, probably due to a better dispersion of the fibers. Note de contenu : - EXPERIMENTAL : Materials - Melt processing - Measurements - RESULTS AND DISCUSSION : Visual characterization - Microscope image characterization - Fiber dimensions - Fiber content - Tensile properties DOI : 10.3139/217.2772 En ligne : https://drive.google.com/file/d/1pc6ZPOsiGncrnENBDZ83P7k0asTzKHEK/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=19287 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
15396	-	Périodique	Bibliothèque principale	Documentaires	Disponible

Evaluation of a model describing the advancing flow front in injection moulding / F. Pisciotti in INTERNATIONAL POLYMER PROCESSING, Vol. XVII, N° 2 (06/2002)  

[article]  inINTERNATIONAL POLYMER PROCESSING > Vol. XVII, N° 2 (06/2002) . - p. 133-145 Titre : Evaluation of a model describing the advancing flow front in injection moulding Type de document : texte imprimé Auteurs : F. Pisciotti, Auteur ; A. Boldizar, Auteur ; M. Rigdahl, Auteur ; G. Aronsson, Auteur ; M. Rigdahl Année de publication : 2002 Article en page(s) : p. 133-145 Note générale : Bibliogr. Langues : Anglais (eng) Index. décimale : 668.9 Polymères Résumé : The simulation of the advancing flow front during mould filling in the injection moulding cycle is important as a way of anticipating manufacturing defects, particularly different types of welds, air traps, cold spots and hot spots. The purpose of the present work was to evaluate a model (the distance model) simulating the advancing flow front and predicting potential issues related to the progression of the flow front such as welds and air traps. The distance model is based on a mathematical theory of Hele-Shaw flow for strongly shear-thinning fluids, i. e. fluids with a power-law index, n, equal to 0,3 or preferably less. Two grades of general-purpose polystyrene were selected according to their abilities to shear thin (weakly or moderately strong) at the selected processing temperature and in the typical shear rate range of the injection moulding process. The two grades were injection moulded into twelve mould configurations derived from two similar single-gated moulds. The flow length from the gate to the weld was measured in the mouldings obtained at three distinct rates of filling (conventional, slower and faster) and compared to the flow lengths obtained by the distance model. Good agreement was found between the predicted flow lengths and the experimental flow lengths at the conventional and faster filling conditions. Larger deviations between simulation and experiment were found at the slower filling rate, particularly for the weakly shear-thinning polystyrene grade. Some comparisons were also made with the predictions obtained using the commercial simulation code Moldflow. A comparison between the advancing front predictions of the distance model and experimental short shots of a commercial polypropylene grade in a lure-box type of mould geometry showed that the distance model, despite its simplicity, could probably be used to detect welds and air traps in more complex and practice-related mouldings. Note de contenu : - INTRODUCTION : Manufacturing defects related to mould filling - The distance model - - EXPERIMENTAL : Materials - Mould geometry - Processing - Flow length measurement - RESULTS AND DISCUSSION : Weld detection - The advancing flow front - A practice-related moulding DOI : 10.3139/217.1682 En ligne : https://drive.google.com/file/d/15mW8TQTMJGeBpUZ0EWylo9zGHAYQhFm4/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=15942 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
001020	-	Périodique	Bibliothèque principale	Documentaires	Disponible

Injection molding of beverage container caps made of a composite consisting of wood cellulose fiber and an ethylene-acrylic acid copolymer / Ruth Ariño in INTERNATIONAL POLYMER PROCESSING, Vol. XXIX, N° 4 (08/2014)  

[article]  inINTERNATIONAL POLYMER PROCESSING > Vol. XXIX, N° 4 (08/2014) . - p. 507-514 Titre : Injection molding of beverage container caps made of a composite consisting of wood cellulose fiber and an ethylene-acrylic acid copolymer Type de document : texte imprimé Auteurs : Ruth Ariño, Auteur ; A. Boldizar, Auteur Année de publication : 2014 Article en page(s) : p. 507-514 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Analyse thermique Bois Composites à fibres végétales -- Moulage par injection Composites à fibres végétales -- Propriétés mécaniques Compoundage Copolymère éthylène acide acrylique Essais dynamiques Etanchéité Fibres cellulosiques Fibres végétales Longueur -- Mesure Polyéthylène haute densité Rhéologie Traction (mécanique) Index. décimale : 668.4 Plastiques, vinyles Résumé : The influence of processing parameters on injection-molded bottle caps consisting of 20 wt% of cellulose fibers and an ethylene-acrylic acid copolymer was studied. The study included three cylinder barrel temperatures and three mold temperatures. For each combination of temperatures, the holding pressure time was varied and the mold sealing time was determined. High density polyethylene caps were also produced as reference material, and injection-molded tensile test bars were also produced in order to assess the tensile mechanical properties. The results showed no major differences in sealing time for the caps containing cellulose fibers, except for the highest melt and mold temperatures where a slightly longer time was observed. The viscosity of the composite material was higher than that of the polymeric matrix. For the highest temperature and high shear rates, the viscosity of the composite material was close to the viscosity of the matrix material. The moisture content of the injection-molded bars was less than 1 %, showing that almost no water was absorbed during the compounding or after several months. The crystallinity decreased when the fibers were included but was not influenced by the mold temperature. Enhanced mechanical properties were obtained by using the fibers compared to the pure ethylene-acrylic acid copolymer, both in the tensile test bars and in the caps. The reference high density polyethylene had, however, a higher mechanical performance than the composite. Note de contenu : - EXPERIMENTAL : Materials - Compounding of composite material - Injection molding - Sealing time measurement - Differential scanning calorimetry (DSC) - Thermogravimetric analysis (TGA) - Rheological measurements - Fiber length measurements - Mechanical properties - RESULTS AND DISCUSSION : Sealing times - DSC measurements - TGA measurements - Rheological measurements - Fiber length - Mechanical properties DOI : 10.3139/217.2899 En ligne : https://drive.google.com/file/d/1H1SH3_MVGc-PgAXEBOZISsMlJxtpUcHP/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=21830 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
16454	-	Périodique	Bibliothèque principale	Documentaires	Disponible

Injection moulding and mechanical properties of recovered polypropylene / F. Pisciotti in INTERNATIONAL POLYMER PROCESSING, Vol. XX, N° 3 (09/2005)  

[article]  inINTERNATIONAL POLYMER PROCESSING > Vol. XX, N° 3 (09/2005) . - p. 257-264 Titre : Injection moulding and mechanical properties of recovered polypropylene Type de document : texte imprimé Auteurs : F. Pisciotti, Auteur ; M. Rigdahl, Auteur ; A. Boldizar, Auteur Année de publication : 2005 Article en page(s) : p. 257-264 Note générale : Bibliogr. Langues : Anglais (eng) Index. décimale : 668.9 Polymères Résumé : This work is a part of a study aiming at assessing the processability of recovered polypropylene in relation to the mechanical and aesthetic performance of as-manufactured and heat aged mouldings. The effects of processing and heat ageing on the mechanical properties of injection-moulded recovered polypropylene were studied here. A similar grade of virgin polypropylene was used as a reference. Multipurpose test specimens were manufactured with a two-cavity mould, according to decoupled moulding procedures. The mouldings were aged at 100 °C for 170 h and 340 h. The stiffness, the strength, the elongation at break and the Charpy impact resistance of asmoulded and heat-treated materials were investigated. The results show that the recovered polypropylene could be processed as the analogous virgin grade. Insignificant changes in the measured properties due to the different filling conditions were observed for each polypropylene used. The stiffness and strength of the recycled polypropylene was systematically 20% lower than that of the analogous virgin grade, whereas the impact resistance of the recycled grade was on average 40% higher than that for the virgin grade. There was no significant difference in the elongation at break of the two materials. After the short ageing period, an increase in stiffness and strength of the materials was observed, together with a sharp decrease in the elongation at break and a modest increase in the impact resistance. This was related to re-crystallisation. The long ageing period reduced the stiffness and strength of the materials but there was no significant change in the elongation at break or in the impact resistance. DOI : 10.3139/217.1887 En ligne : https://drive.google.com/file/d/1TV-Z9jY5eCd9DYlxTh6I8Z2746KA0zeu/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=3062 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
003050	-	Périodique	Bibliothèque principale	Documentaires	Disponible

Melt processing of wood cellulose tissue and ethylene-acrylic copolymer composites / Ruth Ariño in INTERNATIONAL POLYMER PROCESSING, Vol. XXVIII, N° 4 (08/2013)  

[article]  inINTERNATIONAL POLYMER PROCESSING > Vol. XXVIII, N° 4 (08/2013) . - p. 429-436 Titre : Melt processing of wood cellulose tissue and ethylene-acrylic copolymer composites Type de document : texte imprimé Auteurs : Ruth Ariño, Auteur ; A. Boldizar, Auteur Année de publication : 2013 Article en page(s) : p. 429-436 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Bois Cellulose La cellulose est un glucide constitué d'une chaîne linéaire de molécules de D-Glucose (entre 200 et 14 000) et principal constituant des végétaux et en particulier de la paroi de leurs cellules. Composites à fibres végétales -- Propriétés mécaniques Copolymère éthylène acide acrylique Extrudeuse bi-vis Extrudeuses Mélange Textiles et tissus Vis barrière Index. décimale : 668.4 Plastiques, vinyles Résumé : The difficulty of feeding cellulose fibers together with the polymer into the melt processing equipment is a serious disadvantage for the production of cellulose-containing composites on a large scale. In the present work, a continuous method of feeding cellulose in the form of a tissue into a twin-screw extruder through an opening downstream of the extruder cylinder was studied. With this method, composites with different fiber contents were obtained. The tissues used were one made mainly of softwood fibers and another mainly of hardwood fibers. In order to better understand how to improve the fiber dispersion by melt mixing, a second extrusion was performed with a single screw extruder with a barrier-flighted screw and also with the twin-screw used to compound the tissue with the polymer. The compounds produced were then injection molded into test bars. The test bars containing the softwood tissue exhibited some fiber aggregates also after a second extrusion, whereas no fiber aggregates were observed in samples made with the tissue containing hardwood fibers and two passes through the twin screw. The fiber length was in general reduced by each melt processing stage and the shortest fiber length was observed after two extrusions with the twin-screw and injection molding. The tensile modulus increased with increasing fiber content. A higher stiffness was obtained with more softwood fibers in the tissue whereas more hardwood fibers gave a higher tensile strength and greater elongation at break. Note de contenu : - EXPERIMENTAL : Materials - Melt processing - Measurements - RESULTS AND DISCUSSION : Fiber content - Visual characterization - Microscope analysis - Fiber length - Tensile properties DOI : 10.3139/217.2773 En ligne : https://drive.google.com/file/d/1aA9xrzdk3bKtvqEBDoxAnBQfQR8_xdi7/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=19288 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
15396	-	Périodique	Bibliothèque principale	Documentaires	Disponible

On PVT and rheological measurements of polymer melts / T. Sedlacek in INTERNATIONAL POLYMER PROCESSING, Vol. XX, N° 3 (09/2005)  

Permalink

The gloss of injection-moulded recovered polypropylene / F. Pisciotti in INTERNATIONAL POLYMER PROCESSING, Vol. XX, N° 3 (09/2005)  

Permalink

The influence of extrusion conditions on mechanical and thermal properties of virgin and recycled PP, HIPS, ABS and their ternary blends / Erik Stenvall in INTERNATIONAL POLYMER PROCESSING, Vol. XXVIII, N° 5 (11/2013)  

Permalink

---

1 (1 - 8 / 8)