In-line density monitoring of rigid PVC foam during extrusion process / N. H. Abu-Zahra in INTERNATIONAL POLYMER PROCESSING, Vol. XV, N° 4 (12/2000)  

[article]  inINTERNATIONAL POLYMER PROCESSING > Vol. XV, N° 4 (12/2000) . - p. 348-354 Titre : In-line density monitoring of rigid PVC foam during extrusion process Type de document : texte imprimé Auteurs : N. H. Abu-Zahra, Auteur ; H. Chang, Auteur Année de publication : 2000 Article en page(s) : p. 348-354 Note générale : Bibliogr. Langues : Anglais (eng) Index. décimale : 668.9 Polymères Résumé : An ultrasound-based sensor has been investigated to monitor the density of rigid PVC foam, in-line, during the extrusion process. A 2.25 MHz ultrasound transducer was used to measure the acoustic properties; i.e. speed of sound, acoustic impedance, and attenuation, in the polymer melt prior to exiting the extrusion die. A special transducer adapter and wave reflector were incorporated in the design of the extrusion die. The density of PVC foam was varied by varying the blowing agent content in the resin compound prior to extrusion. A mathematical derivation of the behavior of ultrasound waves in the melt is presented and used to calculate the attenuation coefficient of the polymer melt at various foam densities. An empirical relation was derived between the calculated attenuation coefficient of the polymer melt and the measured density of the foam extrudate. This relation can be used to estimate the foam density based on the acoustic measurement of the melt in the extrusion die. Further work is proposed to normalize for the effect of variations in the melt temperature and pressure on the ultrasound measurements. DOI : 10.3139/217.1614 En ligne : https://drive.google.com/file/d/1p_WdW-c4vlRZuAIeL8H6t85CRzqe-Y3D/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=16145 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
001014	-	Périodique	Bibliothèque principale	Documentaires	Disponible

In-line monitoring of PVC melt viscosity using dielectric measurements / N. H. Abu-Zahra in INTERNATIONAL POLYMER PROCESSING, Vol. XIX, N° 1 (03/2004)  

[article]  inINTERNATIONAL POLYMER PROCESSING > Vol. XIX, N° 1 (03/2004) . - p. 16-20 Titre : In-line monitoring of PVC melt viscosity using dielectric measurements Type de document : texte imprimé Auteurs : N. H. Abu-Zahra, Auteur Année de publication : 2004 Article en page(s) : p. 16-20 Note générale : Bibliogr. Langues : Anglais (eng) Index. décimale : 668.9 Polymères Résumé : A dielectric sensor, mounted in an extrusion die, was used to measure the dielectric properties of PVC melt during extrusion process. The dielectric permittivity and loss factor, of the polymer melt, were used to calculate the ionic viscosity and a dielectric viscosity index, which were correlated to the melt viscosity measured by slit rheometry equations. The viscosity of the PVC melt was varied by varying the level of chemical blowing agent (AZO) and processing aid (K400) in the polymer compound. The extrusion conditions; screw speed and heating zones, were fixed throughout the experiments. Strong correlation between the measured dielectric parameters and the melt viscosity was found to be consistent with established theoretical models. Therefore, this technique is capable of monitoring the viscosity of polymer melts accurately and reliably, in real-time, without disturbing the flow stream. DOI : 10.3139/217.1807 En ligne : https://drive.google.com/file/d/19hveNbioVWNxZ3Yac8iSK1Tsg5R_FkX5/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=3290 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
001027	-	Périodique	Bibliothèque principale	Documentaires	Disponible

Measuring polymer melt density and viscosity in real-time during extrusion processes using ultrasound sensors fusion / N. H. Abu-Zahra in INTERNATIONAL POLYMER PROCESSING, Vol. XVIII, N° 4 (12/2003)  

[article]  inINTERNATIONAL POLYMER PROCESSING > Vol. XVIII, N° 4 (12/2003) . - p. 362-367 Titre : Measuring polymer melt density and viscosity in real-time during extrusion processes using ultrasound sensors fusion Type de document : texte imprimé Auteurs : N. H. Abu-Zahra, Auteur Année de publication : 2003 Article en page(s) : p. 362-367 Note générale : Bibliogr. Langues : Anglais (eng) Index. décimale : 668.9 Polymères Résumé : A dual-sensor system is developed to measure the density and viscosity of polymer melts, simultaneously, during extrusion process. The sensory system utilizes a 2.25MHz longitudinal ultrasound transducer in conjunction with a 2.25MHz shear type ultrasound transducer, placed in a modified extrusion die. The acoustic impedance of the polymer melt, corresponding to the longitudinal ultrasound waves (UTL), is used to measure the density of the polymer melt using established physical models. While, the acoustic impedance of the shear waves (UTS) is used to measure the viscosity of the polymer melt, utilizing the density measurements obtained by the longitudinal ultrasound transducer. The system was evaluated using polyvinyl chloride compounds containing various levels of foaming agent and processing aid at fixed processing conditions. The system measurements of the melt density was compared to the density of the extrudate, while the viscosity measurements were compared to the calculated values using slit-rheometry equations. The correlation coefficients between the ultrasound sensor and actual measurements were in the range of 92% and 96% for the melt density and viscosity; respectively. DOI : 10.3139/217.1759 En ligne : https://drive.google.com/file/d/1SwaP2EpXOmBgitJ5iEETsoIi2kGs2_RM/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=15819 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
001026	-	Périodique	Bibliothèque principale	Documentaires	Disponible

Neural network approach to density control of rigid PVC foam in extrusion process / N. H. Abu-Zahra in INTERNATIONAL POLYMER PROCESSING, Vol. XVIII, N° 2 (06/2003)  

[article]  inINTERNATIONAL POLYMER PROCESSING > Vol. XVIII, N° 2 (06/2003) . - p. 122-126 Titre : Neural network approach to density control of rigid PVC foam in extrusion process Type de document : texte imprimé Auteurs : N. H. Abu-Zahra, Auteur Année de publication : 2003 Article en page(s) : p. 122-126 Note générale : Bibliogr. Langues : Anglais (eng) Index. décimale : 668.9 Polymères Résumé : In rigid PVC foam extrusion, foam density is very crucial in determining the mechanical characteristics of the extruded material and the profitability of the manufacturing process. This paper presents a new application of artificial neural computing in the control of PVC foam density in profile extrusion process. A 3-layer multi-layer perceptron (MLP) artificial neural network was developed to estimate the foam density (weight) based on the known processing conditions; mainly heating zones temperatures and screw speed. The network was developed and tested on a specific formula that is used in wood-like products. A two factorial design of experiment was carried out to determine the significant process variables before training the neural networks using a back propagation algorithm. Finally, a comparison between the true weights, and the estimated weights using artificial neural networks is presented. DOI : 10.3139/217.1740 En ligne : https://drive.google.com/file/d/1mke3PYQn9Y_3hDYzUtk9RPDV8HAYsWWi/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=3301 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
001024	-	Périodique	Bibliothèque principale	Documentaires	Disponible

---

1 (1 - 4 / 4)