Effect of second to first normal stress difference ratio at the die exit on neck-in phenomenon in polymeric flat film production

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F70883521%3A28110%2F17%3A63516104" target="_blank" >RIV/70883521:28110/17:63516104 - isvavai.cz</a>

Výsledek na webu

<a href="http://dx.doi.org/10.1063/1.4982989" target="_blank" >http://dx.doi.org/10.1063/1.4982989</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1063/1.4982989" target="_blank" >10.1063/1.4982989</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Effect of second to first normal stress difference ratio at the die exit on neck-in phenomenon in polymeric flat film production

Popis výsledku v původním jazyce

In this study, viscoelastic modeling of the extrusion film casting process, based on the lD membrane model and modified Leonov constitutive equation, was conducted and the effect of the viscoelastic stress state at the die exit (captured here via second to first normal stress difference ratio) on the unwanted neck-in phenomenon has been analyzed for wide range of Deborah numbers and materials having different level of uniaxial and planar extensional strain hardening. Relevant experimental data for LDPE and theoretical predictions based on multimode eXtended Pom-Pom model acquired from the open literature were used for the validation purposes. It was found that firstly, the predicting capabilities of both constitutive equations for given material and processing conditions are comparable even if the single mode modified Leonov model was used and secondly, the agreement between theoretical and experimental data on neck-in is fairly good. Results of the theoretical study revealed that the viscoelastic stress state at the die exit (i.e. -N2/N1 ratio) increases the level of neck-in if uniaxial extensional strain hardening, planar to uniaxial extensional viscosity ratio and Deborah number increases. It has also been revealed that there exists threshold value for Deborah number and extensional strain hardening below which the neck-in becomes independent on the die exit stress state.

Název v anglickém jazyce

Effect of second to first normal stress difference ratio at the die exit on neck-in phenomenon in polymeric flat film production

Popis výsledku anglicky

In this study, viscoelastic modeling of the extrusion film casting process, based on the lD membrane model and modified Leonov constitutive equation, was conducted and the effect of the viscoelastic stress state at the die exit (captured here via second to first normal stress difference ratio) on the unwanted neck-in phenomenon has been analyzed for wide range of Deborah numbers and materials having different level of uniaxial and planar extensional strain hardening. Relevant experimental data for LDPE and theoretical predictions based on multimode eXtended Pom-Pom model acquired from the open literature were used for the validation purposes. It was found that firstly, the predicting capabilities of both constitutive equations for given material and processing conditions are comparable even if the single mode modified Leonov model was used and secondly, the agreement between theoretical and experimental data on neck-in is fairly good. Results of the theoretical study revealed that the viscoelastic stress state at the die exit (i.e. -N2/N1 ratio) increases the level of neck-in if uniaxial extensional strain hardening, planar to uniaxial extensional viscosity ratio and Deborah number increases. It has also been revealed that there exists threshold value for Deborah number and extensional strain hardening below which the neck-in becomes independent on the die exit stress state.

Druh

D - Stať ve sborníku

CEP obor

—

OECD FORD obor

10404 - Polymer science

Projekt

<a href="/cs/project/GA16-05886S" target="_blank" >GA16-05886S: Výzkum vlivu smykové a tahové reologie polymerních tavenin na stabilitu produkce meltblown nanovláken a fólií</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2017

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název statě ve sborníku

AIP Conference Proceedings

ISBN

978-0-7354-1513-3

ISSN

0094-243X

e-ISSN

neuvedeno

Počet stran výsledku

22

Strana od-do

—

Název nakladatele

American Institute of Physics Publising Inc.

Místo vydání

Melville

Místo konání akce

Zlín

Datum konání akce

26. 7. 2017

Typ akce podle státní příslušnosti

WRD - Celosvětová akce

Kód UT WoS článku

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