Rheological Behavior of Molten Polymers in Shearing and in Extensional Flows

1977 ◽  
Vol 21 (3) ◽  
pp. 355-379 ◽  
Author(s):  
P. K. Agrawal ◽  
W. K. Lee ◽  
J. M. Lorntson ◽  
C. I. Richardson ◽  
K. F. Wissbrun ◽  
...  
Keyword(s):  
Rheological Behavior ◽  
Molten Polymers ◽  
Extensional Flows

Rheological Behavior of Molten Polymers

2017 ◽  
pp. 33-175 ◽  
Author(s):  
Jean-François Agassant ◽  
Pierre Avenas ◽  
Pierre J. Carreau ◽  
Bruno Vergnes ◽  
Michel Vincent
Keyword(s):  
Rheological Behavior ◽  
Molten Polymers

EXPERIMENTAL AND NUMERICAL STUDIES OF STRESS FIELDS OF A BRANCHED POLYBUTADIENE IN A FLAT DIE

2021 ◽  
Author(s):  
Abderrazak Mezghani ◽  
Ali Ben Moussa
Keyword(s):  
Stress Field ◽  
Rheological Behavior ◽  
High Performance ◽  
Numerical Study ◽  
Simulation Models ◽  
Ansys Fluent ◽  
Performance Simulation ◽  
Extrusion Die ◽  
Numerical Studies ◽  
Molten Polymers

There is a growing body of laboratory and industrial evidence that the viscoelastic characteristics of molten polymers contribute to improving the efficiency of polymer extrusion molding. Understanding the behavior of molten polymers in manufacturing processes requires the qualitative and quantitative determination of flow kinematics and stress distribution. The optimization of the forming processes and the final properties of the transformed products requires the mastery of high-performance simulation models. So, it is necessary to be able to correctly describe the non-linear rheological behavior of the molten polymers by appropriate constitutive equations and a relatively easy implementation in computer codes. In this work, experimental and numerical studies are performed to investigate the rheological behavior of branched polybutadiene into a two-dimensional channel of a capillary rheometer. The stress field in the flow was analyzed with a birefringence device to identify areas of stress concentration and to show its progress in different areas of the extrusion die. Also, we obtain the stress field with numerical simulations using ANSYS Fluent 16.0 as a solver and Gambit as a mesh generator. The rheological model adopted in the numerical study is the power-law or Ostwald-de Waele model.

Materials Rheology: An Overview

MRS Bulletin ◽  
1991 ◽  
Vol 16 (8) ◽  
pp. 15-18 ◽  
Author(s):  
Stuart J. Kurtz
Keyword(s):  
Rheological Behavior ◽  
Colloidal Suspensions ◽  
Electrorheological Fluids ◽  
Bulk Materials ◽  
Domain Structures ◽  
Wide Range ◽  
Molten Polymers ◽  
Scientists And Engineers ◽  
Elastic Fluids

My fellow authors and I have assembled a series of articles on using rheology to understand the structure and processing of a wide range of materials. We approach this task by presenting an introduction to the concepts of rheology and some illustrative applications, followed by a description of linear vis-coelasticity and a description of the rheological behavior of elastic fluids. These concepts and related tools are then used to describe molten polymers, colloidal suspensions, latex systems, electrorheological fluids, and gels. In each of these areas, we show how rheology provides insights into the structure of materials and the type of information required to process them. We also show that the rheological approach spans macroscopic and microscopic domains. These aspects of rheology are of value to materials scientists and engineers. We hope these examples will clarify the relevance of rheology to materials.If we are successful in this presentation, you will obtain a flavor of the process of rheological studies. While reading through these articles, look for the interplay of the concepts of molecular or domain structures and the flow and deformation of the bulk materials. These articles may even inspire you to examine the role that rheology may play in your own studies.

From biorefineries to bioproducts: conversion of pretreated pulp from biorefining streams to lignocellulose nanofibers

TAPPI Journal ◽  
2019 ◽  
Vol 18 (4) ◽  
pp. 233-241
Author(s):  
CHENGGUI SUN ◽  
RICHARD CHANDRA ◽  
YAMAN BOLUK
Keyword(s):  
Energy Consumption ◽  
Enzymatic Hydrolysis ◽  
Rheological Behavior ◽  
Material Basis ◽  
Softwood Pulp ◽  
Energy Consumptions ◽  
Hardwood Pulp ◽  
The Stability ◽  
Lignocellulose Nanofibers

This study investigates the use of pretreatment and enzymatic hydrolysis side streams and conversion to lignocellulose nanofibers. We used a steam-exploded and partial enzymatic hydrolyzed hardwood pulp and an organosolv pretreated softwood pulp to prepare lignocellulose nanofibers (LCNF) via microfluidization. The energies applied on fibrillation were estimated to examine the energy consumption levels of LCNF production. The energy consumptions of the fibrillation processes of the hardwood LCNF production and the softwood LCNF production were about 7040-14080 kWh/ton and 4640 kWh/ton on a dry material basis, respectively. The morphology and dimension of developed hardwood and softwood LCNFs and the stability and rheological behavior of their suspensions were investigated and are discussed.

Investigation of Rheological Behavior of Modified Polychloroprene Adhesive Compositions

2014 ◽  
Vol 14 (4) ◽  
pp. 227-242
Author(s):  
Darina Ivanova Zheleva ◽  
Vassil Ivanov Samichkov
Keyword(s):  
Rheological Behavior ◽  
Adhesive Compositions

Rheological Behavior of Coating Color and Effects of Rheology Modifier

2017 ◽  
Vol 71 (8) ◽  
pp. 850-854
Author(s):  
Kazutaka Kasuga ◽  
Koichi Tadaki ◽  
Kaori Sasaki
Keyword(s):  
Rheological Behavior ◽  
Coating Color ◽  
Rheology Modifier
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