Experimental Study of Rheological Characteristics of Polymer Melts in the Micro-Die

2012 ◽  
Vol 550-553 ◽  
pp. 716-723
Author(s):  
Tofek Abddiem ◽  
Da Ming Wu ◽  
Jian Zhuang ◽  
Li Jun Hou ◽  
Ying Liu ◽  
...  
Keyword(s):  
Experimental Study ◽  
Shear Rate ◽  
Polymer Melts ◽  
Capillary Flow ◽  
Slip Rate ◽  
Polymer Melt ◽  
Wall Slip ◽  
Rheological Characteristics ◽  
Capillary Rheometer ◽  
Measured Viscosity

Compared with in the conventional scales, the rheological properties of polymer melts have changed in the micro-scales. Based on the principle of capillary flow and modified with the method of Bagley or zero die micro-die, the rheological characteristics of polypropylene (PP) were investigated using the HAAKE capillary rheometer under the micro-die and conventional die. The results show that: the viscosity of polymer melt modified with the method of bagley or zero die micro-die in the different L/D ratio of micro-die is the same and the shear viscosity of PP decreases with the increase of shear rate; Compared with the viscosity in the conventional scales, the measured viscosity of PP in the micro-scales was reduced by 46% in 0.25mm diameter die, 44% in the 0.20mm diameter die and 88% in the 0.15mm diameter die at the same shear rate; a layer of fixed polymer melt was found in the inwall of the micro-die through the calculation of wall slip rate.

Experimental Study on the Rheological Characteristics of Polymer Melts under Micro Scale Effect

2009 ◽  
Vol 628-629 ◽  
pp. 429-434 ◽  
Author(s):  
D.Y. Zhao ◽  
Y.F. Jin ◽  
Min Jie Wang ◽  
X.W. Sun ◽  
M.C. Song
Keyword(s):  
Experimental Study ◽  
Shear Rate ◽  
Scale Effect ◽  
Shear Viscosity ◽  
Arrhenius Equation ◽  
Polymer Melts ◽  
Rheological Characteristics ◽  
Capillary Rheometer ◽  
Micro Scale ◽  
Effects Of Temperature

The rheological characteristics of four polymer melts (PS, PMMA, PP and HDPE) are investigated by a capillary rheometer with the die diameters from 1.5mm to 0.5mm.The effects of temperature on shear viscosity and the effects of both temperature and shear rate on non-Newton exponent of melts are discussed when the die diameter is 0.5mm. The results show that the shear viscosity of four polymers decreases with the rise of shear rate. The shear viscosity of PS and PMMA increases with the decrease of die diameter, the shear viscosity of PP and HDPE decreases with die diameter and minute differences of shear viscosity with different die diameters are observed with the growth of shear rate. When the die diameter is 0.5mm, Arrhenius equation is found to be suitable to describe the relations between shear viscosity and temperature for four polymer melts. The non-Newton exponents of four polymer melts increase with the temperature and decrease with the rise of shear rate.

Experimental Research on the Viscosity of Polymer Melts Filling through Micro Channels

2011 ◽  
Vol 314-316 ◽  
pp. 1346-1349
Author(s):  
Bin Xu ◽  
Yu Bin Lu ◽  
Guang Ming Li ◽  
Song Xue
Keyword(s):  
Shear Rate ◽  
Flow Model ◽  
Capillary Flow ◽  
Polymer Melt ◽  
Characteristic Size ◽  
Micro Channel ◽  
Test Results ◽  
Micro Channels ◽  
Rate Test ◽  
The Difference

Experimental observations indicate that the viscosity of polymer melt flowing through micro channel is altered with variation of characteristic size of micro channels. The explanation about the trend of various viscosity is inconsistent. In this paper, the micro channel dies of 1000μm ,500μm and 350μm diameter were developed and with several polymers, including PP , PS and HDPE, depending on the capillary flow model, the measurement experiments of polymer melt viscosity were investigated at various shear rate. Test results show that with micro-channel size decrease, the percentage reduction in viscosity increases and the difference of viscosities in different micro channels reduces with increasing shear rate.

Rheological behaviour of low/high density polyethylene melt flowing through micro-channels

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Chun-Sheng Chen
Keyword(s):  
High Density Polyethylene ◽  
Capillary Flow ◽  
Rheological Behaviour ◽  
Polymer Melt ◽  
Volumetric Flow Rate ◽  
Wall Slip ◽  
High Density ◽  
Mean Velocity ◽  
Channel Size ◽  
Micro Channels

AbstractThe determination of the proper rheological behaviour of the polymer melt within micro structured geometry is vital for accurately simulating the micro moulding. The paucity of suitable equipments is one of main hurdles in the investigation of micro melt rheology. In the present study, a measurement system for the melt viscosity of low and high density polyethylene polymer melts flowing through micro-channels was established. The capillary flow model with Rabinowitsch correction was used in the calculations of the viscosity based on the measured pressure drop and volumetric flow rate. The effect of the morphology structure on the viscosity characteristics for both the LDPE and HDPE resins within micro-channels was investigated and discussed. It was found that the measured viscosity values for LDPE and HDPE in the test ranges are significantly lower (about 40~56% and 22~29% for LDPE and HDPE, respectively, flowing through a channel size of 150μm) than those obtained with a traditional capillary rheometer. Moreover, both the percentage reduction in the viscosity value and the ratio of the slip velocity to the mean velocity increase as the micro-channel size decreases. It can be observed that the rheological behaviours of the HDPE and LDPE resins in microscopic scale are different from those in macroscopic scale as a result of the wall slip effect. It also revealed that the wall slip occurs more easily for the LDPE resin within micro channels than HDPE resin due to enlarged effect of morphology structure.

Size Design of Capillary and Barrel of Multi-Function and All-Electric Rheometer

2013 ◽  
Vol 853 ◽  
pp. 536-540
Author(s):  
Xiang Gang Li ◽  
Yue Jun Liu ◽  
Yi Chen ◽  
Xiao Yuan Zhou ◽  
Hui Tan ◽  
...  
Keyword(s):  
Shear Rate ◽  
Polymer Melts ◽  
Nonlinear Viscoelasticity ◽  
Wall Slip ◽  
High Shear Rate ◽  
High Shear ◽  
Rate Range ◽  
Pressure Correction ◽  
Precise Calculation ◽  
Entrance Pressure

Multi-function and all-electric rheometer (MAR) was designed by the authors to study the nonlinear viscoelasticity of polymer melts at high shear rate. It is important to design suitable size of capillary and barrel because it is the calculation basis for some other important parts and determines the shear rate range of MAR. Considering the shear rate range, the entrance pressure correction and the wall slip correction, the length and diameter of capillary and barrel of MAR were designed through particular analysis and precise calculation.

scholarly journals An Experimental Study of the Viscosity of Polymer Melts at High Shear Rate

1985 ◽  
Vol 17 (7) ◽  
pp. 863-868 ◽  
Author(s):  
Fumio Kurihara ◽  
Shinichi Kimura
Keyword(s):  
Experimental Study ◽  
Shear Rate ◽  
Polymer Melts ◽  
High Shear Rate ◽  
High Shear

Wall slip and absence of interfacial flow instabilities in capillary flow of various polymer melts

1998 ◽  
Vol 42 (1) ◽  
pp. 63-80 ◽  
Author(s):  
Xiaoping Yang ◽  
Hatsuo Ishida ◽  
Shi-Qing Wang
Keyword(s):  
Polymer Melts ◽  
Capillary Flow ◽  
Wall Slip ◽  
Flow Instabilities ◽  
Interfacial Flow

scholarly journals Quantification of shear viscosity and wall slip velocity of highly concentrated suspensions with non-Newtonian matrices in pressure driven flows

2021 ◽  
Author(s):  
Patrick Wilms ◽  
Jan Wieringa ◽  
Theo Blijdenstein ◽  
Kees van Malssen ◽  
Reinhard Kohlus
Keyword(s):  
Shear Stress ◽  
Liquid Phase ◽  
Shear Rate ◽  
Shear Viscosity ◽  
Slip Velocity ◽  
Volume Fraction ◽  
Solid Volume Fraction ◽  
Wall Slip ◽  
Flow Index ◽  
Concentrated Suspensions

AbstractThe rheological characterization of concentrated suspensions is complicated by the heterogeneous nature of their flow. In this contribution, the shear viscosity and wall slip velocity are quantified for highly concentrated suspensions (solid volume fractions of 0.55–0.60, D4,3 ~ 5 µm). The shear viscosity was determined using a high-pressure capillary rheometer equipped with a 3D-printed die that has a grooved surface of the internal flow channel. The wall slip velocity was then calculated from the difference between the apparent shear rates through a rough and smooth die, at identical wall shear stress. The influence of liquid phase rheology on the wall slip velocity was investigated by using different thickeners, resulting in different degrees of shear rate dependency, i.e. the flow indices varied between 0.20 and 1.00. The wall slip velocity scaled with the flow index of the liquid phase at a solid volume fraction of 0.60 and showed increasingly large deviations with decreasing solid volume fraction. It is hypothesized that these deviations are related to shear-induced migration of solids and macromolecules due to the large shear stress and shear rate gradients.

Modeling of Shear Rheological Behavior of Uncured Rubber Melt

2020 ◽  
Vol 30 (1) ◽  
pp. 130-137
Author(s):  
Hengxiao Yang ◽  
Qimian Mo ◽  
Hengyu Lu ◽  
Shixun Zhang ◽  
Wei Cao ◽  
...  
Keyword(s):  
Shear Rate ◽  
Constitutive Model ◽  
Incompressible Fluid ◽  
Rheological Behavior ◽  
Rheological Characteristics ◽  
One Dimensional ◽  
Ptt Model ◽  
Rate Region ◽  
Proposed Model ◽  
Rheological Experiments

AbstractTo describe uncured rubber melt flow, a modified Phan–Thien–Tanner (PTT) model was proposed to characterize the rheological behavior and a viscoelastic one-dimensional flow theory was established in terms of incompressible fluid. The corresponding numerical method was constructed to determine the solution. Rotational rheological experiments were conducted to validate the proposed model. The influence of the parameters in the constitutive model was investigated by comparing the calculated and experimental viscosity to determine the most suitable parameters. The uncured rubber viscosity was 3–4 orders larger than that of plastic and did not have a visible Newtonian region. Compared with the Cross-Williams-Landel-Ferry (Cross-WLF) and original PTT models, the modified PTT model can describe the rheological characteristics in the entire shear-rate region if the parameters are set correctly.

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