Shear Rate Coat-Hanger Die Using Casson Viscosity Model
Abstract
:1. Introduction
2. Mathematical Modeling
2.1. General
- ▪
- Steady state flow;
- ▪
- Isothermal flow;
- ▪
- Hydrodynamically fully developed flow;
- ▪
- Incompressible fluid;
- ▪
- No external forces (e.g., the effect of gravity is neglected);
- ▪
- No slip boundary condition;
- ▪
- Uniform shear rate at the walls of the manifold and slit region.
- ▪
- The radius of the manifold at the edge is equal to the half-height of the slit .
2.2. Casson Model-Based Design Equations
2.2.1. Manifold Region
2.2.2. Slit Region
2.2.3. Computation of the Design Equations
3. Computational Model
- The polymer melt is a incompressible non-Newtonian fluid;
- The polymer flow is assumed to be isothermal, laminar, and fully developed;
- There is a no-slip condition between die wall and polymer melt.
4. Discussion
5. Conclusions
Author Contributions
Funding
Acknowledgments
Conflicts of Interest
References
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Entrance Diameter, mm | Distance between Inlet and Outlet, mm | Thickness, mm | Width, mm | Height of the Gap, mm | Width of the Gap, mm |
---|---|---|---|---|---|
20 | 250 | 85 | 750 | 3 | 720 |
Simulation # | Mass Flow Rate | Material |
---|---|---|
1 | Material #1 | |
2 | Material #1 | |
3 | Material #1 | |
4 | Material #2 | |
5 | Material #3 |
Material # | Rheological Properties |
---|---|
Material #1 | Casson model: Pa, Pa·s, n [21] |
Material #2 | Carreau–Yasuda model: Pa s, , n , [5] |
Material #3 | Power-law model: Pa·s, [4] |
Simulation # | #1 | #2 | #3 | #4 | #5 |
---|---|---|---|---|---|
Die exit average velocity variation |
Simulation # | #1 | #2 | #3 | #4 | #5 |
---|---|---|---|---|---|
Maximum von Mises stress, Pa |
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Igali, D.; Perveen, A.; Zhang, D.; Wei, D. Shear Rate Coat-Hanger Die Using Casson Viscosity Model. Processes 2020, 8, 1524. https://doi.org/10.3390/pr8121524
Igali D, Perveen A, Zhang D, Wei D. Shear Rate Coat-Hanger Die Using Casson Viscosity Model. Processes. 2020; 8(12):1524. https://doi.org/10.3390/pr8121524
Chicago/Turabian StyleIgali, Dastan, Asma Perveen, Dichuan Zhang, and Dongming Wei. 2020. "Shear Rate Coat-Hanger Die Using Casson Viscosity Model" Processes 8, no. 12: 1524. https://doi.org/10.3390/pr8121524