Color mixing in the metering zone of a single screw extruder: Numerical simulations and experimental validation

Abstract

We present numerical simulations for an acrylonitrilebutadiene-styrene copolymer (ABS) resin extrusion in an industrial conventional single-screw extruder. Based upon the flow field patterns obtained in the simulations, a particle tracking procedure was employed to obtain information about the spatial distribution of particle tracers of two colors. Results of the simulation were compared with experimental data obtained under similar extrusion conditions. To evaluate the degree of color mixing and color homogeneity for the system, we employ a specific index calculated based upon the Shannon entropy for two species populations. POLYM. ENG. SCI.,

A Method for the Validation of Simulated Mixing Characteristics of Two Dynamic Mixers in Single-Screw Extrusion

“…High values of δ gray correspond to a great variety in color and thereby to poor mixing. This method has been used numerous times in analysis of extrudate quality [ 5 , 27 , 35 ], but was also applied to images exported from the flow simulation in this work. In the photographs taken by the camera mentioned above pixels were sized to ca.…”

“…Diffusion of temperature usually is referred to as heat conduction. Considering that plastics are poor conductors of heat [ 1 , 2 ] and very few additives are soluble in plastics melts, convection is the prevalent mechanism [ 5 , 6 ].…”

“…Repetition of these three steps yields increasingly good mixing [ 7 , 8 ]. Some amount of rearrangement is provided by vorticial cross-channel flow during melt pumping in the compression and metering zone of the screw channel [ 5 , 9 ]. This vorticial cross-channel flow can be modified to induce chaotic mixing.…”

Quantifying hierarchical mixture quality in polymer composite materials: Structure and inhomogeneity in multiple scales

“…Typically for a dispersion of spherical * nakayama@chem-eng.kyushu-u.ac.jp particles, the center points of the particles are first identified, then the distribution of the center points is analyzed [15][16][17]. One direct approach to measure the distribution inhomogeneity is to evaluate the deviation from the uniform distribution based on fluctuation of the point density [15,16,[18][19][20][21][22]. Another approach is to evaluate a certain cost function of the inter-point distance, which is the minimum when the points are uniformly distributed [17].…”

Analytical and Numerical Methods for the Design of Maddock Mixers in Single Screw Plasticizing Technology

“…Klason et al computed the flow in Maddock mixers without kinematically reversed boundary conditions 11, 12. Recent studies employed various commercially available computational fluid dynamic (CFD) software packages13, 14 for the simulation of mixing effects and flow pattern in polymer extrusion technology 15, 16…”