Factorial design to quantify the influence of extrusion parameters in the mean residence time

Abstract

Abstract:Residence time distribution (RTD) is a very important parameter in extrusion, either for simple polymer processing or for special processes like compounding, blending, reactive compatibilization, and controlled degradation. This work deals with the values of mean residence time (t n ) as a function of the number of 45 degrees kneading elements in the screw profile, screw speed, and feeding rate. The t n values were calculated from the RTD curves, which in turn were determined by the technique of a marker added as a pulse in the steady state polymer flow. The values of t n were empirically modeled as a function of those parameters. The results showed that feeding rate is the most influent parameter, followed by number of kneading elements and screw speed. The modeling has given a quadratic function relating t n and the operational parameters tested.

A New In‐line Optical System for Monitoring Residence Time during Polymer Processing Along a Twin‐Screw Extruder

“…Processing of a polymeric material in a twin screw extruder involves its melting and homogenization by screw movement. [1] The time the material remains in the extruder, undergoing high shear and heat rates, depends on the processing conditions used. [2] Thus arises the concern with the possible degradation of the material leading to the need of knowing about its residence time (RT) in the machine.…”

“…[2] Thus arises the concern with the possible degradation of the material leading to the need of knowing about its residence time (RT) in the machine. [3] The movement of the screws may cause the material being processed to have its flow advanced or retarded [1] and some parts of the molten material may be retained in neutral generating different residence times. [4] DOI: 10.1002/masy.202000065…”

Development and characterization of post-consumer rubber tire powder, high density polyethylene and ethylene-octene-1copolymer ternary mixtures

“…When rubber tire is ground it can be added to polymeric matrix to produce composites. This is considered an interesting strategy for reusing this waste because the process is relatively simple and involves only mechanical mixing [9,10] . However, the incorporation of rubber tire powder (RTP) can result in materials with poor mechanical properties due to the lack of interfacial adhesion between polymer and RTP [9][10][11][12] .…”

“…This is considered an interesting strategy for reusing this waste because the process is relatively simple and involves only mechanical mixing [9,10] . However, the incorporation of rubber tire powder (RTP) can result in materials with poor mechanical properties due to the lack of interfacial adhesion between polymer and RTP [9][10][11][12] . Several techniques are employed to improve the interfacial properties between these components: partial devulcanization of rubber tire, treatment with peroxides to create reactive sites in the RTP surface, functionalization of the waste tire rubber, and the addition of non-reactive copolymers with chemical affinity with composite components [9,[13][14][15][16][17] .…”

Optimization of wood flour acetylation by factorial design and partial least squares regression

“…2,3 Today, research in this field has become increasingly important in helping manufacturers to tailor competitive wood products for a wider range of applications. [4][5][6][7][8][9][10][11][12][13][14][15][16] Two aspects must be considered: composite processing, since factors such as degradation and residence time are important parameters that influence properties, [17][18][19][20][21] and compatibility between the materials' phases. 7 Wood plastic composites (WPC) have limited applications due to the intrinsic properties of wood, such as its hydrophilicity and the relatively low dimensional stability of lignocellulosic components.…”