The Flow of a Power-Law Fluid in a Melt-Fed Single-Screw Extruder

1973 ◽  
Vol 95 (1) ◽  
pp. 81-90 ◽  
Author(s):  
S. Y. Poon
Keyword(s):  
Power Law ◽  
Moving Boundary ◽  
Isothermal Condition ◽  
Numerical Procedure ◽  
Screw Extruder ◽  
Relative Significance ◽  
Single Screw ◽  
Single Screw Extruder ◽  
Screw Extrusion ◽  
Power Law Index

A simple numerical procedure is proposed for the solution of the two-dimensional power-law flow equations for a wide channel with a moving boundary. The results are used to construct a complete model of the isothermal operation of a single-screw extruder in terms of the compression ratio, the relative lengths of the compression and the metering sections, and the power-law index of the material. It is shown that a number of the main features of screw extrusion are predicted by the model. By way of examples it is shown that, in application, the isothermal condition can be relaxed, and satisfactory correlation between the theory and experiment can be obtained, by the use of an average extrusion temperature. The model provides a broad theoretical framework, by which the relative significance of the geometric parameters and the power-law index on the throughput-pressure characteristics of the screw extrusion can be examined, and the experimental results collated and extrapolated. Examples of the solution are presented in the form of contour plots to assist designers and users of single-screw pumping machines.

N-Lamina Model of Extrusion Pressure of Non-Plug Flow Solid Conveying in Feeding Section by Single-Screw Extrusion Molding

2011 ◽  
Vol 221 ◽  
pp. 271-277 ◽  
Author(s):  
Chun Hui Liu ◽  
Jian Hua Qin ◽  
Da Li Shi
Keyword(s):  
Plug Flow ◽  
Extrusion Pressure ◽  
Powder Materials ◽  
Screw Extruder ◽  
Molding Process ◽  
Single Screw ◽  
Single Screw Extrusion ◽  
Single Screw Extruder ◽  
Screw Extrusion ◽  
Solid Conveying

While extrusion molding with single-screw extruder, extrusion pressure comes into being from feeding section; it is one of the basic conditions to ensure that extrusion process can be carried on normally, in order to ensure molding process goes smoothly, it must meet the following requirement: extrusion pressure generated during the process must be sufficient. Therefore it has certain engineering significance to design structure of a single screw correctly that a mathematical model for formation of extrusion pressure during single-screw extrusion molding will have to be established. This paper conducted a research on theory of extrusion pressure when powder of pure UHMWPE resin is still in feeding section by molding in barrel of the single screw extruder specially designed for pure UHMWPE, and established a n-lamina model of powder materials or grain materials which is in feeding section and at the state of non-plug flow solid conveying, and it provided a method to calculate extrusion pressure of the n-lamina model, thus it enriched and perfected theory of single-screw extrusion molding.

Discussion on N-Lamina Model of Non-Plug Flow Solid Conveying in Feeding Section by Single-Screw Extrusion Molding

2012 ◽  
Vol 501 ◽  
pp. 583-588
Author(s):  
Chun Hui Liu ◽  
Da Li Shi ◽  
Yan Yang Wu ◽  
Jian Hua Qin
Keyword(s):  
Compressive Stress ◽  
Plug Flow ◽  
Screw Extruder ◽  
Molding Process ◽  
Single Screw ◽  
Single Screw Extrusion ◽  
Single Screw Extruder ◽  
Screw Extrusion ◽  
Solid Conveying

This paper analyzed several important issues in theory of non-plug flow solid conveying, which is about the extrusion molding process of the single screw extruder, they are mainly: compressive stress on the front and rear ends of the surface, and ; an increase trend of compressive stress , ; pressure in feeding compression section of the screw, .

Computer simulation of three-dimensional transport during moistened defatted soy flour processing in the metering section of a single-screw extruder

2000 ◽  
Vol 214 (2) ◽  
pp. 335-349 ◽  
Author(s):  
P S Ghoshdastidar ◽  
G Ghai ◽  
R P Chhabra
Keyword(s):  
Power Law ◽  
Plug Flow ◽  
Three Dimensional ◽  
Soy Flour ◽  
Viscous Drag ◽  
Three Dimensional Model ◽  
Screw Extruder ◽  
Defatted Soy Flour ◽  
Single Screw ◽  
Single Screw Extruder

A quasi-three-dimensional steady state finite-volume-based computer model for a power-law fluid is used to describe the three-dimensional transport during the processing of defatted soy flour with 25, 28 and 33 per cent moisture contents by weight in the metering section of a single-screw extruder. The numerical results have been compared with the earlier experimental results of Fong. The results are found to be reliable only for the highest moisture content dough (33 per cent by weight). The conclusion is that the quasi-three-dimensional model showing a viscous drag flow mechanism using a power-law equation for viscosity may be effectively used for predicting the behaviour of moist doughs during the extrusion process while the same model may not be very reliable for drier doughs which show plug flow behaviour during processing.

scholarly journals Influence of the parameters of the extrusion process on the properties of PLA composites with the addition of graphite

2021 ◽  
Vol 1199 (1) ◽  
pp. 012057
Author(s):  
K Fiedurek ◽  
P Szroeder ◽  
M Macko ◽  
A Raszkowska-Kaczor ◽  
N Puszczykowska
Keyword(s):  
Power Consumption ◽  
Cone Calorimeter ◽  
Extrusion Process ◽  
Screw Extruder ◽  
Single Screw ◽  
Grain Sizes ◽  
Single Screw Extrusion ◽  
Single Screw Extruder ◽  
Screw Extrusion ◽  
Screw Diameter

Abstract The main purpose of the work is to determine the influence of the screw diameter on the parameters of the single screw extrusion process, such as power consumption, torque, throughput, the actual temperature of the melt on the extruder die, as well as phase s with the use of a laboratory single-screw extruder.. The research was carried out with the use of various plasticizing systems. Two types of graphite: pre-expanded and normal grade with different grain sizes were used in the research. Flammability tests of the obtained composites were carried out using cone calorimeter.

scholarly journals The Effects of Antioxidants Content on Mechanical Properties and Water Absorption Behaviour of Biocomposites Prepared by Single Screw Extrusion Process

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Mohd Hafizuddin Ab Ghani ◽  
Mohd Nazry Salleh ◽  
Ruey Shan Chen ◽  
Sahrim Ahmad ◽  
Mohd Rashid Yusof Hamid ◽  
...  
Keyword(s):  
Rice Husk ◽  
Extrusion Process ◽  
Modulus Of Rupture ◽  
Screw Extruder ◽  
Single Screw ◽  
Single Screw Extrusion ◽  
Single Screw Extruder ◽  
Flexural Testing ◽  
Hybrid Fillers ◽  
Screw Extrusion

The performance of hybrid fillers between rice husk and sawdust filled recycled high density polyethylene (rHDPE) with the presence of antioxidants (IRGANOX 1010 and IRGAFOS 169, with the ratio of 1 : 1) was investigated. The biocomposites with 30 wt% of matrix and around 70 wt% of hybrid fillers (rice husk and sawdust) and different antioxidants’ contents (0 to 0.7 wt%) were prepared with single screw extruder. Increasing the amount of antioxidants in biocomposites reduced the modulus of elasticity and modulus of rupture on flexural testing. The addition of antioxidants increased the tensile and impact strength of biocomposites. From the study, samples with 0.5 wt% of antioxidants produce the most reasonable strength and elasticity of biocomposites. Furthermore, the effect of antioxidants content on water uptake was minimal. This might be caused by the enhanced interfacial bonding between the polymer matrix and hybrid fillers, as shown from the morphology by using scanning electron microscopy (SEM).

scholarly journals CALCULATION OF A POWER– LAW FLUID FLOW IN A SINGLE–SCREW EXTRUDER

2017 ◽  
pp. 81-104
Author(s):  
Mariya Petrovna BESSONOVA ◽  
◽  
Mariya Andreevna PONOMAREVA ◽  
Vladimir Al’bertovich YAKUTENOK ◽  
◽  
...  
Keyword(s):  
Fluid Flow ◽  
Power Law ◽  
Screw Extruder ◽  
Power Law Fluid ◽  
Single Screw ◽  
Single Screw Extruder

Numerical Simulation of Extrusion Pressure of Non-Plug Flow Solid Conveying in Feeding Section

2011 ◽  
Vol 250-253 ◽  
pp. 4046-4051
Author(s):  
Chun Hui Liu ◽  
Da Li Shi ◽  
Yan Yang Wu ◽  
Jian Hua Qin
Keyword(s):  
Mathematical Model ◽  
Plug Flow ◽  
Extrusion Pressure ◽  
Screw Extruder ◽  
Single Screw ◽  
Single Screw Extrusion ◽  
Single Screw Extruder ◽  
Screw Extrusion ◽  
The Mathematical Model ◽  
Solid Conveying

According to the theory of extrusion pressure by molding in barrel of the single screw extruder specially designed for pure UHMWPE, extrusion pressure generated during the process must be sufficient while extrusion molding with single-screw extruder. The mathematical model for formation of extrusion pressure in feeding section during single-screw extrusion molding has been established. This paper conducted a research on theory of extrusion pressure which is part of n-lamina model of non-plug flow solid conveying in feeding section by single-screw extrusion molding.

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