scholarly journals Failure Analysis and Repair of a Broken Extruder Shaft

2020 ◽  
Vol 5 (1) ◽  
pp. 107-111
Author(s):  
Salem Ali Karrab ◽  
Mohamed Ali Ballem

In this paper a failure analysis of a screw shaft used in a co-rotating intermeshing twin-screw extruder was carried out; furthermore a detailed description for the repair procedure of the fractured part was presented. By means of the preliminary analyses of the failed shaft which includes a visual examination, appearance of fracture face, and photographic documentation of the fractured surfaces, and by summarizing and analyzing all relevant data it was possible to determine that the combination of torsion and bending forces was the cause of the failure. The shaft fractured with evidences of fatigue failure. Repairing of the fractured shaft was mainly performed by welding technique followed by suitable heat treatments and appropriate inspection methods. After repair process is completed, the extruder was put back into service, the recorded data during the trial and regular operations were satisfactory and within the design limits. Finally, in order to avoid future accidents and to prevent such problems in similar equipment, precautionary measures and recommendations were proposed.

Author(s):  
Carlos R. Corleto ◽  
Melvin Briscoe ◽  
Clifton T. Knight

Author(s):  
Dr. G. Kaemof

A mixture of polycarbonate (PC) and styrene-acrylonitrile-copolymer (SAN) represents a very good example for the efficiency of electron microscopic investigations concerning the determination of optimum production procedures for high grade product properties.The following parameters have been varied:components of charge (PC : SAN 50 : 50, 60 : 40, 70 : 30), kind of compounding machine (single screw extruder, twin screw extruder, discontinuous kneader), mass-temperature (lowest and highest possible temperature).The transmission electron microscopic investigations (TEM) were carried out on ultra thin sections, the PC-phase of which was selectively etched by triethylamine.The phase transition (matrix to disperse phase) does not occur - as might be expected - at a PC to SAN ratio of 50 : 50, but at a ratio of 65 : 35. Our results show that the matrix is preferably formed by the components with the lower melting viscosity (in this special case SAN), even at concentrations of less than 50 %.


1996 ◽  
Vol 11 (2) ◽  
pp. 139-146 ◽  
Author(s):  
A. De Loor ◽  
P. Cassagnau ◽  
A. Michel ◽  
L. Delamare ◽  
B. Vergnes

2019 ◽  
pp. 089270571987822
Author(s):  
Saud Aldajah ◽  
Mohammad Y Al-Haik ◽  
Waseem Siddique ◽  
Mohammad M Kabir ◽  
Yousef Haik

This study reveals the enhancement of mechanical and thermal properties of maleic anhydride-grafted polypropylene (PP- g-MA) with the addition of nanocrystalline cellulose (NCC). A nanocomposite was manufactured by blending various percentages of PP, MA, and NCC nanoparticles by means of a twin-screw extruder. The influence of varying the percentages of NCC on the mechanical and thermal behavior of the nanocomposite was studied by performing three-point bending, nanoindentation, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and Fourier-transform infrared (FTIR) spectroscopy tests. The novelty of this study stems on the NCC nanoparticles and their ability to enhance the mechanical and thermal properties of PP. Three-point bending and nanoindentation tests revealed improvement in the mechanical properties in terms of strength, modulus, and hardness of the PP- g-MA nanocomposites as the addition of NCC increased. SEM showed homogeneity between the mixtures which proved the presence of interfacial adhesion between the PP- g-MA incorporated with NCC nanoparticles that was confirmed by the FTIR results. DSC and TGA measurements showed that the thermal stability of the nanocomposites was not compromised due to the addition of the coupling agent and reinforced nanoparticles.


2005 ◽  
Vol 82 (5) ◽  
pp. 574-581 ◽  
Author(s):  
Hanwu Lei ◽  
R. Gary Fulcher ◽  
Roger Ruan ◽  
Bernhard van Lengerich

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