Comparison of Real and Simulated Fiber Orientations in Injection Molded Short Glass Fiber Reinforced Polyamide by X-ray Microtomography

Abstract

During injection molding of short glass fiber reinforced composites, a complex structure is formed due to the fiber movement. The resulting fiber orientation can be predicted using various simulation models. However, the models are known to have inadequacies andthe influence of process and model parameters is not clearly and comprehensively described. In this study, the aforementioned model and process parameters are investigated to determine the dependencies of the individual influences on the real and simulated fiber orientation. For this purpose, specimens are injection molded at different process parameters. Representative regions of the specimens are measured using X-ray microtomography and dynamic image analysis to determine the geometric properties of the fibers as well as their orientations. Furthermore, simulations are performed with the simulation software Moldflow® using different mesh types and densities as well as varying parameters of the MRD model to represent the real fiber orientations. The results show that different orientation areas arise in the samples, which cannot be represented with a simulation varying only one parameter. Several simulations must be carried out in order to represent flow regions occurring in the specimen as realistically as possible.

A fast and effective stiffness prediction method for Short Fiber Reinforced Composites with skin-core structure

“…The industrial CT scan has 0.5um precision. The skin's fiber orientation in the 2 and 3 directions is similar [33]. Cut 3 includes the core and skin, thus, the data are indicative.…”

Development of an Ultrasonic Method for the Quality Control of Polyethylene Tanks Manufactured Using Rotational Molding Technology

“…Another study [ 56 ] described the use of Fourier transform infrared spectroscopy (FT-IR) to identify oxidation products on the surface of products manufactured via RM. Additionally, X-ray diffraction [ 57 ], Raman scattering spectroscopy [ 58 ], and X-ray microtomography [ 59 ] were used to assess changes in the PE crystal morphology for signs of destruction. In [ 59 ], IR spectroscopy revealed that the thermal-oxidative degradation of PE parts manufactured via RM mainly occurs on the inner surfaces (because they interact with heated air, whereas the outer layers are shielded due to their contact with the mold surface).…”

“…Additionally, X-ray diffraction [ 57 ], Raman scattering spectroscopy [ 58 ], and X-ray microtomography [ 59 ] were used to assess changes in the PE crystal morphology for signs of destruction. In [ 59 ], IR spectroscopy revealed that the thermal-oxidative degradation of PE parts manufactured via RM mainly occurs on the inner surfaces (because they interact with heated air, whereas the outer layers are shielded due to their contact with the mold surface). In real production conditions, the inner surface of the product is inaccessible, and the outer surface is not informative due to the absence of thermal-oxidative degradation.…”

Influence of Processing Glass-Fiber Filled Plastics on Different Twin-Screw Extruders and Varying Screw Designs on Fiber Length and Particle Distribution

“…In order to comprehensively determine the correlation of process parameters during compounding experimentally, a high level of testing, personnel and material expenditure is required [ 17 , 18 ]. To date, fiber length change in composites has primarily been determined by microscopic observation and X-ray microtomography of the samples [ 19 , 20 , 21 , 22 , 23 ].…”