Investigation into fibre orientation and weldline reduction of injection moulded short glass-fibre/polyamide 6-6 automotive components

Abstract

Due to the increasing demands on automotive components, manufacturers are relying on injection moulding components from fibre-reinforced polymers in an attempt to increase strength to weight ratio. The use of reinforcing fibres in injection moulded components has led to component failures whereby the material strength is hampered through the formation of weldlines which are also a problem for unreinforced plastics. In this study, an industrial demonstrator component has the injection locations verified through a combination of fibre orientation tensor simulation and optical microscopy analysis of key locations on the component. Furthermore, the automotive component manufactured from 30% glass fibre–reinforced polyamide 6-6 is simulated and optimized through a Taguchi parametric study. A comparison is made between the component, as it is currently manufactured, and the optimum processing parameters determined by the study. It was found that the component can be manufactured with roughly 7.5% fewer weldlines and with a mould fill time 132 ms quicker than the current manufacturing process.

Recent advances in the use of Polyamide-based materials for the automotive industry

“…PA66 has a higher cost than PA6, and their fiber-reinforced composites can be used to produce under-the-hood automotive components. FG-reinforced PA66 is used in manufacturing automotive engine bay components and its production by injection molding was simulated by Moisey et al [38] . Wei et al [39] researched the aging properties of PA12 exposed to biodiesel at high temperatures, citing that PA6 and PA12 can be used in vehicle fuel systems because of their excellent balance of mechanical properties and barriers properties against hydrocarbons.…”

Multi-Scale Numerical Approach to the Polymer Filling Process in the Weld Line Region

“…We introduce U=[u, p, S, Ʌ] and write Eqs. ( 1), ( 2), ( 5) and (6) The system given in Eq. ( 16) is strongly nonlinear and it is difficult to establish a variational principle.…”

“…Therefore, it is great significance to study the weldline's mechanical properties based on the characteristics of microstructure to improve the quality of the products. For this purpose, much literature was appeared using experiments alone [3][4][5][6][7][8][9][10][11], for examples, Minh et al studied the weld line strength by using various venting systems in injection molding process [3]. Li, et al [4] and Wang, et al [5] proved that the rapid heat cycle molding (RHCM) was an effective way to improvement of the mechanical properties of weld lines.…”

“…Li, et al [4] and Wang, et al [5] proved that the rapid heat cycle molding (RHCM) was an effective way to improvement of the mechanical properties of weld lines. Mosey, et al [6] and Hashimoto, et al [7] researched the weldline reduction of injection based on different processing parameters. Baradi, et al [8] and Liao, et al [9] found that the experimental X-ray tomography provides us with an effective tool to ensuring the mechanical and geometrical characters of the weldlines and predict the location of weld lines via molecular orientation distribution.…”

High-Performance of a Thick-Walled Polyamide Composite Produced by Microcellular Injection Molding

“…Nabiałek et al, one of the few, used the same software to determine cells size distribution and foamed moldings of glass fiber reinforced polypropylene, obtained by MuCell ® [ 33 ]. Simulation software was also used to evaluate fiber distribution and orientation, weldline reduction, and determine melt viscosity, flow rate, melt and mold temperature, and optimize injection point position [ 34 , 35 ]. MIM process simulation results using Cadmould 3D-F software were not found.…”