Effect of packing pressure on fiber orientation in injection molding of fiber-reinforced thermoplastics

2007 ◽  
Vol 28 (2) ◽  
pp. 214-223 ◽  
Author(s):  
Parvin Shokri ◽  
Naresh Bhatnagar
Keyword(s):  
Injection Molding ◽  
Fiber Orientation ◽  
Fiber Reinforced ◽  
Packing Pressure ◽  
Reinforced Thermoplastics ◽  
Fiber Reinforced Thermoplastics

scholarly journals Calibration of Fiber Orientation Simulations for LFT—A New Approach

2020 ◽  
Vol 4 (4) ◽  
pp. 163
Author(s):  
Fabian Willems ◽  
Philip Reitinger ◽  
Christian Bonten
Keyword(s):  
Mechanical Properties ◽  
Injection Molding ◽  
Process Simulation ◽  
Fiber Orientation ◽  
Model Parameters ◽  
Fiber Reinforced ◽  
Orientation Model ◽  
Fiber Microstructure ◽  
Reinforced Thermoplastics ◽  
Fiber Reinforced Thermoplastics

Short fiber reinforced thermoplastics (SFT) are extensively used due to their excellent mechanical properties and low processing costs. Long fiber reinforced thermoplastics (LFT) show an even more interesting property profile and are increasingly used for structural parts. However, their processing by injection molding is not as simple as for SFT, and their anisotropic properties resulting from the fiber microstructure (fiber orientation, length, and concentration) pose a challenge with regard to the engineering design process. To reliably predict the structural mechanical properties of fiber reinforced thermoplastics by means of micromechanical models, it is also necessary to reliable predict the fiber microstructure. Therefore, it is crucial to calibrate the underlying prediction models, such as the fiber orientation model, within the process simulation. In general, these models may be adjusted manually, but this is usually ineffective and time-consuming. To overcome this challenge, a new calibration method was developed to automatically calibrate the fiber orientation model parameters of the injection molding simulation by means of optimization methods. This optimization routine is based on experimentally determined fiber orientation distributions and leads to optimized parameters for the fiber orientation prediction model within a few minutes. To better understand the influence of the model parameters, different versions of the fiber orientation model, as well as process and material influences on the resulting fiber orientation distribution, were investigated. Finally, the developed approach to calibrate the fiber orientation model was compared with a classical approach, a direct optimization of the whole process simulation. Thereby, the new optimization approach shows a calculation time reduced by the factor 15 with comparable error variance.

scholarly journals Influence of the Initial Fiber Orientation on the Weld Strength in Welding of Glass Fiber Reinforced Thermoplastics

2016 ◽  
Vol 2016 ◽  
pp. 1-16 ◽  
Author(s):  
Isabel Fiebig ◽  
Volker Schoeppner
Keyword(s):  
Glass Fiber ◽  
Fiber Orientation ◽  
Weld Strength ◽  
Fiber Reinforced ◽  
Hot Plate ◽  
Glass Fiber Reinforced ◽  
Vibration Welding ◽  
Reinforced Thermoplastics ◽  
Fiber Reinforced Thermoplastics ◽  
Initial Fiber

The welding factors are significantly lower in welding of fiber reinforced thermoplastics than in welding of unreinforced thermoplastics due to the fiber orientation in the weld. This paper presents results from investigations on the influence of the initial fiber orientation on the weld strength in hot plate and vibration welding for glass fiber reinforced polypropylene and polyamide 6. Injection molded specimens are compared to specimens with main initial fiber orientation being longitudinal and transverse to the joining direction. The results of CT analysis of the fiber orientation in the weld show the opportunity to achieve a higher weld strength by using specimens with fibers being initially oriented longitudinally to the joining direction. The influence of the initial fiber orientation in the parts to be welded on the weld strength in hot plate welding is more distinct than in vibration welding.

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