Tensile properties of glass fiber reinforced polypropylene composite and its carbon fiber hybrid composite fabricated by direct fiber feeding injection molding process

2017 ◽  
Vol 39 (10) ◽  
pp. 3564-3574 ◽  
Author(s):  
Xiaofei Yan ◽  
Yuqiu Yang ◽  
Hiroyuki Hamada
Author(s):  
Emel Kuram

It is essential to determine the micro-machinability performance of polymer and glass fiber–reinforced polymer composite in order to effectively utilize the polymer and its composite as an engineering material at the micro-scale world. However, a literature survey revealed that not much work was done on the micro-milling of polymer and its composite. In the light of literature surveys, it can be said that the novelty of this study is to investigate the micro-milling performance of polypropylene and glass fiber–reinforced polypropylene manufactured with plastic injection molding process. The tests were performed at different feed rates and spindle speeds and the effect of these parameters on tool wear, burr width and micro-milling forces was investigated. In general, it was concluded that wear and forces in micro-milling of reinforced polypropylene composite were higher than that of unreinforced polypropylene. Micro-milling forces increased with feed rate and spindle speed for both materials. The lowest top burr size and force values were obtained at the feed of 50 mm/min and the spindle speed of 20,000 r/min. Unreinforced polypropylene gave better performance with respect to glass fiber–reinforced polypropylene composite from micro-machinability aspect.


Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1569
Author(s):  
Selim Mrzljak ◽  
Alexander Delp ◽  
André Schlink ◽  
Jan-Christoph Zarges ◽  
Daniel Hülsbusch ◽  
...  

Short glass fiber reinforced plastics (SGFRP) offer superior mechanical properties compared to polymers, while still also enabling almost unlimited geometric variations of components at large-scale production. PA6-GF30 represents one of the most used SGFRP for series components, but the impact of injection molding process parameters on the fatigue properties is still insufficiently investigated. In this study, various injection molding parameter configurations were investigated on PA6-GF30. To take the significant frequency dependency into account, tension–tension fatigue tests were performed using multiple amplitude tests, considering surface temperature-adjusted frequency to limit self-heating. The frequency adjustment leads to shorter testing durations as well as up to 20% higher lifetime under fatigue loading. A higher melt temperature and volume flow rate during injection molding lead to an increase of 16% regarding fatigue life. In situ Xray microtomography analysis revealed that this result was attributed to a stronger fiber alignment with larger fiber lengths in the flow direction. Using digital volume correlation, differences of up to 100% in local strain values at the same stress level for different injection molding process parameters were identified. The results prove that the injection molding parameters have a high influence on the fatigue properties and thus offer a large optimization potential, e.g., with regard to the component design.


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