Author Owen M. Cannings from the University of New South Wales University of Australia, discussed the effect of chopped carbon fibers on the yield strength of acrylonitrile-butadiene styrene in a paper entitled "The Effect of Chopped Carbon Fibers on the Yield Strength of Acrylonitrile-Butadiene Styrene" Issue of yield strength. Although carbon fiber is a common reinforcing material in 3D printing materials, it usually runs through the entire material in the form of continuous fibers. The author's goal was to find out whether shredded carbon fibers had the same effect.
Cannings tested ordinary ABS and ABS samples reinforced with chopped carbon fibers. Carbon fiber reinforced specimens have more deformation than conventional ABS specimens, which indicates that CF-ABS materials are more ductile. He also tested the yield stress of 3D printed specimens of both materials. The yield strength of the 3D printed part is lower than that of the unprocessed filament, which indicates that the printed part may have some voids or defects in its interior.
"Although a similar level of stress to the filament is desirable, a reduction in the strength of the carbon fiber-ABS part can still be observed." Cannings said, "For 0-90 orientations, an average 21.1% reduction in strength was observed. For the ± 45 ° orientation Samples, an average decrease in strength of 12.9% was observed. "
Cannings tried to contact the company responsible for filament manufacturing but did not receive a response.
"From previous research on products, it has been suggested that CF particles have an aspect ratio of about 1, which means that they do not show overall benefits in either direction," he continued. "This means that the failed test mode is currently unhelpful, because the low aspect ratio means that the fiber does not show an increase in tensile strength in any direction. Therefore, the possibility of increasing the YS of ABS depends on the ABS and CF The bond strength between ABS and ABS is higher than the bond strength between the ABS and the author. The author could not find any research in this field. Other substrates, such as epoxy resin, use chopped particles at high viscosity between the CF particles and the substrate. Exhibits lower adhesive strength. Due to the high viscosity of ABS, the company responsible for manufacturing may not consider using an appropriate mixing process for ABS in chopped CF. "
This may be the main factor affecting the strength difference between ABS and carbon fiber reinforced ABS samples. The author believes that future work should focus on appropriate mixing processes and modifications to the carbon fiber geometry. Surprisingly, 3D prints printed with ordinary ABS achieved higher yield strength values than 3D prints printed with carbon fiber reinforced ABS. The inclusion of chopped carbon fiber particles in ABS resulted in a 13% to 29% reduction in tensile strength. More research is needed to determine the cause, but preliminary estimates indicate that the bond between carbon fiber particles and ABS plastics has weakened the material.
Many operators purchase CF filaments, hoping that their performance will be better than ordinary filaments. In many cases, we already know that for most users in most applications, the added cost is simply not worth it. Most carbon fiber filaments are non-functional and stupid. This is a useful study to support this. We are also grateful that one of the negative results in the positive research results is also very good!