A variety of claims have been made concerning the purported advantages of including chopped carbon fiber to FDM filaments, however what number of of those claims are literally true? Within the case of PLA no less than, the [I built a thing] channel on YouTube makes a convincing case that for PLA filament, the presence of chopped CF may be thought of a contaminant that weakens the half.
Utilizing the services of the College of Basel for its superior imaging gear, the PLA-CF elements have been subjected to each scanning electron microscope (SEM) and Micro CT imaging. The SEM photographs have been carried out on the fracture surfaces of elements that have been snapped to see what this revealed concerning the inner construction. From this, it turns into obvious that the chopped fibers distribute themselves each inside and between the layers, with no important adherence between the PLA polymer and the CF. There’s additionally proof for voids created by the presence of the CF.
To substantiate this, an intact PLA-CF print was scanned utilizing a Micro CT scanner over 13 hours. This confirmed the SEM findings, in that the voids have been clearly seen, as was the shortage of integration of the CF into the polymer. This latter level shouldn’t be stunning, because the thermal coefficient of PLA is way larger than that of the roughly zero-to-negative of CF. This interprets right into a cooling PLA half shrinking across the CF, thus creating the voids.
What this implies is that for PLA-CF, the presence of CF is by all measures an undesirable contaminant that successfully compromises it as a lot as having important moisture within the filament earlier than printing. Though for different thermoplastics used with FDM printing, chopped CF could make extra sense, with PLA-CF, you’re successfully throwing away cash for worse outcomes.
As additionally famous within the video, in medical settings, these CF-reinforced FDM filaments aren’t permitted as a result of chopped CF fragments. This subject has featured extra extensively in each the scientific literature and YouTube movies lately, with some important indications that fragments of those chopped fibers can have asbestos-like implications when inhaled.
In the meantime, are you’re searching for the fun of a bizarre filament? Perhaps strive considered one of these.
