Developing Filaticum Engineering our aim was to exploit the potential of PLA to create an easily printable, sustainable, biopolymer composite with properties similar to engineering plastics. The purpose of this blog post is to explain what gives PLA-based filaments such outstanding impact resistance and mechanical properties.
In a previous blog post, we described what gives Filaticum Engineering’ outstanding heat resistance.
Carbon or glass fiber?
Fiber-reinforced plastics have been used for long in 3D printing and are popular because of their high mechanical strength. Carbon fiber reinforced plastics are the most popular in this category. In filament manufacturing, we have found that carbon fibers break apart. In order to achieve fiber reinforcement, the fibers need to be ‘set’ in the flow direction of the material, and this requires high viscosity PLA. Failing that, if the fibers are not aligned in the flow direction during production or in the print head and are crossed, nozzle clogging will occur. Thus, fiber reinforcement is not achieved. This phenomenon is well known to 3D printing professionals.
In the development of Filaticum Engineering, we wanted to use fiber reinforcement, but for the reasons mentioned above, we chose glass fiber instead of carbon. The glass fiber itself is stiffer and not prone to “tangling”. And the mechanical properties of glass fiber reinforced materials are only slightly weaker to those of carbon. However, due to the stiffness and size of the fibers, the chances of clogging are orders of magnitude lower.
The disadvantage of fiber reinforcement is the abrasive effect of ceramic fibers, and such materials often require a special nozzle. After much experimentation, a reasonable compromise has been reached: the fiber reinforcement ratio has been reduced to a level that does not cause noticeable damage to the nozzle, but still provides mechanical reinforcement. What does this mean in practice? Using standard copper nozzles you can print 20 to 30 kg of Filaticum Engineering without damage, so no measurable harm to the nozzles is caused when printing a single spool.
Proper printing - good impact resistance
As PLA’ impact resistance is not very good and the glass fibers makes the filament even stiffer, it is necessary to use an additive to help with this. The impact resistance thus achieved also depends to a large extent on the printing parameters, generally, higher printing temperature is recommended.
Impact resistance is also influenced by the density and pattern of infill. In our experience, the best result is obtained with 45% Concentric infill.
In light of the above, Filaticum Engineering can be used to print extremely tough, high heat resistant objects for general engineering and technical applications. Moreover, the filament is compatible with any 3D printer available on the market. In addition, it is a sustainable biopolymer.