Monday, March 2, 2015

Real World Carbon Fiber 3D Printing Results.

Photo credit Ryan Carag and Thingiverse file by NeverDun

The 3D printing filament is getting better with the availability of this new carbon fiber filled 3D printer filament.  

Manufacturers are claiming a 60% increase in tensile strength, however that is not the advantage.  Nor is the weight issue, as it only results in a moderate weight reduction over regular plastic.  The real issue is dimensional accuracy and resistance to warping.

Plastic when printed is a liquid and like most things, they shrink as they cool.  Just the way it is.  

However the addition of carbon fiber to the filament changes this.  Not by chemical effect, rather by a physical interaction between the tiny solid carbon fibers mixed into the plastic that have different rates of contraction. With this filament they effectively cancel each other out. 

This results in parts that are much more accurate vs the previous methods used by the big company printers that used a heated build chamber to prevent warping but did nothing about overall shrinkage.

However more research is needed on this material.   We do not yet know its weather resistance, temperature resistance, or even it's radar cross section. All useful things to know for applications ranging from aeronautical to automotive, to electronics.  

One interesting theory, is that stealth parts could be made easier by tailoring the infill length to the wavelength of the radar frequency.  Radar absorbing foam is made this way by adding graphite to open cell foam with the cells being the size of the radar wavelength. One could adjust the infill percentage to get this same effect. 

With weather resistance data we will know how suitable it is for automotive parts like trim, or engine parts.

Other data needed is how post processing will need to be handled.  Currently the usual method is lots of wet sanding, and filing to get a final finish on a item.  Carbon fiber presents special health issues using this type of processing.

Finally due to the materials stiffness, could is be the material for 3D  printing musical instruments?

The stiffness could lend a resonance that most other 3D printing filaments lack.

Exciting times we are in.

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