[Thomas] wanted to try baking some carbon fiber 3D printing filament because the vendor had promised higher strength and rigidity after the parts were annealed in the oven. Being of a scientific mindset, he did some controls and found that annealing parts printed with the carbon fiber-bearing filament didn’t benefit much from the treatment. However, parts printed with standard PLA became quite a bit stronger and more rigid.
The downside? The parts (regardless of material) tend to shrink a bit in the X and Y axis. They also tend to expand in the Z direction. However, the dimension changes were not that much. The test parts shrunk by about 5% and grew by 2%. He didn’t mention if this was repeatable, which is a shame because if it is repeatable, it isn’t a big deal to adjust part dimensions before printing. Of course, if it isn’t repeatable, it will be difficult to get a particular finished size after the annealing process.
The resulting PLA parts were 40% stronger and 25% more rigid than the same part before treatment. In addition, the parts had better resistance to heat, which is a common issue with PLA parts. The heating process is as simple as putting the parts in a 110° C oven for an hour, so it shouldn’t require any special equipment to replicate the test.
We’d be interested to see how fine details survive the heating and cooling. However, even if this isn’t for every part, it could be another trick in your arsenal for making 3D printed parts.
If you have the urge to try different filament types, this earlier post will keep you busy for at least a month. The vendor [Thomas] used for the carbon fiber filament makes a lot of different exotic blends.