What's special about carbon fiber PLA?

[Oliveros 11]

I've been reading about people using carbon fiber PETG, PLA and Nylon and I'm just wondering what the big benefit is of having carbon fiber infused into the filament?

 

I understand it makes it stronger but how much stronger, anyone have experience with this?

[AndersK 59]

Reinforced  nylon has about 15% higher tensile strength but only about 25% elongation at break compared to 45% for regular nylon.

 

Regular PETG has very similar mechanical properties as reinforced nylon.

Haven't seen the data sheet for reinforced petg yet but it is strong and stiff.

Have printed pressure vessels tested up to 5MPa without cracking and with very limited deformation.

 

Carbon fiber also increase the temperature range and makes it less prone to warping.

 

I was also pleased to find the carbon petg could be printed on glass without chipping it and very easy to remove.

Edited January 22, 2020 by AndersK

[Oliveros 11]

Interesting, okay awesome.

 

I'm thinking the CF infused PETG would be the most useful?

[AndersK 59]

It very much depend on the application.

CF Nylon has better impact resistance which sometimes is more important than tensile strength.

It's not as easy as just comparing data sheets. I have a very good example from a lever I designed. It had to endure 100 Nm bending and we chose a 30% GF PA that from both specs and FEA looked great. It held static load well but very easy to snap.

Changed to another PA with less strength but higher flexibility and we just couldn't break it.

[Ishy 8]

I have used BAST Innofil PAHT which I think is carbon reinforced nylon. I couldn't break the parts but they were far to flexible for the application. Will try the PETG version next to see if that's stiffer.

[Oliveros 11]

Interesting.

 

Well, I guess i'll have to collect me some CF infused filaments now, since not one is the best, I'll have to get them all 😄

[Job_van_gennip 23]

The novamid CF is also really interesting. That stuf is super strong and super stiff. I just printed a clamp with it and it was impossible to even get it to budge.