weird cracking with ABS

[lucidpsykosis]

I made a item with white ABS from E-SUN for a customer, to which he showed me that it cracked like crazy. This isn't any normal cracking...it looks like delaminated. Other areas just plain cracked about 1/2" long. I've NEVER seen this before. The only thing I can think of was that the acetone bath did something to it somehow? If anyone has any idea, please let me know.
ABS-crack-2.jpg

[Bassna]

Looks like it was peeled after the acetone bath or something?

[lucidpsykosis]

I dunno. The guy said it flaked off. I don't know if I believe him or not. It's just weird.

[Ella Yang]

As a 3d plastic filament manufacturer, I think maybe the problem in the raw material of ABS.
People mixed another plastic into ABS while producing ABS filament, in plastic industry it was called "off-grade ABS", it'll happen this crack,

[lucidpsykosis]

As a 3d plastic filament manufacturer, I think maybe the problem in the raw material of ABS.
People mixed another plastic into ABS while producing ABS filament, in plastic industry it was called "off-grade ABS", it'll happen this crack,

I hadn't thought of that. So "off-grade ABS" will flake off and delaminate? I'm assuming it looks like this because the layers seperated?

[Ella Yang]

Yes, sometimes off-grade ABS will cause problems, because it's impurities, it's not same as 100% brand new raw material ABS. And the raw material price for off-grade is much cheaper, but there are still some good quality off-grade plastics, but unstable quality are the most.

well, I think you should check with Esun stuff for real answer.

[jimc]

No, the problem is that you were ever so slightly underextruding. Your flow rate was just a touch low causing the edges of the extrusions to not touch. Each perimeter was actually not bonded with the one next to it.