PLA Filament cracking when sitting in printer too long?

[Vandal968]

I normally use my printer almost every day. The first time it sat idle for more than a day or two was a few weeks ago when I was at the SHOT show and it sat unused for a week. When I returned, I found that the filament had snapped where it entered the PTFE tube and the filament in the tube was cracked every inch or so inside the tube. I figured that my kids had probably messed with it in my absence and cracked the filament. I reloaded from the same spool and was back in business. Now a couple of weeks later, I let the printer sit idle for a few days and the same thing happened again! It wasn't the kids it was the filament itself (Hatchbox red PLA). I've never seen this before and I was wondering if anyone else had. This is from the same spool that cracked last time, I have never left any other spool on it unused for days at a time. Here are some pictures.





Weird, right?

cheers,
c

[Bratag]

I normally use my printer almost every day. The first time it sat idle for more than a day or two was a few weeks ago when I was at the SHOT show and it sat unused for a week. When I returned, I found that the filament had snapped where it entered the PTFE tube and the filament in the tube was cracked every inch or so inside the tube. I figured that my kids had probably messed with it in my absence and cracked the filament. I reloaded from the same spool and was back in business. Now a couple of weeks later, I let the printer sit idle for a few days and the same thing happened again! It wasn't the kids it was the filament itself (Hatchbox red PLA). I've never seen this before and I was wondering if anyone else had. This is from the same spool that cracked last time, I have never left any other spool on it unused for days at a time. Here are some pictures.





Weird, right?

cheers,
c

Welcome to the wonderful world of PLA. The thing about PLA is it loves water ... sucks it right out of the air in fact. That makes it brittle (more so than usual) and if you have heat variations where your printer is it will flex and break off. If you are going to leave your printer idle for a while then best to put your filament (pla anyway) in an air tight container with some desiccant. You can bake your spool in the oven at very low temps to dry it out if it has become really brittle or you notice popping and hissing while printing.

[thunderbt3]

+1

I have the same thing happen with esun PLA

[Jules]

+2 Yep, that's PLA.

[innkeeper]

I'm not a big pla user but, Inland (eSun) pla did that a lot to me when i was using it for a project. I didn't have that problem with other brands i had on hand.. but.. maybe i was just lucky.

[Vandal968]

This seems to be the only spool that's acting up, but I can't be certain since I was printing pretty much continuously until recently and this spool is only tricky when left loaded in the machine (ie: under tension) and not printing. Most of my spools are Hatchbox which is what this trouble spool is and I've got FAR older spools that seem ok. This red spool seems VERY tightly wound and stiff. I'm in AZ and humidity is pretty low.

cheers,
c

[Kulturfolger]

I had spools manufactured with a bad spooling method and they where cracking as well. Spools with a small inner diameter, the closer you get to the core the more often it happends. Humidity here is low as well. It taught me to buy better material.

[Jules]

I've had spools have issues with too much humidity breaking right out of the sealed package. Sometimes I think they get manufactured under high humidity conditions, or the dye ratio in the filament is too high (tends to happen on darker filaments) and those tend to snap more easily as well. Just have to watch those if you want to use them.

[Kulturfolger]

Jules, now I recall I had such spools, too. They where scattering. There was some point where I stopped buying stuff from china.

[Jules]

Jules, now I recall I had such spools, too. They where scattering. There was some point where I stopped buying stuff from china.

I've still got a lot of it left. Unfortunately.