Stuck broken screw tip in barrel...

[moldingppm]

Hey guys.

Long story short I had a big issue the other night. I was running some acetal and I guess either one of the T/Cs fell out and kept heating up or something. Long story short when I went to purge the machine, there was a big bang that blew material out of the top of the hopper and snapped the tip off of the screw. I have everything apart, but the screw tip is broken off inside the barrel, and it's stuck, like stuck stuck.

I've tried using a brass rod and tapping on it, and now the brass rod is stuck between the flutes of the tip and the barrel...

Has this happened to anyone before? Any suggestions?

Thanks in advance.

[brentb]

I've seen Acetal"volcanoes through the hopper,but never this bad! Can you put a brass rod of similar diameter of the screw, and put it in front of the screw and at acetal temps,slowly push the screw tip out.
Good luck, and please let us know the outcome?

KOM

brent

[Suhas]

Wow! That is a problem!
I have had something similar before and was able to use the machine hydraulics to push the screw out. Break the coupling, move the hydraulics back, use a short brass rod closer to the dia of the screw and try to push it out. Safety please! Dont put your hand between moving parts. It was easy for me since it was a small Arburg.
Let us know.
Suhas

[iautry1973]

The only worry I would have is that if it is stuck that bad did it damage the barrel. Don't have any great advice as the couple of broken tips I saw fell out when you moved the screw forward.

[Suhas]

Sorry to say but most likely the barrel is damaged. You do not have to replace the whole barrel, you can sleeve it.
Suhas

[moldingppm]

Sorry for the late reply, but thank you for all the responses. We ended up putting a whole new screw and barrel on the machine.

Another question, it seems that the machine alarmed out sometime last night, first shift came in and tried to restart without purging the machine out, now I have all the sticky burnt acetal throughout the cavities, vents, and all over the face. Anyone have a suggestion for the best way to clean this? I'm using IMS White 2000 and blue shop towels, but it's not coming off. I was thinking acetone and actual rags, but wanted to see if anyone had a suggestion.

Thanks again

[rickbatey]

Slide Products makes a cleaner for POM that they used to call The Stripper. You can request a free sample from them. You just spray the mold while running parts and that garbage is pulled off the mold and sticks in the parts. It's great for build up and hazy parts finishes.
Rick.