Screeching Screw?

[moldingppm]

So, I've come up with another interesting issue. Van Dorn ET-80 / 2 oz / 25mm screw.

Upon injection fwd as well as recovery, my screw is making a screeching noise. I know it's not the motor, I lubed it up. Seems to be coming out of the end of the barrel (motor side).

This happen to anyone else?

[Suhas]

Hi,
Never seen this but (I am sure you thought of this) you may want to dismantle the back end and look to see if you have started galling something. You may need to pull the screw out to see the shank portion that has no flights. The sooner you do it, the better to avoid any further damage.
Regards,
Suhas

[brentb]

Define "lubed motor", please!. If "screech" happens on injection, then it is probably something other than "motor". Do as Suhas says, pay attention to quill area for galling and play. Check out whole barrel for scratches and galling.
Try dry cycling PP or PE if you don't see anything. What resin are you using?

KOM

brent

[Chris]

Define "lubed motor", please!. If "screech" happens on injection, then it is probably something other than "motor". Do as Suhas says, pay attention to quill area for galling and play. Check out whole barrel for scratches and galling.
Try dry cycling PP or PE if you don't see anything. What resin are you using?

KOM

brent


I think brent is onto something, i have seen previous molders tring to run resin with wrong screw combinations, with lower heats to keep the sheer down in screw.

here it was the resin squealing in the screw, did no damage to either component, was just annoying.

[nemanja]

I had same problem in past. In my case was condensation above screw. I clean it, put some oil (WD-40) and this solved problem. This oiling i put in weekly maintenance of machine, and we don't have this problem anymore.

regards,
Nemanja.

[moldingppm]

Define "lubed motor", please!. If "screech" happens on injection, then it is probably something other than "motor". Do as Suhas says, pay attention to quill area for galling and play. Check out whole barrel for scratches and galling.
Try dry cycling PP or PE if you don't see anything. What resin are you using?

KOM

brent

I should have made more sense, by lubed I mean that I greased the bearings

I wish I had downtime to pull the screw, I'll be doing that soon. I've only heard this recently running Nylon (which I run all the time without this problem in this machine)

Nope, haven't tried PE, that's going in next so I'll report back when I have that job running.



Hi,
Never seen this but (I am sure you thought of this) you may want to dismantle the back end and look to see if you have started galling something. You may need to pull the screw out to see the shank portion that has no flights. The sooner you do it, the better to avoid any further damage.
Regards,
Suhas

I'll check into it hopefully this weekend.


I think brent is onto something, i have seen previous molders tring to run resin with wrong screw combinations, with lower heats to keep the sheer down in screw.

here it was the resin squealing in the screw, did no damage to either component, was just annoying.

I always run this material (ST-801) with no problem...


I had same problem in past. In my case was condensation above screw. I clean it, put some oil (WD-40) and this solved problem. This oiling i put in weekly maintenance of machine, and we don't have this problem anymore.

regards,
Nemanja.

That'll be my last try if I get stuck



Thanks everyone.

[nemanja]

Today during some inspeciton of machine i notice that i have some rost on metal part that connect motor and crew. main trouble here is that i work on verttical injection unit, and i have loots of condensation from scrw heaters in that erea. So far i dont have problems, but will be simple oiling be enough, or i can expect some bigger problems? Is there some solution to keep condensation away from metal parts?

regards,
Nemanja,

[brentb]

Run area above dew point temperature. Or remove humidity from air in environment.
Probably getting condensate from running feed throat area too cold. Choke down flow to water jacket of feed throat.

Keep on Molding!

brent

[Mark Lewis]

Yea I come across this nearly every day, but unusually the machine only screeches when high density clear raw materials are used like Hi Heat PP , When ABS/PC is used the machine is as quiet as Laptop ventilator :)

[nemanja]

For now there is no solution for rost problem, becose there is no way to remove humidity from that part and also material is MEGOL , who also don't hellp (even dryed still have rest of moisture inside). For now oiling and cleaning regulary is only solution.

[Mark Lewis]

But nemanja

What material are you using, is the screeching only happening in the barrel as the screw turns ??

[moldingppm]

Sorry for the late reply. I was running PA66 Custom Resins 132 (comparable to chemlon 100) Im currently running ST-801 in it now without the noise.