parts stick, to A side.... Help

[Joel Burger]

Help........ parts stick to A side..... its a cupholder part....mold built with the cores on the A side(?), using ABS resin....... hotter front side water, less pack time, both of which helps, but as pack time is increased for sink parts stick....... have had some limited success but not much........any other ideas?

thx - Joel

[rickbatey]

Have you tried spraying mold on the sticking side with mold release to see if it will stop? Is part of the mold grained/textured? There may be an issue with not enough draft due to grain. There might be flash between the core other mating half. What's the mold water temps? Is the core over heating causing the issue?
Rick.

[Joel Burger]

thx.......it takes mold release to start it..... looking at adding texture to B side..... customer needs parts now before texture..... water temps are 130 A side, 100 B side...... runs better after mold heats up.

Joel

[Suhas]

Joel,
Looks like spraying is the only solution you have now before any mold mods. Processing is not going to help a whole lot. Also add some undercuts if possible.
Suhas

[Josue]

try to fill most with transfer position , to reduce the pack and hold,,, injecting slow to reduce sink marks,,,

or may be make some undercuts

regards

[rickbatey]

Since it runs better after some shots are made, I think there's room to increase the A-side water temp and get it pulling better. Colder on the moving side could also help plus there's got to be places to add undercuts by hand until you can get the mold grained. Add the undercuts by hand while running for best results. BTW-could you add ring pullers to some or all of the ejector pins to make the part pull? I'd make them too aggressive and soften in the press by hand while running to get them dialed in.
Rick.

[Joel Burger]

thx for all the comments...... the undercuts we've added have not worked..........replying to Rickbatey, the ejector pins are flush now so how would you do the ring pullers?

thx - Joel

[rickbatey]

Grind a small reverse tapered angle around the end of the pin. Very easy for an accomplished tool maker to do but make sure that you do this on the pins that the ring won't interfere with functionality or any assembly. Are you using automation to remove from mold or just ejecting part off after mold opens? I ask because you may have to adjust that to pause for a short time when out to allow the shrinking plastic to push the part off pin/mold.
Rick.

[Jendalf]

Hi,
"A" side is what? the pattern side without ejectors? So it means that you have problem with sticking part on wrong side during opening right?
can you make some photos? of the part, opened tool and tool with ejectors out?
In what degrees are those 130 and 100? °C, °K, °F ?
thx

[englemold]

I think it is caused by vacuum, I also met before,Considering deflated. the more highlights, the more is to absorb.