Flaring

Hi Guys,
We have a cap which is approx. 30mm in height and 2.5mm wall section. The issue is the cap is flaring out at the base. Any ideas that could help. Thankyou.

Do you have photos of the issue?

Two ideas. One is that the ejection of these parts should be made as easy and stress free as possible. Meaning that the speed and pressure should be adjusted to see what happens to the part. Secondly I’d look at the color in this part. I had an old friend contact me about a similar issue and when we got done we felt that this particular color had something in it that was causing his issues. Turned out to be something in the blue color was acting as a nucleating agent causing the issue. The color was reformulated and the issue cleared up.
Rick

Thanks rickbatey. Will try different speed and also colour.

Hi chrisprocess,
Apologies for late reply. Was trying to figure out attaching the photo. I have another issue. The first picture will show the flaring of the cap and the in the second picture there is a line close to the OD of the cap. Any help would be highly appreciated. I did try different colour and natural product. Also tried slow injection speed and no hold pressure but flaring is still there.Attachment 278Attachment 279

The first picture I wasn't too sure what was going on, is the flaring at the base of the part, all the way to the right?
The flaring could be from a thin wall section opening up after ejection.. Adjusting cooling time (more or less) could help.. As well as playing with pack pressure and ejection settings (slow/fast etc.) But it could also be a part design flaw..
Also since you mentioned it's a cap, it could have some sort of unwinding core torsion-type flaring going on if there are threads on the part.

The second picture looks like delamination maybe? If the steel checks out okay, first thought was to play with the melt temp and mold temps to see if you can make better or worse.. But it could be a few different things

Thanks. In the first picture the flaring is at the base. Yes there are threads in the cap. The cap is bumped off rather than having unwinding core. The wall thickness is 2.5mm all the way from top to bottom. The area where ruler is touching is the base and that is flaring out in comparison to the top. There is also half degree draft from top to base.

I will check the melt/tool temperatures and see if that helps. Thanks a lot.

Does it flare as soon as it ejects or even before? We had a part similar that bowed inwards and we dropped it straight in water and found it kept its shape better. The part was made out of peek though at high temperatures.

I'm wondering, is it possible that the flaring caused by material itself? I mean that's a fake resin perhaps...