Radel R-5800T Pre-Colored

[joeprocess]

Having issues with trying to color Radel with a concentrate. Needs a 20% loading and still produces plenty of scrap for swirls, etc. Anyone know of a compounder or supplier that would pre-color the Radel for me.

[Suhas]

How much % of the shot size are you using? If the usage is low, no matter how compatible the colorant is, you will still get the swirls and non mix sections.
Suhas

[rickbatey]

What changes have you made and what are the settings you currently use to mold parts?
Rick.

[joeprocess]

Parts are of various size. 90T to 610T press size. Just trying to find a supplier that can provide pre-colored.

[rickbatey]

Another question just hit me. Do you know the L/D ratio and compression ratio of these machines? Perhaps that is incorrect for this resin?
Rick

[joeprocess]

We need to run GP screws due to the gambit of different materials we run in all of our different presses.

[rickbatey]

Joe, I'm not a proponent of specialty screws due to loss of flexibility. But I have learned that a low compression ratio screw when running certain resins is a losing combination. Also trying to run shear sensitive resins like PC in machines with 3:1 compression ratio press causes shear splay as well.
So do you know the compression and L/D ratios on these machines?
Rick.

[pjhall]

Coloring high temp materials can be tricky. We had a Bright Blue PPS part and the blue concentrate kept turning green. It all about the carrier resin. We ended up drying the concentrate at a lower temperature and mixing it into the dried PPS until we were able to have the concentrate reformulated with a high temp carrier.

20% loading is HIGH

[joeprocess]

Yes we mix the material with concentrate and then dry it. 20% is high, but it is needed because the part is white and the Radel is yellow. Contacted RTP who actually produces the conc. for us and they feel they can provide the material pre-colored as well.

[pjhall]

It can be difficult to color high temp materials. Its all about the carrier of the concentrate. I was trying to color Ryton R7 PPS with bright blue concentrate. I dried the concentrate with the PPS and my bright blue parts started turning green! The concentrate carrier was getting degraded in the dryer. I ended up drying the concentrate at 185 and mixing it with the dried PPS until we were able to have the concentrate reformulated with a high temp carrier. Even nylon carriers can degrade if dried too long. I'm with Rick on specialty screws.

20% is VERY HIGH!

[joeprocess]

Carrier resin is Radel.