Issues with EPDM spinning

[LorenzaG.]

Hello Everyone.
We are polyolefin fiber spinners, and I am currently working on a project using a formulation based on a polyolefin polymer + 20 wt.% EPDM (specifically, Dow's NORDEL IP 4725P).
The formulation is perfectly spinnable, but we are experiencing random breaks. Namely, the process can run smoothly for hours (or even days!), then suddenly encounter continuous breaks lasting (a few) hours, before stabilizing again; this cycle repeats unpredictably.
Since I am familiar with the behavior of the polyolefin polymer, I am confident that the issue originates from the EPDM. The inconsistency appears within the same lot and has affected almost all the lots I have tested so far (at least five).
I do not have experience with rubbers, so I am unsure whether this type of behavior is expected. I have read about potential issues related to variable gel content in rubbers (which could naturally impact spinning); however, Dow states that their NORDEL products are "virtually gel-free."
Has anyone else experienced a similar inconsistency? Any insights or suggestions on how to identify and resolve the issue would be greatly appreciated.
Thank you for your time and attention.

 

[btrueblood]

Nordel will be "substantially gel free" at room temperature. But you are heating the material blend to some temperature to make it soft enough to extrude/spin into a fiber? At some temperature over about 250/300 F the epdm will begin to revert, i.e. the crosslinking induced in curing of the rubber will break down, and areas of the rubber will soften and become a sticky goo rather than a firm elastomer.