we are a new company in the LV XLPE compounding. we produce both the grafted compound and the catalyst master batch. Our main customer is complaining about two main problems:
1) Longer curing time up to 12 hours.
2) Rough surfaces when they run for small wires.
How do I solve these problems?
With regard to the first complaint:
We need just a bit more information please. Is the cross-linking achieved by hot water immersion or via a steam room? It would also seem that you are not chemically grafting sufficient vinyl silane to the base polymer but that may not be the case. Finally please confirm that your investigation showed that your customer is properly storing and using the compound and masterbatch within the prescribed shelf life.
With regard to the second complaint:
The base polymer (PE) that you are using may indeed be something they are not used to. What are you using? Low density, linear-low density, medium density or possibly even high density? Moreover if it is a medium density compound, is it a mixture of low and high density or a true, polymerized medium density compound? If it is a different compound to their experience, then their extrusion tooling might need modification when it comes to the small wires Likewise are they preheating the wires and are they using gradient cooling?
Regarding the above, we have assumed of course that your customer is using proper dessicant type dehumidifiers to pull the dew point down to -40C or F and that they are using gravimetrics to properly mix the ingredients, including a color masterbatch, at the extrusion line.
Peter J. Stewart-Hay
Stewart-Hay Associates www.Stewart-Hay.com
519 641- 3212