About the temperature setting by EVA leftover material re-granulation Problem discussion.

EVA Film leftover material waste recovery and re-granulation unit

The processing temperature of EVA is not high, one of which melts at 80-90 degrees.

I have two kinds of EVA raw materials at hand (leftover material, half transparent, and almost non-transparent).

We use 150 diameters of single screw extruder to granulate. One is the low-temperature re-granulation, the temperature is set at about 80 degrees, the die heads temperature is set at 60 degrees, the water tank is equipped with chiller cooling, and the temperature is set at 26 degrees. The extrusion strip is perfect.

For another kind of opaque material, we have tried many times, but the results failed. The temperature setting is the same as the transparent material one, but it is not successful after many times testing. The material is either burnt out or degraded and foaming. This is what it looks like.

I have been unable to extrude granulation, and I even began to wonder if there was something wrong with the original design of the extrusion machine:

1. Is the L/D ratio too long? L/D: 28:1

2. Single screw shafts didn’t design a water runner in the middle of the shafts for cooling?

But if there is a problem, why the transparent EVA  material could be re-granulation?

Then it occurred to me that we could do the opposite and directly increase the temperature of the nose to about 150 degrees. The situation was completely changed and the material came out at once. Granulation is also perfect.