Find the reasons for the excessive white core in polypropylene granules and the solutions
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Find the reasons for the excessive white core in polypropylene granules and the solutions
Control the temperature of the particle water, and pay attention to the moisture content of the powder material. If the extruder has an exhaust section, check the exhaust condition.
Sometimes, I find that some white cores are hollow when cut open – is this caused by poor degassing? Are there any other possible reasons?
It’s due to poor degassing; it contains volatile substances
Everything mentioned earlier is correct; it could also be stress whitening
For the fish-eye pellets, adjust the steam and drying processes upstream, and try fine-tuning the temperature of the water used for pelletizing
Polypropylene? This has also occurred in our case when the MFR is above 20; it’s mainly due to poor control of the water temperature used for pelletizing. It should not happen with a low MFR. Remember to adjust parameters such as the barrel temperature, the water temperature for pelletizing, the flow rate of the pelletizing water, and the speed of the cutting blade in a timely manner when the MFR changes