Which expert knows how the fine powder in granules is formed? There will be a reward for those who reply
Thread Content
Does anyone know how the fine powder in the granules is formed and how it gets out? Replies will be rewarded
Which type of granule are you referring to? Granules of PE and PP?
I have only done PVC granulation. Those fine particles usually form when granulation is not carried out properly – the cutting edges do not separate completely, leaving a small tail; once cooled, the particles rub against each other and cause these tails to fall off ； Or the outlet temperature is too high, causing sticking of the material at the mold outlet. Scraped off by a knife ； Another issue is the poor external lubrication of the materials; the particle surfaces are rough, and they rub against each other and wear away after cooling ； Another possibility is incomplete plasticization, resulting in a rough surface.
PE pellets PE pellets PE pellets
1. Cutter issue: Some blades may be worn or need to be replaced; the particles have tails. 2. The template temperature is too low. 3. Excessive amount of slip agent has been added, causing some of it to precipitate from the surface of the particles
One time I saw it was a cutter issue. . .
I have only seen PP pellets; there are several reasons for the excessive amount of fine powder. One is the cutting tool issue; it needs to be sharpened or replaced ； The second issue is the granulation water problem; the temperature is too low ； Third is the high template temperature.
With the cutting tool issue, some of the blades may be worn or need to be replaced. The particles have tails; the template temperature is too low, and too much lubricant has been added, causing some of it to precipitate from the surface of the particles
As a supplementary note, it’s also necessary to check whether the template needs to be cleaned; generally, it should be cleaned once every year or so.
It may be due to the following reasons: 1. The homogenization time is too long； 2. There are issues with the extruder pelletizing ；