Analysis of the causes of irregular cutting of underwater pelletizers-pelletizing knife holder and pelletizing knife（2）
Problem analysis
According to the phenomenon of cutting out irregular particles, and then based on past maintenance experience, we decided to start the analysis from the following aspects.
(2) Fixed knife.
Because the movable knife has multiple teeth, the fixed knife wears faster than the movable knife.
When the cutting edge surface of the fixed knife is worn to a certain degree, the cut pellets have sharp corners or burrs, which affect the appearance quality of the cut pellets, and the blade must be changed or sharpened.
(3) The gap between the fixed knife holder and the scraping template
With the multiple grinding of the movable knife, its outer diameter has been greatly reduced.
In order to ensure the process gap between the rear feed roller and the scraping template, a larger gap between the fixed knife holder and the scraping template will be produced.
Clearance (measurement> 3 mm), resulting in material clamping, random cutting, and a large number of irregularities in cutting.
(4) Feed gap
When the feed roller is in operation, the cast strip is brought in mainly by the friction generated between the front and rear feed rollers.
The force of the rotating feed roller on the contacting cast strip includes positive pressure and friction.
When these two forces are less than the vertical downward component of the cutting force, the cast strip is between the two feed rollers.
The sliding of the relative displacement caused by pulling makes the feeding speed and the cutter speed do not match, which will cause irregular cutting.
To make the appearance of the pellets qualified, it is necessary to ensure that the positive pressure of the front and rear feed rollers on the cast strip is large enough, and the friction force generated is greater than the vertical downward component force generated during cutting.
Quote-[1] Sun Lin. Analysis of the causes of irregular cutting of underwater pelletizers and solutions [J]. Silicon Valley, 2014,000(013): 107-107,104
