Method of Operation

The PolyGrinder® pulverizing systems, type PKMM 300 R, PKMM 600 R and PKMN 800 R are designed to produce powders from polyethylene with a 500 micron (35 mesh) top cut, which is perfect for rotational moulding. Pellets are fed into a feed hopper and a screw feeder meters the material into the pulverizer. Powderized material is pneumatically conveyed into a cyclone separator. Material is separated from air. Product discharge is through a rotary airlock valve onto a multi-deck screening machine. Coarse material is fed back to the pulverizer. Powder with the desired particle size is discharged into a bag or bin. Air for cooling and conveying is sucked through the system by a radial fan. As an option for cleaning the air, a dust
collector can be provided, other options are an all metal separator and an air chiller.

The PKMM-R pulverizer is a mono-bloc disc mill with serrated key segments designed and machined for easy cleaning. The rotating segments can be adjusted axially to set the grinding gap. The stationary grinding segments in the door are eccentrically off-set to achieve optimum grinding results. A rear air inlet and a side air inlet allow for a cool grinding operation. The electric control panel is designed for 380 Volt, 50 cycles, with temperature control and load control.

The material in granular form is fed with a vibratory feeder from a feeding hopper to the pulverizer. The material is pulverized between the two rings of segments mounted on carrier discs, then air conveyed to a screening machine. The coarse material is recycled to the pulverizer for further size reduction. The desired powder is diverted to fill bags or containers, or conveyed to silos. A one pass system, without a sifter is also available.