Common Problems and Countermeasures of Plastic Granulation Modification Processing(4)

Material come out from natural exhaust and vacuum vent

From nautrual exhaust:

Feed speed and host speed does not match. It should appropriately reduce feed speed or increase the speed of the host;

Temperature of feeding section to the natural exhaust area is too low, the material is not plasticizated, in the screw extrusion, resulting in raw material coming out;

Temperature near the natural exhaust is too high, material viscosity seriously reduced, the screw in this section skidding, material can not be delivered in time, and in the subsequent extrusion of mateiral flow, resulting in clinker coming out;

The natural exhaust position of the screw is not matched with the natural exhaust position of the barrel, resulting in material coming out;

There is no reverse conveying element or reverse meshing block, which can not reduce the pressure of the natural vent screw groove, in the subsequent extrusion of material flow, resulting in material coming out.

 

From vacuum vent

The materail is sucked into the vacuum pipe by the large force of vacuum pumping, which results in material coming out.

There is no reverse conveying element or reverse meshing block in the screw vacuum position, which can not reduce the vacuum section pressure, in the vacuum function, resulting in material coming out;

Temperature of the vacuum section is too high, material viscosity seriously reduced, and the screw in this section skidding, material can not be delivered in time, in the vacuum pumping force, resulting in material coming out;

Temperature of the extrusion process is too low, the material is not plasticzing or additives is not fully dispersed in the resin, under the action of vacuum pumping, resulting in material coming out;

The screw combination is reasonable, position is match and the temperature and teh speed of the host and feeder is also match, but the vacuum gasket is low, in the material flow squeeze and vacuum pumping force, resulting in the material coming out;

The diehead pressure is too heavy (the reason may includes: diehead plug, to much filter, to low diehead temperature), resulting in increased reflux, in the vacuum pumping force, resulting in the material coming out.