Common problems and solutions in the process of waste plastic granulation

More black spots

Recycled material itself has more impurities

Strengthen cleaning and screening, increase the number of meshes or layers

Local overheating of the barrel, causing material to char

Reduce extruder temperature and increase filter mesh or number of layers

Extrusion local shear is too strong, causing material carbonization

Reduce extruder speed and increase filter mesh or number of layers

The pressure on the head is large, which increases the backflow of the material and causes the material to be charred.

Raise the temperature of the head; replace the filter and reduce the number of screens

The equipment is aging and there is too much adherence on the wall of the barrel

Replacement of equipment or parts

Carbonization of the accumulated material in the vent hole is taken out

Clean the vents regularly

The discharge port is not smooth, and the accumulated material is carbonized

Clean or replace parts

Mold cleaning is not clean

Clean up regularly

Screw thread damage, dead corner material carbonization

Replace or repair the screw

Poor exhaust, causing material carbonization

Clean the vents and keep them open

Frequent broken bars

More impurities

See the solution to the problem particle black spots

Insufficient amount of extrusion

Increase screw speed, increase feed rate or replace filter

The head temperature is too high and the material viscosity is lowered.

Properly reduce the temperature of the head

Poor plasticization

Properly increase the extrusion temperature or speed to promote complete plasticization

Mixture material, large difference in properties

Adjust the temperature or speed according to the actual situation

Poor exhaust, air holes in the strip

Ensure that the vent hole is unobstructed and reduce the extrusion temperature reasonably

Towing too fast

Increase the speed or reduce the traction speed

Particle hollow

High moisture content of the material

Increase drying temperature or time to ensure smooth venting

The extruder has a high temperature and has an auxiliary decomposition

Increase extrusion rate and reduce extrusion temperature reasonably

Low processing temperature, material not fully plasticized

Reasonably increase processing temperature

The water temperature is too low, the material shrinks, causing shrinkage

Reasonably reduce the temperature of the head and properly increase the temperature of the cooling water

Natural exhaust port, vacuum material

Feed speed does not match host speed

Properly reduce the feed speed or increase the host speed

The natural exhaust port area has a low temperature, and the plasticization is not good.

Improve the temperature of the natural exhaust port area and promote plasticization

The temperature of the natural exhaust port area is too high, the viscosity of the material is seriously reduced, and the clinker is taken under the action of extrusion.

Reduce the temperature of the natural exhaust area

The natural exhaust ports of the screw and barrel do not match

Select matching screw and barrel

No reverse conveying element or reverse meshing block is provided here

Set reverse conveying element or reverse meshing block

Vacuum material

The vacuum pumping force is too large, and the material is sucked into the vacuum pipe.

Reduce vacuum pumping force

No reverse conveying element or reverse meshing block is provided here

Set reverse conveying element or reverse meshing block

The temperature in this area is too high, the viscosity of the material is seriously reduced, and the material is caused by the extrusion.

Properly reduce the temperature in this area too high

Vacuum gasket is low

Adjust the gasket position reasonably

Low processing temperature, uneven plasticization of materials

Reasonably increase processing temperature

Large head pressure, material return

Check if the die is clogged, change the net or increase the temperature of the head

Hopper bridge

Too much filler, moisture absorption, agglomeration, resulting in increased friction between the mixture and the hopper wall

Appropriate addition of external lubricant to reduce friction between the mixture and the hopper wall and the mixture

Mixture agglomeration

Reduce the drying temperature or high mixing time and reduce the amount of liquid additives

Cutting bridge

The processing temperature in the first zone and the second zone is high, the material is softened in the feeding silo, and the adhesion to the equipment wall causes subsequent feeding difficulties.

Properly reduce the processing temperature of one zone and two zones

Continuous problem

In some cases, the particles are joined together by end faces of the film or tangentially.

Lowering the water temperature to give the particle surface sufficient quenching;

Increase the flow rate of water flow to avoid agglomeration;

A die with a large pitch and a small number of holes is used.

Trailing problem

Cutting disadvantage

Replace the cutter