Strand Cutting Granulating Machine

Strand Cutting Granulating Machine

INTRODUCTION: 

The processing granulation is usually used in plastic compounding and plastic recycling. Concerning the process compounding, it means that the mixing of two or more components in an extruder to produce a new product. During compounding, the virgin resins will be shaped with certain desired character by adding ingredients. And the plastic with new character will be extruded and granulated into pellets for storage and further application.

STRAND PELLETIZING PROCESS DESCRIPTION:

In plastic granulating line, polymer is cut into pellets after cooled and solidified. The molten polymer flows into a strand die which looks like a sheet die, and the material exits the die through multiple holes. Each hole shapes the material into polymer strand. The strands will be firstly cooled in water bath or trough, then dried by a de-watering unit or air knife, finally are fed into a strand pelletizer, where they are cut into pellets. This pelletizing concept can also be called as "dry cut", and the strand will be pelletized after de-watering. 

With water slide system, the water bath will be replaced. The extruded strands enter a water slide, in which spray nozzles cool the strands and provide a water flow that takes the strands toward the pelletizer. Before the pelletizer, the water will be away from the strand. But after pelletizing, the pellets will be flowed with water. The pellets can get further cooling. The pellets with water enter the centrifugal dryer at the dryer bottom. The de-watered pellets will be lifted at the top of the dryer. The pelletizing with water slide system can be called as "wet cut".

ADVANTAGES AND DISADVANTAGES OF STRAND PELLETIZING: 

Totally understanding the strand pelletizing process is conducive to figuring out whether the process fits the production condition or not.

As a universal granulating method, the strand pelletizing has following advantages:

• low equipment cost

• easy maintenance

• suitable for most of the materials

Disadvantages are listed in comparison with other granulating methods such as water ring or under water granulating:

• Relatively low automation grad

• high energy consumption

• more human resource needed