nicety PET pelletizing system

Plastic pelletizing system: the comprehensive guide

As plastic manufacturing companies continue to expand, so does the production of plastic waste. However, repurposing plastic waste is possible through the plastic pelletizing recycling system. This system converts plastic scraps into usable clean raw material in a closed-loop recycling process.

What is Plastic Pelletizing?

Plastic pelletizing is the process of converting scrap plastic into pelletized plastics. The process involves cutting plastic scraps into small pieces and heating them until they melt. The molten plastic is then passed through a die, which produces cylindrical pellets. These pellets can be reused as raw material in manufacturing plants, thereby reducing raw material costs.

Types of Pelletizers

There are different types of pelletizers, and the choice of pelletizing machine depends on the type of plastic scrap material and the quality of pellets needed. The different types of pelletizers include strand pelletizers, underwater pelletizers, and water ring pelletizers.

Strand plastic pelletizing line
Strand plastic pelletizing line

The strand pelletizer cuts molten plastic strands into pellets, while the underwater pelletizer submerges the plastic melt into water to cool and solidify the pellets.

The water ring pelletizer cools and solidifies the plastic melt in a ring of water before cutting it into pellets.

Difference Between Underwater Pelletizer and Water Ring Pelletizer

water-ring pelletizing machine
Water-ring pelletizing machine

The main difference between the underwater pelletizer and water ring pelletizer lies in the cooling and solidification process.

The underwater pelletizer cools the molten plastic in water, which reduces the heat transfer process and allows for a better quality pellet.

The water ring pelletizer, on the other hand, uses a ring of water to cool and solidify the plastic melt.

Advantages of Pelletization

The main advantage of pelletization is the reduction of plastic waste.

Pelletization allows plastics manufacturers to realize their green initiatives by reducing waste and converting scrap plastic into high-quality materials that can be used in manufacturing processes.

Additionally, pelletization allows for easy storage, transportation, and handling of plastic pellets.

Disadvantages of Pelletization

The main disadvantage of pelletization is the cost of the pelletizing system, including the heating and cooling system, transmission system, and extrusion system.

Additionally, third-party services may be needed to attain high-quality materials. However, these costs can be offset by the savings in raw material costs and the environmental benefits of the recycling process.

Feed Size in Pelletization

PET Flakes
PET flakes: 8mm

The feed size in pelletization depends on the type of plastic scrap material and the type of pelletizing machine. Generally, the smaller the feed size, the better the quality of pellets produced.

Purpose of Pelletization

The purpose of pelletization is to convert plastic waste into usable clean raw material for manufacturing processes. Pelletization allows plastics manufacturers to reduce their environmental impact by reducing waste and reusing materials.

Difference Between Pelleting and Extrusion

Pelleting and extrusion are similar processes, but they differ in the form of the end product. Pelleting produces cylindrical pellets, while extrusion produces plastic film or other shapes.

Pelleting is ideal for converting scrap plastic into raw material for manufacturing processes, while extrusion is ideal for producing plastic packaging or other products.

Factors that Determine the Quality of Pellets

The quality of pellets is determined by several factors, including the type of plastic scrap material, the type of pelletizing machine, and the heating and cooling system used.

Additionally, the quality of pellets can be affected by the transmission system and the extrusion process. It is essential to work with a reputable plastic pelletizing company that values the quality of their products and the satisfaction of their customers.


When selecting a custom plastic pelletizing system, it is essential to consider factors such as the transmission system, extrusion process, heating and cooling system, and third-party services offered by the manufacturer.

Many plastic pelletizing companies, including Nicety, offer custom plastic pelletizing systems that can be tailored to meet the needs of plastics manufacturers.


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Matt. Lau

Matt. Lau

Hi, I'm the author of this post, and I have been in this field for more than 5 years. If you want to build a plastic recycling line or plastic related machines, feel free to ask me any questions.

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