The pelletizing machine is key production equipment in the plastic industry. When the plastic pelletizing system is working, polyester, polyethene, polypropylene and other polymer products are extruded through a die head at high pressure and temperature to form long strands of molten polymer that can be cut into pellets.
Pelletizing equipment can be divided into different types of machines: Underwater pelletizer(underwater pelletizing system), water ring pelletizer(water-ring hot face pelletizing system),Air-cooling hot-face pelletizer(air-cooling hot face pelletizing system), strand pelletizer(strand pelletizing system) and so on.
What is a plastic pelletizing system?
The main purpose of plastic pelletizer is to form the pellets from the compounding polymer, or to reconvert used plastics into useful and clean raw materials. Plastic granulation consists of mixing and cutting polymers to form easily processed plastic granules that can then be used for other functions. The main components of a plastic pelletizer are the extrusion system（die parts）, the drive system and the temperature control system. Plastic pelletizer is an essential piece of equipment for the compounding plastic, recycling and reuse of scrap plastic.
Different Types of plastic pelletizing machine
Underwater Pelletizer(underwater pelletizing system)
Underwater pelletizer is a relatively advanced pelletizing system. With advantages of easy operation and high degree of automation, can be adapted to the majority of plastic modified granulation or raw material polymerization granulation, at the same time, the output is also very high, from tens of kilograms to thousands of kilograms per hour that all can achieve continuous production of underwater pelletizing. Of course, the output of different plastics and different compounding is different. Except for high equipment cost and complexity, the disadvantage of underwater pelletizer has other disadvantage is high maintenance cost.
Water Ring Pelletizer(water-ring hot face pelletizing system)
A water ring pelletizer is a die-face pelletizer. Melt materials flow from the die head of multiple holes and are cut into melt particles by rotating knives, the rotating cutter cuts into melt particles, take advantage of centrifugal force to throw the particles to the inner wall of the water ring cover, and the circulating water washes them away for cooling, and then for dehydration and drying by a centrifugal dehydrator. This water-ring pelletizing system is suitable for raw materials with low melt temperature and low viscosity, some PE/PP and carbon black, calcium carbonate, titanium dioxide, barium sulfate and other minerals filled and modified granulation. The output is generally less than 2000kg/h.
Air-cooling Hot-face Pelletizer(air-cooling hot face pelletizing system)
Air-cooling hot-face pelletizer is also a die-face pelletizer.Unlike water ring pelletizer, its cooling method is air cooling – the fan blows the melt particles into the cyclone separator through the pipeline for cooling. It is mainly suitable for some materials that are easy to absorb water and difficult to dry, such as PE/PP, filled with CaCo3, Talc, BaSO and other minerals modification granulation. It can also be used in PVC modified granulation, puffed food granulation, etc. As PP PE and CaCo3 filler modified granulation, its output is lower than water ring pelletizer.
Strand Pelletizer (strand pelletizing system)
The strand pelletizer has two methods, one is water-cooling strands pelletizer and the other is air-cooling strands pelletizer. For the water-cooling strands, pelletizer is suitable for engineering plastics, High-temperature plastic recycling and granulation or modified granulation, such as PA+GF, ABS+GF, LCP modification, PEEK recycling or modified granulation, etc. It consists of a stranding die head, a cooling water tank, a drying machine and a pelletizer. With the advantages of simple structure, easy operation, convenient maintenance and low cost. Applicable to most plastic granulation, the output is within 1500kg.
The air-cooling strands pelletizer is suitable for some materials that are easy to absorb water and difficult to dry, especially suitable for 100% fully degradable plastics such as PLA PBAT + starch blending modification, because of its easy water absorption characteristics that are only suitable for air-cooling strands pelletizer. The air-cooled strand consists of a strand die, an air-cooling conveyor belt, and a pelletizer. With simple structure and easy operation, the output is generally within 1000kg.
Benefits of using plastic pelletizing machine
- Less waste to landfill: Plastic pellets have a post-consumer content of less than 10%.
- Economical: Prices of plastic pellets will be lower than other materials such as iron, alumina and steel.
- Durable: Plastic pellets have a very long life, especially in dry environments (e.g. food and beverage packaging).
- Portable: Plastic pellets of certain types can be transported very quickly (e.g.the lightweight polyethylene).
- Flexible: Plastic pellets are easy to transport and stored in small spaces.
- Recyclable: It is much easier to recycle than other materials (e.g Polyethylene).
- Environmentally friendly: the use of plastic pellets helps to save energy and reduce pollution. Other benefits include biodegradability, lightweight, insulating properties and resistance to corrosion to name a few.
What to consider before buying a plastic pelletizing system?
Size – Choosing a plastic pelletizer with a compact design can save you a lot of space on the job site.
Cost – Selecting a machine supplied by a Chinese pelletizing system manufacturer is more competitive in price and has a guaranteed quality that can help you save on production costs.
Material – When choosing a plastic pelletizing system, the shape or material of the plastic is an important consideration, and different materials correspond to different pelletizing systems. For example, film, woven bags and other soft plastics are one plastic pelletizing line; PET bottle flakes, filling, mixing modified class is one line; ABS, HDPE and other hollow crushed hard materials are one line.
Spare parts stock – The stock of spare parts is also one of the key considerations before you make your final decision. Sometimes your pelletizer supplier may fail to keep spare parts in stock, which takes a long time when you need to repair your machine. Thus, choosing a supplier who can provide spare parts quickly and have good after-sales service will save you a lot of trouble as well as reduce your losses.
The plastic pelletizing system is a very important system in the plastics processing industry. It is highly recommended for those who want to start a small business or for those who want to do this type of business on a large scale. Because of the low investment that you need to make, you are able to produce finished goods from raw materials easily and quickly.