Choosing the right plastic granulator for your needs depend on several characteristics including the application (ie., the type of plastic material you plan on granulating), cutting chamber and knives sizes, quality of knives, quantity of knives, speed of electric motor, and mesh screen size. Based on a combination of these factors, you can determine which granulator is right for you and how quickly the granulator can produce plastic scrap regrinds. Let’s take a closer look at these characteristics:
- Application: The speed of regrinds depend heavily on the type of plastic you put into the cutting chamber. For common post-consumer plastics such as PP and PE (polyethylene and polypropylene), the cutting speeds will be relatively fast as these plastic types are soft with high impact strength. Engineering plastics such as ABS, Nylon, and PC are used for higher grade products and are much tougher to fracture and will be slower to granulate.
- Cutting Chamber & Knives: Larger cutting chamber combined with longer rotor and bed knives will result in higher processing capacities including greater volumes of plastic scrap the plastic granulator can process at one time.
- Quality of Knives: ASG Recycling uses only the highest quality material for our cutting knives. We understand that while cutting knife array and design play an important role in cutting, all is loss if low quality knives are used. Cheap quality knives affect production rates by requiring constant sharpening as it dull easily. Generally speaking, our high quality knives are made from high-carbon, high-chromium D2 / SKD11 steel.
- Quantity of Knives: The number of knives used in each granulator is different and based on design. While common granulators will have 3-6 rotor knives with 2-3 bed or stationary knives, some models may have in excess of 30 rotor knives. It’s the combination of the cutting chamber size, granulator type, number of knives, and speed of motor that will affect the overall speed of a granulator.
- Electric Motor: The electric motor is one of the most expensive parts used in a plastic granulator. To cut costs, many manufacturers, especially in Asia, will choose to use a lower grade motor to bring about competitive prices. Generally speaking, electric motors will spin between 200-800 rotations per minute and have powers between 1 KW/H to 800 KW/H. It is not necessarily true that a faster motor will produce better results, however, its the combination of various factors (the overall design) that bring about the highest granulation efficiency.
- Screen Size: A granulator’s sizing screen controls the size of the resulting regrinds. The simple truth is that smaller regrinds will result in slower speeds as the plastic material must stay in the cutting chamber longer. In general, screen hole sizes range from 1 inch to 1/8 inch, or 25mm to 3mm in diameter.