Just like any other piece of heavy machinery, plastic granulators need to be well-maintained in order to ensure long-lasting equipment, a high-quality finished product, and fewer potential larger repairs throughout its life. A granulator that is properly maintained will produce uniform regrind with clean cuts and that is free of dust and fines. However, there are a variety of problems that can occur when a granulator is not properly maintained:
- Reduced Throughput: The granulating process should be quick and quiet, and improper or infrequent maintenance can cause throughput rates to drop.
- Increased Noise: Moving parts will begin to grind against each other and the rotor will simply smash material instead of cut it, resulting in more noise.
- Increased Heat: Heat can build up within the cutting chamber when the material isn’t being cut properly.
The cause of these issues generally comes down to two things: the knives and the screen.
Within a plastics granulator, there are fixed knives and rotating knives with a small gap, or clearance, in between them. With sharp knife edges and a precise clearance, the material will be cut into smooth and uniform granulate. Over time, however, knives will be worn down and the clearance between the blades will increase. Wearing down of the knives can accelerate when the granulator is processing glass or calcium-carbonate filled materials, dirty or recycled scrap plastic, tough or thick material, or is processing high volumes of material. As the knives become dull and the clearance expands, there will be fewer clean cuts, an increase in dust and fines, impact marks, chipping, and shattering.
As material is processed in the cutting chamber, it becomes small enough to pass through the screen at the bottom, and will fall into a collection bin. However, when a plastic granulator isn’t properly maintained, it will also increase the space in between the screen and the knife edges. This causes larger pieces of low-bulk-regrind to build up on top of the screen, preventing correctly sized granulate from falling through the screen. This can cause a reduction in throughput or clogs. A clog will require the machine to be shut down and cleaned, significantly reducing production rates. Clogs can also cause premature wear of drive belts or even a burned-out electrical motor and reducer.
On the other hand, the screen itself can also wear down. Small circular holes in the screen can eventually become larger, allowing bigger, non-uniform pieces of plastic to fall through the screen. These non-uniform pieces will affect the overall finished product that you are trying to sell or repurpose into products.
Proper Plastic Granulator Maintenance
- Sharpen the Knives: Both fixed and rotating knives should be kept sharp and clean, and should be rotated regularly. This will ensure that the efficiency of the granulator remains consistent and will reduce wear and tear on the machine.
- Foreign Objects: Metal objects like nuts and bolts, or any stiff material should be kept away from the granulator during operation.
- Rotate the Screen: The screen should be cleaned, inspected, and rotated regularly to prevent build-up of material and ensure even wear and tear of the screen.
- Inspections: Granulator inspections should be completed regularly to prevent minor issues from becoming large repairs.
Work With Cumberland For Your Plastic Granulator Needs
The Cumberland team has been providing customers with high-quality size reduction equipment as well as granulator repair and refurbishing services since 1939. If your existing equipment simply needs a replacement part or a more complex repair, our team will ensure the process is smooth and efficient, helping you get back up and running quicker. We will completely disassemble the machine, inspect each component, and will remanufacture or replace the part as necessary. We also offer OEM upgraded safety features so you can benefit from a like-new machine without the expense. Our work is backed by a six-month warranty as well.
The Cumberland plastic granulator and shredding products are known throughout the industry for their reliability and durability. Whether you’re using injection molding, blow molding, extrusion, or other processing techniques, you can count on us to provide the equipment and service you need for a high-quality finished product. Contact us today and experience what innovative technology and superior equipment can do for your processing plant.