Industrial Recycling Equipment: How Blade Design Affects Throughput and Quality

On average, Americans recycle or compost 32% of waste every day. At a rate of 4.9 pounds of waste per person per day, this equates to 1.57 pounds of recycling per person per day. Industrial recycling centers process all this recycling, along with commercial recycling. 

Processing high volumes of abrasive and often contaminated materials takes a toll on industrial recycling equipment. Choosing the right cutting tools increases machine throughput so centers can process more materials. Blades specifically engineered for different types of plastics make machines more efficient by delivering cleaner cuts and higher output. 

The Material Challenges That Slow Industrial Recycling Lines

Industrial recycling is rarely ideal. Many people don’t sort their recyclables correctly. Recycled materials often contain contaminants, such as food, dirt and rocks, chemicals, and other non-recyclable materials that can affect blade wear.  

Even in ideal circumstances, plastic processing and recycling equipment​ works hard. These materials are hard and abrasive, and processing them generates significant friction, which wears out plastic recycling equipment​ blades faster.

If your center processes multiple materials, the mixed feedstock can wear down your blades. Cutting mixed materials changes the tensile stress and torsion. These can weaken blades, leading to chips and other damage over time. 

As blades dull, they can’t process at the same volume, and you lose processing time. Excessive blade wear also means more frequent repairs or replacements, which require machine downtime.

How Blade Geometry Drives Higher Throughput

Blade geometry refers to your blade’s shape, angle, thickness, and edge design. Each of these factors impacts a knife’s sharpness, durability, and ability to cut with precision:

• Edge Angles: Low-angled blades are sharper but more fragile, while high-angled blades are more durable but not as sharp. Aggressive blade angles have higher angles that pull in material faster and improve your feed efficiency. 
• Hook Profiles: On blades with teeth, hook profiles refer to the angle at which the tooth leans forward or backward. A positive hook profile means the teeth lean forward and pull material into the blades. A negative hook profile has teeth that lean backward, away from the cutting direction, which gives you more control. 
• Multi-Blade Configurations: Industrial recycling equipment often uses machines with variable tooth patterns and multiple blades to increase cutting speeds or reduce resistance. 

Custom blade selection for plastic recycling lets you cut through plastics and other recycled materials at speed. Customized edge angles and hook profiles slice through tough plastics with less force, which reduces friction and wear on your blades. It also helps you control cutting edges and improves shredding or granulating performance. Altogether, you can process high volumes of material without constantly sharpening or replacing your blades. A good regrinding supplier also speeds up routine maintenance.

In plastics recycling, the different materials require specific blade geometry. Flat, sharp blades are suitable for processing soft plastics, including film or shrink wrap, because they cut cleanly with minimal friction. You can also use claw blades to shred these plastics to reduce clogging. 

Process harder plastics using hooked blades, high-angled blades, or a combination of the two to increase your throughput. You want a durable blade that can withstand abrasive materials and friction. 

Choose a blade that is compatible with your set RPMs. Plastic recycling granulating involves cutting plastic into smaller, uniform pieces using high RPMs. Plastic recycling pelletizer blades deliver uniform cuts at higher speeds. Make sure your blades are compatible to avoid overheating or chipping.

Design Factors That Control Particle Size and Regrind Quality

Regrind quality is crucial in the recycling industry. Pure, uniform plastic scrap is more useful in manufacturing because it can be blended with new materials. To achieve uniformity, blade design features such as sharpness and angle impact cut quality, while blade size and thickness help you control cutting speed and power.

Rotor-Stator Clearance

Plastics recycling machines with the proper rotor-stator clearance produce high-quality regrind. A smaller gap between the blade and the stator gives you more precise regrind quality. However, if the gap is too small, your machine is more prone to jams. Tight gaps can also cause the rotor to strike the stator, damaging the blades and other machine components. 

Tight Tolerances

Tolerance is the minimal amount of variation in blade geometry allowed in your machine. Tight tolerances enable blades to fit into machines more precisely. Choosing plastics recycling equipment with tighter blade tolerances may require different machines for different materials, but it also produces more consistent regrind. 

Materials

Industrial granulator blades and other recycling blades made of durable high-carbon steel or carbide can cut through abrasive plastics without being damaged. Blades with titanium or carbide coatings are also more wear-resistant. Coatings such as Teflon, diamond-like carbon (DLC), and titanium nitride keep contaminants from sticking to your blades.

Matching Blade Types to Each Stage of the Recycling Process 

You’ll need different blades throughout the recycling process to get the desired results. Hyde Industrial Blades offers custom solutions for every stage: 

• Map Shredders: A study of plastics recycling equipment showed that double-edged blades in a spiral orientation shred more efficiently. In general, the best blade angle for map shredders is about 35°, but it varies by machine and the type of plastic you’re shredding. 
• Granulators: High-volume granulators produce better regrind using V-type blades with 35°-45° angles on the rotor blades and 75° angles on the stationary blades. 
• Pelletizers with Blade Requirements: Pelletizing blades are usually trapezoidal, thick, and sharp. They are made of high-carbon steel and other durable materials to resist wear. 

Why Hyde’s Engineering Gives Recyclers Cleaner Cuts and More Uptime

The right blades for plastic and industrial recycling screening equipment can drastically impact your efficiency. With 150 years of custom blade experience, Hyde Tools can develop blades to OEM tolerances for your machines. We have experts in metallurgy and applications engineering who design custom geometries for blades to make your equipment more efficient while extending its useful life. 

Contact us today for high-quality plastics processing supplies that improve your output.