Discarded material like slag, green waste, concrete and asphalt are sent to recycling facilities to be processed and transformed for a second life; however, they usually arrive dirty, wet and odorous. This creates sticky, moisture-laden material that presents processing challenges. The key to success is often one of the most overlooked yet critical components of the operation: screen media.

Material Recycling

Below, we take an in-depth look at green waste, slag and construction and demolition materials as well as what type of screen media is best for these facilities.

1) Green Waste

The screening of green waste, whether that’s grass clippings, branches, twigs or other biodegradable material, often results in clogging and excessive wear on screen media. The frustration of these problems is only amplified by the smell of rotting vegetation. FLEX-MAT’s high-vibration screens feature individual wires that vibrate independently to create a self-cleaning action that fights clogging and negates material buildup, breaking down odors and maintaining screen performance.

2) Slag

The highly abrasive nature of furnace slag shortens the lifespan for some screen media options by breaking down the polyurethane. Compounding this challenge are the inherent problems with blinding when working with the material. In the blinding process, the material builds up on the wire and clogs the screen media openings. One way to address this is by switching to MAJOR’s new advanced polyurethane strip variant, used to hold the wires in place, which increases durability and extends the screen media’s lifespan. MAJOR’s FLEX-MAT resolves the blinding issue with high-vibration wires that vibrate independently from one another, serving to clean the screen and ensuring continuous material flow and efficient screening.

3) Construction & Demolition

There are several types of construction and demolition waste, and each type of material needs to be carefully assessed before choosing the right screen media. Below, we go through three common types of waste and the right screen media choices for each application.

a. Concrete

Concrete often encounters blinding and pegging issues, which require screen media to be cleaned two-to-three times per day. This can result in around an hour and a half of downtime each day. FLEX-MAT screen media reduces cleaning frequency to once per day with high-vibration wire. The increased stratification dislodges stuck material, offsetting the challenges posed by traditional woven wire options.

b. Recycled Asphalt Pavement (RAP)

Recycling asphalt pavement cuts transportation costs, but things can get sticky during screening. RAP retains much of the oils needed to bind asphalt and often absorbs moisture, which makes it stick to the wire on screen media, causing severe blinding.

High-vibration screen media dislodges any blinding material and optimizes the open area of the screen. The vibration also breaks apart the stuck material to be sized and sent along to the next step in the process instead of requiring multiple rounds of screening.

c. Glass

Recycling glass also uses screen media, but the process is a bit more complicated. Many glass bottles retain the label on the outside, which stick to the screening wire. On woven wire screen media, the labels can stick over the open areas on the screen and lead to blinding and pegging. FLEX-MAT, specifically the S Series, features independently vibrating wires. This means there aren’t any holes on the deck due to the independent wires, which allows the label to stick to the wire without worrying about the material blocking individual holes.

Recycling Success

In one real-world customer example, a recycled asphalt plant with a double-deck screen box traditionally used woven wire screens. Severe blinding and pegging appeared on both decks. This resulted in blinding up to 6 inches deep, which required the facility to shut down every two hours to clean their screen media. The team at MAJOR took a look at their process and determined that the woven wire screen media being used was causing the issue. They recommended the facility switch to FLEX-MAT Type D, which eliminated blinding and pegging and reduced downtime while increasing throughput. The recycled asphalt plant plans to continue using FLEX-MAT moving forward after seeing increased output.

Work with an Expert

Screen media might be the magic behind the recycling process, but it still requires careful consideration to choose the best option for each facility to get a refreshed, useable material. To learn more about the benefits FLEX-MAT can bring to your recycling facility, contact our experts today.

By Serge Raymond, MAJOR Product Specialist