Screening Solutions for Difficult Materials

Wet, sticky, clumping, fibrous, and abrasive materials can create significant challenges for conventional screening equipment. Screen blinding, clogging, wrapping, and inconsistent separation can reduce throughput, increase maintenance, and make it difficult to achieve the desired product specifications.

AEI Screens provides custom-engineered screening solutions designed to handle challenging material streams, including:

• Compost: needs fine screening despite high moisture content
• Mulch and wood waste: fibrous and prone to wrapping or tangling
• Incinerator ash: highly abrasive and prone to clumping; requires durable and aggressive screening
• Waste coal: fine, wet, and variable-sized material that can be difficult to separate efficiently
• Wet ores and clay-heavy aggregates: materials that instantly blind standard wire cloth screens
• Slag: sticky, dense, and challenging to separate efficiently
• and other difficult materials

What Makes a Material “Difficult to Screen?”

Certain materials have physical characteristics that make them more challenging to separate with conventional screening equipment. Understanding these characteristics can help determine what type of screening technology is best suited for an application.

High Moisture Content

High moisture levels can cause fine particles to adhere to one another and change the way material flows across a screen. Wet material may also become heavier and more difficult to separate, particularly when moisture causes fines to stick to larger particles.

Sticky or Adhesive Materials

Materials containing clay, mud, organic matter, and other adhesive components can stick to screening media instead of moving freely across the screen. These properties can make it difficult for individual particles to separate according to size.

Clumping

Wet or sticky particles can bind together to form larger clumps. Because these agglomerated particles behave differently from individual particles, material that contains smaller particles may be carried over the screen instead of separating properly.

Variable Material Characteristics

Some difficult-to-screen materials contain a mixture of particle sizes, moisture levels, densities, or other characteristics that can make consistent separation more challenging. The specific properties of the material should be considered when selecting screening equipment and media.

The Challenges of Screening Wet, Sticky, and Clumping Materials

The characteristics that make certain materials difficult to screen can create costly problems for processing operations. When conventional equipment struggles to handle these materials, the effects can extend beyond screening efficiency to impact production, labor costs, and product recovery.

Screen Blinding and Clogging

When material builds up on or blocks the screening surface, less open area is available for properly sized particles to pass through. Severe buildup can significantly restrict material flow and, in extreme cases, bring production to a halt.

Learn how to minimize blinding in a vibratory screen.

Excessive Downtime and Maintenance

Blocked or blinded screens often require operators to stop equipment to remove built-up material or manually clean the screening surface. Frequent interruptions increase labor requirements, maintenance demands, and equipment downtime.

Inconsistent End-Product Quality

When a screen cannot effectively separate material, properly sized particles may remain with the oversize material rather than being recovered as product. This can lead to inconsistent product specifications, reduced recovery, and lost revenue.

AEI’s Difficult Material Screening Solutions

BIVITEC® Flip Flow Screen

The BIVITEC® flip flow screen’s unique dual-vibratory principle causes the polyurethane screen panels to rapidly expand and contract, creating a high-acceleration “trampoline effect.” This action helps actively repel wet, sticky, and fine particles from the screen surface rather than allowing them to build up and block the openings. 

The result is effective screening of challenging materials, such as compost, incinerator ash, clay, waste coal, and other difficult-to-screen materials while helping maintain screening efficiency. For more information, learn about compost screening with the BIVITEC.

Freedom Disc Screen

The Freedom Disc Screen is designed for applications involving bulky, fibrous, or clumping materials that can be difficult to size with conventional screening equipment. Its rotating HARDOX discs provide an aggressive screening action that helps separate materials, such as mulch and wood waste while minimizing the wrapping and tangling problems often associated with traditional star screens and trommels.

Custom Engineered Screening Systems

AEI designs custom-engineered and turnkey screening systems around the specific requirements of each customer’s operation. Factors (such as material characteristics, moisture content, desired separation, throughput, and available space) can all influence the right equipment configuration.

Whether you’re processing wet compost, sticky ash, bulky mulch, or another challenging material, AEI can help determine the screening technology and system configuration best suited to your application.

Contact our team to learn more about our equipment capabilities.