Blinding is when there is a decrease in the open area of a screen due to coating or plugging.

What is Plug Blinding?

We will focus on plug blinding as it has become more prevalent due to the increase in recycling. Plug blinding occurs when you screen material containing particles with irregular shapes. Think of candy corn: if the pointed end falls into a screen opening and then gets stuck or plugs the opening, it can prevent the fine material from passing.

Eventually, the screen section can lose its screening effectiveness as more particles plug into screen openings. Since this material wedges into the screen opening, the vibration energy used to screen the material isn’t always sufficient to knock them out of the opening. For example, the recycling of plastics creates irregularly shaped materials that can plug openings, thereby adversely affecting screening. Our challenge is to find a way to reduce plug blinding to keep our screening efficiency and reduce the downtime cost to clean the screen deck manually.

What is a Ball Tray Deck and How Does it Reduce Plug Blinding?

The most efficient means to reduce plug blinding is installing a ball tray deck beneath the screen section. The ball tray consists of compartments with a perforated plate at the bottom. We constructed segmented compartments and added balls to freely bounce during the operation of the screener. The balls strike the underside of the screen surface and randomly knock out the clogged material. The fine material that passes through the screen then passes through the perforated plate at the bottom of the ball tray where it can then be collected.

Ball trays are most effective when the vibrations produced make the balls more active. Vibratory Screeners that produce linear force like our model EMS electromechanical screeners are ideal for making the balls more active and more effective in reducing plug blinding. Screeners that use an electric motor to rotate a shaft with counterweights on both ends can also be effective.

Below, you can see a drawing of a ball deck application for screening plastic regrind. The cutaway illustrates the ball tray deck. The requirement for this application was two screen decks with different openings to create three separate product streams. In this case, we used a single deck profile by inserting a fine screen at the feed end and the coarse screen at the discharge end. The ball tray deck effectively reduced plug blinding of both screens.

We recommend considering ball tray decks if you are experiencing plug blinding. The savings in valuable man-hours to keep your screen openings clear should ultimately offset the additional expense. However, if you are experiencing other issues preventing the optimal performance of your screener, this blog discusses how to improve your screening efficiency.

For more information about The Cleveland Vibrator Company’s Vibratory Screeners and other products, click here!

Featured Image: Cleveland Vibrator Co.’s Ball Tray Deck Illustration 

Featured Image: Cleveland Vibrator Co.’s Ball Tray Deck Spec Sheet

Jack Steinbuch

Jack Steinbuch has been with The Cleveland Vibrator Company for over 36 years accumulatively. He has previous experience in the manufacturing industry as a Senior Application Engineer and has worn many hats on our team in sales and managerial capacities. Now, he’s in the position of General Sales Manager. With a BSCE from The University of Toledo, he is an expert in the realm of sizing vibratory screeners and feeders, and sizing vibratory drives for tables and other vibratory equipment. Understanding that customer service is crucial, Jack believes it is important to provide the proper product for every application, even if it happens to not be supplied by The Cleveland Vibrator Company.

In his off-hours, you can find Jack spending time with his family and playing with his grandchildren. He loves sports; both watching and playing, and is an avid golfer and a league bowler during the winter. He will be retiring at the end of September 2021 and hopes to spend his winters vacationing in Florida.