technology
Engineered screen media is made with thicker material for increased durability, but this results in less open area. This is ideal for screening many small aggregates materials or for decks with mixed media. Hybrid screens are an option that combines woven wire with polyurethane to achieve open area closer to wire cloth, but with four to six times longer wear life, while weighing less than woven wire. Other polyurethane screens achieve additional durability with thicker wire to hold up to deep bed depths, large top sizes, and wide bar rail spacing. There are misconceptions that polyurethane is strictly for dry applications or only for wet applications; in fact, it works well in both. Look for rubber screen media when screening material with a top size larger than 30cm, or when an application requires an opening bigger than 10cm. Manufacturers can create rubber screens thicker than polyurethane for improved durability. The screens also dramatically reduce noise, handle high-impact applications, and resist abrasion.
Consider perforated steel plates for heavy-duty operations that require a large amount of open area. Some manufacturers customise each plate’ s thickness to a customer’ s application and can create almost any size opening. The screens should be manufactured with tapered openings to resist pegging. Many perforated plates come in different abrasionresistance levels, so be sure to choose a plate appropriate for the application.
Maintaining longevity
After determining the best combination of materials, open area, and opening size and shape, think about how the screen media will be installed. If a vibrating screen has a cambered deck, switching to a modular system can cost between R65 000 and R200 000. Look for a manufacturer that offers tensionable screen sections that hook for a cambered deck to eliminate the need for a costly deck conversion. This allows an operator to test the media on a vibrating screen with no additional costs or commitment, as well as the option to blend engineered media with woven wire cloth or self-cleaning screens. Engineered screen media products also come in modular panels for flat decks.
Also, be aware that engineered screen media is often heavier than woven wire cloth, so the weight of a vibrating screen may change.
Calling a screen mediza expert is a fast way to assess an operation and find the most effective screen media choices for an operation’ s specific needs. Look for a company that offers certified technicians with years of experience in vibrating screen media selection and maintenance. Some manufacturers not only offer consultations to help an operation find the best combination of screen media, but also provide on-site training to make sure the entire team knows how to properly install it to maximise wear life.
Ask the manufacturer to do a vibration analysis before and after installing the engineered screen media to ensure everything runs correctly. It’ s a good idea for producers to complete a weekly inspection of screen media. Inspect square holes carefully. Wear becomes apparent if the openings in engineered media begin to round. Make sure tensioning remains correct by checking screen tension weekly.
Make sure to look for a manufacturer that provides ongoing support, and find a company that follows up to make sure the screen media works well once in use. Some companies employ service technicians who can be on site within 24 hours to find, diagnose, and fix any problems that might arise.
Make the best choice
If an operations manager finds that traditional screen media isn’ t working and unscheduled changeouts are eating into profits, it might be time to consider a polyurethane, rubber or perforated plate product. Engineered screen media has the advantage of being versatile while bringing improved durability and longevity to a wide range of applications.
Perhaps most importantly, look for a company that takes pride in its work, provides great service, and has integrity. That, too, will save time and money. Following these tips will improve an operation’ s screen media life, profits and satisfaction for years to come. n
About the author
Steve Fair is the Tyler engineered media manager at Haver & Boecker. He has over 21 years of industry experience, and works with customers to identify screening challenges, improve their screening applications, and increase screening efficiency.
Multotec Progress Eco Haver & Boecker
Haver & Boecker
Polymer screen media, such as polyurethane and rubber, offer longer wear life than traditional screen media. Multotec’ s polyurethane screen media, for example, are manufactured with an internal steel frame for increased strength and longevity in heavy-duty applications.
Consider perforated steel plates for heavy-duty operations that require a large amount of open area, and make sure to choose the appropriate abrasion-resistance level for the application.
Haver & Boecker’ s Ty-Max is an opencast product manufactured by pouring polyurethane over a wire grid. This results in a durable product with high wearability.
Hybrid engineered screen media combine the qualities of woven wire cloth with polyurethane. Haver & Boecker’ s Ty-Wire, for example, has polyurethane’ s durable and abrasive-resistant qualities, but closer open area and less weight than woven wire.
32 _ QUARRY SA | March 2017