Flip-Flow screen

The precise design of a tension-shaft screening machine is always tailored to the recycled material. Factors such as the composition of the input material, its moisture content, contaminants, throughput requirements, and the recycling goals associated with the input material form the basis for this. Working with you, we define screening sizes, purity requirements, and throughput rates, and use this information to configure the exact machine settings—from screening panels to amplitude and machine features such as the SPALECK FineSideCOVER (FSC) or our MultiDECK technology with a split push rod. Learn more here about our ModularDESIGN+ concept, which we use to find the optimal screening machine for your material. We’d be happy to test the respective recycling material together with you free of charge at the SPALECK TestCenter.

Precise screening of the fine fraction results in clearly defined particle sizes. For example, if the fine fraction ranging from 0 to 10 mm is reliably screened out, downstream sorting equipment—such as eddy current separators, NIR sorters, sensor sorters, and X-ray sorters—operates more reliably and efficiently as a result. In addition, the system’s cleaning requirements are reduced, and higher material purity levels can be achieved. You can see a good example of the benefits of a tensioned-shaft screen in the reference video on municipal solid waste processing at our Swedish customer Tekniska verken. The video demonstrates how a SPALECK tension-shaft screen reduces the load on the downstream eddy current sorters and NIR sorting processes. You can find all the details about the project here.

The service life of screening mats for Flip-Flow screening machines depends heavily on the recycled material, the Recycling process, and factors such as the abrasiveness of the material stream. In many recycling applications, very long service lives are possible. Thanks to our bolt-free, modular clamping system, individual screening mats can be replaced quickly and easily as needed. You can see how this works in the video on our landing page for tension-shaft screen machines. You can get a competitive quote for replacement screening mats through our spare parts service.

Flip-Flow screening machines are designed for low-maintenance, continuous operation. The self-cleaning effect of the screen mats significantly reduces the need for manual cleaning. Maintenance is usually limited to regular visual inspections and the replacement of individual wear parts after extended periods of operation.

A Flip-Flow screening machine operates with two frame systems that move relative to one another. Screening mats are stretched between the base frame and the dynamic frame. These are stretched and tensioned by the cyclic movements of the dynamic frame. This generates extremely high accelerations in the screening panel. The material is actively loosened, allowing the fine particles to be screened through the mesh openings.

Tensioned-shaft screening panels are robust. They are suitable for a wide variety of recycled materials. They are also used in very demanding recycling applications, such as construction material recycling. While steel screening panels are generally more durable, screen mats made of PU or PVC also achieve very long service lives. We would be happy to advise you on the optimal screening panel for your material.

The screening mats used in Flip-Flow screening machines are made of highly wear-resistant, elastic materials such as polyurethane or rubber. They are specifically designed to withstand high dynamic loads. Depending on the type of recycled material, special abrasive screening mats, for example, may be used. With proper maintenance, damage caused by individual foreign objects can be minimized and service life maximized. Should damage occur, the mats can be replaced quickly and easily. You can find a video on this topic here. You can also view customer feedback from one of Europe’s largest non-ferrous metal recycling plants, in which the customer confirms the low maintenance requirements.

Depending on the machine configuration and screening panels, Flip-Flow screening machines can achieve separation cuts ranging from approximately 0.2 mm to about 50 mm. This makes them particularly well-suited for the precise separation of fine particles in Recycling processes. Depending on whether the machine is a single-deck or double-deck tension-shaft screen, up to three or up to four fractions, respectively, can be produced with a single machine.

Flip-Flow screening machines are used worldwide in a wide variety of recycling processes. Typical screening materials include, for example, materials from metal recycling, incinerator grate ash and non-ferrous concentrates from waste incineration, plastic waste, Compost, Biomass, construction waste, substitute fuels, and mixed municipal solid waste.

In the Recycling process, Flip-Flow screening machines are often operated in series with, for example, Recycling Waste Screens. SPALECK also offers the proven SPALECK 3D COMBI screening machine for this purpose. This machine combines a Recycling Waste Screen on the upper deck and a Flip-Flow screening machine on the lower deck in a single unit.

A Flip-Flow screening machine is a screening machine used to classify fine and difficult-to-screen materials. Flip-Flow screening machines use elastic screening mats that compress and tension very quickly during operation. The screening mats have holes of a specific size through which the target particles can fall and be screened out.

During compaction and tensioning, a so-called “trampoline effect” occurs in the screening mats. During the screening process, the material is constantly propelled upward and loosened.

If the fine grain with the appropriate particle size then falls back onto the screen mat, it can pass through one of the openings in the screen mat.

There is no difference between a tension-shaft screening machine and a flip-flow or flip-flop screening machine. The term “flip-flow” is used in recycling practice and originates from English. Tension-shaft screening machines are sometimes also referred to as flip-flop screening machines.

Recycled materials and the associated recycling processes and goals vary widely. Through targeted screening tests with your recycled materials, we will work together to determine the optimal Machine configuration for your tension-shaft screen.

The tests are valid and robust because they are conducted using realistic industrial quantities of the actual material. This allows for highly reliable conclusions regarding optimal machine design and subsequent Screening results.

Of course, you can also use the material prepared in this way for further testing with the screening equipment manufacturers of your choice. A free screening test at the SPALECK TestCenter using your own material often yields significant benefits for the entire Recycling process, as the tensioned-shaft screening technology is optimally designed.

The moist and sticky fine fraction can often lead to unwanted contamination, blockages, and material carryover during the Recycling process. In this context, Flip-Flow screening machines are less prone to sticking and blockages of the screening areas. With a Flip-Flow screening machine, the dynamic trampoline effect prevents the screening area from clogging. This minimizes the cleaning effort. In addition, moist and sticky materials can be reliably screened out.

The decision on whether to use a single-deck or double-deck tension-shaft screen depends entirely on the material and process. In practice, a SPALECK single-deck tension-shaft screen is usually sufficient, as it can produce up to three fractions. In processing and production processes, such as fertilizer production, double-deck tension-shaft screens are sometimes used. These allow for additional classification steps and produce up to four defined particle size fractions within a single screening process.