Elastic Mesh or Flip-Flop Screens. What are they and how do they work.

In the field of bulk separation of materials, the market demands advanced solutions every day to allow more added value to the products. The elastic mesh screen, also known as the Flip-Flop screen, has recently been installed in today’s installations and is a highly effective solution for the screening of sticky and colchant products, which cannot be screened with traditional screen.

Criba de Malla Elástica (también llamada Criba Flip-Flop).

Elastic Mesh Screens (also called Flip-Flop Screens)

What are elastic mesh or Flip-Flop screens?

They are screens in which the meshes are of elastic polyurethane (see picture 1), which are moved by the mechanical action of another external element and which can be external vibration or direct mechanical movement.

These meshes can cut from 2mm to 100mm. Its holes can be round, square and oblong. In the case of Rollier Flip-Flop screens, there are different mesh qualities, depending on the temperature conditions, acidity or toughness of the material that runs on them. Rollier has specific polyurethane formulations for this purpose.

 

How Flip-Flop screens Work

There are several types of operation

  • By direct mechanical movement of mesh: a connecting rod directly agitates the meshes while the frame remains static (see picture 2). In order for the material to flow, these machines need a lot of slope, so their installation is complicated.

  • By  indirect vibration movement in the mesh and elastic cranks: multiple elastic cranks move, due to vibration, an additional plate that accommodates the securing of the meshes at one end, while the other end of the mesh is attached to the main frame. The fact that this type of screen has multiple elastic rods makes these screens require a careful maintenance. (See picture 3).
Figura 3. Criba con funcionamiento por movimiento indirecto por vibración en la malla y bielas elásticas

Picture 3. Screen functioning with the indirect vibration movement in the mesh and elastic cranks

  • By movement by sympathy of a floating bridge: The screen has a floating bridge (made of structural profile) on sandwich blockbars. This bridge secures the meshes at one end while the other is attached to the main frame. The floating bridge moves with a much greater amplitude than the screen, which causes an alternative stretching and contraction of the mesh. This is the most reliable system due to its robustness and compactness (See Picture 4). The Rollier MFX sieves belong to this type of Flip-Flop or mesh screens.

Picture 4. Floating bridge Flip-Flop Screen system

What is the use of elastic mesh screens or flip-flops?

Their applications are multiple and are summarized in that they are able to sift any product that is difficult to screen in a conventional screen, either by its humidity or by its tackiness or adhesion.
We highlight the following fields:

  • Quarry sterile with clay content
  • Compost
  • Municipal Waste
  • Recycling of plastics
  • Dirty or very dirty coal
  • Sterile minerals
  • Slag
  • Glass
  • Paper pulp
  • Dried sludge
  • Vegetable waste
  • Sawdust, woods
  • Crushed gum
  • Recycled concrete waste

Rollier manufactures screens of elastic mesh or flip-flops up to four decks. All or part of them in elastic mesh and the rest according to customer requirements.

Cribas flip-flop o de malla elástica de Rollier listas para expedición

Rollier Flip-Flop screens (or Elastic Mesh Screens) ready for delivery

 

Foto 5. Criba Flip-Flop o de malla elástica MFX II 220-700 (2.200 mm ancho x 7.000mm) con dos pisos: superior en poliuretano fijo e inferior en malla elástica (Flip-Flop).

Photo 5. Flip-Flop Screen or Elastic Mesh Screen model MFX II 220-700 (2.200 mm wide x 7.000mm) with two levels: upper made in poliuretane fixed and lower level with elastic mesh (Flip-Flop).

Rollier Vibrating Machinery