Choosing the right conical mill screen for your application is crucial in achieving your desired particle size range and enhancing the performance of the mill. There is a choice of Round Hole, Grater Hole, Conidur Hole, Square Hole, Slotted Hole and Diffusion Bonded mill screens.
- Round Hole Screen
Used for the particle size reduction of free-flowing materials, granules, small lumps and powders.
- Grater Hole Screen
Used for milling materials such as seeds and other hard products for reclaim purposes (e.g. tablets, sweets).
- Conidur Hole Screen
Designed for milling hard materials (e.g. seeds, tablets and sweets) which require a more aggressive milling action.
- Square Hole Screen
Used for coarse milling applications, producing flakes of material, as well as being suitable for wet milling applications.
- Slotted Hole Screen
Suited for wet granulation sizing and milling applications; these screens produce larger particle sizes than a square hole mill screen.
- Diffusion Bonded Conical Mill Screen
Used to produce even finer particle sizes than is achievable with standard screens.
Round Hole
This is the most commonly used mill screen for cone milling applications. Typically used for the size reduction of free-flowing materials, granules, small lumps and powders can be easily milled through the round hole screen. Common round hole applications include most powders, APIs or most other dry, friable materials. A wide range of screen meshes are available, in different sizes and with different apertures.
A round hole screen is designed for the standard milling applications and is used to size product before it leaves the screen. As the impeller rotates, it forces the material through the holes in the screen, reducing the size of the particles. It should be noted that the particles exiting through the hole will be smaller than the hole itself, as the particle exits at a diagonal trajectory, rather than head-on. Therefore the speed of the impeller will impact particle size (faster speed = smaller particle).
Grater Hole
The surface of the screen is raised to create a rasp, which creates a shearing action for breaking up the material. Typical applications for a grater hole screen include seeds, and hard products which are trying to be reclaimed, such as tablets or sweets.
A grater screen is designed for the milling of particularly hard materials, which require a more aggressive milling action than a conventional round hole screen. Typically these applications will require a square-bar impeller.
Conidur Hole
A conidur screen is similar to a grater hole screen with a raised hole to create a rasp, but a conidur screen can be used to produce a smaller particle size. A conidur hole screen is made from conidur sheet, allowing it to be manufactured with a smaller hole size than is available with grater hole screens.
It is designed for the milling of hard materials which require a more aggressive milling action (e.g. seeds, tablets and sweets).
Square Hole
Large aperture square hole screens are mainly used for coarse milling applications such as deagglomeration of fruits or for producing flakes of material. The square hole screen is also suitable for wet milling (moist) applications such as de-lumping of wet mass granulation in pharmaceutical processing.
Slotted Hole
Similar to square hole screens, the slotted hole is suited for wet granulation sizing and milling applications. These screens typically produce larger particle sizes than a square hole mill screen.
Diffusion Bonded
The pioneering design of the diffusion bonded mill screen uses no adhesive for an ultra hygienic, GMP compliant solution. These screens allow customers to produce even finer particle sizes than achievable with standard screens.
Get in Touch
If you would like to speak to one of our experts regarding our range of Mill Screens or you would like a quote for one of our products, send us a message using our Contact Form or call us on +44 (0)1702 549 777.
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