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Glossary A-Z

Loss of screening material that occurs due to operation and environmental impact.

Adhesive grain
Fine particles that stick to coarse material or the screen.

Adhesive layer formation
See also clogging.

Several connected particles.

European directive for the prevention of explosions. See ATEX product line 94/9/EC and ATEX operating line 1999/92/EC.

Ball deck
Deck under the screen surface to support the rubber balls for bouncing.

Consecutive curves on a wire as a result of pre-forming or weaving.

Blind bottom
A sheet of metal in place of a screen.

Bulk wire
The mass of a material to be screened divided by its volume at the time it is loaded onto the screen.

Clamping element
General term for one of many tensioning elements that tighten a screen cloth on the screen frame.

Clamping jaw
Metal part to clamp and/or fix the screen.

Separation of a screened material into fractions defined by their limiting sizes.

Separation of granular material into groups of specific particle sizes.

Reduction or complete blockage of the sieve openings caused by very fine particles adhering to the screen.

Coarse material
Screening material whose grain size is larger than the openings of the associated screen in at least one direction.

Control sieve
Sieve which determines the largest grain.

The dry removal of very fine particles from a feeding material.

Removal of fine particles from wet material on a sieve.

Separation of loose water from the solids.

Double bending
Screen cloth with bent warp and weft wires.

All elements which set the sieve in motion, e.g. motor, V-belt, pulleys, etc.

Drum screen
Cylindrical drum made of perforated plate or stiff mesh.

Drum screening machine
Screening machine in which the screening surface forms a cylindrical, polygonal, or conical drum which is set in rotation about its longitudinal axis, which may be horizontal or inclined. The material to be screened is put into the drum.

Dry sieving
Separating screenings that do not have free liquid and therefore do not show adherence.

Effective screen area
The portion of the screen deck area available for screenings separation.

Feed hopper
An extension of the screen frame for receiving the feed material.

Feed material
Screening material that is fed to the screening surface for classification.

Fine grain output
Screening passage, where the missing grain is accounted for.

Fine material
Screening material that is essentially smaller than the mesh size of the screening surface. Its equation with „passage“ is not recommended.

Happens when a screening machine is overloaded.

Free screen area
The ratio of sieve opening areas to screen area.

Harp sieve
Woven wire screens with a ratio between longitudinal and transverse wire meshes significantly greater than 1:5.

Hook plates on both sides with which the screens are hooked and tensioned.

Particles jammed in screen openings (plugged grain).

Longitudinal tensioner
The screen is stretched longitudinally to the material flow.

Number of screen holes per inch. American measure of mesh size is inaccurate.

Mesh count
Number of holes per unit length in a wire cloth.

Mesh size w
Length of the characteristic holes of a sieve surface.

A row of screen decks parallel to each other on the throw sieve.

Nominal particle size
The particle sizes that describe the output material.

Oblong mesh, wide mesh
Wire screen in which one dimension of the mesh size is larger than the other. It is common that the mesh ratio is 3:1.

Open screen area
Screen mesh: percentage of all mesh openings on the total screen area. Perforated plates: percentage of all openings on the entire plate.

Open screen area
For wire screen: percentage of all mesh area on total screen area. For perforated plates: percentage of the area of all holes to the total area of the perforated portion of the plate (excluding any unperforated portions).

Opening width
Size of the opening in a screen.

The portion of the feed material that does not pass through the openings of the screen.

The total material passing through a screen, including extraneous material.

Perforated metal
Perforated sheet with holes of various shapes.

Perforated plate
Screen consisting of a plate with evenly and regularly arranged holes. The holes may be square, slit-shaped, or round or have any other regular geometric shape.

Distance between two comparable centers of adjacent openings in a wire cloth, wire screen, wire screen, or perforated plate.

Plain weave
Weave in which each warp wire crosses alternately under and over each weft wire, or vice versa.

Dry sieving under 1mm.

Protective sieve
A vibrating screen for protective screening.

Protective screen
Screen with large openings as a support structure underneath a sieve cloth with a smaller mesh size.

Rectangular mesh
Elongated screen opening in screen cloth and perforated plate.

Screen cloth
A screen surface with square, rectangular or slotted woven openings.

Screen deck
Part of a screening machine, consisting of screening surface, screen frame and accessories.

Screen edge preparation
Placement of hooks, folds and joints on the screen edges into which the tendons engage.

Screen passage
The part of the feed material that passes the screen.


Screening frame
Fixed frame that supports the vibrating body.

Screening machine
Device used to classify a mixture of grains by sieving for industrial purposes. NOTE: The English term „screen“ is usually also used as an abbreviation of „screening surface“ or „screen deck“.

Screening surface
The component that contains the openings for the passage of the fine material.

Selvage edge
A prepared edge of the screen cloth, made during weaving.

The process of offering openings to grains, rejecting them if larger and allowing them to pass if smaller.

Sieve analysis, particle size analysis
Determination of the proportion of grain categories in the total quantity.

Sieve box
Construction in which the screen mesh is fixed.

Sieve cover
For surface screens with regularly arranged holes of similar shape and size.

Sieve tensioning
Attachment of a prestressed screen cloth to a frame. This can be done by gluing, welding or stapling.

Finished screen surface including tensioning folds.

A mechanical process for separating particles according to particle size by comparison with the size of the sieve opening.

Sieving area
Sieve area complete with tensioning device.

Size fraction
The range between two specified limit sizes of the screenings with particle sizes between these limits.

Slotted sieve, screen with profiled wires
The screen consists of wires with a wedge or trapezoidal cross-section, equally spaced from each other. In this way, the material passes through an opening of increasing cross-section.

Separation of material according to its type.

Square mesh
Screen mesh of equal length in warp and weft directions.

Support fabric
Coarse-mesh screen fabric for protecting fine-mesh separating fabrics

Support frame
Part of the screen frame that provides special support for the screen cloth.

Tensioning edges
Edge treatment of a screen mesh for fastening or tensioning.

Test sieve
Determination of particle size distribution by test sieves with defined mesh size.

Test sieve
A circular sieve frame with a tightly tensioned screen of standardized dimensions.

Transverse tension
The screen is tensioned transversely to the material flow.

Tumbler screen
Circularly oscillating tumbler screen with superimposed tumbler motion.

Twill weave
Weave in which each warp wire alternately under crosses and over crosses several wires, or vice versa.


Ultrasonic excitation
The use of ultrasound to prevent screen clogging in fine meshes.

The portion of the feed that passes at least in one direction of the screen.

All wires of a wire screen running parallel to the weaving direction.

Warp wire
Wires that run in the longitudinal direction.

Removal of finer or foreign particles trapped between or adhering to the larger particles by spraying, usually with water.

Washing, rinsing
Removal of fine material during wet screening.

All wires of a wire screen running at right angles to the weaving direction.

Weft wire
Wires running perpendicular to the longitudinal direction of the sieve.

Wet sieving
Screening by means of a liquid; generally by spraying.

Wire cloth; wire mesh
A screen made either by weaving or by pressure welding two layers of parallel wires. The wires form equally sized square or rectangular openings. They can be bent before the weaving process.

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