A triple layer non-plugging screen for use with a vibrating screening machine to filter particles from a liquid has an upper filtering layer made of warp and shute wires that intersect to form an array of small openings, a lower strengthening layer having an array of large openings, and an anti-plugging layer. The anti-plugging layer is sandwiched between the upper filtering and lower strengthening layers and is made of warp and shute wires that intersect to form an array of openings. The upper filtering and anti-plugging layers are oriented within the screen so that at least one of the warp and shute wires of the anti-plugging layer obstructs at least some of the openings in the upper filtering layer. This reduces the likelihood of entrapment of undesirable particles in the obstructed openings of the upper filtering layer.

A method for efficiently producing a toner for developing electrostatic images, which contains very few coarse particles and having excellent printing characteristics. The method can comprise a sieving step of removing coarse particles from colored resin particles by, using an air flow, supplying the colored resin particles to a sieve, wherein a metal mesh laminate comprising at least two metal meshes attached to each other by sintering, the metal meshes being different in opening size, is used as the sieve; wherein the metal meshes of the metal mesh laminate are laminated in order of opening size and, of the metal meshes constituting the metal mesh laminate, one having a smallest opening size is disposed on a side of supplying the colored resin particles; and wherein the opening size of the metal mesh having the smallest opening size is in a range of from 32 to 110 m.

An apparatus for washing and grading sand and aggregate includes a first multi-deck screen and a sump for collecting undersize material from the plurality of decks. A first set of hydrocyclones receives undersize material and water from the sump of the first screen. A second screen has a deck for producing at least one sand product and a sump beneath the deck, the deck of the second screen receiving an underflow from each cyclone of the first set of hydrocyclones. A second set of hydrocyclones receives undersize material and water from the sump of the second vibratory screen. The deck of a third screen receives an underflow from each cyclone of the second set of hydrocyclones. A further hydrocyclone receives undersize material and water from the sump of the third screen, and an underflow from the further hydrocyclone is delivered onto the deck of the third screen.

A screening tool includes at least a first screen lining which is coupled to a metal coupling element to which an ultrasonic transducer is connected which is connected by electrical lines to an ultrasonic generator. The screening tool includes a metal work plate which has a connection region and at least one first transfer region with first transfer openings, which first transfer region forms the first screen lining through which particles of the process material which are larger than the transfer openings can pass, from particles of the process material smaller than the transfer openings, wherein the coupling element is a curved or straight rod having a first end piece welded to the connection region and a second end piece mechanically connected to the ultrasonic transducer. The screening device includes one or more such screening tools and a control unit by means of which the ultrasonic generator is controllable.

Screening members, screening assemblies, methods for fabricating screening members and assemblies and methods for screening materials are provided for vibratory screening machines that incorporate the use of injection molded materials. Use of injection molded screen elements provide, inter alia, for: varying screening surface configurations; fast and relatively simple screen assembly fabrication; and a combination of outstanding screen assembly mechanical and electrical properties, including toughness, wear and chemical resistance. Embodiments of the present invention use a thermoplastic injection molded material.

Screening members, screening assemblies, methods for fabricating screening members and assemblies and methods for screening materials are provided for vibratory screening machines that incorporate the use of injection molded materials. Use of injection molded screen elements provide, inter alia, for: varying screening surface configurations; fast and relatively simple screen assembly fabrication; and a combination of outstanding screen assembly mechanical and electrical properties, including toughness, wear and chemical resistance. Embodiments of the present invention use a thermoplastic injection molded material.

Screening members, screening assemblies, methods for fabricating screening members and assemblies and methods for screening materials are provided for vibratory screening machines that incorporate the use of injection molded materials. Use of injection molded screen elements provide, inter alia, for: varying screening surface configurations; fast and relatively simple screen assembly fabrication; and a combination of outstanding screen assembly mechanical and electrical properties, including toughness, wear and chemical resistance. Embodiments of the present invention use a thermoplastic injection molded material.

According to one aspect there is provided a screen assembly for a vibrating screening machine. The screen assembly comprises a screen chassis and a screen for screening material such as a solution containing liquid and solids. The screen chassis comprises a first face and a second face opposite to the first face, the screen chassis defining a plurality of openings therethrough from the first face to the second face for allowing passage of a material that has been screened. The screen is attached to the first face of the screen chassis and covering the openings of the screen chassis at the first face. The screen chassis may be made of a light-weight, stiff material. The screen may be made of a durable material such as metal. A method for making a screen assembly is also provided.

Vibratory separator screens separate solids and/or fluids, methods form said screens and vibratory screen apparatuses utilize said screens. The vibratory separator screens, methods and apparatuses have a mesh portion having a first side of the mesh portion and an opposite second side of the mesh portion, a first hem crimp affixed to the first side of the mesh portion, and a second hem crimp affixed to the second side of the mesh portion.

A shaker screen for attachment to a bed of a shaker includes a screen frame having at least one mesh screen attached to the top side of the screen frame, wherein the screen frame is preferentially bowed prior to attaching the mesh screen to the screen frame.