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.

A screen panel assembly includes a screen panel and a raised screen component disposed thereon. The raised screen component includes an inclined screen surface that defines a first plane oriented at a first angle relative to the screen panel and a wedge surface positioned at a back side of the raised screen component. The inclined screen surface has a front edge that is aligned with a top surface of the screen panel and is substantially perpendicular to a longitudinal axis of the screen panel, the first plane being substantially perpendicular to a displacement vector along which the screen panel assembly is accelerated by a vibratory separation device. The wedge surface is adapted to disrupt a flow path of a flow of a material mixture flowing in a longitudinal direction across the screen panel by redirecting the flow around opposing sides of the raised screen component.

A screen panel assembly includes a screen panel and one or more raised screen components, wherein at least one of the raised screen components is disposed on the screen panel. Furthermore, each of the one or more raised screen components includes at least one inclined screen surface that defines a first plane that is oriented at a first angle relative to said screen panel. Additionally, the first plane is substantially aligned with a second plane that is oriented at a second angle relative to a third plane that is perpendicular to a displacement vector along which the screen panel assembly is accelerated by a vibratory separation device.

A vibratory screening machine includes replaceable screen assemblies. Compression mechanisms are used to secure replaceable screen assemblies to the vibratory screening machine. Each compression mechanism applies a force to a replaceable screen assembly that includes both a horizontal component and a downward vertical component. Each replaceable screen assembly is typically substantially flat prior to installation on a vibratory screening machine. The force applied to a screen assembly by one or more compression mechanisms causes the screen assembly to be pushed into engagement with underlying concave support members such that the screen assembly itself assumes a concave shape with the center of the screen assembly being lower than the side edges. The vertical downward component of the force helps to secure the screen assembly to the screening machine.

A modular, pre-tensioned, self-cleaning screening panel having a frame and at least one pre-tensioned wire that is fastened to the frame.

An apparatus for producing a construction material for use in the building industry is disclosed. The apparatus comprises a hopper (10) which includes a trough (11) having a base section and an open top to allow material to be added to the hopper. The base section of the hopper includes a grinding array (24). A separation array (152) is deployed above the open top with the separation array comprising a plurality of elongate tines (151), each having a first end and a second end, mounted parallel to each other, and secured at least at one end to a support means.

A disclosed screening apparatus includes a subgrid, and a screen element attached to the subgrid via laser welding at a plurality of attachment positions such that, under vibrational excitation, the screen element has a pre-determined profile of vibrational motion relative to the subgrid. The screen element may be attached at a maximal number of attachment locations to the subgrid to minimize relative motion of the screen element and the subgrid under vibrational excitation, or the screen element may be attached a sub-set of the maximal number of attachment locations to allow vibrational motion of the screen element relative to the subgrid. A disclosed method may include attaching a plurality of screen elements to a respective plurality of subgrids, attaching the plurality of subgrids to one another to form a screening pre-assembly, and cutting edges of the screening pre-assembly to form the screen assembly having a perimeter with a pre-determined shape.