Abstract: Screen member for use in fixed or rotating screen support devices and in either a vibrating or non-vibrating mode for grading or dewatering comprises a first plurality of elongated, parallel surface wire members which are formed by extruding a resilient, abrasion resistant layer of elastomeric material completely around a core portion which is more rigid than the elastomeric layer. A second plurality of elongated, parallel support rod members arranged transverse to the first plurality are also formed by extruding a layer of elastomeric material completely around a more rigid core portion. The first and second plurality of wire members are bonded to each other at every intersection by a partial melting together of the contacting elastomeric layers under pressure.

Abstract: Plastic well screen has tapered, undercut slots formed by a laser beam focused through a lens having its focal point located at or slightly away from the surface of the plastic cylinder being slotted so that the laser beam diverges as it passes through the plastic. The cylinder is rotated and simultaneously moved axially relative to the laser beam to produce a series of transverse slots. In one embodiment, the laser beam is interrupted to provide continuous longitudinal support portions in the cylinder. In a modified embodiment, the cylinder has integral internal ribs which remain intact even though the laser is operated continuously to remove surface material located between the ribs and the laser beam.

Abstract: Plastic well screen has tapered, undercut slots formed by a laser beam focused through a lens having its focal point located at or slightly away from the surface of the plastic cylinder being slotted so that the laser beam diverges as it passes through the plastic. The cylinder is rotated and simultaneously moved axially relative to the laser beam to produce a series of transverse slots. In one embodiment, the laser beam is interrupted to provide continuous longitudinal support portions in the cylinder. In a modified embodiment, the cylinder has integral internal ribs which remain intact even though the laser is operated continuously to remove surface material located between the ribs and the laser beam.

Abstract: A well screen formed of an extruded wedge shaped plastic strip wound about cylindrically disposed supporting rods in which the flexible strip is extruded of dual durometer dissimilar materials in the form of a unitary strip having complementary characteristics in which one body portion is formed of a suitable substantially rigid plastic material and another body portion is formed of a plastic material which has relatively greater strength characteristics whereby in the event of cracking of one of the portions, the strip is held together in a useable condition by the other body portion and a coating of abrasive resistant material is extruded unitarily with the strip to form an outer surface portion having substantial resistance to wear.