| 摘要 |
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.
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