Magnetically detectable plastic pipe
First Claim
1. A method of producing magnetically detectable plastic pipe for underground use, comprising;
- providing an organic plastic for extrusion,providing particles of magnetic material comprising electrically-nonconductive, highly-magnetizable iron oxide or barium ferrite,mixing said particles of electrically-nonconductive, highly-magnetizable iron oxide or barium ferrite uniformly with said organic plastic, heating and extruding said mixture of organic plastic and electrically-nonconductive, highly-magnetizable iron oxide or barium ferrite and highly magnetizing said particles to produce a hollow tubular pipe having said highly magnetized particles distributed and proportioned such that the plastic pipe may be easily detected by magnetic detection apparatus on the surface when the plastic pipe is buried at three to five feet or more under the ground.
1 Assignment
0 Petitions
Accused Products
Abstract
A magnetically detectable plastic, e.g., polyethylene, polyvinyl, etc., pipe for underground use comprises a hollow tubular plastic pipe having particles of magnetic material embedded in plastic and secured integrally with the wall of the pipe. The magnetic particles are of iron oxide or barium ferrite and of a size, shape, distribution and proportion such that the plastic pipe may be easily detected by magnetic detection apparatus on the surface when the plastic pipe is buried at a selected depth under the ground. The magnetic particles are uniformly distributed throughout the thickness and uniformly distributed around the entire circumference of the plastic pipe or the magnetic particles may be distributed in discrete portions of the plastic pipe, as for example, a uniform outer layer of the pipe or in stripes or strips extending along the pipe. The particles may be extruded with the plastic in forming the pipe, whether uniformly dispersed or in discrete regions or the pipe may be formed of plastic free of the magnetic particles and the magnetic particles provided in a separately applied strip which may be coextruded or fused or adhered to the wall of the pipe. The magnetic strips or magnetic portions of the plastic pipe may have selective areas or portions magnetized to encode information readable from the surface of the ground above the buried pipe or in inventorying pipe on the surface.
59 Citations
17 Claims
-
1. A method of producing magnetically detectable plastic pipe for underground use, comprising;
-
providing an organic plastic for extrusion, providing particles of magnetic material comprising electrically-nonconductive, highly-magnetizable iron oxide or barium ferrite, mixing said particles of electrically-nonconductive, highly-magnetizable iron oxide or barium ferrite uniformly with said organic plastic, heating and extruding said mixture of organic plastic and electrically-nonconductive, highly-magnetizable iron oxide or barium ferrite and highly magnetizing said particles to produce a hollow tubular pipe having said highly magnetized particles distributed and proportioned such that the plastic pipe may be easily detected by magnetic detection apparatus on the surface when the plastic pipe is buried at three to five feet or more under the ground. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. A method of producing magnetically detectable polymeric pipe for underground use, comprising:
-
providing a hollow tubular pipe of organic polymer, providing a strip of organic plastic containing particles of electrically-nonconductive, highly-magnetized iron oxide or barium ferrite, affixing at least one said strip of organic polymer containing particles of electrically-nonconductive, highly-magnetized iron oxide or barium ferrite to said plastic pipe to produce a composite pipe having said electrically-nonconductive, highly-magnetized iron oxide or barium ferrite particles positioned and proportioned such that the plastic pipe may be easily detected by magnetic detection apparatus on the surface when the plastic pipe is buried at a selected depth under the ground or otherwise at a distance from the plastic pipe. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17)
-
Specification