Impact-protective coating for plastic pipe

Claim 2

The combination of a plastic pipe, a film of bonding material on the pipe exterior surface, and an outer layer of crushable, multicellular, inorganic particles selected from the group consisting of natural volcanic lightweight aggregate, expanded shale, expanded clay, pumice, slag, and furnace cinder, or mixtures thereof, embedded in the bonding material so as to cover the exterior surface of the pipe, the particles being of substantially greater thickness than the film of bonding material so that the unembedded portions of the particles project away from the pipe body to provide a multicellular, inorganic coating which crushes by breaking to absorb energy upon impact and provides a level of impact protection for the pipe body.

Claim 3

The combination according to claim 1 in which the plastic pipe is made from a thermosetting resinous material.

Claim 4

The combination according to claim 1 in which the film of bonding material is between about 0.015 to about 0.025 inch thick, and the outer layer of particles is at least about one-sixteenth inch thick.

Claim 5

The combination according to claim 1 in which the outer layer of particles is between about one-sixteenth to about one-fourth inch in thickness.

Claim 6

The combination according to claim 4 in which the film of bonding material is between about 0.015 to about 0.025 inch thick.

Claim 7

The combination according to claim 5 in which the particles are distributed uniformly about the pipe surface in a single layer which covers substantially the entire exterior surface of the pipe.

Claim 8

A plastic pipe having a particulate, inorganic, multicellular crushable outer coating of particles selected from the group consisting of natural volcanic lightweight aggregate, expanded shale, expanded clay, pumice, slag, and furnace cinder, or mixtures thereof, embedded in a thin film of bonding material covering the exterior surface of the pipe, the particles being of sufficient thickness that a major portion of the particles projects freely away from the film of bonding material to form an impact protective outer layer which crushes by breaking apart to absorb energy upon impact and provide a level of impact protection for the pipe body.

Claim 9

A plastic pipe having a particulate, inorganic, multicellular crushable outer coating of particles selected from the group consisting of natural volcanic lightweight aggregate, expanded shale, expanded clay, pumice, slag, and furnace cinder, or mixtures thereof, embedded in a thin film of bonding material covering the exterior surface of the pipe, the particles being of sufficient thickness that a major portion of the particles projects freely away from the film of bonding material to form an impact protective outer layer which crushes by breaking apart to absorb energy upon impact and provide a level of impact protection for the pipe body.

Claim 10

A plastic pipe according to claim 7 in which the outer layer of particles is between about one-sixteenth to about one-fourth inch thick.

Claim 11

A plastic pipe according to claim 7 in which the film of bonding material is between about 0.015 to about 0.025 inch thick, and the outer layer of particles is at least about one-sixteenth inch thick.

Claim 12

The combination of a plastic pipe, a film of bonding material on the pipe exterior surface, and an outer layer of crushable, multicellular, inorganic particles selected from the group consisting of natural volcanic lightweight aggregate, expanded shale, expanded clay, pumice, slag, and furnace cinder, or mixtures thereof, embedded in the bonding material so as to cover the exterior surface of the pipe, the film of bonding material being about 0.015 to about 0.025 inch in thickness, and the outer layer of particles being between about one-sixteenth to about one-fourth inch thick so the unembedded portions of the particles project away from the pipe body to form a multicellular inorganic protective coating which crushes by breaking to absorb energy upon impact and provides a level of impact protection for the pipe body.

Claim 13

The combination of a plastic pipe, a film of bonding material on the pipe exterior surface, and an outer layer of crushable, multicellular, inorganic particles selected from the group consisting of natural volcanic lightweight aggregate, expanded shale, expanded clay, pumice, slag, and furnace cinder, or mixtures thereof, embedded in the bonding material so as to cover the exterior surface of the pipe, the film of bonding material being about 0.015 to about 0.025 inch in thickness, and the outer layer of particles being between about one-sixteenth to about one-fourth inch thick so the unembedded portions of the particles project away from the pipe body to form a multicellular inorganic protective coating which crushes by breaking to absorb energy upon impact and provides a level of impact protection for the pipe body.