Process for the continuous production of pipe from particulate materials

Claim 2

A process for continuously producing pipe which comprises: (a) coating a particulate material with an acid gascurable resin and an oxidizing agent suitable for accelerating curing of the resin, the amount of resin relative to the amount of particulate material being insufficient to reduce gas permeability of the compacted coated particulate material recited herebelow; (b) compacting and forming said coated particulate material into an annular pipe configuration, which is gas permeable, in an annular space defined by the inlet ends of spaced inner and outer walls; (c) feeding said compacted coated particulate material in said annular pipe configuration along a path, the initial part of which is said annular space between said inner and outer walls; (d) feeding an acid curing gas through perforations in one of said inner and outer walls and through said gas permeable compacted coated particulate material in said annular pipe configuration as said compacted coated particulate material in said annular pipe configuration moves along said path and is supported by said inner and outer walls to diffuse said curing gas through said compacted coated particulate material and cure said resin and form said particulate material into a self-supporting pipe having a porous wall; (e) gripping said self-supporting pipe at a position along said path downstream from the outlet end of said outer wall and drawing said self-supporting pipe along said path; (f) feeding a sealant into said porous wall of said self-supporting pipe to impregnate said porous wall with said sealant at a position along said path downstream from said outlet end of said outer wall; and (g) recovering the cured and impregnated pipe.

Claim 3

The process according to claim 1 wherein said particulate material is selected from the group consisting of sand, glass fibers and mixtures thereof.

Claim 4

The process according to claim 1 wherein said particulate material is coated with an acid gas-curable resin selected from the group consisting of urea formaldehydes, phenol formaldehydes, furans and furan copolymers.

Claim 5

The process according to claim 3 wherein said particulate material is coated with an oxidizing agent selected from the group consisting of peroxides, hydroperoxides, hydrooxyhydroperoxides, ring-substituted aralkyl hydroperoxides and perbenzoates.

Claim 6

The process according to claim 3 wherein said acid gas-curable resin applied to said particulate material ranges between about 0.5% and about 20% by weight based upon the weight of said particulate material.

Claim 7

The process according to claim 3 wherein said acid gas-curable resin applied to said particulate material ranges between about 0.5% and about 10% by weight based upon the weight of said particulate material.

Claim 8

The process according to claim 4 wherein said oxidizing agent applied to said particulate material ranges between about 1% and about 50% by weight based on the weight of said resin.

Claim 9

The process according to claim 4 wherein said oxidizing agent applied to said particulate material ranges between about 5% and about 30% by weight based on the weight of said resin.

Claim 10

The process according to claim 4 wherein said oxidizing agent applied to said particulate material is about 15% by weight based on the weight of said gas-curable resin.

Claim 11

The process according to claim 4 further comprising adding a coupling agent to said acid gas-curable resin and oxidizing agent coated on said particulate material.

Claim 12

The process according to claim 10 wherein said coupling agent is a silane.

Claim 13

The process according to claim 11 wherein said silane is selected from the group consisting of 3-aminopropyltriethoxysilane and 3-aminopropyltrimethoxysilane.

Claim 14

The process according to claim 11 wherein the amount of said silane applied to said particulate material ranges between about 0.05% to about 2.0% by weight based upon the weight of said acid gas-curable resin.

Claim 15

The process according to claim 11 wherein the amount of said silane applied to said particulate material ranges between about 0.1% to about 1.0% by weight based upon the weight of said acid gas-curable resin.

Claim 16

The process according to claim 4 wherein said acid curing gas is selected from the group consisting of sulfur dioxide and sulfuryl chloride.

Claim 17

The process according to claim 15 wherein the amount of said acid curing gas diffused through said compacted coated particulate material ranges up to about 3.0 molar equivalents per mol of oxidizing agent.

Claim 18

The process according to claim 16 wherein said acid gas curing agent is diffused through said compacted coated particulate material for a period of from about 0.5 seconds to about 2.0 minutes.

Claim 19

The process according to claim 16 wherein said resin on said particulate material is cured by said acid curing gas at a temperature ranging from room temperature to 140° F.

Claim 20

The process according to claim 1 wherein said sealant for impregnating said self-supporting pipe is selected from the group consisting of an asphaltic composition and a resinous composition.

Claim 21

The process according to claim 19 wherein said resinous composition is selected from the group consisting of thermoplastic and thermosetting resins.

Claim 22

The process according to claim 20 wherein said resin is selected from the group consisting of polystyrene, polyethylene, polystyrene cross-linked polyester thermosets and furan-phenolic thermosets.

Claim 23

The process according to claim 1 further comprising the step of winding a resinous or glass filament about the exterior surface of said impregnated pipe.

Claim 24

The process according to claim 22 wherein the denier of said filament is between about 1 and about 15.

Claim 25

The process according to claim 23 wherein the denier of said filament is between about 1.5 and about 10.

Claim 26

the process according to claim 1 wherein said acid gas-curable particulate material is compacted by forcing the particulate material with said auger into an annular space.

Claim 27

A process for continuously producing pipe which comprises: (a) coating a particulate material selected from the group consisting of sand and glass fibers and mixtures thereof with a mixture of an acid gas-curable resin selected from the group consisting of urea fomaldehydes, phenol formaldehydes, furans and furan copolymers and an oxidant selected from the group consisting of peroxides, hydroperoxides, hydrooxyperoxides, ring-substituted aralkyl hydroperoxides and perbenzoates, the amount of resin relative to the amount of particulate material being insufficient to reduce gas permeability of the compacted coated particulate material recited herebelow; (b) compacting and forming said acid gas-curable resin coated particulate material into an annular pipe configuration, which is gas curable, by forcing it into an annular space defined by the inlet ends of spaced inner and outer walls by means of an auger; (c) feeding said compacted coated particulate material in said annular pipe configuration along a path, the initial part of which is said annular space between said inner and outer walls; (d) feeding an acid curing gas, selected from the group consisting of sulfur dioxide and sulfuryl chloride, through perforations in one of said inner and outer walls and through said gas permeable compacted coated particulate material in said annular pipe configuration as said compacted coated particulate material in said annular pipe configuration moves along said path and is supported by said inner and outer walls to diffuse said curing gas through said compacted coated particulate material and cure said resin and form said particulate material into a self-supporting pipe having a porous wall; (e) gripping said self-supporting pipe at a position along said path downstream from the outlet end of said outer wall and drawing said self-supporting pipe along said path; (f) feeding a sealant, selected from the group consisting of asphaltic and resinous compositions, into said porous wall of said self-supporting pipe to impregnate said porous wall with said sealant, at a position along said path downstream from said outlet end of said outer wall; (g) applying a filament binding to the exterior surface of the impregnated pipe; and (h) recovering the cured and impregnated pipe.

Claim 28

A process for continuously producing pipe which comprises: (a) coating a particulate material selected from the group consisting of sand and glass fibers and mixtures thereof with a mixture of an acid gas-curable resin selected from the group consisting of urea fomaldehydes, phenol formaldehydes, furans and furan copolymers and an oxidant selected from the group consisting of peroxides, hydroperoxides, hydrooxyperoxides, ring-substituted aralkyl hydroperoxides and perbenzoates, the amount of resin relative to the amount of particulate material being insufficient to reduce gas permeability of the compacted coated particulate material recited herebelow; (b) compacting and forming said acid gas-curable resin coated particulate material into an annular pipe configuration, which is gas curable, by forcing it into an annular space defined by the inlet ends of spaced inner and outer walls by means of an auger; (c) feeding said compacted coated particulate material in said annular pipe configuration along a path, the initial part of which is said annular space between said inner and outer walls; (d) feeding an acid curing gas, selected from the group consisting of sulfur dioxide and sulfuryl chloride, through perforations in one of said inner and outer walls and through said gas permeable compacted coated particulate material in said annular pipe configuration as said compacted coated particulate material in said annular pipe configuration moves along said path and is supported by said inner and outer walls to diffuse said curing gas through said compacted coated particulate material and cure said resin and form said particulate material into a self-supporting pipe having a porous wall; (e) gripping said self-supporting pipe at a position along said path downstream from the outlet end of said outer wall and drawing said self-supporting pipe along said path; (f) feeding a sealant, selected from the group consisting of asphaltic and resinous compositions, into said porous wall of said self-supporting pipe to impregnate said porous wall with said sealant, at a position along said path downstream from said outlet end of said outer wall; (g) applying a filament binding to the exterior surface of the impregnated pipe; and (h) recovering the cured and impregnated pipe.

Claim 29

The process according to claim 15 wherein said sealant for impregnating said self-supporting pipe is selected from the group consisting of an asphaltic composition and a resinous composition.

Claim 30

The process according to claim 27 wherein said resinous composition is selected from the group consisting of thermoplastic and thermosetting resins.

Claim 31

The process according to claim 28 wherein said resin is selected from the group consisting of polystyrene, polyethylene, polystyrene cross-linked polyester thermosets and furan-phenolic thermosets.

Claim 32

The process of claim 1 wherein said self-supporting pipe having a porous wall is continuously fed along said path through a manifold surrounding said porous wall of said selfsupporting pipe and said sealant is fed under pressure from said manifold into said porous wall of said pipe to impregnate and seal said porous wall.

Claim 33

The process of claim 26 wherein said self-supporting pipe having a porous wall is continuously fed along said path through a manifold surrounding said porous wall of said selfsupporting pipe and said sealant is fed under pressure from said manifold into said porous wall of said pipe to impregnate and seal said porous wall.

Claim 34

The process according to claim 26 wherein said resinous composition is selected from the group consisting of thermoplastic and thermosetting resins.

Claim 35

The process according to claim 32 wherein said resin is selected from the group consisting of polystyrene, polyethylen, polystyrene cross-linked polyester thermosets and furan-phenolic thermosets.