Method of continuously producing a synthetic resin coated pipe

Claim 1

A method for continuously producing an elongated pipe, suitable for use as a supporting pole for growing plants, tightly coated with a synthetic resin coating and having annular projections, which comprises: a. forming a hollow elongated pipe from an elongated band of metal by means of a forming machine and welding the seam, b. subjecting the surface of the pipe thus prepared to an alkali treatment and a chemical treatment, c. coating the surface of the pipe thus treated with an adhesive consisting of an organic solvent solution of at least one component selected from the group consisting of a terpolymer of vinyl chloride, vinyl acetate and maleic anhydride, a nitrilebutadiene rubber, as epoxy resin-modified phenol resin, a dehydrated castor oil-modified epoxy resin, and a terpolymer of an acrylic ester, acrylamide and styrene, followed by d. drying and baking the layer formed, and e. applying to the surface of the adhesive layer a synthetic resin coating having annular projections at regular intervals by means of an extruder having a cross head die including therein, in the space between the die body and the top portion of the mandrel a projection forming member movable reciprocally in the axial direction.

Claim 2

A method for continuously producing an elongated pipe, suitable for use as a supporting pole for growing plants, tightly coated with a synthetic resin coating and having annular projections, which comprises: a. forming a hollow elongated pipe from an elongated band of metal by means of a forming machine and welding the seam, b. subjecting the surface of the pipe thus prepared to an alkali treatment and a chemical treatment, c. coating the surface of the pipe thus treated with an adhesive consisting of an organic solvent solution of at least one component selected from the group consisting of a terpolymer of vinyl chloride, vinyl acetate and maleic anhydride, a nitrilebutadiene rubber, as epoxy resin-modified phenol resin, a dehydrated castor oil-modified epoxy resin, and a terpolymer of an acrylic ester, acrylamide and styrene, followed by d. drying and baking the layer formed, and e. applying to the surface of the adhesive layer a synthetic resin coating having annular projections at regular intervals by means of an extruder having a cross head die including therein, in the space between the die body and the top portion of the mandrel a projection forming member movable reciprocally in the axial direction.

Claim 3

A method for continuously producing an elongated pipe suitable for use as a supporting pole for growing plants tightly coated with a synthetic resin coating having annular projections at regular intervals which comprises: a. forming a hollow elongated pipe having a proper rigidity from an elongated band of metal by means of a forming machine, b. welding the seam of the pipe, c. subjecting the surface of the pipe to an alkali treatment and a chemical treatment, d. forming tightly on the treated surface of the pipe a first adhesive layer by applying to the surface an organic solvent solution of a mixture of a terpolymer of an acrylic ester, acrylamide and styrene, and an epoxy resin-modified phenol resin, followed by e. drying, f. forming further on the surface of the first adhesive layer a second adhesive layer by applying to the surface an organic solvent solution of a mixture of a terpolymer of vinyl chloride, vinyl acetate and maleic anhydride, and a nitrile-butadiene rubber, followed by g. drying and backing the layer formed, and h. applying to the second adhesive layer a synthetic resin coating having annular projections at regular intervals by means of an extruder having a cross head die including therein, in the space between the die body and the top portion of a mandrel, a projection forming member movable reciprocally in the axial direction.

Claim 4

A method for continuously producing an elongated pipe suitable for use as a supporting pole for growing plants tightly coated with a synthetic resin coating having annular projections at regular intervals which comprises: a. forming a hollow elongated pipe having a proper rigidity from an elongated band of metal by means of a forming machine, b. welding the seam of the pipe, c. subjecting the surface of the pipe to an alkali treatment and a chemical treatment, d. forming tightly on the treated surface of the pipe a first adhesive layer by applying to the surface an organic solvent solution of a mixture of a terpolymer of an acrylic ester, acrylamide and styrene, and an epoxy resin-modified phenol resin, followed by e. drying, f. forming further on the surface of the first adhesive layer a second adhesive layer by applying to the surface an organic solvent solution of a mixture of a terpolymer of vinyl chloride, vinyl acetate and maleic anhydride, and a nitrile-butadiene rubber, followed by g. drying and backing the layer formed, and h. applying to the second adhesive layer a synthetic resin coating having annular projections at regular intervals by means of an extruder having a cross head die including therein, in the space between the die body and the top portion of a mandrel, a projection forming member movable reciprocally in the axial direction.

Claim 6

A method for continuously producing an elongated pipe suitable as a support for growing plants, coated with a synthetic resin coating having annular projections at regular intervals, which comprises: a. forming a hollow elongated pipe having a proper rigiDity from an elongated band of metal by means of a forming machine, b. welding the seam of the pipe, c. subjecting the surface of the pipe to an alkali treatment and a chemical treatment, d. forming tightly on the treated surface of the pipe a first adhesive layer by applying to the surface an organic solvent solution of a mixture of a terpolymer of an acrylic ester, acrylamide and styrene, and a dehydrated castor oil-modified epoxy resin followed by e. drying and baking, f. forming further on the surface of the first adhesive layer a second adhesive layer by applying to the surface, an organic solvent solution of a mixture of a terpolymer of vinyl chloride, vinyl acetate and maleic anhydrides, and a nitrile-butadiene rubber, followed by g. drying and baking, and h. applying, tightly to the second adhesive layer a synthetic resin coating having annular projections at regular intervals by means of an extruder having a cross head die including therein in the space between the die body and the top portion of a mandrel a projection forming member movable reciprocally in axial direction.

Claim 7

A method for continuously producing an elongated pipe suitable as a support for growing plants, coated with a synthetic resin coating having annular projections at regular intervals, which comprises: a. forming a hollow elongated pipe having a proper rigiDity from an elongated band of metal by means of a forming machine, b. welding the seam of the pipe, c. subjecting the surface of the pipe to an alkali treatment and a chemical treatment, d. forming tightly on the treated surface of the pipe a first adhesive layer by applying to the surface an organic solvent solution of a mixture of a terpolymer of an acrylic ester, acrylamide and styrene, and a dehydrated castor oil-modified epoxy resin followed by e. drying and baking, f. forming further on the surface of the first adhesive layer a second adhesive layer by applying to the surface, an organic solvent solution of a mixture of a terpolymer of vinyl chloride, vinyl acetate and maleic anhydrides, and a nitrile-butadiene rubber, followed by g. drying and baking, and h. applying, tightly to the second adhesive layer a synthetic resin coating having annular projections at regular intervals by means of an extruder having a cross head die including therein in the space between the die body and the top portion of a mandrel a projection forming member movable reciprocally in axial direction.