Reinforced plastic pipe and process for manufacturing the said pipe
AssigneeSolvay SA
InventorsClaude Dehennau, Pierre Matz
Life of this patent
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Abstract
Reinforced pipe obtained by winding, onto a tubular support based on a polymeric composition, of reinforcing tapes comprising an oriented polymeric composition in layers crossed at an equal but opposite angle relative to the axis of the pipe. The tapes are selected from those whose polymeric composition exhibits particular mechanical strength properties in tension.
Claims9
A reinforced multilayer plastic pipe formed from a tubular support based on a polymeric composition, onto which support are wound reinforcing tapes comprising an oriented polymeric composition, wherein the tapes are selected from those that satisfy the following relationship:
- SI
- SI
- 0
- ≥
- 4
- where:
- SI is a strength index of the reinforcing tape, calculated as follows:
- SI
- =
- σ
- 3
-
- E
- with:
- σ representing the maximum value of the stress reached during a tensile test on the tapes in the orientation direction, for an elongation corresponding to the yield point of the support or, otherwise, to the break point of the tape if the elongation at this break point is less than that of the elongation at the yield point of the support;
- E being the tensile elastic modulus of the oriented tapes;
- SI
- 0
- =
- σ
- 0
- 3
-
- E
- 0
- being the strength index of the support;
- and
- σ0 and E0 being the stress at the yield point and the tensile elastic modulus of the support, respectively, in which σ, E, σ0 and E0 are expressed in the same arbitrary tension units;
- and wherein it comprises at least two layers of tapes wound onto the support, each layer being formed from tapes making a similar angle, but of opposite sign, with the tapes of the other layer relative to the axis of the pipe.
A process for the production of a reinforced plastic pipe comprising the application, by winding around a tubular support based on a polymeric composition, of reinforcing tapes comprising an oriented polymeric composition, wherein the tapes are selected from those which satisfy the following relationship:
- SI
- SI
- 0
- ≥
- 4
- SI is a strength index of the reinforcing tape, calculated as follows:
- SI
- =
- σ
- 3
-
- E
- with:
- σ representing the maximum value of the stress reached during a tensile test on the tapes in the orientation direction, for an elongation corresponding to the yield point of the support or, otherwise, to the break point of the tape if the elongation at this break point is less than that of the elongation at the yield point of the support;
- E being the tensile elastic modulus of the oriented tapes;
- SI
- 0
- =
- σ
- 0
- 3
-
- E
- 0
- being the strength index of the support;
- and
- σ0 and E0 being the stress at the yield point and the tensile elastic modulus of the support, respectively, in which σ, E, σ0 and E0 are expressed in the same arbitrary tension units;
- and which comprises at least two layers of tapes wound onto the support, each layer being formed from tapes making a similar angle, but of opposite sign, with the tapes of the other layer relative to the axis of the pipe.
Dependencies are inferred from the claim text.