Tubular body and manufacturing method thereof

1. A method of manufacturing a tubular body by a sheet winding process, said manufacturing method comprising steps of:

winding a fiber reinforced resin member containing a fiber and a matrix resin around a mandrel to obtain an intermediate formed body;

winding a wrapping tape around an outer peripheral surface of the intermediate formed body with an application of a tension;

heating the intermediate formed body having the wrapping tape wound therearound to cure the matrix resin; and

pulling out the mandrel only after the step of heating and subsequently removing the wrapping tape to obtain a cured tubular body,

wherein a base polymer of a base material of the wrapping tape is a polyolefin resin and/or a polyester resin, and

the step of heating including:

a first heating stage for heating the intermediate formed body at a temperature of 70° C. or higher and 90° C. or lower for a time of 120 minutes or longer and 4320 minutes or shorter; and

a second heating stage for heating the intermediate formed body at a temperature of 120° C. or higher and 200° C. or lower for a time of 5 minutes or longer and 20 minutes or shorter after the first heating stage.

2. The method according to claim 1 , wherein a tensile stress T 1 to be applied to the wrapping tape is 20 (Mpa) or greater and 200 (Mpa) or less in the step of winding the wrapping tape.

3. The method according to claim 1 , wherein an internal surface of the wrapping tape is provided with a silicone type or fluorine type coating material.

4. The method according to claim 1 , wherein a fiber content S 1 of the intermediate formed body is 50% by weight or greater and 92% by weight or less.

5. The method according to claim 1 , wherein a wind starting end and a wind terminating end of the wrapping tape are fixed respectively to the intermediate formed body with an adhesive tape in the step of winding the wrapping tape.

6. The method according to claim 1 , wherein the base material of the wrapping tape is a uniaxially-stretched film.

7. The method according to claim 1 , wherein a thickness d 2 of the wrapping tape is equal to or greater than 10 μm and equal to or less than 120 μm.

8. The method according to claim 1 , wherein a width W 1 of the wrapping tape is equal to or greater than 10 mm and equal to or less than 35 mm.

9. The method according to claim 1 , wherein a tensile modulus of elasticity of the fiber is equal to or higher than 5 t/mm 2 and equal to or lower than 100 t/mm 2 .

10. The method according to claim 1 , wherein an average number La of a wrapping layer wound in the step of winding wrapping tape is equal to or larger than two.

11. The method according to claim 10 , wherein the average number La is equal to or larger than three and equal to or less than 15.

12. The method according to claim 1 , further comprising steps of:

cutting off a portion Xt which is adjacent to a wind starting point and in which a number L 1 of the wrapping layer is one; and

cutting off a portion Yt which is adjacent to the wind terminating point and in which a number L 1 of the wrapping layer is one.

13. The method according to claim 1 , wherein the wrapping tape is removed after the pull-out of the mandrel in the step of pulling out the mandrel and removing the wrapping tape.

14. The method according to claim 1 , wherein the temperature of the first heating stage is 85° C. or lower.

15. The method according to claim 1 , wherein the temperature of the first heating stage is 80° C. or lower.

16. The method according to claim 1 , wherein the temperature of the second heating stage is 130° C. or lower.