Tubular structures and knurling systems and methods of manufacture and use thereof

1. A method comprising:

bending a sheet about a mandrel such that the sheet is tubular, wherein the sheet includes a first longitudinal end portion and a second longitudinal end portion;

interlocking the first longitudinal end portion with the second longitudinal end portion over the mandrel;

passing the sheet between a plurality of knurling wheels such that the sheet is knurled, wherein the mandrel hosts one of the knurling wheels; and

pushing the sheet along the mandrel to the knurling wheels via a base portion, wherein the base portion moves along the mandrel.

2. The method of claim 1 , wherein the sheet defines a cavity when the sheet is tubular, wherein the sheet is knurled such that the first longitudinal end portion and the second longitudinal end portion do not disengage to enable a leak of a fluid from the cavity as the fluid flows within the cavity.

3. The method of claim 2 , wherein the fluid is a liquid.

4. The method of claim 1 , wherein the mandrel is C-shaped such that the mandrel defines a cavity containing the one of the knurling wheels.

5. The method of claim 1 , wherein the one of the wheels is an idler wheel.

6. The method of claim 1 , wherein the one of the wheels is a driver wheel.

7. The method of claim 1 , wherein the bending is via a pair of arcuate portions, wherein at least one of the arcuate portions extends over the one of the knurling wheels during the bending.

8. The method of claim 7 , wherein the pair of arcuate portions pivot about a shaft common thereto.

9. The method of claim 1 , wherein the mandrel includes a U-shaped cavity containing the one of the knurling wheels.

10. The method of claim 1 , wherein the base portion moves between a first position and a second position, wherein the base portion is more distal to the knurling wheels in the first position than the base portion to the knurling wheels in the second position.

11. The method of claim 1 , wherein the pushing is via the base portion plunging along the mandrel longitudinally.

12. The method of claim 1 , wherein the pushing for a limited time period.

13. The method of claim 1 , wherein the pushing is for a limited distance along the mandrel.

14. The method of claim 1 , further comprising:

retracting the base portion to a default position responsive to the pushing.

15. The method of claim 1 , further comprising:

outputting the sheet as knurled into a container.

16. The method of claim 1 , wherein the interlocking includes mating the first longitudinal end portion with the second longitudinal end portion over the mandrel.

17. The method of claim 16 , wherein the first longitudinal end portion includes a male portion, wherein the second longitudinal end portion includes a female portion, wherein the female portion includes an S-bend configured to receive the male portion.

18. The method of claim 1 , further comprising:

lowering a housing hosting a wheel such that the wheel contacts the sheet after the bending and before the passing.