METHOD OF PRODUCING A HOLLOW BODY

Abstract

A method for producing a hollow body for storing gases, the hollow body including at least one boss part having a projection. The method includes providing a sheathing composed of a plastic material or a reactive material, over the at least one boss part, at least in a region of the projection. The sheathed at least one boss part is then heated and introduced into a blow mould, where it is surrounding with a plastic tube to form the hollow body. The plastic tube is then brought into permanent contact with the sheathing on the projection to thereby obtain a permanent material connection between the plastic of the plastic tube to the plastic or the reactive material of the sheathing. An internal pressure is then applied to the plastic of the plastic tube to obtain a final shape of the hollow body.

Claims

1. A method for producing a hollow body for storing gases, the hollow body including at least one boss part having a projection, the method comprising: sheathing the at least one boss part, at least in a region of the projection, with a plastic material; heating the sheathed at least one boss part; introducing the heated, sheathed at least one boss part into a blow mould, and surrounding the heated, sheathed at least one boss part with a tube composed of a plastic material to form the hollow body; bringing the tube into permanent contact with the sheathing on the projection to thereby obtain a permanent material connection between the plastic of the tube to the plastic material of the sheathing; and applying an internal pressure to the plastic of the tube to obtain a final shape of the hollow body.

2. The method of claim 1, wherein bringing the tube into permanent contact with the sheathing comprises bringing the tube into permanent contact with the sheathing at least on an outer side of the projection facing away from the container interior.

3. The method of claim 1, wherein bringing the tube into permanent contact with the sheathing comprises bringing the tube into permanent contact with the sheathing on the projection by performing an axial lifting movement of the at least one boss part relative to the blow mould.

4. The method of claim 1, wherein bringing the tube into permanent contact with the sheathing comprises bringing the projection into a defined proximity relative to the blow mould in a manner such that the plastic of the tube is pressed together with the plastic material of the sheathing.

5. The method of claim 1, wherein sheathing the at least one boss part comprises sheathing the at least one boss part at least in a region of the projection, by overmoulding the at least one boss part.

6. The method of claim 1, wherein the at least one boss part has a porous surface which is prepared for adhesion of the sheathing.

7. The method of claim 1, further comprising closing the blow mould, after introducing the heated, sheathed at least one boss part into the blow mould and surrounding the heated, sheathed at least one boss part with the tube, to thereby bring the tube into contact, at least partially and/or at least temporarily, with the sheathing on the projection.

8. The method of claim 1, wherein applying the internal pressure to the plastic of the tube is performed after the tube is brought into permanent contact with the sheathing on the projection.

9. The method of claim 1, wherein applying the internal pressure to the plastic of the tube is performed before the tube is brought into permanent contact with the sheathing on the projection.

10. The method of claim 1, wherein the blow mould comprises two mould halves and a blowing mandrel.

11. The method of claim 10, wherein the sheathed at least one boss part is mounted on the blowing mandrel of the blow mould and the tube is extruded between the mould halves and around the blowing mandrel in order to surround the at least one boss part.

12. The method of claim 1, wherein the plastic material of the tube comprises an impermeable multilayer plastic.

13. The method of claim 1, further comprising, after applying the internal pressure to the plastic of the tube, wrapping the hollow body with a fibre composite material.

14. A method for producing a hollow body for storing gases, the hollow body including at least one boss part having a projection, the method comprising: sheathing the at least one boss part with a sheathing material; heating the sheathed at least one boss part; introducing the heated, sheathed at least one boss part into a blow mould, and surrounding the heated, sheathed at least one boss part with a tube composed of an impermeable multilayer plastic to form the hollow body; bringing then the tube into permanent contact with the sheathing on the projection to thereby obtain a permanent material connection between the impermeable multilayer plastic of the tube to the reactive material of the sheathing; and applying an internal pressure to the impermeable multilayer plastic of the tube to obtain a final shape of the hollow body.

15. The method of claim 14, wherein bringing the tube into permanent contact with the sheathing comprises: bringing the tube into permanent contact with the sheathing at least on an outer side of the projection facing away from the container interior, and performing an axial lifting movement of the at least one boss part relative to the blow mould.

16. The method of claim 14, wherein bringing the tube into permanent contact with the sheathing comprises bringing the projection into a defined proximity relative to the blow mould in a manner such that the impermeable multilayer plastic of the tube is pressed together with the reactive material of the sheathing.

17. The method of claim 14, wherein sheathing the at least one boss part comprises sheathing the at least one boss part at least in a region of the projection, by overmoulding the at least one boss part.

18. The method of claim 14, further comprising closing the blow mould, after introducing the heated, sheathed at least one boss part into the blow mould and surrounding the heated, sheathed at least one boss part with the tube, to thereby bring the tube into contact, at least partially and/or at least temporarily, with the sheathing on the projection.

19. The method of claim 14, wherein applying the internal pressure to the impermeable multilayer plastic of the tube is performed: after the tube is brought into permanent contact with the sheathing on the projection, or before the tube is brought into permanent contact with the sheathing on the projection.

20. The method of claim 14, further comprising, after applying the internal pressure to the impermeable multilayer plastic of the tube, wrapping the hollow body with a fibre composite material.

Description

DRAWINGS

[0027] Embodiments will be illustrated by way of example in the drawings and explained in the description hereinbelow:

[0028] FIG. 1 illustrates a schematic sectional view of a first step in a method for producing a hollow body, in accordance with one or more embodiments.

[0029] FIG. 2 illustrates a schematic sectional view of a second step in a method for producing a hollow body, in accordance with one or more embodiments.

[0030] FIG. 3 illustrates a schematic sectional view of a third step in a method for producing a hollow body, in accordance with one or more embodiments.

[0031] FIG. 4 illustrates a schematic sectional view of a fourth step in a method for producing a hollow body, in accordance with one or more embodiments.

DESCRIPTION

[0032] FIGS. 1 through 4 illustrate steps (performed in chronological sequential order) of a method for producing a hollow body, in accordance with one or more embodiments. In this context, the use of a sheathing plastic is described as sheathing. It is also possible, however, to use a reactive layer as sheathing.

[0033] FIG. 1 illustrates how a heated insert part, namely, a boss part 1 with a projection 2 at a foot end of the boss part 1 facing the interior of the subsequent container, the boss part 1 being sheathed in the region of the projection 2 with a plastic as sheathing 3, was fastened to a blowing mandrel 6 of a blow mould 4 and brought into position manually or by a suitable automated device.

[0034] In addition to the central blowing mandrel 6, the blow mould 4 also comprises two mould halves, which form mould halves for shaping the hollow body. In FIG. 1, the mould halves are initially in the open position. A plastic tube 5 is discharged, in particular, extruded, into the opened blow mould 4.

[0035] FIG. 2 illustrates that the mould halves of the blow mould 4 have been closed. Here, the plastic tube 5 already bears roughly against the outer contour of the boss part 1, in particular, against the outer side of the projection 2, in the upper region of the boss part 1. The plastic tube 5 is brought into contact at least partially and/or at least temporarily, or even already permanently, with the sheathing plastic 3 on the projection 2 of the boss part 1.

[0036] In a next step, as illustrated in FIG. 3, the plastic of the plastic tube 5 can be pressed against the shape of the closed blow mould 4 by blow moulding in order to bring the latter already, at least approximately, into the shape of the desired hollow body. During this process, the plastic of the plastic tube 5 may possibly be at least partially detached again from the sheathing plastic 3 on the projection 2 of the boss part 1.

[0037] As illustrated in FIG. 4, the boss part 1, in particular, the plastic overmoulding 3, and the plastic tube 5 are compressed to a defined cross-section on the outer side of the projection 2 via a vertical stroke of the boss part 1 relative to the outer mould, that is to say to the mould halves of the blow mould 4. During this process, a permanent material connection is brought about between the overmoulding 3 of the boss part 1 and the tube 5 in the compressed region.

[0038] After compression and welding have been carried out in the upper region of the boss part 1, the liner, i.e., the plastic tube 5, is given its final shape by applying an internal pressure.

[0039] The step described in FIG. 3 can also be omitted, such that the application of an internal pressure to the plastic tube 5 to give the latter the shape of the desired hollow body takes place only once, namely after the pressing together of the plastic 3, which sheaths the boss part 1, with the plastic tube 5. Alternatively, the application of the internal pressure can also begin even before pressing, for example, and the pressing together of the plastics 3, 5 can take place during the application of the internal pressure, i.e., during blow moulding, for example.

[0040] The terms “coupled,” “attached,” or “connected” may be used herein to refer to any type of relationship, direct or indirect, between the components in question, and may apply to electrical, mechanical, fluid, optical, electromagnetic, electromechanical or other connections. In addition, the terms “first,” “second,” etc. are used herein only to facilitate discussion, and carry no particular temporal or chronological significance unless otherwise indicated.

[0041] Those skilled in the art will appreciate from the foregoing description that the broad techniques of the embodiments can be implemented in a variety of forms. Therefore, while the embodiments have been described in connection with particular examples thereof, the true scope of the embodiments should not be so limited since other modifications will become apparent to the skilled practitioner upon a study of the drawings, specification, and following claims.

LIST OF REFERENCE SYMBOLS

[0042] 1 boss part [0043] 2 projection [0044] 3 sheathing (plastic material or reactive material) [0045] 4 blow mould [0046] 5 plastic tube [0047] 6 blowing mandrel