METHOD FOR THE EXTRUSION BLOW MOULDING OF A CONTAINER OF THERMOPLASTIC MATERIAL AND EXTRUSION BLOW-MOULDED CONTAINER

Abstract

The invention relates to a method for extrusion blow-molding a container from a thermoplastics material, having at least one conduit through a wall of the container, wherein the method comprises providing an insert part from a thermoplastics material, said insert part having a conduit; incorporating a preform from a thermoplastics material into a blow-molding tool having a mold cavity which defines the contour of the container; molding the preform within the mold cavity, wherein the preform on the mold cavity side encloses the insert part and is welded to the insert part; removing the container from the blow-molding tool; and producing an opening in the wall of the container by means of a tool which is guided from the outside through the conduit of the insert part. The invention furthermore relates to an extrusion blow-molded container from a thermoplastics material.

Claims

1-16. (canceled)

17. A method for extrusion blow-molding a container formed of a thermoplastic material, having at least one conduit through a wall of the container, said method comprising: providing a insert part formed of at least one thermoplastic material, said insert part having a conduit; incorporating a preform formed of a thermoplastic material into a blow-molding tool having a mold cavity which defines a contour of the container; molding the preform within the mold cavity to form the wall of the container, wherein the preform has a mold cavity side, and on the mold cavity side encloses the insert part and is welded to the insert part; producing an opening in the wall of the container by a tool which is guided from outside the container through the conduit of the insert part; and wherein the insert part comprises a first thermoplastic material and a second thermoplastic material, wherein the first thermoplastic material of the insert part is weldable with the thermoplastic material of the preform forming the wall of the container.

18. The method as claimed in claim 17, wherein the second thermoplastic material of the insert part is not weldable to the thermoplastic material of the preform forming the wall of the container.

19. The method as claimed in claim 17, wherein producing the opening in the wall of the container comprises melting the wall with a hot mandrel.

20. The method as claimed in claim 17, wherein producing the opening in the wall of the container comprises at least one of milling and reaming the wall of the container.

21. The method as claimed in claim 17, wherein the insert part is configured as an injection-molded multi-component part.

22. The method as claimed in claim 17, wherein the insert part comprises a bush having an encircling collar, and wherein the collar encloses a port of the conduit.

23. The method as claimed in claim 22, wherein the collar has a width which corresponds to at least a depth of the conduit.

24. The method as claimed in claim 22, wherein the port of the conduit faces an internal side of the container, and is angled in a direction toward an external side of the container such that the insert part forms a trough on the external side of the container in the wall of the container.

25. An extrusion blow-molded container comprising: the extrusion blow-molded container formed of thermoplastic material, and having a conduit in a wall of the container, wherein an insert part is enclosed by the wall of the container and is welded to the wall of the container, wherein the insert part provides the conduit and has an encircling collar, wherein the insert part comprises a first thermoplastic material and a second thermoplastic material, and wherein the first thermoplastic material of the insert part is welded to the wall of the container.

26. The extrusion blow-molded container as claimed in claim 25, wherein the collar encloses a port of the conduit that faces an internal side of the container, and is angled in a direction toward an external side of the container such that the insert part forms a trough on the external side of the container n the wall of the container.

27. The extrusion blow-molded container as claimed in claim 25, wherein the conduit has a smooth inner wall.

28. The extrusion blow-molded container as claimed in claim 25, wherein the collar is welded to the wall of the container in a fully planar manner, and a width of the collar is at least as large as a depth of the conduit.

29. The extrusion blow-molded container as claimed in claim 26, wherein a depth of the trough corresponds to at least a depth of the conduit.

30. The extrusion blow-molded container as claimed in claim 25, wherein the conduit receives at least one of a connector port, a nipple, a valve, and a fastening element for an installation part of the container.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0056] The invention will be explained hereunder by means of an exemplary embodiment that is illustrated in the drawings.

[0057] In the drawings:

[0058] FIG. 1 shows a partial section through the wall of an extrusion blow-molded container according to the invention, as per a first variant; and

[0059] FIG. 2 shows a section through the wall of an extrusion blow-molded container according to the invention, prior to the opening in the wall of the container having been opened outward by means of a tool, that is to say immediately after the removal of the container from a blow-molding tool.

DETAILED DESCRIPTION

[0060] For the sake of simplification, only part of a wall 1 of a container 2 according to the invention is illustrated in FIG. 1.

[0061] The container 2 is produced by extrusion blow-molding from a thermoplastics material. To this end a preform in the form of a preferably multi-layered tubular extrudate can be provided by means of a conventional extruder head (not shown), for example. The extruder head can be disposed above a blow-molding tool (not illustrated), for example, the latter potentially having two blow-mold halves, for example, which in a known manner are disposed on mold clamping plates of a closing frame. The blow-mold halves can be opened and closed by way of the mold clamping plates. The blow-mold halves in each case have at least one cavity, the latter in the case of the closed blow-molding tool forming a mold cavity of which the contour corresponds to the external design of the container that is to be produced by extrusion blow-molding.

[0062] The tubular preform in the direction of gravity is ejected from the extruder head in either a continuous or a discontinuous manner and is cut to length between the opened parts of the blow-molding tool, the blow-molding tool thereupon closing about the tubular preform. Widening of the preform in the mold cavity of the blow-molding tool is thereupon performed while using negative pressure within the mold cavity and/or while using positive pressure by including a blow needle in the preform.

[0063] The method according to the invention now provides that an insert part 3 is incorporated in at least one cavity of at least one blow-mold half prior to the tubular preform being moved into the blow-molding tool.

[0064] FIG. 1 shows the insert part 3 in the wall 1 of the finished container 2.

[0065] The wall 1 of the container 2 can be composed of a single-layered or a multi-layered thermoplastics material. For the sake of simplification, the wall 1 of the container 2 in FIG. 1 is illustrated as being single-layered, whereas the wall 1 of the container 2 in FIG. 2 is illustrated as being multi-layered. The wall 1 of the container in FIG. 2 comprises two layers, said container potentially having up to six different layers; for example, said container can be configured as a co-extrudate based on HDPE having a barrier layer from EVOH.

[0066] The insert part 3 at the beginning of a blowing cycle is inserted into a correspondingly configured depression or receptacle in a cavity of the blow-molding tool, for example by means of a handling robot.

[0067] Subsequently or during the above, the tubular extrudate or the preform, respectively, is moved between the opened parts of the blow-molding tool. The blow-molding tool closes about the preform, the preform thereupon being widened within the mold cavity that is formed by the cavities. The preform herein bears on the mold-cavity side parts of the insert part and connects to the latter.

[0068] For example, the insert part 3 has the configuration illustrated in FIG. 1, having a central and cylindrical conduit 4 and an encircling collar 6 which is contiguous to a port 5 of the conduit 4. The collar 6 in the arrangement illustrated in FIG. 1 faces a container internal side 7 and is welded across a large area to the wall 1 of the container 2. A connection stopper 9 having a line connector 10 is inserted into the conduit 4 on a container external side 8. The connection stopper 9 can be welded or adhesively bonded within the conduit 4; in the case of the exemplary embodiment illustrated in FIG. 1, the connection stopper 9 is inserted in a releasable manner into the conduit 4 and by means of O-rings 11 is sealed in relation to an internal shell area of the conduit 4.

[0069] The collar 6 is angled in the direction toward the container external side 8 and in relation to a longitudinal central axis of the conduit 4 forms an acute angle. The insert part 3 by virtue of this design embodiment of the insert part 3 is sunk into the container 2, or the insert part 3 together with the wall 1 of the container 2 forms a trough 12, respectively. The trough 12 has a depth which corresponds approximately to the depth or length, respectively, of the conduit 4 such that the port of the conduit 4 that faces the container external side 8 aligns approximately with the remaining face of the wall 1 of the container 2.

[0070] As has already been mentioned above, the insert part 3 can be configured as an injection-molded bi-component part, wherein the insert part 3 illustrated in FIG. 2 on that face of the collar 6 that faces the wall 1 and the container internal side 7 comprises an LDPE or an HDPE, for example, and the remainder of the body of the insert part 3 can be composed of a polyamide or another thermoplastics material.

[0071] In principle, the insert part 3 can also be composed of a single injection-molded thermoplastics material which has properties other than those of the thermoplastics material of the container 2 or of the wall 1 of the container 2, respectively.

[0072] An alternative design embodiment of the container according to the invention is illustrated in FIG. 2, wherein the conduit 4 in the case of the container illustrated in FIG. 2 has not yet been opened. The figure shows a section through the wall of the container 2 immediately upon removal of the container 2 from the blow-molding tool, wherein like in FIG. 1 the container internal side is identified by the reference sign 7 and the container external side is identified by the reference sign 8.

[0073] The insert part 3 is configured substantially as a bush which likewise has an encircling collar 6 which surrounds the port 5 of the conduit 4 on the container external side 8. The collar 6 is inserted completely in the container external side 8 and aligns with the latter.

[0074] The insert part 3 on the container internal side 7 is closed by the wall 1 of the container.

[0075] The insert part 3 likewise has a cylindrical conduit 4 that is smooth-walled on the inside, wherein the internal shell area of the conduit 4 is formed by an LDPE layer, and the external shell area of the insert part 3, which is welded to the wall 1 of the container 2, is formed by an HDPE layer. The insert part 3 furthermore comprises a support element 13 which can be composed of polyamide, for example.

LIST OF REFERENCE SIGNS

[0076] 1 Wall [0077] 2 Container [0078] 3 Insert part [0079] 4 Conduit [0080] 5 Port [0081] 6 Collar [0082] 7 Container internal side [0083] 8 Container external side [0084] 9 Connection stopper [0085] 10 Line connector [0086] 11 O-rings [0087] 12 Trough [0088] 13 Support element