Details for Patent: 6,503,440

Title:	Process for making a container with a pressure equalization opening and containers produced accordingly
Abstract:	A process for the production of a container (1) comprising an outer container (2), an inner bag (3) disposed therein and a pressure equalisation opening (10) disposed in the outer container (2), and also a container (1) produced according to this process, is described, wherein firstly a pre-moulding, comprising two coaxial tubes, is first produced by co-extrusion with the help of a blow mould and with an outwardly-projecting base seam (5) being formed. The process is to form a pressure equalisation opening (10) in the outer container (2) of the container (1) without endangering the integrity of the container (1), wherein a lower wastage rate and higher productivity are to be achieved. This is attained by a process wherein the base seam (5) is partially cut off and a force which acts in the direction of the seam is introduced into the pre-moulding, which still has a temperature of 40.degree. C. to 70.degree.C., which force breaks open and plastically deforms the base seam (5) so that a pressure equalisation opening (10) is formed in the base area (4).
Inventor(s):	Kuehn; Torsten (Ingelheim, DE), Metzger; Burkhard Peter (Ingelheim, DE)
Assignee:	Boehringer Ingelheim Pharma KG (Ingelheim, DE)
Filing Date:	Apr 06, 2001
Application Number:	09/828,109
Claims:	1. A process for the production of a container having a container opening, the container having substantially rigid outer container having an inner surface and an outer surface and an inner bag having an inner surface and an outer surface disposed therein, the outer container having a pressure equalization opening in a base area thereof for equalizing a pressure difference between the outer container and the inner bag, wherein the outer container and inner bag respectively comprise different thermoplastic plastics not bonded to each other, the process comprising: coextruding a preliminary moulding having an inner surface and an outer surface from an inner coaxial tube and an outer coaxial tube having sufficient length for manufacture of the container using a blow mould having interior surface contours, to form an outwardly-projecting base seam in the preliminary moulding and to compress excess material in a base area of the preliminary moulding such that: (i) material of the outer coaxial tube in contact near the base seam is welded together, (ii) the inner coaxial tube forming the inner bag is clamped, axially fixed, and welded between the wall sections of the outer container, and (iii) the inner bag is subjected to pressure so that the outer surface of the preliminary moulding lie against the interior contours of the blow mould, wherein on closing the blow mould and with the associated formation of the base seam, the outer surface of the inner bag is at least partially fixed axially by the inner surface of the outer container and at least one pressure equalization opening is formed in that the base seam is at least partially cut off after shaping, and a radial force which acts in the direction of the base seam is exerted in the base area in such a way that the base seam breaks open, and wherein the temperature of the preliminary moulding is between 40.degree. C. and 70.degree. C. when the base seam is cut off and the outer container is still plastically deformable to some degree, so that a permanent deformation results from the force which is not neutralized by elastic restoration. 2. The process according to claim 1, wherein when the base seam is broken open, the, material comprising the inner bag remains stuck, on one side of the base seam, to the outer container and the ends of the base seam, whereby axial fixing is maintained. 3. The process according to claim 2, wherein the base seam of the outer container is only partially broken open and the seam of the inner bag is fixed by the unbroken part of the base seam of the outer container. 4. The process according to claim 3, wherein the cutting off of the base seam and the application of the force which opens and permanently deforms the outer container occur simultaneously in one work step. 5. The process according to claim 3, wherein the cutting off of the base seam and the application of the force which opens and permanently deforms the outer container occur separately in separate work steps. 6. The process according to claim 3 ,wherein the cutting off the base seam and the application of the force which opens and permanently deforms the outer container occur in the plastic blowing machine. 7. The process according to claim 3, wherein the container is configured in the shape of a bottle having a bottle neck with a face side. 8. The process according to claim7, wherein the inner bag is fixed in the area of the bottle neck in addition to the fixing in the base area. 9. The process according to claim 8, wherein the inner bag is at least partially clamped in the wall of the outer container during the formation of the bottle neck. 10. The process according to claim 9, wherein the bottle neck is configured with a projection on its face side extending outwards in the radial direction. 11. The process according to claim 10, wherein the inner bag is connected with the outer container by means of an upright or horizontal fold in the area of the projection. 12. The process according to claim 1, wherein the base seam of the outer container is only partially broken open and the seam of the inner bag is fixed by the unbroken part of the base seam of the outer container. 13. The process according to claim 12, wherein the cutting off of the base seam and the application of the force which opens and permanently deforms the outer container occur simultaneously in one work step. 14. The process according to claim 13, wherein the cutting off the base seam and the application of the force which opens and permanently deforms the outer container occur in a machine which is attached to the plastic blowing machine. 15. The process according to claim 12, wherein the cutting off of the base seam and the application of the force which opens and permanently deforms the outer container occur separately in separate work steps. 16. The process according to claim 12, wherein the cutting off the base seam and the application of the force which opens and permanently deforms the outer container occur in the plastic blowing machine. 17. The process according to claim 12, wherein the cutting off the base seam and the application of the force which opens and permanently deforms the outer container occur in a machine which is attached to the plastic blowing machine. 18. The process according to claim 12, wherein the container is configured in the shape of a bottle having a bottle neck with a face side. 19. The process according to claim 18, wherein the inner bag is fixed in the area of the bottle neck in addition to the fixing in the base area. 20. The process according to claim 19, wherein the inner bag is at least partially clamped in the wall of the outer container during the formation of the bottle neck. 21. The process according to claim 20, wherein the bottle neck is configured with a projection on its face side extending outwards in the radial direction. 22. The process according to claim 21, wherein the inner bag is connected with the outer container by means of an upright or horizontal fold in the area of the projection. 23. The process according to claim 1, wherein the cutting off of the base seam and the application of the force which opens and permanently deforms the outer container occur simultaneously in one work step. 24. The process according to claim 23, wherein the cutting off the base seam and the application of the force which opens and permanently deforms the outer container occur in the plastic blowing machine. 25. The process according to claim 1, wherein the cutting off of the base seam and the application of the force which opens and permanently deforms the outer container occur separately in separate work steps. 26. The process according to claim 1, wherein the cutting off the base seam and the application of the force which opens and permanently deforms the outer container occur in the plastic blowing machine. 27. The process according to claim 1, wherein the container is within the blow mould. 28. The process according to claim 1 , wherein the cutting off the base seam and the application of the force which opens and permanently deforms the outer container occur in a machine which is attached to the plastic blowing machine. 29. The process according to claim 7, wherein the container is configured in the shape of a bottle having a bottle neck with a face side. 30. The process according to claim 29, wherein the inner bag is fixed in the area of the bottle neck in addition to the fixing in the base area. 31. The process according to claim 30, wherein the inner bag is at least partially clamped in the wall of the outer container during the formation of the bottle neck. 32. The process according to claim 31, wherein the bottle neck is configured with a projection on its face side extending outwards in the radial direction. 33. The process according to claim 32, wherein the inner bag is connected with the outer container by means of an upright or horizontal fold in the area of the projection. 34. A container with a container opening substantially comprising a rigid outer container and an inner bag disposed therein, the container made according to the process of one of claims 1 to 33.