DE3318704C2 - Process for the manufacture of an end closure for containers - Google Patents

Abstract

The invention relates to a method for producing an end closure for containers which consist of a shell-like and a bottom-like part made of sealable material or plastic-coated paper or similar material on one or both sides and in which the end of the shell-like part to be closed over the raised edge of the bottom-like Part is turned over. According to the invention, the end closure formed in this way is clamped between a sonotrode as an ultrasonic transmitter and an anvil and then ultrasonically sealed in the radial direction.

Description

25th

The invention relates to a method for producing an end closure for containers according to the preamble of the claim. This method is known from DE-AS 12 97 975. For example, the Manufacture of drinking cups from paper or a similar material intended.

In this known method, in which the necessary heat is either supplied from the outside or is generated by exposure to high frequencies, the frame and jacket are first pressed together then the edge of the jacket is placed around the floor frame. This procedure is that time consuming Production cannot take place quickly enough to put in a desired number of such containers to be able to produce a given time.

The invention is therefore based on the object of developing the known method in such a way that the completion of the end closure of such containers is significantly accelerated. This is the case at the beginning The described method achieved according to the invention through the use of the conical ring as a sonotrode for the purpose of welding the completely folded bottom edge in a single process step.

So an ultrasonic welding is carried out, in which the frame edges are welded together in the radial direction by the action of ultrasound will. Up to now, ultrasonic welding of such a three-layer termination was not possible possible.

The method according to the invention and the device for performing this method are shown in FIG Drawing explained using an exemplary embodiment.

In Fig. 1 is initially drawn a cup-shaped container, from which you can see the connection between the shell-like and the bottom-like part can be recognized.

In Fig. 2 are drawn schematically the essential parts of the device with which the connection is produced between the shell-like and the bottom-like part and in FIG. 3 is a section of this Device according to FIG. 2 drawn, the section approximately the dash-dotted circle in F i g. 2 corresponds

The container to be produced consists according to FIG. 1 of the jacket-like part 1 and the bottom-like part Part 2, which are connected to one another in that the end to be closed of the jacket-like part 1 is folded over the raised edge of the bottom-like part 2. A container prepared in this way however, it is not yet liquid-tight and must therefore be appropriately sealed in order to produce this tightness will. For this purpose, in the manufacturing process according to FIG. 2 a sonotrode 5 over the end of the container pushed and at the same time a counter pressure is created on the inside of the floor opposite the sonotrode This pressure is transmitted through the anvil 6 in the direction of the arrows 7 shown. This pressure is directed against the frame 4 of the bottom-like part 2 and the flange 3 at the end of the jacket-like part 1.

The anvil 6 is designed as a spreading device which consists of several jaws, which are when generated of the counter pressure on the end cap.

This type of connection is shown on an enlarged scale from FIG. 3 to be recognized again.

In a container according to FIG. 1 filled liquids make it necessary in all cases that in particular the inner surface of the container jacket is coated with plastic. Such a container jacket can, however also be coated on both sides, i.e. inside and outside, and then ultrasonically sealed in the manner proposed will.

1 sheet of drawings

Claims (1)

Claim: Process for making an end closure of containers from a conically shaped Sheath-like and a bottom-like part with a frame made of sealable material or one or There are plastic-coated paper or similar material on both sides, with the one to be sealed conical end of the jacket-like part folded over the raised edge of the frame or is applied to this, and wherein the connection and pressing of the shell part and bottom frame takes place under the action of heat, using a conical one lying on the outside of the jacket part Ring and an anvil designed as a spreading device and having several ring sector-like jaws, characterized by the use of the conical ring as a sonotrode (5) for the purpose of welding the completely folded bottom edge (1, 3, 4) in a single process step.