Method for mounting a bottom on a container

The present invention relates to a method for positioning the bottom of a package comprising a tubular body of non-round cross section of non-round cross-section closed by a cover and containing the product to be packaged, said bottom having the form of a cup whose dimensions correspond to the cross section of the tubular body, the cup being fixed after its introduction, by means of a male tool into the body by activation of an adhesive and folding the edge of the tubular body.

In patent application EP-A-0668151 of the applicant there has been proposed a method of manufacturing a tubular package preferably made of a recyclable material such as paper or cardboard of which the lid and base are also made of an at least similar. After attaching the lid and possible tamperproof membrane, the package is filled with the product to be packaged and sets the background. The background is a cuvette having the dimensions and shape of the cross section of the tubular body and is inserted into the body with a male tool. However, upon introduction of the basin which rubs against the inner circumference of the tubular body the air that is expelled by the movement of said cup has difficulty out which either retards the method of introduction and finally fixing the bottom, or it creates a positive pressure inside of the package which is not desired. On the contrary, it is desired to leave, after the sealing of the packaging, remain negative pressure inside the package. This negative pressure allows on the one hand, a better conservation of the packaged product and, on the other hand, where the package heating to avoid the creation of an overpressure within the package may lead to the destruction of its seal.

various methods have been proposed to help dissipate this air, in particular to use a source of negative pressure to evacuate and thus allow the establishment of the bowl. This way of working has its disadvantages, because depending on the shape of the section of the tubular body, it is sometimes difficult to obtain a perfect seal when placed under negative pressure and the result of internal pressure changes that may affect sealing the package.

The present invention aims to provide a method to overcome these disadvantages by simple means.

The method according to the invention is characterized in that one proceeds according to the following steps:<ul><li>a) inserting the open end of the tubular body between two fixed opposed jaws perfectly matching two opposite end parts of the tubular body, and the distance between the two jaws being less than the distance between said opposed parts so that the parts not clamped in said jaws undergo non-permanent deformation by moving away from one another;</li><li>b) is placed the bottom by means of a punch, said are being maintained at its final position by said fixed jaws and the punch; </li><li>c) clamp two opposite regions of the lateral surface of the tubular body by two clamping members situated below two movable jaws intended to act on the portions of the free end of tubular body not clamped by the fixed jaws for hunt at least partially the air contained in the tubular body;</li><li>d) tightening the movable jaws for contacting the entire inside edge of the free end of the tubular body with the bowl;</li><li>e) conducting the activation of the adhesive film and thereafter the release of the closed package.</li></ul>

The advantage of the present invention resides in the fact that by using simple means for applying opposing forces on diametrically opposed surfaces of the package, there is obtained a deformation of the packing edge sufficient to allow the introduction of the bowl while allowing to evacuate the air expelled by the introduction, between the edge of the bowl and the deformed edge of the package. It is obvious that the method is applicable on a package allowing a slight elastic deformation. In addition, the partial discharge is obtained of the air contained in the package by squeezing the sides of the tubular body.

It is of course expected that the deformations to which the package is subjected remain in the field of elasticity of the material to avoid damage to the packaging.

According to an alternative embodiment, if the packaging section is rectangular fixed jaws act on the narrow sides of the surface of the tubular body.

According to another variant embodiment, the packaging is elliptical section and the fixed jaws grip the regions lying on either side of the ends of the major axis of the ellipse.

According to another alternative embodiment, the section has a semicircular shape and the fixed jaws grip the regions lying at the ends of the rope.

Finally, in another variant of execution and order to speed up the process of setting up the background, forming the matrix we endow the bottom of the bowl suction channels for the rapid evacuation of the air expelled by the implementation of the background in the tubular body.

The invention will be described in more detail with the aid of the accompanying drawing

Figure 1 is a top view of the tubular body of a package with the jaws.

Figure 2 is a side view.

Figure 3 is a side view of an alternative embodiment.

A package 1 of substantially rectangular cross section, whose one end is already sealed by a lid and optionally a sealing membrane and already containing the product to be packaged is inserted between two jaws M1, M2 fixed having surfaces corresponding to the shape and dimensions of the lateral surface of two portions 2, 3 opposed to the package 1. in the present case, the selection is focused on the two faces having the smallest area. It is necessary that the jaws M1, M2 espouse said faces, because the spacing between the jaws is less than the spacing of the faces 2, 3 of the package so as to obtain the distance between the two other sides 4, 5 of edge of the package.

By means of a punch P having the shape of the bowl 6 which forms the bottom, is placed between the bowl M1 and M2 jaws, the bowl being thus in its final position. Subsequently by means of two clamping members S1 and S2 are applied to opposing forces F3 and F4 against the two opposite portions of the side surface of the package 1 and in particular in areas under two movable jaws M3 and M4. This clamp has the effect of driving at least a portion of the air being still in the tubular body 1. Thereafter, while maintaining the clamping forces S3, S4 we compare two jaws M3 and M4 by applying forces F1 and F2 to press the edges 4 and 5 of the package against the corresponding edge of the bowl 6. from this point, the adhesive film is activated by heating or high frequency or similar means thus obtaining the sealing of background on the edge of the tubular body 1. subsequently releasing the forces F1, F2, F3 and F4, and packaging finds its final form as the forces F3, F4 and the distance between M1 and M2 are provided jaws to cause a non-permanent deformation of the package.

Whatever the shape of the cross section, other than round, the method can be used successfully.

Thereafter, the package continues its manufacturing cycle as provided in the aforementioned patent of the same applicant (hemming ...).

Thus, by a simple process we get to put in place a cup having the final form without the air in the packaging slows the development of this basin as it can move when moving the bowl by the space between the deformed edge 4 and 5 (drawn in dashed lines in Figure 1) and the bowl and then we get to still chase a further part of the air using the S1 and S2 clamps.

In order to be able to proceed at a very high rate of the background formatting Placed 6 of the package 1, there is provided the forming die 7 of the bottom of the bowl described in the aforementioned patent application of the same inventor, of channel 8 connected to a suction source (not shown). Thus, during the implementation of the background by the punch P, the expelled air is sucked through the channels 8, so that any particles of the packaged product thereby avoiding contamination of the forming die 7. Otherwise, the procedure is identical to that previously described.