EP2193349A1

EP2193349A1 - A method and an apparatus for controlling packs

Info

Publication number: EP2193349A1
Application number: EP08804111A
Authority: EP
Inventors: Antonio Caporale; Miquel Galan; Pierluigi Tampieri
Original assignee: IMA Safe Srl
Current assignee: IMA Safe Srl
Priority date: 2007-09-26
Filing date: 2008-09-12
Publication date: 2010-06-09
Also published as: WO2009040259A9; WO2009040259A2

Abstract

A method for controlling packs,in particular blister packs, comprising stages of infeeding, in a determined direction, blister packs into a forming station of at least a stack of the blister packs, transferring the stack to at least a control station of the stack in order to test a seal quality of the blister packs, rejecting any defective blister packs, and transferring the stack of blister packs by means of conveyors; the seal quality test being performed with use of an inert gas.

Description

A METHOD AND AN APPARATUS FOR CONTROLLING PACKS

TECHNICAL FIELD

The invention relates to a method and a relative apparatus for controlling packs.

In particular, the present invention is advantageously applied in control of blister packs preferably containing pharmaceutical products, with the aim of controlling a state of seal of the packs.

BACKGROUND ART

The sealing process of a strip formed with a relative covering strip, necessary to forming of packaging packs, such as for example blister packs or sachets, must be realised using methodologies which guarantee a perfect seal of the packs, such as to prevent any form of contamination of the products contained therein.

There exist various methodologies for controlling the seal, and in more general for controlling leakage. Some of these are: tests using methylene blue, pressure loss tests, pressure gain tests, optical tests, helium mass spectrometry tests, deformation (or stress) tests in depressuhsed environments etc.

Almost all of these methodologies as they are at present applied exhibit some limitations. The analysis must normally be performed out of line with respect to the production cycle of the packs; samples have to be taken which are tested apart, using special apparatus. It is therefore obvious that this process does not enable the totality of the produced packs to be tested. This limitation is imposed by the times required by the various test methodologies which are not compatible with the high production rhythms of the packing machines. Further, many of the methodologies used are destructive and therefore the test product cannot be re-introduced following the relative production batch.

In particular one of the most effective processes is the vacuum method which uses a helium mass spectrometer; with this method it is possible to detect even very small losses which are not detectable with the majority of the other types of test. This method is known and has been used for some time, but in the case of non-rigid pack seal analysis such as for example blister packs, there are some limitations connected to the depression values necessary to perform the analysis and the times necessary for it. The depression values commonly used in this type of analysis would permanently deform the blister pack, risking falsifying the result of the test and leaving the blister pack certainly unusable, and further the times needed for the analysis of the single blister pack are also in this case incompatible with the speed of production commonly required by production machines.

The aim of the present invention is to obviate the drawbacks and problems in the cited prior art.

This aim is obtained according to the content of claim 1.

DISCLOSURE OF INVENTION

A method for controlling packs, in particular blister packs, comprising stages of infeeding, in a determined direction, blister packs into a forming station of at least a stack of the blister packs, transferring the stack to at least a control station of the stack in order to test a seal quality of the blister packs, rejecting any defective blister packs, and transferring the stack of blister packs by means of conveyors; the seal quality test being performed with use of an inert gas.

BEST MODE FOR CARRYING OUT THE INVENTION

The solution of the present invention, illustrated in the accompanying figures 1 a, 1 b, 2 and 3 of the drawings, provides a control process of the sealing which is integrated in the packing machine and is able to analyse 100% of the produced packs. In particular, the packing machine is a blister-pack machine for producing blister packs containing pharmaceutical products, to which the following description will make explicit reference without losing in terms of a more generalised reference.

With the apparatus of the invention, at least a blister pack is removed from a conveyor belt, forming an at least a stack of blister packs, the stack is moved into an adjacent station where a control analysis is made for any leakage, and the blister pack stack is transferred into another station where the single blister packs can be re-introduced into a conveyor belt.

Some of the possible non-limiting embodiments of an apparatus, denoted in its entirety by 100 and performing the above-described functions are schematically represented in figures 1 a, 1 b and 2. In both figures characteristic elements are:

1. a first blister pack transport strip;

2. a blister pack stack former;

3. a test or control station; 4. a station for possible rejects;

5. a blister pack re-introduction station;

6. a second blister pack transport conveyor.

According to what is illustrated in figures 1 a, 1 b and 2, the blister packs B already containing the product and specially sealed are transported by a special strip 1 in an advancement direction K, are then loaded in succession into a station 2, at which a stack of blister packs P is formed.

Figure 1 b illustrates a possible embodiment in which the stack P is subsequently translated into a control station 3, which is made up of a chamber set up for the blister pack seal test where a check of the sealed closure of the blister pack is performed by a leak-detection process; the stack P is then transferred or translated into a reject station 4 in which the blister packs B found to be defective, i.e. not perfectly sealed, are discarded. Finally, if the test has not detected leakage in the blister packs B of the stack P, the stack P is taken into the re-insertion station 5 of the blister packs B on a special conveyor belt 6. The strip 1 and the belt 6 preferably coincide and advance the blister pack B in the same horizontal direction K.

In the embodiment illustrated in figure 2, the control station 3 is reached via a rotation of a plate or turntable 10 at ends of which stations 2, 3 and 4 are fixed. After finishing the seal test the turntable 10 rotates further, bringing the stack P into the re-insertion station 5 of the blister packs on the belt 6. As already mentioned, re-insertion is done only if the test has confirmed absence of leaks in the blister packs in the stack; if leaks have been found, the blister packs remain in the warehouse and are further rotated into the station 4 where they are rejected. With this production scheme, control can be performed on all of the blister packs produced; if a leak is found in only one of the blister pack, the test will detect it.

One of the innovative characteristics of production schemes such as the one described herein is that the leak analysis system can be adapted to blister pack packing machines having high production speeds. If the packing machine production is n (packs per minute), and the time to complete the seal analysis in all its stages is t (seconds), it will be possible to integrate the analysis device in-line with the blister pack production machine using a warehouse which can contain a pack P formed by N blister packs where

N = _n_ * t

60

Thus, for example, to control the presence of leaks in a blister pack packing machine at a speed of 200 (packs per minute) and assuming an analysis time of 9 (seconds), it will be necessary to design a system working with a stack with:

N = 200 ^* 9 = 30 packs.

60

The methodology on which the process is based via which the seal test is performed is the depression method, which uses an inert gas (preferably helium (He)) mass spectrometer. This method, of known type, is widely used in various sectors, and is particularly advantageous in the present case since it has the characteristic of identifying leaks of smaller size than what is possible with alternative methods, and, as it can be adapted for automation, it is capable of completely annulling the influence of the human factor and thus the possibility of operating error.

In the present invention the inert gas or helium (He) is injected internally of the blister pack B or the stack P to be tested, which is then placed in the station 3, internally of which a depressed environment is created such as to force exit of helium from any leaks present. At this point a leak-detecting device signals a presence (or not) of escaped helium and thus leaks in the tested blister pack B.

In the proposed solution, as can be seen in figure 3, the test is performed using pressure values of the depression which are compatible with the characteristics of the blister pack B.

To do this, the above-described cycle includes an injection of a flow of nitrogen into the atmosphere contained in the test station 3 such as to reduce the helium into the atmosphere and make possible very accurate analyses including using relatively less strong depression values.

A possible non-limiting configuration of the operating unit required for the above-described cycle is schematically represented in figure 3, where the following characteristic elements are illustrated:

a test chamber (denoted by no. 50 in figure 3)

an auxiliary vacuum group (PV)

a leak detector (LD)

nitrogen inlet branch (N2)

a chamber evacuation branch (V3)

an analysis branch (V2) (V4). The operating cycle of the unit, of known type and therefore not requiring further explanation, might be summarised in the following operating stages:

closure of the test chamber 50;

opening of valves V1+V2+V3 up to reaching the required depression for the test;

closure of valve V3;

opening of valve V4;

seal analysis;

closure of valve V4;

closure of valve V1 + V2;

test chamber 50 venting;

opening of test chamber 50.

Claims

1 ). A method for controlling packs, in particular blister packs, comprising stages of infeeding, in a determined direction, blister packs into a forming station of at least a stack of the blister packs, transferring the stack to at least a control station of the stack in order to test a seal quality of the blister packs, rejecting any defective blister packs, and transferring the stack of blister packs to conveyors; the seal quality test being performed with use of an inert gas.

2). The method of claim 1 , characterised in that the seal quality test is performed using an inert gas mass spectrometry technology, the inert gas being preferably helium.

3). The method of claim 1 or 2, characterised in that it includes injection of a flow of nitrogen into a closed chamber, such as to limit a presence of the inert gas and enable the seal quality test by subjecting the blister packs to depressions of a limited extent which are compatible with a structure of the blister packs.