GB2222687A

GB2222687A - A method and apparatus for testing and/or verifying the tightness of filled and hermetically sealed containers

Info

Publication number: GB2222687A
Application number: GB8917707A
Authority: GB
Inventors: Giuseppe Bonfiglioli
Original assignee: Individual
Current assignee: Individual
Priority date: 1988-09-13
Filing date: 1989-08-02
Publication date: 1990-03-14
Also published as: IT1225063B; DE3925494A1; IT8803591A0; GB8917707D0; FR2636428A1

Description

1 A method and apparatus for testing and/or verifying the tightness of

filled and hermetically sealed containers 22268 7 L The invention relates to a method for testing and/or -,,erifvincf the fluid-tightness of filled and hermeticallv sealed containers, and to apparatus for the implementation of such a method. The current state of the art embraces apparatus by means of which to test the integrity of empty containers such as bottles, phials, jars and the like, provided with a removable sealing element generally referred to as a top or cap, or lid. Such apparatus is used to charge the container with compressed air, and thus seek out any microporositv attributable to defects in manufacture, for example in the blowing process, where glass containers are concerned, or the moulding or extrusion process in the case of plastic products; the same apparatus can be used to test tin cans for microscopic gaps that may remain after their edges have been welded together. The need to avoid such defects is particularly well known in the manufacture of pharmaceuticals, where 2 widespread use is made of moulded plastic bottles; such items are especially prone to the defects in question by reason of the very nature of plastics, and of the special process by which the container is formed. Containers of the type are almost invariably used in bottling physiological or medicinal solutions, for assumption parenterally or intravenously by a patient, that tend to deteriorate easily if exposed to air; it is therefore of particular importance that bottles remain faultlessly fluid-tight once filled and capped. Apparatus as mentioned above, however, is capable of testing a container only when empty, whereas no similar provision is made for verifying tightness after filling and capping. Accordingly, the object of the present invention is to allow of verifying and/or testing the tightness of containers that are already filled, capped and ready for distribution and sale. The stated object is achieved with a method, and with apparatus for the implementation of such a method, which comprises the steps of evacuating an environment encompassing at least a section of the container to be tested, allowing a given interval 3 of time for stabilization of pressure within the environment, measuring the residual pressure level and comparing the result with a previously selected set point, and thereafter rejecting any container showing a difference between the residual pressure and set point pressure levels that is greater than a previously selected permissible margin of shift. One of the advantages afforded by the invention is that it permits of testing and/or verifying the tightness of substantially any type of container, including jars and cans in general, and phials. The invention will now be described in detail, bN way of example, with the aid of the accompanying drawings, in which: -fig I illustrates apparatus for implementation of the method according to the invention, viewed in frontal elevation with certain parts omitted better to reveal others; - fig 2 shows an alternative embodiment of apparatus for implementation of the method according to the invention, viewed in frontal elevation with certain parts omitted better to reveal others; -fig 3 is the schematic illustration of automatic machinery incorporating a plurality of apparatus as in fig 1 for implementation of the method according 4 1 to the invention; -fig 4 shows a further embodiment of apparatus as in fig 2 for implementation of the method according to the invention, viewed in frontal elevation with certain parts omitted better to reveal others; - fig 5 shows an embodiment of apparatus as in fig 1 designed for testing and/or verifying phial type containers in groups, viewed in frontal elevation with certain parts omitted better to reveal others. With reference to figs 1, 2, 4 and 5 of the above drawings, a method according to the invention for testing and/or verifying the fluid tightness of bottles, jars, tubs, phials and similar containers that have alreadv been filled, includes the initial step of evacuating the space that surrounds a given section 4 of the container I under inspection. Fig 1, in particular, shows a container 1 having a neck 2 of circular cross section, which is filled and hermetically sealed by a cap 3 of transverse dimensions less than those of the main body of the container 1; according to the invention, negative pressure is generated internally of a hermetically sealed environment encompassing a given section 4 of the container that comprises at least a part of the neck 2, and the cap 3.

z In the event that the fluid tightness test and/or verification is to be carried out on jars or tubs or similar containers 5 without removable caps, or containers 6 with a lid 7 of transverse dimensions substantially identical to those of the main body of the container 6 itself, the space evacuated will encompass the container 5 or 6 in its entirety (see figs 2 and 4). Similarly, an all-encompassing environment will be evacuated in the case of containers 38 arranged in groups, such as the phials illustrated in fig 5. After a relatively generous interval of time has been allowed to lapse, in order to attenuate the inevitable turbulence created by evacuation and thus stabilize the pressure level internally of the encompassed space, the residual pressure level is measured, and a real time comparison effected with a previously selectable set point. In the event that the difference between effective and set point residual pressure levels should be greater than a selected maximum permissible margin of shift, the container affected will be rejected as substandard, since such a result is indicative of the presence of perforation and/or fracture at the section 4 of the container 1 under test, or of 6 Q, the fact that the cap 3 is not sufficiently tight; in either of these conditions, in fact, pressure in the space will tend to return to the preevacuated condition,-i.e. atmospheric. The same principle also applies in the case of the containers denoted 5 (in fig 4), 6 (in fig 2) and 38 (in fig 5). Apparatus for implementation of the above method will now be described. Where the verification is effected on bottles and similar containers 1, for example, as used in the pharmaceutical industry to bottle physiological or medicinal solutions (see fig 1), having a neck 2 of circular cross section and provided with a cap 3 the transverse dimensions of which are less than those of the body of the container 1, apparatus comprises means 9 for hermetically delimiting a chamber 10 such as will encompass a section 4 of the container comprising the neck 2, at least in part, and the cap 3. Still referring to fig 1, the delimiting means in question consist in an open ended vessel 9 the bottom inner edge 13 of which is provided with sealing means 14 such as a ring, for example, engaging in direct contact with the outer surface of the neck 2 and/or of the bodv of the Q 7 container 1 create the chamber 10. The chamber 10 connects by way of two respective passages 15 and 16 in the vessel 9 with means of generating negative pressure, for example a vacuum pump (not illustrated), and with means by which to measure residual pressure in the chamber 10, such as a vacuometer (not illustrated); the pressure measuring means are connected with monitoring and control means 12, illustrated schematically as a displav in fig 3. It should be emphasized that, in the instance of fig 1, the creation of a negatively pressurized environment around the section 4 of the tested bottle 1 is equivalent to generating a force such as tends to separate the cap 3 from the neck 2 of the bottle 1; accordingly, one has an additional parameter in establishing the quality and accuracy of the hermetic seal, inasmuch as the verification takes place with the cap 3 subjected to a critical condition. When testing the tightness of single cans, tubs or other such containers 5 without a removable cap, or of single containers 6 sealed by a removable lid 7 the transverse dimensions of which are essentially and combining hermeticallv therewith to 8 the same as those of the rest of the container 6, (see figs 4 and 2), apparatus for implementation of the method disclosed will comprise means 11 for hermetically delimiting a chamber 10 by which the single container 5 or 6 is totally encompassed. Still referring to figs 2 and 4, the vessel 11 of the delimiting means is embodied as a cylindrical housing lla, the top of which will be enclosed by a cover 22, and the bottom edge 11b provided with sealing means 18 such as a ring, for example. The sealing ring 18 in this embodiment operates by entering into contact with a flat locating element denoted 19, located beneath the housing 11, upon which the single container 5 or 6 is positioned within the annular area of contact between the sealing ring 18 and the flat element 19 itself. Thus, the vessel 11-22 and the locating element 19 together create a chamber 10 by which the single container 5 or 6 is totally encompassed. The chamber 10 is connected by way of respective passages 20 and 21, located in the cover 22, with means for generating negative pressure and means for measuring the residual pressure registering internally of chamber 10 following the prescribed stabilization interval.

9 Fig 4 illustrates an embodiment of the vessel 11 in which the cylindrical housing 11a accommodates a vertically slidable piston 23 engaged in fluidtight contact with the internal wall llc of the housing 11a. With this arrangement, the height of the piston 23 can be adjusted, according to the longitudinal dimensions of the single container 5 or 6 positioned inside the vessel 11, to the end of keeping the dimensions of the chamber 10 smaller and thus producing a swifter pressure response. In fig 5, which illustrates a plurality of single containers 38 without removable caps, arranged together in a group, the delimiting means consist in a vessel 39 positioned beneath and accommodating the aroup of containers 38 in what is substantiallv a matching fit, and a plate 40, positioned above, the underside of which is provided with sealing means 41 such as a ring, designed to register.with the top edge 39b of the vessel 39. The vessel 39 and plate 40 thus combine to create a chamber 10 by which a group of the containers 38 can be totally encompassed. The plate 40 will afford holes (not illustrated) connecting respectively with means of generating negative pressure and with means of measuring the residual pressure level in the chamber 10 following the stabilization interval. Means 42 may also be provided inside the vessel 39, perhaps integral with the vessel itself and/or with the plate 40, the purpose of which is to occupy space internally of the chamber 10, thereby gaining a reduction in volume and a swifter response in operation. 17 denotes means (fig 3) by which single vessels 9 or 11 or plates 40 are supported from an automatic machine and traversed vertically between a raised, at-rest position, and a lowered operating position in which the seal 14 of the vessel denoted 9 enters into contact with the outer surface of the relative container I (fig 1), or alternatively, the seal 18 of the vessel denoted 11 engages the flat locating element 19 (figs 2 and 4), or again, in which the seal 41 of the plate 40 registers with the top edge 39b of the vessel denoted 39. The support means 17 consist in rods 33 connected one to the top of each vessel 9 or 11, or plate 40, and forming part of the machine (illustrated purely in schematic manner in fig 3 and denoted 34 in its entirety); more exactly, the machine comprises a carousel 30 located uppermost and rotatable about a 11 vertical axis, by which the rods 33 are carried and afforded freedom of vertical movement. The machine 34 further comprises means 8 by which the containers or vessels 39 are conveyed toward the carousel 30, for example, a guide 36 and a driven element 37 that might be embodied as a belt or a screw. Also provided are: a support 31 located at bottom, on which the single containers or flat elements 19 or vessels 39 are rotated coaxially and synchronously with the carousel 30; means 32 by which the single containers, or single vessels 39 with their groups of containers 38, are conveyed to the next station following the test; and means not illustrated, but interlocked to the monitoring and control means 12, by which to eject containers that have been tested and found substandard.

12 Claims

1) 1 A method for testing and/or verifying the tightness of filled and hermetically sealed containers, characterized in that it comprises the steps of: -generating negative pressure in a hermetically sealed environment encompassing at least a section of the container to be tested; -allowing a given interval of time for pressure to stabilize in the environment, and then measuring the residual pressure level; -effecting a comparison in real time between the effective residual pressure level measured in the environment, and a previously selectable residual pressure set point; -rejecting any container found to be substandard by reason of the fact that effective residual pressure differs from the residual pressure set point by an amount greater than a given previously established permissible margin of shift.

a 13 2) 3) 4) A method as in.claim 1 for testing and/or verifying bottles and similar containers exhibiting a neck of circular cross section and sealed with a removable cap of transverse dimensions less than those of the main body of the container, wherein the environment in which negative pressure is generated encompasses only a given section of the container, comprising the neck at least in part, and the cap.

A method as in claim 1 for testing and/or verifying cans, tubs and similar containers not having a removable cap, and containers with a removable lid of transverse dimensions substantially identical to those of the bodv of the container, wherein the environment in which negative pressure is generated totally encompasses the container.

A method as in claim I for testing and/or verifying containers not having a removable cap, which can be associated one with the next and tested in groups, wherein the environment in which negative pressure is generated totally encompasses a group of the containers.

14 Apparatus for implementation of the method as in preceding claims, characterized in that it comprises: -means for conveying the containers to a testing and/or verification location; -means for hermetically delimiting a chamber by which at least one section of the single container is encompassed; -means for generating negative pressure internally of the chamber; -means by which to measure the residual level of pressure in the chamber following a given interval of time allowed for stabilization; -means by which to effect a comparison between the residual pressure level measured and a previously selectable residual pressure set point, and to trigger the ejection of containers whenever the effective and set point pressure levels differ by an amount greater than a previously established maximum permissible margin of shift; -means for conveying positively tested and/or verified containers to a successive production line station.

1 A 6) 7) Apparatus as in claim 5 for testing and/or verifying bottles and similar containers exhibiting a neck of circular cross section and sealed with a removable cap of transverse dimensions less than those of the main body of the container, wherein delimiting means consist in at least one open ended vessel the bottom inner edge of which is provided with sealing means designed to enter into contact with the external surface of the neck and/or the main body of the container, and combine therewith to create a chamber connected by two respective passages with means of generating negative pressure and means for measuring residual pressure inside the chamber, further comprising means designed to support the vessel and bring about its movement at least vertically between a raised at-rest position and a lowered operating position in which the sealing means enter into contact with the neck and/or the main body of the container.

Apparatus as in claim 5 for testing and/or verifying cans, tubs and similar containers not having a removable cap, and containers with a removable lid of transverse dimensions essentially identical to those of the body of the container, 16 wherein delimiting means consist in at least one vessel the bottom edge of which is provided with sealing means designed to enter into contact with a flat locating element upon which single containers are positioned within the area of contact between the sealing means and the locating element, in such a way that the vessel and the flat locating element combine to create a chamber totally encompassing the container and connecting by way of respective passages, afforded by the vessel and/or by the flat locating element, with means of generating negative pressure and means for measuring residual pressure inside the chamber, further comprising means that are designed to support the vessel and bring about its movement at least vertically between a raised at-rest position and a lowered operating position in which the sealing means enter into contact with the flat locating element.

8) Apparatus as in claim 5 for testing and/or verifying cans, tubs and similar containers not having a removable cap, and containers with a removable lid of transverse dimensions essentially identical to those of the body of the container, wherein the vessel appears as a cylindrical housing 17 enclosed uppermost by a cover and accommodating a vertically slidable piston that is engaged in fluid-tight contact with the internal wall of the housing and adjustable automatically for position according to the height of the single container occupying the vessel, and combines with the flat locating element and the cylindrical housing to create the hermetically sealed chamber.

Apparatus as in claim 5 for testing and/or verifying containers not having a removable cap, connectable one with the next and arranged in groups, wherein delimiting means consist in at least one plate the underside of which affords sealing means designed to register with the peripheral top edge of a vessel containing one group of containers, in such a way that the plate and vessel combine to create a chamber totally encompassing the containers and connecting by way of respective passages, located in the plate, with means of generating negative pressure and means for measuring residual pressure inside the chamber, further comprising means that are designed to support the plate and bring about its movement at least vertically between a raised at-rest position 18 and a lowered operating position in which the sealing means enter into contact with the vessel.

10) 11) 12) Apparatus as in claim 9, wherein the internal shape of the vessel substantially matches the external shape of the relative group of containers.

Apparatus as in claim 6, 7 or 9, comprising a plurality of-delimiting means, carried by way of support means from an overhead carousel rotatable about a vertical axis, and an element located beneath the carousel, coaxial and rotatable synchronously therewith, by which the containers are supported directly or indirectly.

A method as in claims 1... 4 and apparatus as in claims 5... 11, as described and illustrated with reference to the figures of the accompanying drawings, and as intended for the stated objects.

Published 1990 atThe Patent OMce. State House. 86-7 t 1xiihHolburn.London WCIR4TP- Pirtkier copies maybe obt&MdfroMThG Patent OMCG. S31es BrancIL St Mary Cray. Orpington. Xsnt 13F.5 3RD. printed by multiplex tec=quos itcL St Mary Cray. Kent. Con. 1.87 z