GB2196130A

GB2196130A - Method and apparatus for testing filled containers for leakage

Info

Publication number: GB2196130A
Application number: GB08620490A
Authority: GB
Inventors: Bernard Charles Iliffe Stokes; David Howley
Original assignee: Jeyes Group Ltd
Current assignee: Jeyes Group Ltd
Priority date: 1986-08-22
Filing date: 1986-08-22
Publication date: 1988-04-20
Also published as: GB8620490D0

Abstract

A method for testing a filled sealed deformable container 9 for leakage comprises the steps of: (i) placing the container (9) between a rigid back (1) plate and a movable ram (6); (ii) moving the ram under a predetermined pressure and for a predetermined period of time to deform a wall of the container, and then returning the ram to its original position; and (iii) comparing the distance by which the ram has moved at the end of the predetermined time with a standard to evaluate possible leakage of the container. <IMAGE>

Description

SPECIFICATION Method and apparatus for testing filled containers for leakage This invention is concerned with a method and apparatus for testing filled sealed containers, formed of a deformable material, for leakage.

The use of containers, such as bottles, formed of deformable materials, i.e. plastics materials such as polyethylene or polyvinyl chloride is now widespread. Such containers are especially used for a variety of liquids such as liquid beverages and cleansing compositions. It is common experience that a proportion of such containers, when filled and sealed, (e.g. with a screw cap in the case of a plastics bottle), will tend to leak on storage.

Leakage is always inconvenient and in the case of some liquids, such as hypochlorite bleaches, may also be hazardous. It is, therefore, desirable that filled, sealed containers be tested for possible leakage.

According to the invention there is provided a method for testing a filled sealed deformable container for leakage which comprises the steps of: (i) placing the container between a rigid back plate and a movable ram; (ii) moving the ram under a predetermined pressure and for a predetermined period of time to deform a wall of the container, and then returning the ram to its original position; and (iii) comparing the distance by which the ram has moved at the end of the predetermined time with a standard to evaluate possible leakage of the container.

The invention further provides apparatus for carrying out the above test method which apparatus comprises a support for supporting a container to be tested, a generally vertical back plate secured to the support, a movable ram having a face opposing the back plate and normally spaced apart from the back plate to permit a container to be tested to be introduced between back plate and ram; means for moving the ram towards the back plate under a predetermined pressure and for a predetermined period of time and subsequently returning the ram to its original position; and means for comparing with a stardard the distance by which the ram has moved at the end of the predetermined time.

As will be appreciated, when tested in accordance with the invention, a container is adjudged to be a potential leaker if the ram moves beyond a predetermined distance whilst under pressure and deforming the container wall. This particular distance may be ascertained, in any particular case, by simple experimentation and will, of course, depend on a number of variables such as container size, the period of test, the pressure applied to the ram, possible variations in the head space above the liquid in the container and .the location of any potential leak.

In order that the invention may be well understood, reference will now be made to the accompanying drawings in which: Figure 1 is a schematic cross-section through testing apparatus in accordance with the invention, with a container for in position for test therein; and Figure 2 is a diagrammatic section showing a container under test.

As shown in Fig. 1, test apparatus in accordance with the invention comprises a pair of generally vertical supports, 1 and 2 having horizontally disposed therebetween container support member 3. Support member 1 carries a back plate 4 which faces a ram head 5 mounted on piston rod 6 which, in turn, is connected to piston 7 within pneumatic cyciin- der 8.

A container for testing, 9, is supported on support 3 between back plate 4 and ram head 5 and guiderails 10 are provided for the introduction of containers into the gap between back plate 4 and ram head 5.

In operation, air at a predetermined pressure, to is introduced into cylinder 8 (via means not shown) to urge ram head 5 against the wall of container 9 and to deform it as shown in Fig. 2. Should the container be a leaker it will tend to deform further under the action of ram head 5, e.g. as shown in dotted outline in Fig. 2.

Suitable means (not shown) are provided associated with piston rods or piston 8 to ascertain when ram head 5 moves beyond a predetermined position and in this instance, for example, an alarm may be sounded or means actuated to remove the container from a filling line extending downstream of the test apparatus.

1. A method for testing a filled sealed deformable container for leakage which comprises the steps of: (i) placing the container between a rigid back plate and a movable ram; (ii) moving the ram under a predetermined pressure and for a predetermined period of time to deform a wall of the container, and then returning the ram to its original position; and (iii) comparing the distance by which the ram has moved at the end of the predetermined time with a standard to evaluate possible leakage of the container.

2. A method as claimed in claim Claim 1 substantially as hereinbefore described.

3. Apparatus for testing a filled sealed deformable container for leakage, which appartus comprises a support for supporting a container to be tested, a generally vertical back plate secured to the support, a movable ram

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Method and apparatus for testing filled containers for leakage This invention is concerned with a method and apparatus for testing filled sealed containers, formed of a deformable material, for leakage. The use of containers, such as bottles, formed of deformable materials, i.e. plastics materials such as polyethylene or polyvinyl chloride is now widespread. Such containers are especially used for a variety of liquids such as liquid beverages and cleansing compositions. It is common experience that a proportion of such containers, when filled and sealed, (e.g. with a screw cap in the case of a plastics bottle), will tend to leak on storage. Leakage is always inconvenient and in the case of some liquids, such as hypochlorite bleaches, may also be hazardous. It is, therefore, desirable that filled, sealed containers be tested for possible leakage. According to the invention there is provided a method for testing a filled sealed deformable container for leakage which comprises the steps of: (i) placing the container between a rigid back plate and a movable ram; (ii) moving the ram under a predetermined pressure and for a predetermined period of time to deform a wall of the container, and then returning the ram to its original position; and (iii) comparing the distance by which the ram has moved at the end of the predetermined time with a standard to evaluate possible leakage of the container. The invention further provides apparatus for carrying out the above test method which apparatus comprises a support for supporting a container to be tested, a generally vertical back plate secured to the support, a movable ram having a face opposing the back plate and normally spaced apart from the back plate to permit a container to be tested to be introduced between back plate and ram; means for moving the ram towards the back plate under a predetermined pressure and for a predetermined period of time and subsequently returning the ram to its original position; and means for comparing with a stardard the distance by which the ram has moved at the end of the predetermined time. As will be appreciated, when tested in accordance with the invention, a container is adjudged to be a potential leaker if the ram moves beyond a predetermined distance whilst under pressure and deforming the container wall. This particular distance may be ascertained, in any particular case, by simple experimentation and will, of course, depend on a number of variables such as container size, the period of test, the pressure applied to the ram, possible variations in the head space above the liquid in the container and .the location of any potential leak. In order that the invention may be well understood, reference will now be made to the accompanying drawings in which: Figure 1 is a schematic cross-section through testing apparatus in accordance with the invention, with a container for in position for test therein; and Figure 2 is a diagrammatic section showing a container under test. As shown in Fig. 1, test apparatus in accordance with the invention comprises a pair of generally vertical supports, 1 and 2 having horizontally disposed therebetween container support member 3. Support member 1 carries a back plate 4 which faces a ram head 5 mounted on piston rod 6 which, in turn, is connected to piston 7 within pneumatic cyciin- der 8. A container for testing, 9, is supported on support 3 between back plate 4 and ram head 5 and guiderails 10 are provided for the introduction of containers into the gap between back plate 4 and ram head 5. In operation, air at a predetermined pressure, to is introduced into cylinder 8 (via means not shown) to urge ram head 5 against the wall of container 9 and to deform it as shown in Fig. 2. Should the container be a leaker it will tend to deform further under the action of ram head 5, e.g. as shown in dotted outline in Fig. 2. Suitable means (not shown) are provided associated with piston rods or piston 8 to ascertain when ram head 5 moves beyond a predetermined position and in this instance, for example, an alarm may be sounded or means actuated to remove the container from a filling line extending downstream of the test apparatus. CLAIMS

3. Apparatus for testing a filled sealed deformable container for leakage, which appartus comprises a support for supporting a container to be tested, a generally vertical back plate secured to the support, a movable ram having a face opposing the back plate and normally spaced apart from the back plate to permit a container to be tested to b introduced between back plate and ram; means for moving the ram towards the back plate under a predetermined pressure and for a predetermined period of time and subsequently returning the ram to its original position, and means for comparing with a stardard the distance by which the ram has moved at the end of the predetermined time.

4. Apparatus as claimed in Claim 3 substantially as hereinbefore described with reference to the accompanying drawings.