Apparatus for detecting leaks in composite packages

Apparatus for testing leakage of composite packages is disclosed. The apparatus includes a hollow arbor for supporting a composite package to be tested for leakage, the open end of the composite package being sealed to a support for the hollow arbor, the interior of the latter being connected to means for placing pressure on the interior of the composite package at a value less than ambient, and being subsequently connected to means for measuring leakage in the container while being supported on the arbor.

BACKGROUND OF THE INVENTION 
The present invention relates to the provision of apparatus for testing for 
leakage, either through an opening or by permeation, in a composite 
package which is defined as a semi-rigid container body, deriving its 
strength principally from one or more cylindrically wound fibreboard plies 
or laminations thereof, and having closures attached to one or both ends 
thereof to contain a product. The apparatus of the present invention can 
be used to test the entire package, not just the body or closures. 
The composite packages are generally random tested by subjecting the 
interior of the package to a pressure less than ambient and then exposing 
the exterior of the package to an inert gas, such as helium, for example, 
and connecting the interior of the package to apparatus responsive to the 
gas by leakage thereof into the package, and measuring such leakage. 
SUMMARY OF THE INVENTION 
With the foregoing consideration in mind it is the purpose of this 
invention to provide an efficient apparatus for the testing of composite 
packages for leakage, particularly those made of fibreboard or paperboard 
and having end closures.

The leakage testing apparatus is referred to generally by the reference 
numeral 10 and includes a hollow support arbor 11 having a central 
longitudinal passage 12 therein, the lower end of passage 12 being 
threaded at 13A to engage a ferrule or boss 13 threaded at 13A whereby 
arbor 11 can be held to a support 16. 
A composite package has an end closure CL attached to the upper end of 
composite package at a seam S. The lower end of composite package has a 
flange F seated on an annular gasket 17 resting upon an external shoulder 
18 on support 16. 
Support 16 has a seat 18 for an O-ring seal 19 and the lower end of arbor 
11 has a lowermost seat 21 for an O-ring seal 22 engaged with seal 19, 
both bearing against the interior face of composite package, seals 19 and 
22 and gasket 17 defining an annular chamber 23 in turn connected by 
radial passageways 24 to a chamber 26 in support 16. 
Arbor 11 has vertical grooves 11A and these are connected by radial 
passageways 11B to the passage 12 in arbor 11. Such passageways aid in 
subjecting the inside of composite package to a pressure less than ambient 
for a purpose as will appear. 
Chamber 26 is connected to a vacuum source shown in FIG. 1 by a line 27, 
and chamber 26 is enabled to be vented to ambient by a line 28 having a 
vent valve 29 therein. When valve 29 is closed and vacuum source is 
operable through 25, composite package is held in position on annular 
gasket 27 and against O-ring seals 19 and 22. 
Structure is provided for subjecting, as desired, the remainder of 
composite package to a pressure less than ambient, and surrounding 
composite package with a gas which may pass through the composite package 
if in fact the composite package leaks for some reason. To this end 
support 16 has a passageway 31 therethrough coextensive with passage 12 
and coextensive with a passageway 32 within annular chamber 26, passageway 
32 being connected to a test line 33 which is part of a test circuit to be 
described. 
Test line 33 has a spool valve 34 therein with spool 36 therein having 
spaced lands 37, 38 and 39. A port 41 in valve 34 is connected to line 33 
and through a shutoff valve 35 between lands 38 and 39 to a port 42 in 
turn connected to a vacuum pump 43 through a shutoff valve 44. 
When it is desired to test the seal integrity of composite package, it is 
placed on the arbor 11 and seated on gasket 17 and over O-ring seals 19 
and 22. A vent valve 47 is connected in a line 48 branching from test line 
33 and a vacuum gauge 49 is likewise connected in a line 51 branching from 
test line 33. 
Spool valve 34 is in the position shown and valves 35 and 44 are opened 
when vacuum pump 43 is operated. When a desired subambient pressure is 
indicated by gauge 49, spool valve 34 is actuated with lands 37, 38 and 39 
shifted to the dotted line position. 
At this time a port 52 in valve 34 is unlapped and a leak rate meter 53 is 
connected to port 52 and is now subject to the subambient pressure 
interior of composite package. The exterior of composite package is now 
exposed to a gas, such as helium, meter 53 being responsive to leakage of 
such gas through composite package. If the meter 53 does not change 
reading, or such change is within permissible limits, composite package is 
acceptable. 
When the test is completed valve 34 is actuated to its original position, 
valve 49 closed and vent valve 47 opened. Valve 29 is then opened 
relieving the pressure in chamber 26 for release of the composite package. 
It should be borne in mind that the test described is made only after 
calibration of meter by use of a test container of known properties. The 
test and calibrating procedure of meter 53 with such a test container is 
not described as such is a common practice in the use of a test instrument 
.