The aseptic package is only as good as the final sealing of the ingredients. A small amount of inert gas is injected into a package of dairy and meat products to ensure freshness. The gas is injected at atmospheric pressure to keep the package dimensions stable. Testing the presence of a minimum amount of the inert gas and the integrity of the package seal posed a problem to the manufacturer. Loss of gas either by a puncture or from a poor seal means inevitable product spoilage. To reduce the potential of loss, a method of testing the final package had to be developed. Intrusive testing was eliminated as test method because it too time consuming.

Solution to Load Cell Application

Honeywell worked with the customer to come up with a 100% inspection method by placing several sealed packages in a chamber with a reduced atmosphere and allowed the gas filled package to enlarge. A Honeywell Load Cell with a platen attachment was automatically lowered against the top of the package to sense the force created by the increase in relative pressure. A force-level window was created to reject under pressurized packages.

Honeywell’s Model 31 Load cell was selected because of the capability to hermetically seal the all-welded, stainless steel load cell and to provide a submersible cable for the sanitary wash-down procedure. The Model 31 Load Cell would also have to operate in a near vacuum condition inside the test chamber.

The quick response time of the Model 31 in the range of 0-50 lbs, allowed up to 2,500 packages per hour to be inspected. The high overload protection option in the Model 31 assured continuous operation of the testing equipment even though a jam in the process could generate up to 500 lbs or ten times the Load Cell range. Space was also a premium in the package testing chamber and the Model 31 fit the bill perfectly with the small footprint.

Conclusion

Honeywell supplied a standard model load cell with standard options to 100% monitor the integrity of a complicated food package seal. The load cell was located in a wash-down area and reliably operated in a reduced pressure atmosphere. The quick response by the Honeywell Sales and Engineering Team was rewarded by the continuing success of this customer's high quality product in the consumer market place.