Aerosol cans are becoming increasingly popular as a packaging solution for a wide range of products from cosmetics to medications. However, aerosol cans pose a number of challenges when it comes to inspection for packaging integrity. Containers intended to store aerosol products must be inspected for holes, because aerosol cans are filled with propellant gas under high pressure, and holes or weak spots cause dangerous leaks and render the aerosol product totally unusable.
Bonfiglioli Engineering has developed a machine designed specifically for leak testing aerosol cans. The KBA Leak Tester is an alternative to traditional methods to quickly and effectively inspect this type of container.
Traditional test method: the Water Bath Method
The traditional method for testing the integrity of aerosol cans is the water bath method, where operators immerse containers in a water tank and watch for air bubbles rising to the surface. Bubbles indicate that the containers have holes or cracks. This very simple type of test is commonly used but has certain limitations that make it ineffective:
The inspection must be done by an operator who has to visually watch for bubbles and remove the product manually if leakages are detected. Therefore, the test is operator dependent, which can lead to errors due to physiological lapses in attention. As a result, not all damaged products are always correctly found, and there is also the risk of false negatives.
Risk when dangerous or flammable products are tested: if a perforated container is immersed in water, its contents can be dispersed in the tank, exposing the operator to danger and potentially damaging the testing area.
Need for a drying system for tested products: once tested, intact and compliant products must be dried, which requires the use of appropriate equipment.
It should also be noted that international regulations do not require the aerosol can manufacturer to perform the package integrity test. The company selling the finished product is responsible for this, which means that damaged aerosol cans are not detected at the time of manufacture, but only after they have been filled. The product manufacturing process can be made more efficient if, instead, the manufacturer tests empty containers and then sells only those that pass the integrity test. This is why Bonfiglioli Engineering has developed the KBA Leak Tester, an empty aerosol can testing machine for use by manufacturers so they can offer products that have already been tested and approved.
Bonfiglioli Engineering’s KBA Leak Tester, a high-speed in-line solution
The KBA Leak Tester automatically inspects the integrity of empty cans. The testing method combines the vacuum decay method (VDM) and the pressure decay method (PDM). The containers are placed in a vacuum chamber and then subjected to high pressure. The vacuum level is measured immediately after product insertion and then again a few seconds later. If the difference between the two values is greater than the threshold value defined during machine calibration, the non-conforming product is automatically rejected.
The KBA system provides important benefits:
The inspection is automated, result evaluation is not operator dependent and the level of accuracy is consistent over time.
Cans are tested before they are filled, not after. In this way, the company responsible for selling finished products can be certain that it is filling intact containers, so no product is wasted and operators are not exposed to any risk of contamination.
The system is automated, so inspection is very quick. The equipment can be sized to test up to 600 products per minute.
Products passing the inspection are ready to be sold and do not need to be dried.
Thanks to Bonfiglioli Engineering’s special handling solutions, the KBA leak testing system effectively inspects any type of can—even on high-speed lines—and guarantees accurate results that are fully compliant with international regulations.