X-ray inspection machines are very valuable parts of your quality control process but their value is ensured when you follow certain best practices.
First, let’s start with challenge pieces. One of the most fundamental things that customers do to make sure their machines operating correctly is they create special what we call “challenge pieces.” They are contaminated product that they run through the system and this they then verify this system can find that contaminant and eject that jar.
We recommend that you do this for all of your inspection types. If you’re looking for foreign material that’s one type of challenge piece. If you’re looking for under-filled containers, that’s another kind of challenge piece.
You should not run those two within one jar because it can lead to analysis errors in terms of making sure the machine found the correct defect and ejected it properly.
How Often do I Challenge the Machine?
People often ask “how often should I challenge your machine?” The challenge process is really a risk-reducing activity meaning you should do it as often as you think you need to, to narrow the window of product that in case there’s something wrong you have to potentially inspect that product.
Most customers challenge their machine every 20 to 30 minutes, and that’s more than adequate.
In addition, today’s machines can have image recording capability in them that can store all the images. So, something goes wrong you can go back and electronically inspect those images without actually touching any of your product.
This is extremely important because if you’re busy meeting production goals the last thing you want to do is to have to run product back through your machine. The other thing that is important about challenging your machine is to make sure that you actually create the most difficult challenge containers possible.
So if you think about X-ray inspection, this machine has the capability to know when the challenge piece is coming through. It will build a heat map of all the locations that are tested and you want to test the bottom of the container against the side wall. That is the most challenging, that’s the most high-risk area where you’re going to find contamination in the middle of the container. It is certainly possible to have contamination in a product like jam, but it’s also much easier to inspect.
We want to encourage customers to really challenge the machine to make sure they’re getting the most difficult inspections properly. The other thing that we’re starting to introduce in fielded systems is something called electronic or non-destructive challenging. This is where the system will take the container and it will place a glass or metal contaminant within the container and check to make sure the software correctly detects that condition and if it does it will constantly do that test.
It will run the test every five to ten seconds which gives you a kind of real-time challenging and for customers who still do the physical challenge it merely decreases the odds of that not working to almost zero. It’s a very popular option that you can now get with our machines to ensure that they’re running properly.
Heat Map Checking
Another thing that you’ll do at the end of the day, is just making sure you look at the heat map that the machine draws and make sure you got a good distribution of your challenge contaminants across the entire container.
You will want to do a thorough job, making sure everything got properly checked. Finally, you should check when you get rejected containers that those containers match the rejected images in the machine.
One of the things that we offer through our partnership with Domino printers is that the printer can actually print coding information on the rejected image such as a sequence number and the reason for rejection. It allows you to look in the machine and map that to the exact image that was rejected.
This is the ultimate form of traceability and it leaves no doubt that you got all of the rejected containers actually off of your production line. Customers often ask me “Well, what do I need to do if I have a CCP or a critical control point application?”
If you do the two things previously mentioned, inspection traceability and good challenging, you’re in good shape and the machine will provide you with the kind of protection you need to use it continuously in your production process.