A thirst for perfection
How do you create the perfect coating on your beverage can? Industrial Physics outlines how to ensure the integrity of metal packaging…
Perfection in packaging is important for so many reasons – from standing out on the shelves to ensuring the safety of contents, quality assurance tests are carried out for a range of purposes.
For manufacturers and production lines dealing with metal packaging in food, beverage and aerosol industries, numerous tests are needed to protect the integrity of your finished product. And many of these tests are designed specifically to assure the quality of your can’s coating.
Operating across a family of brands, including TQC Sheen, CMC-KUHNKE, Systech Illinois and Eagle Vision, Industrial Physics is a global test and inspection provider. Why do we exist? It’s simple, we offer solutions that protect the integrity of packaging, products and materials.
In fact, we recently put a report together that analysed the biggest trends and challenges facing beverage packaging manufacturers today.
For can fillers, can makers and food and beverage companies, there’s a thirst for perfection. So we thought we’d break things down a little and explore some of the different testing applications that can ensure the integrity of your can’s coating.
Let’s take a look at how the right test and inspection solutions can help you to seamlessly get from the start to the end of the quality control process. And discover how simple it can be to produce a finished can that is safe, durable and of the highest quality possible using equipment that’s exceptionally efficient.
Step 1 – Protect your metal coating
Before we even start to think about protecting the contents and design of your can, ensuring the integrity of your metal coating is key.
This seems like a simple enough process – the steel roll is submerged in a tub of tin or chrome particles, and it’s then coated using passivation. So, what could possibly go wrong?
Well, quite a lot as it turns out. If the coating is too thin, the can could rust – this is bad for the can maker or can filler. However, if it’s too thick, then the process becomes wasteful and expensive. However, the layer is too thin to be measured mechanically or visually. As such, the only viable option is to use the STANNOMetal / CHROMetal method.
Put simply, the STANNOMetal and CHROMetal analysers are computerised coulometric metal thickness gauges that can be used for tinplated steel or chrome plate steel respectively.
The systems use new electrolytic/coulometric hardware and software. These coulometer cells are used by the analysers to inspect tinplate samples and perform thickness measurement testing on the tinplated steel. The operator inserts the sample into the cell, electrolytic fluid fills the cell, and the cell is then closed.
Next, the measurement process can proceed on both sides of the sample. The software uses a standard Windows operating system and provides a live profiling graph of the deplating process.
When the measurement process is completed, a measurement report is then produced alongside a tested sample that the plant can keep.
Step 2 – Ensure the contents of your can are protected
It goes without saying that ensuring the safety or your can’s contents is a critical part of quality control. And in order to adhere to food and beverage safety standards, protect the integrity of your business, and prioritise consumer safety, you need the right instrument in place.
There are many tests that need to take place to ensure food and beverage safety within metal packaging. But when we’re dealing with the protection of coatings specifically, the CMC-KUHNKE ENR-4000, which tests for metal exposure, is critical.
The purpose of this instrument is simple – it exists to test the integrity of the inside of the can. Essentially, this tool allows you to identify any small gaps that could cause significant food or beverage safety problems.
The ENR-4000 determines the lacquer permeability on three-piece cans, two-piece cans, aerosol cans, can ends, side seams, bottle caps and even tubes. And by seeking out any small defects within the lacquer, you can feel confident that the interior of your can is safe and suitable to move to the next stage of production.
Another great tool is the Eagle Vision Empty Can Inspection – this performs an inline check on the internal can to identify any contamination and damages that can contaminate or corrode the product living inside the can. It also inspects the flange quality to assure proper seaming – without seamer crashes.
Step 3 – Check the quality of your can labels
Once you’ve ensured that the can coating is fit to protect the contents, it’s time to make sure the exterior of the can is presented perfectly. And that means making sure that your all labels have been thoroughly inspected.
To get that right, you’ll need a truly state-of-the-art system that can spot even the smallest of errors. A dodgy design, incorrect barcode, or wrong best before date imprinted on your can is far from ideal. But with the Eagle Vision 360° Label Inspection module and our Code Reading module, you can prevent errors like this from taking place.
Using advanced technology, the system inspects labels with a 360° field of view – checking for mixed-up labels, label positions, misprints, and damages. It also comes with barcode reading, 2D data matrix code reading, OCR label number reading, and allows for decoration artwork print inspection in color to be carried out.
By integrating multiple technologies into one system, the system offers you a highly reliable and accurate solution.
After the chemical treatment of the cans, an organic coating is applied to provide protection against acidic products and create the aesthetics of the can.
Though thin, this coating needs to be very resilient. It’s also important to carry out rub tests that are performed on the exterior of the can – the TQC Sheen Washability test can determine the quality of the cure. This is especially important as under cured coatings could have a serious impact later in the filling and transportation process.
Step 4 – Simulate the journey of a can
After all that work getting your can up to scratch, the last thing you want is for it to arrive at your customer’s doorstep looking battered and bruised.
That’s where our TQC Sheen Comprehensive Abrasion Tester comes in. This smart tool tests the abrasion resistance of inks and coatings on your aluminium can. How? By allowing you to simulate realistic transport scenarios that ensure your can will be able to withstand the pressures of travel – allowing you to feel confident that everything can arrive in one piece.
And what’s more – you can even select different scenarios depending on your circumstances. Want to test against a bumpy drive down a motorway? Or would you prefer to simulate a smoother journey? The choice is yours!
Step 5 – Curing your finished can!
The TQC Sheen Cureview Gradient Oven is the final piece of the puzzle you need to achieve the perfect coating on your can. Essentially, this is a flexible oven that allows you to heat up test panels on a glass bed to a variety of temperature profiles.
However, this step isn’t exclusively reserved for the end of your process – it’s a testing procedure that should be carried out at numerous stages of production.
The first time you carry out this process should be right after you’ve conducted your enamel rating (step 2). The purpose of this is to cure your cans after checking the interior. Then, it’s also important to cure your can in an oven after the label inspection and abrasion testing has been carried out – this acts as a final inspection on the aesthetics of your can.
You can also take this procedure to the next level by investing in CurveX 3 Standard Oven Logger Kit – this data logger allows you to easily measure and analyze insights from your paint curing oven.
Our extensive solutions
As your global test and inspection partner, we have a wealth of solutions available to ensure the integrity of your metal packaging.
This includes a wide variety of seam inspection instruments – we have multiple products on offer depending on your unique needs. One of these is our advanced in-line seam inspection instrument that uses vision technology to inspect the seam of every single can on your line – you can learn about this here.
And you can explore our full portfolio of products created exclusively for beverage packaging manufacturers:
About Industrial Physics
At Industrial Physics, we’re here to protect the integrity of manufacturers, laboratories, and production lines all over the world. And we do this by providing test and inspection solutions that ensure the integrity of your packaging, materials, and products.
Across our portfolio of products, we offer an extensive range of solutions for the metal packaging industry. If like to speak with us to hear about how we can support your needs, just get in touch.