With the automation add-ons available to ensure quality and increase productivity, aluminum canning lines are fast becoming the choice of beverage manufacturers world-wide.
At the heart of any aluminum canning line, the right machine automates filling, lid application, and seaming ensuring that you have repeatable, high-speed, quality filling and seaming process. That much is necessary, but there’s more canning automation than these 3 things to consider. Unless you want your friends and family doing processes that can be automated.
Aluminum can depalletizers
Let’s start at the beginning of the aluminum canning line. How will you get your cans into the filler? Aluminum cans come on a pallet stacked in layers. The number of layers depends upon the size of the cans you are filling. Before you can fill, the cans need to be removed from the layers and put into the filler in-feed. Julietta or Bob (fictional production laborers that could be freed up for other tasks if not working on the canning line) could manually place them into the canner by hand.
It’s a highly manual process and not very cost effective since you need a Julietta or a Bob to keep feeding the canner its cans. With a little more footprint, you can add a depalletizer. A semi-automated one (often called a shaker table or a “whale tail” is not much more than a shelf at a height above the top of your fullest pallet of empty cans. You pull a layer of cans (389 of them if you’re doing standard-sized cans) onto the shelf and tilt it up. Gravity and a vibrator do the job of bringing them down to the canner. It’s a big improvement over hand loading since you can load almost 400 cans at a time. However, it still means a person is having to periodically tend to the canning in-feed.
For the most labor-free canning lines the best solution is a fully automated depalletizer. These are great! Once a pallet is parked inside of one of these, everything is automated. The depalletizer removes the slip sheets and feeds the canning line layer after layer of the aluminum cans until empty. The amount of time someone needs to attend to the canning in-feed is reduced significantly. Now Julietta and Bob can go clean tanks instead of feeding the canning line.
Pre-fill rinsing aluminum cans is a required step for most beverage producers. Why rinse? Aluminum cans should be sterile inside with nothing that bacteria or other spoilage critters can live on, right? Unfortunately, manufacturing, shipping and depalletizing is not a sterile process. The cans are not perfectly sealed from dust particles so there is the possibility of contamination.
Most canning facilities recognize the problem and rinse out the dust to ensure any colonies of bacteria and yeast are swept out of the cans before filling begins. Most use clean water, others prefer using a sanitizing solution, and others go the extra mile and use ionized air to charge the particles of dust away from the cans and suck them up with a vacuum system. If you’re going to rinse, do you want Bob doing it or the canning automation?
Your aluminum can is filled… now what?
Where does dosing fit in? There are two types of dosing found in canning. Microdosing is used when a precise small quantity of concentrate (flavoring, CBD, the sandworm spice) is added to each can prior to applying the lid. More specifically, liquid nitrogen dosing is often done in canning for 3 reasons.
- The most obvious reason is if you need a nitro (think Guinness) product. With or without widgets, enough liquid nitrogen put into a can will provide the creamy nitro product you expect from a nitro fill. Without a widget, it’s best to shake the can prior to opening it.
- A less obvious but more common reason is if the beverage is still (not carbonated). Aluminum cans need internal pressure to become stable enough to handle and stack without denting and collapsing. The beverage provides the pressure because it’s carbonated or pressure needs to be added using a little LN2 (as we like to call liquid nitrogen) which expands into a gas shortly after the can is sealed.
- The third reason to add LN2? It can push out the air in the headspace before the can is sealed to help keep the oxygen out of the cans. This is particularly helpful when canning beverages that don’t have good head retention where the foam can provide the same level of protection from oxygen in the headspace.
Rinsing and Drying
When aluminum cans run through a filler they often can get drips of beverage on the outside. Consumers don’t want to buy cans that are sticky, moldy, or covered in usual substances. For most canning applications, a post-seam rinse/dry is done on the cans to remove the drips and pools to ensure a clean can for customers.
Some beverage manufacturers are required to mark their cans to record what batch they came from? A date coder will record several lines of information including date, born on, use by, “monkeys rule”, batch number, whatever you want. If you are applying adhesive labels (more on that shortly), you can use a Hot Stamp to apply the code anywhere on the label before the label is applied to the can. For a larger investment, you can date code onto the bottom of the can using a special ink jet printer designed for this purpose. There are tricks to this process to make sure the codes are always legible. The best way to code onto cans is when they are dry, which is sometimes hard to achieve. Some manufacturers add more equipment to either dry the cans or to control their motion.
Adhesive label applicators are used by those beverage manufacturers that choose to put adhesive labels onto their cans. This is usually for done for small batches or because they prefer to purchase bulk un-decorated cans and then label as needed. If you plan to do shrink-sleeve labeling, you may want to consider starting a side business that does it for your operation and for others.
Shrink sleeve labelers run pretty fast (120 cans/minute or more) and can be big and expensive, making them a dubious choice for a small footprint brewery running their canning line a couple of times a week.
The last pieces of the line are for downstream packaging. Options can vary and include 4-pack and 6-pack applicators, box erection and fill machines, even robot palletizing systems (very cool and very $$$).
With so many canning line automation options available, be sure to do research and ask questions before you invest. Twin Monkeys has integrated canning lines with all of these options and more. If you are considering one of our aluminum canning lines or already have, our canning experts are available to chat about the possibilities (like the people who came to us and asked if we could put pelletized hops into cans . . . we most definitely can).