Welcome back to Crazy About Packaging! Today, we're beginning a new series that highlights specific packaging processes. First up: hot fill packaging. So what is hot fill and why does it matter? Read on to see a sneak peek of the episode.

In our latest podcast episode, the C.A.P. Pack is joined by a guest host whose experience with plastic recycling brings a fresh perspective to the ways in which the industry is seeking to more effectively recycle and reclaim plastic materials as part of the circular economy.

Sneak Peek for Episode #13

Check out the latest podcast to hear us discuss all things hot fill: what is hot fill, who uses it, and how it’s changed. You can watch or listen on our website or subscribe on Spotify, Apple, or Google. Want a sneak peek? Read on to see some of the topics we cover.

Round 2: Can I Recycle That?

We’re continuing with our monthly game: “Can I Recycle That?” In this episode, Natalie brings us a seemingly simple item — an applesauce cup. It's a classic example of a hot fill packaged product. Natalie’s applesauce cup is made of clear polypropylene with a metal lid. So: can Natalie recycle this?

Jonathan and Mike give this applesauce cup a resounding “Yes!” They explain that applesauce cups like this have undergone a lot of changes over the years, from the removal of labels to the shift from opaque plastics to clear polypropylene. It’s clear this applesauce cup was made with recyclability in mind. However, they do give one caution: Natalie must remove the metal lid before sending t

What is Hot Fill Packaging?

We’re highlighting hot fill packaging in this episode — but what does that mean?

What is hot fill? It’s a process in which food products are heated to a high temperature to cook the product and eliminate bacteria. At this point, the product is filled into a container, sealed, and rapidly cooled. The process is excellent for applications like sauces, jams, and jellies. It helps keep the food shelf-stable and ensures a high-quality product.

The process sounds simple, but it truly is a balancing act. Mike mentions that hot fill packaging often comes down to temperature over time. Jonathan expands on this point. “Like most things it comes down to time, temperature, and pressure. There is a specific time that the processors will anticipate prior to filling how long that product needs to be cooked. They'll vary depending on what the pH is, depending on how much shelf life they're trying to get out of it. And then you have that cooling effect as well. Generally, you want to get that heat out as fast as possible. That has other implications on the package when you are hot filling.”

Material Properties for Hot Filling

No matter your packaging method, it’s always essential to select the right material for your application. When it comes to this process, you need a material that can not only withstand the high temperature of the cooking process but also be flexible enough to undergo the rapid cooling process.

The Scale of Hot Fill Equipment and Production

This process and hot fill equipment have undergone quite a few changes over the years, in both production and sustainability. “Roll the clock back 30, 40 years,” says Jonathan, “when they had four-lane machines. And now, they’re eight lanes across — they’re just amazing. They have all of that control and that ability to fill at a really high volume.”

Mike chimes in with his view on how things have changed. “There’s not a lot of human labor involved in the whole process. It's a very complex, robust system. This industry has been moving towards this efficient packaging for 30 years. They've picked all the low hanging fruit. Now we have some other ideas — but hey, we'll talk about that later!”

Finally, Natalie wraps up the point. “The concept seems pretty basic. But the automation and scale of it is what leads to it seeming like a more complex process. You have to imagine the volume that’s going through these machines. If I was canning in my kitchen, I’d make three or four of these. They’re making three or four million. PLUS.

Looking Ahead: Sustainability and Efficiency

Hot fill equipment and processes have changed quite a bit over the years. The process has been refined to be more efficient and effective. However, things are still changing and the future is bright — the industry is moving towards more sustainable practices, with recyclability playing a central role. This is no exception. The shift towards materials like XPP polypropylene not only enhances recyclability but also operational efficiency, offering exciting possibilities for product line extensions and new product development.

Let’s Talk About Hot Fill

Interested in learning more about hot fill packaging and the way it’s changing? Want to let us know your thoughts on the process and its applications? Tell us your thoughts — follow us on LinkedIn, Facebook, and Instagram to join the conversation! And be sure to listen and subscribe on Spotify, Apple, Google, or our website.


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