You have probably seen packaging machines on that TV show that demonstrates how things are made. I don’t think they ever highlighted the packaging machines, but you see them all the time when they are showing how products are made. One super fast and widely used packaging device is the VFFS packaging machine. You start with a roll of film, and it ends with it being turned into bags to hold products. The contents can be anything from your breakfast cereal to pretty much anything else that is sold in bags or bags that get shoved into boxes.
Think of a roll of plastic wrap. It is just one long roll of plastic. Now think of it not being clingy but made of the same stuff your potato chip bag is made of. Now imagine unrolling a couple of feet of that. Take the end of it and begin to form it into a tube as you continually roll it off the roll. Now heat seal that tube as you continually roll it out a little at a time. The VFFS packaging machine does that. The big roll unrolls vertically, and then it gets curved into a tube and sealed as it moves along downward.
The next step is to seal across that tube at the bottom. It would be one very long bag if not for the next steps. Dump some product into it, and it drops to the bottom. Then seal it again just above where the top of the product is. This makes the top of the bag, and the bottom of the next bag. Cut across the middle of that seal, and you have one sealed bag ready to ship. Do that hundreds of times per minute, and that is how a VFFS packaging machine works. You can get all kinds of different plastic films to make the bags you are forming. It can be the metallized bags such as potato chips need, or it can be the waxy looking plastic of cereal bags.