PET (polyethylene terephthalate) is one of the most common plastics that we see on a day-to-day basis. It’s what they make water and soda (or ‘soft drink’ or ‘pop’, depending on where you live) bottles out of, along with a lot of other products you find on the shelves and in the refrigerated cases of your local grocery store. A couple of times a week, we cook up a nice piece of fish from the seafood counter at our corner grocery: salmon if my wife stops in; whatever white fish is on sale if I do. Whichever becomes that night’s dinner, in any case, is packaged in a PET tray and sealed with plastic film.
I recently had the pleasure of talking with a caller whose company makes those trays. Turns out, they begin life as great big sheets, before they’re cut into smaller rectangles and formed in a mold press. Most anything that’s formed into a shape like that, with force and heat, needs to have some sort of lubricant – called a release agent – applied to the surface to make sure it exits the mold quickly and easily. In ANY molded product application, it’s advantageous to use as little as possible, for two reasons: specialty chemicals like these release agents can get expensive – especially the ones for food, beverage, or pharmaceutical use – and also because any remaining agent will get sealed up with whatever’s getting packaged.
Anyway, my caller’s molding machine came with spray nozzles that, no matter how low the flow was regulated, still sprayed too much. That meant the trays had no problem at all with falling right out of the mold, but the excess release agent was oftentimes causing HIS customer’s plastic film to not seal properly onto the finished food product, and he’d recently gotten an earful about it. He wished there was something he could use that didn’t spray much more than a light fog, because his supplier for the premium food grade release agent he used was always bragging that a light fog was all that was needed. In fact, the supplier actually recommended an EXAIR Model AF2010SS No-Drip Internal Mix, Flat Fan Atomizing Spray Nozzle.
With a flow rate as low as 1.2 gallons per hour, a one-second ‘spritz’ means 0.04 fluid ounces (that’s about a quarter of a teaspoon) gets spread out over the 16″ width of the mold. Which is just enough to let the freshly molded tray fall right out, with almost no residue left over.
Whether your liquid spraying application involves pricey fluids that you don’t want to waste, or if you just don’t want to have to deal with the mess of over spraying, EXAIR has a wide selection of Air Atomizing Spray Nozzles to choose from. If you’d like to find out more, give me a call.
Russ Bowman, CCASS
Application Engineer
Visit us on the Web
Follow me on Twitter
Like us on Facebook
