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Ever wonder why the sides of plastic container suck in after a long stay on the shelf? All extreme temperature and pressure changes excluded, the answer is called paneling. A perfect example of paneling is shown above. Contents in the untreated bottle on the left have compromised the plastic walls, causing the container to resemble a water bottle at 35,000 feet. The Fluorinated bottle, which looks perfectly normal, has been treated to prevent paneling. The secret behind its strength is fluorination.
Plastic bottle paneling is prevented by a process called fluorination, in which the surface of container is treated by fluorine gas. Fluorine atoms bond to the plastic, creating a permanent protective barrier. After treatment, the plastic container is less receptive to permeation, discoloration, weight loss, odor emission and (most of all) panelling.
There are two types of surface fluorination. Post-mold fluorination occurs when containers are exposed to fluorine gas in a sealed reactor. Don’t have one of those lying around? The second approach, in-mold fluorination, takes place during the blowing process by mixing fluorine and nitrogen into the air supply. The prior is approved by the FDA for food and pharmaceutical containers. The latter creates a higher level of fluorination, but it is still awaiting clearance.
There are a variety of chemicals that prefer to be packaged in fluorinated containers. The following table outlines some of them.
Hello and welcome to the Qorpak packaging laboratory.Today, we are discussing plastic paneling and the benefits of fluorination. You might be wondering why you would want to fluorinate a bottle. Certain products react with the plastics in a bottle, which causes paneling, such as a sucking in that you might see on your store shelves.
The paneling on the bottles tends to indicate that there is an incompatibility between the product and the resin that the bottle is made out of.
Fortunately, there are solutions to these products so that we can continue to handle them in plastic. You can make the bottle structurally stronger by adding ribs or changing the shape of the bottle, like oil bottles that are square. But, maybe, making a mold is not an option for you. That’s where fluorination comes into play.
The process of fluorination bombards the plastic with fluorine ions. When they do that, they replace the hydrogen atoms on the outside of the surface with fluorine atoms, which are larger. It essentially plugs the holes so the product does not escape and air does not get in.
This can be done during the forming process or after forming the bottle. If you are thinking about small quantities, it is cheaper and easier to do it after the bottle has been formed.
Fluorination is FDA safe because it causes a permanent modification to the plastic. It does not wear off or seep into food. Fluorinated bottles are also just as recyclable as any other bottle of the same material.
Now, what materials can be fluorinated? Common packaging materials include polypropylene, polyethylene and PVC. Examples of polypropylene are closures, high-density bottles, such as a typical shampoo bottles, and LDPE squeeze bottles.
It is important to note that PET, which is the material that water bottles are made out of, is not able to be fluorinated.