Since 2007, Multifilm has been offering a high gas barrier alternative to PVdC, AlOx, and SiOx films called N-Coat. A thin layer of nano-sized clay particles are added to polyester (PET) or oriented polypropylene (OPP) and laminated to a sealant web. The result is crystal clear film with a gas barrier of less than 0.12, which is on par with metalized PET and five times the barrier of PVdC coated PET.
N-Coat’s coating is basically regular clay made up of platelets and applied to PET and OPP films. The clay platelets are oblong in shape, and very long, narrow, and ultra-thin, at about 3-10 nanometers thick and about 500-1000 nanometers long (one nanometer is about one 25 millionth of an inch). Four to five platelets are stacked on top of each other and create a tortuous path, where the gas simply runs out of steam as it works its way through a maze of platelets.
Clay pots have been used for food storage for thousands of years, and clay is known to be an excellent barrier material. Traditionally, the issue has been to get the clay nano particles oriented correctly in the length direction of the film. If the platelets don’t lay flat and stand up, or fold over, the barrier is lost. After three years of tedious R&D, Multifilm figured it out and launched the product.
While the word “clay” typically conjures up images of hazy, cloudy film, N-Coat film is basically just as clear as before the coating is applied. Unlike expensive SiOx or AlOx films, N-Coat is not subject to flex cracking, and its coat weight is less than PVdC, lower cost, and completely PVC free.
N-Coat offers an outstanding gas barrier but adds no water barrier to the film and it is an excellent barrier option for clear films. It can be laminated to CPP or PE and is an ideal material for granola, beef jerky, nuts, dried fruits, dried cheese, coffee, and much more.