Barrier Coatings

Oxidation and Moisture Protection

The CCVD Process has been used in the development of oxidation and chemical protective nanolaminates. Such protective coatings can be used to improve water or corrosion resistance, thermal stability and/or the service life of aluminum, iron and titanium-based metals. In addition, customers are demanding coating solutions that are inexpensive and environmentally benign. Numerous opportunities exist for coatings that provide diffusion protection that can be applied in situ and that are economically viable.

CCVD coatings have shown promise for chemical and water diffusion and oxidation protection of electronics, metallic and ceramic substrates. For example, nGimat has demonstrated coating results illustrating significant oxidation and wet corrosion protection of a variety of metals, as described in U.S. Patents #6,214,473 B1 and #6,416,870 B1. In fact, independent test results showed our nanolaminates exceeded the performance of the commonly-used, environmentally unfriendly, chromate conversion coating. Ultimately, the CCVD Process is uniquely positioned to offer significant cost savings and benefits for protective coatings by its open atmosphere operation, in situ application potential and environmental compatibility.

Food and Beverage

For many food and beverage products, packaging plays an important role not only in advertising the product, but also in maintaining flavor, texture, and appearance. nGimat has developed processes utilizing nGimat’s proprietary NanomiserTM device to apply carbon dioxide and oxygen gas barrier coatings to polymers such as polyethylene terapthalate (“PET”) containers and PET/polyolefin films.

Coating requirements for food and beverage packaging generally fall into four categories:

  • Functional (such as barrier properties)
  • Physical (such as dimensional stability) and appearance
  • Environmental (including both environmentally friendly manufacturing processes and recycling requirements)
  • Cost

While barrier coatings have been available for a number of years, they require a significant investment in equipment to apply and cannot be easily deposited in a continuous high-rate process. nGimat’s process allows barrier coatings to be applied in a continuous operation with much less costly equipment.

One family of nGimat’s barrier coatings reduce the carbon dioxide (the carbonation) diffusion through plastic soft drink bottles, thus extending shelf life and enabling smaller plastic beverage containers. This extended shelf-life will lower producers’ costs by reducing losses due to “stale” product. These barrier coatings will also enable the production of smaller plastic containers for carbonated beverages, a capability the soft drink industry has been aggressively pursuing (market research indicates consumers overwhelmingly prefer plastic bottles to cans in sizes smaller than currently available). Carbonated beverages are not predominantly sold in plastic bottles in sizes less than 20 ounces, because their shelf lives are extremely short (the relatively large ratio of surface area to volume in small plastic bottles accelerates the loss of carbonation). For 20 oz. bottles, the shelf life of uncoated vs. coated PET bottles is extended from 10 weeks to 30 weeks, allowing significantly improved inventory management (both for the bottler/distributor and the retailer). For 12 oz. bottles, the shelf life of uncoated PET bottles is too short for anything but targeted special order production, such as for sports events, which has resulted in the popularity of aluminum cans. By developing a coating that significantly extends the shelf life of the 12 oz. PET bottle, such bottles will become more competitive with cans.

Barrier Coatings

Oxygen barrier coatings are needed for film packaging applications to increase product life, while maintaining package transparency and lowering the cost of the overall package. Thin metal coatings like aluminum provide lowered oxygen transmission rates, but at the cost of transparency. nGimat’s 30-60 nm thick layers have comparable barrier levels, but are transparent, allowing for easier marketing of food or beverage products. Silica coatings are typically deposited as thin films using available vacuum-based technologies. nGimat’s oxygen barrier coatings, utilizing its open-atmosphere CCVD process, achieved state-of-the-art O2 barrier performance.