Cheap, scratch-resistant glass containers
A European consortium of industrial partners and two leading research entities successfully developed advanced glass coatings and process technologies within the scope of the project ONECOAT (Development of a polymer strengthening coating system for glass containers). Researchers achieved production speeds up to 800 bottles per minute of products with a 25 % increase in resistance to scratching, a 10 % reduction in weight and substantial decreases in costs. ONECOAT focused on coated glass containers exploiting polysiloxanes (organosilicon polymers) in a polymeric water emulsion for improved resistance to scratching, light weight and durability. Special additives helped reduce costs and made it possible to use decorative pigments as well. Processing eliminated the use of toxic chemicals and volatile organic compounds. Polysiloxane combines the benefits of epoxy and polyurethane, offering coatings of low viscosity, improved colour and gloss retention, and superior resistance to chemicals and abrasion. The coating is a waterborne product that can be applied by spraying during the container manufacturing process and more specifically during the cold end phase after the containers leave the annealing lehr. Different commercial polysiloxanes containing acrylate and epoxide moieties were emulsified in water and then applied over glass, revealing good film-forming capacity. Different additives for improving wetting and levelling of the coating were also tested. ONECOAT developed improved coating materials and processing technologies for high-performance glass containers compatible with decorative finishing at a competitive price. Outcomes should enhance the position of the numerous SMEs along the supply chain currently facing stiff competition from other countries and other types of containers. Beneficiaries include glass manufacturers, coatings and pigments manufacturers, and end users such as wineries, breweries, soft drink producers and cosmetics manufacturers.
Keywords
Glass containers, packaging, coatings, ONECOAT, polysiloxane, decorative pigment
