Project objectives

OneCoat is presented by a group of European SMEs devoted to the preparation and supply of coatings for a wide range of industrial applications. Among others, we serve the glass industry and specifically the glass containers sector, a major European market. We have detected a series of problems that can be addressed by the development of the technology proposed herein. By the improvement of the coating technology for the glass containers industry our competitiveness will be increased and, as a result, the growth and sustainability of industries directly related to the glass containers market such as manufacturing, glass decorators or users of packaging materials (wineries, breweries, soft drink or cosmetics producers).

Different types of coating materials and technologies are applied within the glass industry and in particular in the glass containers sub-sector. Production of standard protective coatings for glass is much dominated by large companies which difficult the growing of SMEs with reduced resources for investing in technology. In addition, large groups are growing by acquiring smaller production plants thus increasing competence for SMEs and threatening their survival. There is a great demand from the glass containers industry itself for advanced coatings that can meet different technical requirements as demonstrated by the publication of the Technology Roadmap Workshop by the Glass Manufacturer’s Industry Council and the US Department of Energy.

The technological challenges of protective coatings for the glass container industry:

Resistance to scratching

The greatest challenge regarding glass surface. After glass is formed a number of microscopic defects are present on the glass surface. These defects are impossible to eliminate and if no treatment is used it would lead to breakage as the strength of the glass is largely reduced.

Resistance to scuffing

Directly related to the naturally low anti-scratching resistance of glass is the appearance of external damage on the surface of glass containers as a result of continued glass-to-glass contact,  phenomenon known as scuffing. Scuffing is even more important in the case of returnable bottles, since it renders the containers unable to be reused again as the external look drastically changes.

Weight reduction

The greatest drawback of glass compared to other packaging materials is its weight. Weight of hollow glass containers has been reduced over the years which allows for savings in raw materials and energy for production, reduced cost of glass articles and reduced emissions. If thickness variation across a bottle could be reduced to around 10-20%, this could on average allow a 10% reduction in glass weight without design change, and in turn increase profit by approximately 5% of total turnover.

Impact and internal burst pressure resistance

In addition to the primary effect of improving scratch resistance, glass coatings increase and preserve the strength of the container by reducing the likelihood that defects in the glass will lead to breakage. They can increase the burst pressure of glass containers by over threefold, from less than 10 bars to more than 30 bars, which is especially important for carbonated beverages.

Adequacy to industrial production rates

Price will be a critical issue for any successful development to be introduced in the industrial processes involved in the manufacture and transformation of glass containers. It is important to note that the coating represents a small percentage in the production costs of glass containers and it requires very competitive prices to enter the market. Many efforts made in the past to develop coatings for glass failed in the market place due to a high cost of the material, of the application methodology or a combination of both.

Compatibility with decorative pigments

Apart from a protective function, a coating of different colours and finishes on the glass surface represents an opportunity for differentiation of some items from that of the competence. It has to be transparent so the product contained can be observed and it must be ‘invisible’ so the presence of the coating remains unnoticed and still retain glass sense of touch. It has to provide no discolouration after immersion in water or alkaline solution, gloss retention and no migration of pigments with time. Currently, decorative coatings used for glass containers do not provide good performance mechanical properties.

Reduction of adherence

The application of protective coatings makes it extremely difficult to form a secure bond between any further transparencies, printing, painting or coating material applied to the glass.

The OneCoat solution

OneCoat will develop a coating material and application technology for glass containers based on polysiloxane polymeric water emulsion that provides higher overall strength and scratch resistance to the treated containers while ensuring good and varied decorative properties.

The development of the proposed solution implies the realization of a collection of scientific as well as technological objectives in order to achieve the desired results.

OneCoat Scientific and Technological objectives

  • Synthesis of an organically modified polysiloxane
  • Study of the properties of the formulated polysiloxane
  • Preparation of a water emulsion from the polysiloxane
  • Study of the influence of pigments on mechanical and optical properties
  • Improvement of overall strength, internal burst pressure and resistance to scratching and scuffing
  • Adaptation to the market’s economic requirements
  • Compatibilisation of pigments for colouring Application by spraying and drying of water emulsion