Waste Prevention In Composite Materials: Additives Optimise Sustainability And Efficiency

Improving recycling rates and thus improving the consumption of resources is one of the outstanding tasks in the development and production of composite materials today. To this end, waste must be reduced and production residues returned to the manufacturing process, which is an important factor in reducing costs and increasing efficiency in plastics processing.

For example, newly developed polymer stabilizers enable a significant increase in the proportion of recycled materials in the production process and make it possible to operate at high speed. Film damage is avoided, and a consistent, uninterrupted production is guaranteed. Tests with a 30 percent recycled content and the use of the polymer stabiliser have shown a reduction of film stippling by up to 25 percent.

Sustainable solutions are in demand not only for processors of packaging films, but also for manufacturers of plastic components for the transport or electronics industry, write the authors Dr. Diederik Cioyvaerts and Dr. Christian Battenberg (Global Segment Manager Processors, BL) in the trade journal “Plastverarbeiter 1/20”. The focus is not only on the recycling of components, but also on the use of materials that contribute to improved sustainability. As a result, plastics are increasingly being used in transport applications to reduce the weight of the means of transport and their fuel consumption. Fibre-reinforced composites are increasingly being used for sophisticated components. In order to bring their advanced material properties further towards the required target values, various additives such as flame retardants are used. This is essential due to the high carbon and hydrogen content of the underlying plastics and the associated low flammability.

Sustainability Requires Flame Retardants In Fibre Composites

The weight of vehicles can be reduced by using flame-retardant fibre composites, also for structural components. Carbon fibre reinforced composites are used – such as thermoplastics, but especially thermosets, e.g. epoxy resin systems. These weight savings and the resulting increased range are a decisive advantage, especially for the constantly growing electric mobility. It must be taken into account that each individual application has different fire protection standards, which may even differ from country to country.

Flame retardants must therefore be carefully selected and matched to the system in question. According to the Swiss authors, the chemical nature of the flame retardant as well as its decomposition products in case of fire plus their interaction with the plastic influences the mode of action and effectiveness. Therefore, the selection of the appropriate flame retardant is not trivial – on the contrary, it requires a lot of testing, experience and chemical expertise.

As far as flame retardancy is concerned, halogen-free solutions used as additives are the benchmark today for preventing the spread of a fire or the ignition point of plastic components in an environmentally friendly way. In addition to the existing additive flame retardants, the market is showing an increasing demand for additives that are soluble and reactive in the resin. A great advantage is the slightly increased viscosity compared to powdery agents.