Fleece Covers

Glacier covers have been used in Swiss ski resorts since 2005 to protect the infrastructure needed for skiing (glacier access, training slopes in autumn). The glacier and snow surfaces are covered in May and the covers are removed at the beginning of autumn (late August/early September). Covering the snow and ice surfaces can reduce melting by up to 60%. However, due to the polypropylene (PP) material used, this type of snow and ice conservation has come under criticism as it contributes to microplastic pollution in high mountain areas.

For example, after being covered with a fleece for 10 years, the Diavolezza glacier has become about 10 meters thicker instead of shrinking. Even today, the glacier is still partially covered during the summer months to protect it from further melting.

Thanks to the generous commitment of Mastercard Switzerland, the GlaciersAlive Foundation was able to set up a test facility for glacier covers in January 2022. The aim is to test different materials and methods so that glacier covers can be installed with fewer emissions in terms of microplastics and mechanical use.

The newly developed cover film, made from microplastic-free PLA material* and covering an area of over 20,000 m², was produced in spring 2025 and delivered to five different mountain railway companies, which use it to protect glacier areas or for snow farming. Initial field tests and feedback on the new material have been positive.

The Weisse Arena Bergbahnen AG reports that the PLA fleece used provided a level of protection comparable to that of conventional PP fleeces. However, due to its greater weight, sewing it together and removing it is somewhat more labour-intensive.

Also, Corvatsch AG has reported positive results. The PLA fleece was easy to lay out and roll up again. Furthermore, a snow layer around 15 to 20 centimetres thicker was measured compared to a PP fleece.

Initial feedback suggests that microplastic-free PLA fleece could be a promising alternative to conventional glacier protection fleece. Further testing and analysis will help to better assess its potential for the sustainable protection of snow and ice surfaces.

PLA falls under the category of synthetic polymers, as the material is produced artificially in a laboratory. Unlike conventional plastic, PLA is considered a “bioplastic” because it is produced from renewable raw materials: PLA consists of corn starch and lactic acid and thus meets the criteria for renewable biomass. The manufactured molecular structure of PLA is biodegradable and compostable..