24.09.2010 | Intelligent Flax Fibers

Natural fibres used in the manufacturing of technical textiles and nonwovens address the needs of our times.

Environmental awareness is growing manifold within various sectors and the advantages of the natural fibers characteristics are becoming more prominent. Depending on the end use, producers of technical textiles and nonwovens have started to care about biodegradable or recyclable materials to provide their customers with what they require.

When a material needs to be durable, robust and should have great tensile strength, one option is to make use of the natural characteristics of the flax fiber. Through their natural strengthening qualities, their low weight compared to carbon or glass fibers, as well as their vibrant absorbing properties, flax fibers have many attributes which can be capitalized in composites.

Norafin, a manufacturer of innovative technical nonwovens and composites, has ventured into flax fiber processing and introduced the material into its hydroentangling process. Because of their special characteristics, the use of natural fibers always involves irregularities. In order to achieve a better uniformity of the fibers used, the long flax fibers can be processed to shorter staple fibers to increase their quality level. The specific fiber properties may also lead to special machinery adjustments in the area of the spunlace technology. For example, it is necessary to counteract elutriation so that the chemical substances in the fibers do not have too strong an influence on the production line. Despite various material challenges, the advantages of flax fibers outweigh them, which become apparent for a few application examples.

Thanks to the UV resistance of the flax fibers, their positive eco-balance as well as their natural aspect, flax fibers can be used in the home furnishing market, as for example as sun shades. In the construction industry, flax fibers are used as high breathable roofing membranes. Since flax is exceptionally tear resistant and robust, which make the fibers tough, hard-wearing and long lasting, it represents a valuable alternative to synthetically manufactured membranes in the roofing sector. For a 125 g/m² weight nonwoven material made of 100% flax, a tensile strength value of 220 N/5 cm is achieved. If a scrim made of natural fibers or fiberglass is additionally included into the nonwoven material, tensile strength values can be achieved that are far beyond those of the scrim by itself. When using a 135 g/m² weighted nonwoven material with a fiberglass scrim, the tensile strength value is 955 N/5 cm (see table).

If flax is used within composites that use natural resins only, the product advantages are even more evident. Apart from having a strong product solution, the good recyclabililty of the fiber allows the reutilization of the material as for example as cellulose paper. The future of various natural fibers and especially of flax fibers seems to be promising as several novelty options such as bio-refining processes are being explored.

Author: Marc Jolly, Head of Development, Norafin

Future Materials 2009