Regional hemp textile production chain
The European textile industry is faced with increasing competition of emerging economies, especially from Asia. To maintain their position on the world market, textile companies are looking for innovative new products. At the same time the European Union is expanding and agriculture has to accommodate, to cope with reduction of subsidies. Farm profitability can be increased by new crops that can be used as feedstock for high added value industries (non food). Hemp answers both demands. Hemp fiber can produce high quality fabrics for specialized markets which gains textile companies a competitive advantage and the hemp crop fits well on European farms enhancing farm profitability. However, there is a gap in transforming the crude fiber into a fiber that can be used on industry standard spinning machines. Previous EU-funded projects have shown that steam explosion techniques, which were originally developed for the conversion of biomass, can be successfully applied for flax and hemp fiber refining. On a laboratory scale high quality fibers are obtained with adjustable specifications of fiber length and degree of a-cellulose. These fibers have a good spinning performance on open-end and ring spinning frames. On laboratory scale, modified steam treatment processes have been developed which allowed to produce designed hemp fibers of high regularity, cleanness and softness. Consistent quality can be guaranteed and retting of the fiber is less crucial. The present textile market in Europe, especially the area of high quality clothing, is governed by cotton and wool products (in special fashion and functional textiles also by man-made fibers). The renaissance of bast fibers as a renewable fibrous raw material, and especially the reintroduction of hemp into European agriculture, leads to a raising interest in hemp textiles in Europe. Despite all the enthusiastic activities in the last years, hemp has not yet reached a real breakthrough in the textile industry and clothing market. The European primary production of hemp fibers is currently used for technical applications like car interior parts, composites and insulation material. The applied processing technologies do not allow to produce fine, homogeneous fibers for textile use, and due to lack of chain integration, the steam explosion technology has not been converted to an industrial scale. Therefore, the European hemp textile industry is dependent on raw hemp fiber imports mainly from China. Most of these hemp fibers and yarns do not match the requirements regarding quality, sustainability and security of supplies.
Project Results
In order to develop an integrated production chain to develop hemp fibers that are suitable for textile applications a number of companies and research institutes started the ‘Regional hemp textile chain’ project. This project is funded by Interreg IIIa and aims to develop a production chain in the Euregio Rhine-Waal. In 2005 and 2006 the hemp variety Chamaeleon has been cultivated in this region. The crop has been harvested and left on the field for a process called retting.
During this time enzymes produced by micro-organisms break down the connecting tissues between individual fibers. This allows an easy separation of fibers from the core part of the stem and the isolation of individual fiber bundles. After three weeks the stems were collected and transported to BaFa GmbH (Malsch) where the fiber bundles were separated from the core part. Subsequently the fiber bundles were refined by steam explosion at the experimental installation at IAF Reutlingen. During this process the fibers are impregnated with steam and incubated for 10 minutes at high pressure. When the pressure is released the steam expands thereby refining the fiber bundles. After washing, the refined hemp fibers were cleaned and mixed with cotton in the technicum of Trützschler GmbH (Mönchengladbach). The sliver (see picture) was subsequently spun on a rotor system by Schlafhorst-Saurer GmbH (Mönchengladbach).
A 12 Nm yarn with 50% hemp and 50% cotton was obtained that is suited to produce denim fabrics. Hecking Deotexis (Neuenkirchen) used the yarn as weft on a 100% cotton warp. In this way a fabric containing 25% hemp was obtained. This denim fabric showed a higher ability to transport moisture when compared to a 100% cotton fabric. Also the abrasion resistance of the hemp fabric was higher compared to the cotton fabric. The denim fabric was used by the fashion company Gardeur (Mönchengladbach) to make a number of jeans. The choice for a mixed hemp-cotton yarn facilitates an easy market introduction in a cotton dominated market and reduces the technical complexity of hemp yarn spinning.
In addition a 50% hemp fabric was produced by G&V in Metzingen. The fabric will be used to produce samples of clothing and home textiles. In 2007 an aditional 400 kg of this 50% hemp fabric will be producted to further characterise the fabric and evaluate various applications.
The 50% hemp yarn was also used to produce special elastic knitwear at Boos GmbH (Goch). This product is for a large part based on synthetic fibers and is applied in orthopaedic products. Since the synthetic fibers do not transport moisture, natural fibers are incorporated in the fabric for moisture transport. It is expected that elastic knitwear containing hemp yarn will give a higher comfort for the users of orthopaedic bandages, due to the excellent moisture transporting capacities of the hemp fibers. Comfort, trend, sustainability, design and image are important arguments for comsumers to buy hemp textiles. It is apparent that textile companies are interested in the new hemp fabrics. Three companies have indicated their interest in a sample collection. This can be achieved with the production of 1000 meter of hemp fabric. This will be achieved in a second project funded by Inspire&Innovate. The project will enable the production of 1500 kg of a 50% hemp yarn and 100 kg of a 100% hemp yarn by ring spinning. The 100% hemp yarn will be used by BOOS in their orthopeadic materials. The 50% hemp yarn will be used to produce 1000 meter of a 50% hemp denim fabric that can be used to develop sample collections by fashion companies. The sample collections will be used to define the market potential of the hemp based textiles in more detail.