Needle leno - opportunities and obstacles for the weaving industry using this revolutionary technology (2007 - 2009)

Leno fabrics present interesting characteristics compared to standard woven fabrics. In standard woven fabrics all warp ends are parallel to another. In leno fabrics warp ends are divided in leno couples, one being the standard or straight warp, the other the leno or crossing warp. Between two the ends of the leno couples cross one another. One of the main drawbacks of the leno weaves compared with plain weaves is shifting and its direction-related character: resistance to shifting of a leno weave is higher in warp direction than in weft direction. The leno structures can be open or closed, therefore their applications vary accordingly: packaging materials (Fig 1a), secondary backing for carpets (Fig 1b), upholstery (Fig 1c), ballistic applications (Fig 1d), etc.

              a                                                              b
                            c                                            d

 Figure 1 Applications of Leno structures

Due to the low production speed and limited applications, the earliest leno weaving technology (using special heddles) is one of the least studied textile technologies. The recent needle leno technology (using needle bars and pilot bars) is, however, a very promising weaving technology due to its high yield ( 500 rpm) compared to heddle leno technology ( 200 rpm) and because it offers opportunities for new applications. The present project proposes to: get insight into the needle leno technique (Optileno machine); perform comparative studies between heddle leno and needle leno (e.g. technology and products); process various raw materials (e.g. spun yarns, fancy yarns, filaments and tapes) and identify further application fields; evaluate and compare the available testing methods (e.g. slip resistance); compare woven, warp knitted and leno structures in order to identify the potential of needle leno fabrics to replace other textile structures.

The above-mentioned constraints of the needle leno technology slowed down its penetration in the (Belgian) textile industry. The project has a wide consortium, including many industrial partners (e.g. leno fabrics producers, yarns manufacturers, leno machine manufacturer, potential end-users, etc.) and its overall aim is to transfer the knowledge related to needle leno technology to the industry.

Supported by: IWT - TETRA

Contact: Prof. Dr. ir. Lieva Van Langenhove