September 2010 - Versatile research subject EasyLeno®

Versatile research subject – the DORNIER EasyLeno® technology

The EasyLeno® technology of Lindauer DORNIER GmbH was established seven years ago and since then has constantly been developed further. It is the subject of various research projects on the part of textile universities or research and development institutes: two students of the University Niederrhein have designed a very special cord-like fabric with the help of the EasyLeno® 2T. At the same time, the ITV Denkendorf does research with innovative leno fabrics having a high fabric density and the ITM Dresden works on the development of leno fabrics for composites.

DORNIER EasyLeno® technology

2003: more efficiency and less wear thanks to DORNIER EasyLeno®
For the textile industry, the patented DORNIER EasyLeno® system is a versatile and highly productive new development with regard to leno technology. The efficiency potential of weaving machines equipped with EasyLeno® is up to 100 % higher compared with the traditional procedure with shedding motion, heald frames and leno heddles. DORNIER offers this system for both air-jet and rapier weaving machines and it is suitable for all kinds of leno fabrics – ranging from the lightest curtains to carpet backings and heavy open mesh glass fabrics.

2005: less material requirement, higher productivity
EasyLeno® 2T is an extension of the EasyLeno® system by two warp systems with different warp tensions. This system allows setting the warp tension for leno and ground threads separately. For the first time, it is possible to produce not only open mesh types of fabrics but also „Drebfabrics“ with closed and double-face surface structure. In contrast to classic fabrics, weavers who favour the EasyLeno® 2T system achieve fabrics with considerably less shrinking and without weft bowing. The colours of the weft yarns dominate and add high colour luminosity to the Drebfabric.

2007: wider variety of patterns, high quality
DORNIER’s latest new development concerning the leno technology, EasyLeno® MultiPattern, combines the DORNIER EasyLeno® technology with the Jacquard technology and thus, offers considerably more pattern variants but still with the same low material requirement. DORNIER rapier weaving machines with EasyLeno® MultiPattern can produce light to medium-weight textiles which stand out due to an excellent seam resistance, a high abrasion resistance and a good drapability. With this highly efficient technology it is possible to use different coarse yarns in the warp so that numerous textile constructions for different fields of application can be produced with EasyLeno® MultiPattern.

LenoCord – the new type of fabric for a casual women’s and men’s collection

Two students of the department of Textile and Clothing Technology at the University Niederrhein, Sonja Kampermann and Katrin Wortelkamp, designed a new type of cord fabric with the help of the EasyLeno® 2T technology in their diploma theses.
The idea of both theses is to develop the conventional cord fabric to LenoCord and to set a trend with this innovation.
Whereas the traditional cord fabric has cut and brushed pile tubes and is made in costly production processes, different types of yarn are combined with the innovative EasyLeno® 2T technology to produce LenoCord. Through the combination of standard and chenille yarns, rips are created and hence the cord look. With a variable use of the standard yarns, also the rips can vary, which means that depending on how many chenille yarns per weaving shed are inserted, the rips are more or less pronounced. Up to three chenille yarns can be inserted per weaving shed.
In the warp, fine and stable polyester yarns are used which are mainly invisible in the fabric. The combination of wool and polyacrylics in the weft makes sure that the material keeps warm and transports humidity. At the same time, it is easier to wash than pure wool. Depending on the intended purpose within the collection, e. g. as a skirt, sports jacket, vest or pair of trousers, the materials were varied in order to adapt feel, flexural strength, substance and further parameters. Final textile examinations showed that the LenoCord achieves the quality standards which are required for apparel fabrics.

„With gree and respect“ („Mit Gunst und Verlaub“ – Old carpenter journeymen saying)

The seven-piece women’s and men’s collection called „Mit Gunst und Verlaub“ follows the typical way of clothing of the carpenter journeymen: the collection interprets the guild’s idea of a new look regarding the outerwear and plays with the contrast between old and new, as well as with the one between nature and architecture. This is not only reflected by natural materials such as leather and wool but also by an elaborate workmanship. When cutting and making-up the garment, several special characteristics of the fabric had to be observed carefully, e. g. the nap direction of the chenille yarn, the straightness of the seam despite of the rips in the fabric and the protection of the pile when ironing.
Finally, a women’s collection was created consisting of a skirt, pair of trousers and vest as well as a men’s outerwear collection consisting of a vest, pair of trousers and a sports jacket. The innovative concept of the collection revives the recurring fashion of cord clothing with the help of the novel possibilities of the DORNIER EasyLeno® technology.

Innovative leno fabrics with high fabric density

In the context of a research project, the Institute for Textile Technology and Process Engineering (ITV) Denkendorf analyzed the fields of application of the new EasyLeno® 2T leno fabrics. By means of experimental examinations of selected articles the different fields of applications were studied.
Beside the net-like leno fabrics, the new efficient EasyLeno® leno technique also makes dense fabric constructions economically attractive. Completely new applications emerge, e. g. for innovative technical textiles, which could be adapted to the advantages induced by the new leno fabrics or „drebfabrics“.
Especially for dense fabrics, setting guidelines were elaborated which systematically show the interdependency between yarn materials, weaving machine settings and fabric characteristics for closed leno fabrics. Thanks to the multitude of possible settings of the EasyLeno® 2T technology, fabric characteristics can be changed specifically or adapted in an optimal way. Here, the tractive forces of the warp threads play a decisive role in achieving certain parameters of the final product. The fabric characteristics were examined experimentally on selected products which are well-established on the market: work clothes, shading textiles, backing fabrics and automotive fabrics.
The ITV compiled the results for each application in a kind of navigation matrix. The intention is to encourage weavers – on the basis of this knowledge – to use the enormous potential of the EasyLeno® technology to develop other novel products.

Leno fabrics for composites

Also in the context of a research project, the ITM (Institute of textile machinery and high performance material technology) of the TU Dresden examined the applicability of leno fabrics for the production of composites. During this research project, the technologies of different machine manufacturers were analyzed, amongst others the DORNIER EasyLeno® system.
Due to the constant increase of energy costs, the demand for lightweight, high-strength materials for the machine, vehicle and aircraft construction increases, too. While the mechanical properties of the end product remain the same, this calls for a cost reduction and a higher automation level in the production of composites.
For the production of FRP (fiber reinforced plastic), woven fabrics as well as knit fabrics and unidirectional fabrics have several advantages and disadvantages which are tried to be eliminated by using novel textiles.
In the scope of this project, it was possible to demonstrate that leno fabrics with straight position of the filling and ground threads and at the same time a high yarn density can be produced. In contrast to fabrics with a similar construction, the leno fabrics are easier to drape and have a better shape accuracy. Compared to knit fabrics, their production is much cheaper. Leno fabrics stand out due to their good slip resistance in comparison to normal types of fabrics. The problem of yarn damages by an additional binding thread system which is necessary for the stabilization of unidirectional fabrics is avoided, too.
It is expected that the publication of the results will lead to new innovative fields of application for leno fabrics and synergetic effects in other industrial sectors.

© LenoCord pictures: Sonja Kampermann, Katrin Wortelkamp

Sources:

HS Niederrhein „Mit Gunst und Verlaub“ diploma theses by Mrs. Kampermann and Mrs. Wortelkamp; summary by Prof. Rieschel
http://www.hs-niederrhein.de/news/news-detailseite/absolventen-der-textil-und-bekleidungstechnik-raeumen-zahlreiche-preise-ab/

ITV Denkendorf – „Analyse der Einsatzgebiete von Geweben mit Hilfe des neuen Dreherwebverfahrens“
http://www.itv-denkendorf.de/images/Forschung/Kurzveroeffentlichungen/2010/aif15321n.pdf

ITM of TU Dresden – „Forschungsarbeit „Entwicklung von ein- und mehrlagigen Drehergeweben für die Verbundwerkstoffindustrie mit gestreckten Kett- und Schussfadenlagen
http://tu-dresden.de/die_tu_dresden/fakultaeten/fakultaet_maschinenwesen/itm/