Sustainable denim production:latest spinning and weaving technologies

Flexibility in Denim yarn spinning

René Bucken， Saurer Spinning

From workwear with 100 percent coarse cotton， to leisure wear with blends and core yarn， to smart casual with finer count and special finish， the denim never lost its appeal but was continuously redesigned and expressed. The change of denim cannot leave the change of fabric and count. While changing counts and materials require flexibility in production and innovation of technologies.

Ring spun yarns were traditionally used in denim up until the late 1970s， but later supplanted by cheaper Open End （Rotor） yarns. The rising amount of new materials increase studies into comfort and improved performance. More blends also mean more challenges in spinning. Today finer denim yarns are still ring spun. For stretch or bi- stretch elasthane is added. Rotor has a higher utilization of short fiber， making it well suited to spinning re-generated fiber. Today focus is set on comfort， performance and sustainability in production. The machinery needs to adapt to material changes， for example， core yarns need to be well spliced in the winder to be evenly dyed.

With Autoairo air spinning machine Saurer completes the circle of five end-spinning applications. Ring， compact， worsted ring， rotor and air spinning are all results of Saurers customer-focused product innovation. Automation and digitalisation are necessities in todays smart and connected world. Technologies for tomorrow‘s smart mill are developed today.

Denim yarn characteristics depend on spinning， and rotor spinning give an excellent choice for recycled raw material， reduced waste and re-worn Denim.

The most sustainable and profitable way to make denim

Enzo Paoli， GREENDYE

GREENDYE transforms the way denim is made. The technology is three times more efficient and two times cleaner than a conventional indigo dyeing machine. With GREENDYE， you are going to get sustainability and profitability.

The GREENDYE indigo dyeing uses nitrogen technology to control the chemical process of dyeing， which provides users high dyeing efficiency. The nitrogen technology increases up to 3 times the pick-up of a conventional dye vat thanks to the longer dwelling time and the increase of the indigo concentration.

It drastically reduces the chemical and yarn waste and the use of hydrosulphite and caustic soda （> 50 percent compared to conventional） that are the main polluter in this process. That means you save 50 percent of the cost for chemicals. Since the machine length is overall shorter than a traditional indigo dyeing machine， yarn waste can be reduced too. The same indigo shade can now be achieved with 3 dyeing baths instead of 9 baths （water reduction by two thirds）. The higher fixation of the indigo on the fiber allows a drastically reduced consumption of water in the washing phase. Water consumption in the finishing process can be reduced by around 50 percent.

Compared to a conventional machine， the GREENDYE is only two thirds of its length. Requiring less space， less operators and less spare parts with the same output. The amount of chemicals and water used in the daily business is half of a traditional indigo dyeing machine.

The problem with the conventional method is timing. The time between dipping and skying is too short for diffusion and fixation of dyestuff to take place. This phase is basically absent in the traditional method. With the nitrogen technology the oxidation is temporarily prevented. In the NOX chamber the dyestuff has enough time to diffuse and fixate on the yarn. This way the GREENDYE can pick up 3 times more dye with even higher indigo concentration.

The machine is designed to be used by everyone. The GREENDYE comes with powerful assistive Human-Machine-Interface， which helps operators manage the denim production with minimal touch and easy navigation. The window in the NOX chamber is designed to facilitate easy operator handling and accessibility inside the machine.

GREENDYE have installed a built to scale pilot machine and a fully equipped laboratory to support you with woven and finished denim samples that you can use to show your customers. The pilot machine is approximately 13 meters long and will reproduce exactly on a scale 1：10 the industrial process by producing samples 200 mm wide.

Customers will be able to show different samples of GREENDYE produced fabrics to your customer. This will help you test the market and decide which products to make in full production. We provide you with all the details for machine adjustment so that you can produce the fabric your customer wants. With GREENDYE， we offer fully integrated support for the whole technology from R&D to finished samples.

Most versatile and efficient denim weaving

Lars Oeller， Lindauer DORNIER GmbH

Lindauer DORNIER GmbH own weaving machines such as air-jet weaving machine and rapier weaving machine， and some specialty machines like film stretching lines as well as DORNIER Composite Systems？. They have different technology center： weaving trials， weft trials， trial machines at customer， exhibitions， development/ application testing and sales support in the end.

The market need flexibility， effectiveness and sustainability， especially from the denim sector： we receive more and more enquiries for article combinations of cotton， elastic， linen， recycled and effect materials， yarns.

75 percent more rigid central frame structure ensures optimum flow of forces. Because of the higher stiffness of the reed shaft， fabric quality increased； The P2 reed shaft is in the diameter stronger instead of the P1； torsion stiffness increased by 50 percent； start-mark prevention has become better.

The drive technology

DORNIER Patent SyncroDrive？： Low-maintenance drive system without clutch-brake unit， with a separate motor for the shedding device； Intelligent drive concept presents extremely low speed fluctuations； Timing of shed closing is electronically adjustable during full speed operation； Memorized with the article data and thus reproducible anytime.

And its DirectDrive represents a reliable and lowmaintenance drive concept – without clutch-brake unit； lowers the staff workload through reduced setup times； highly dynamic synchronous motor serves as main drive， providing unsurpassed precision for start mark prevention.

In terms of dialog panels， there are more space in front of the machine. And positioning CUA sideways possible. DORNIER ErgoWeave？ meet people the goal of personalize clear menu structured interface， easy to operate touchscreen. In addition， fast-Ethernet-Technology control system provide reliable transfer of large data volumes in real time and less downtime and easier machine handling. At the same time， it supports online documentation and machine data exchange.

New developments： DORNIER DisCoS（DCS） and DORNIER DoPPIO？

The D for “dornier”， C for “color”， S for “selector”， until now it is up to 16 colors， and boasts well performance of point-weft-presentation， lower rapier speed during thread take-up， tool-free working without draw-in hooks， guided draw-in after weft break， fixed mounting position and no need of adjustments， settabel motion profiles via DoXWeave dialog panel， timesaving in case of weft break. And DORNIER DoPPIO？， which means “double pick parallel insertion operation”， has double weft rapier heads with free color transfer and parallel weft insertion， reduced take-off speed weft bobbins， longer running time， as all bobbins are used consistently， time-saving in case of weft break， easier handling after weft break， weaving with APS function and knot-free weaving，etc.

With a DORNIER Rapier Weaving Machine， you are flexibly prepared for the future on changing markets.