Digital Processes for the Future       ( First patented 22.09.2003)


The textile industry is composed of a wide number of sub-sectors, covering the entire production chain from the production of raw materials (man-made fibres) to semi-processed (yarn, woven and knitting fabrics and their finishing processes) and the final products (carpets, home textile, clothing and industrial use (textiles). Within this production chain, the textile finishing processes have inevitably a significant impact on the environment. Dyeing, printing, coating and finishing processes involve one or more of the following unit operations: (wet) impregnation: applying chemicals into or onto the substrate; reaction/fixation: chemically binding the chemicals to the substrate;-washing/rinsing: removal of the excess chemicals with water; - drying: evaporation of water absorbed in the textile substrate.The sequence and the number of unit operations are very variable and dependent on the requirements of the final user of the finished substrate. All unit operations however have a significant environmental impact. Environmental issues are: consumption of (hazardous) chemicals and water;water discharge and chemical load it carries; energy consumption; air emissions; solid wastes and odours. Although a lot of effort has been made, the unit operations and the process equipment applied have not fundamentally been changed in the last 50 years or so. Main environmental benefits realised so far are in most cases the result of good anagement practices introduced, quality management of incoming fibre, smart selection and substitution of chemicals used and to a minor extend technological improvements in process equipment. In this project I will implement and demonstrate a high speed industrial digital finishing technology that can replace (a major) part of the traditional dyeing, coating and finishing operations as is, leading to a significant reduction of environmental impact and at same time an improved economical performance due to increased production flexibility, shorter runtimes and significantly less consumption of chemicals, water and energy. The process to be demonstrated is based upon the principle of an ink-jet system that has been made suitable for not only printing, but also dyeing, coating and finishing operations. Contrary to the current ink jet systems available, that are only suitable for printing, the technology to be demonstrated in this project can operate at high industrial production speeds, processing up to 20 meters of substrate each minute. Existing digital textile ink-jet printers operate at maximum performance speeds of about 100 -150 m2 an hour (that is approximately 2 -2.5 meters per minute). The relatively low achievable performance speeds of existing digital textile ink-jet printing machines limits the economic attractiveness of these machines to runs with maximum lengths of 100 to 200 meter (see also BREF for Textile Industries - chapter 4, page 372 - this document states that speeds are even limited to a maximum of 40 m2/h). Also the application of these existing machines is limited to printing only. The machine to be demonstrated in this project however will be utilized for dyeing , coating and finishing operations.

The traditional finishing process As mentioned above, the traditional finishing operations are involving a number of unit operations. As it is usually not possible to realise the desired result (colour intensity, waterproof effect, etc.) in/on the substrate by running it trough one series of unit operations the finishing operations are mostly performed in one or more cycles. These standard processes are not very selective and

overdoses of chemicals are required to bring about the wanted result. To transport these chemicals

to the fibre of the substrate, at which it should be reacting, water is used as a transport and dilution/dispersion medium. For batch as well as for (semi-)continuous operations this results in a significant production of hard to treat (often poor biodegradability) waste water and the consumption of significant amounts of energy for drying the substrate. In this case it should be noted that drying is not only a last step treatment, but often for different finishing steps drying is required (as dry substrate is required for the previous as well as following finishing operation). This means that a final finished cloth sometimes has undergone three or more washing and drying steps. The digital finishing process to be demonstrated The high speed digital finishing technology to be demonstrated consists of a series of sequential ink- jet beams located above a moving textile substrate to be finished. The fixed position of the ink-jet heads above the substrate, in stead of one head moving alongside the beam, offers the potential for a high speed continuous operation and substrate transport. A sequence of beams equipped with ink-jet heads offers the potential for dyeing, coating and finishing in case a number of sequential beams are running with digitally spray-able dyes, coatings or finishes. The number of beams utilized and the nozzle size, drop frequency (50 - 85 kHz) and speed of the substrate determines the amount of chemical that can be applied. In principle with an eight beam-machine dyeing (1-2 beams), coating (2-4 beams) and finishing (2-4 beams) operations can be performed in one machine run. The digital execution of the finish operations results in a significant reduction in the consumption of chemicals (almost no excess of chemical is required), water (no water bared chemical batches are required) and energy (reduced water load of substrate). This subsequently results in significantly less polluted water discharge. SUMMARY OF THE PROJECT Project title : Digital printing/dyeing, coating and finishing with Continuous High Speed Ink-Jet technology, significantly improving sustainability, flexibility and economic performance of textile finishing industry Objectives The objective of this project is to emonstrate the new (ink)jet based digital finishing technology and its associated environmental benefits and economic viability and to disseminate the project results and the potential of the technology to relevant target groups. It will be demonstrated that digital finishing of textile substrate: can be performed at industrial speeds approx. 20-100 m/min requires significantly less water, energy and chemicals to achieve desired finish-results results in significantly less spillage of fabric (no start-up meters) produces the same or better finish-quality as textiles produced with traditional methods is very flexible in its operation can replace approx. 50 - 70% of traditional finishing operations Actions and means involved In this project the continuous high speed ink-jet technology will be demonstrated full-scale, this will show that this new technology is suitable for industrial use and that it can replace 50-70% of the traditional finishing operations, with a significant improvement of the nvironmental impact. The fixed position of the ink-jet heads above the substrate, in stead of one head moving alongside the beam, enables high speed operation and substrate transport. The project will show that digital finishing technology is a good alternative for a major part of the traditional finishing ethods. Results will be isseminated to a broad audience.Expected results Demonstration of an innovative and economical viable solution that compared to traditional finishing technology: Improves environmental performance by reducing: water usage -70-80% energy usage -70-80% chemical usage -50% waste water -70-80% production solid waste -50-70%. Improves economical performance as a result of: industrial finishing speeds of 20-100 m/min and more high flexibility for substrates, run-lengths, type and order of finish operations, etc. With a typical annual production of 6.000.000 meters of substrate and a typical product mix for dyeing, coating and finishing (for operations that can be replaced) realistic reductions possible are: water usage: 16.800 m³/yr energy usage: 26.000 MWh/yr chemicals for dyeing: 47.000 kg/yr chemicals for coating/finishing: 69.000 kg/yr secondary chemicals: 57.000 kg/yr waste water: 12.000 m³/yr solid wastes: 90.000 kg/yr  Reproduction potential and transferability With a turnover in the EU of€ 198 billion created at 114.000 companies with about 2.2 million employees (year 2000 figures) the EU textile industry represents approximately 3.5% of EU manufacturing and 7% of industrial employment. The textile sector therefore is a sector of ajor importance to the socio-economic position of the EU. The re-production potential of the technology demonstrated in this project can be found within the textile finishing industry, a sub-sector of the textile industry. The total turnover of the textile finishing industry amounts in 2000 nearly €11 billion and this sub-sector employs more than 117.000 employees. The majority of the EU textile  finishing companies are SMEs. The share of the main type of fibres used in the textile finishing industry is :cotton 45% wool 8% polyester 14% acrylic 2% others 15% The technology will demonstrate in this project covers in principle all finishing operations where chemicals are applied to the textile substrate (that is dyeing, coating and finishing). These chemicals however have to be (made) jet-able for continuous jet-flow application before they can be applied in this digital process (this means right dilution or dispersion with specified particle size distribution and electrical chargeable -for this an extra agent might have to be applied). In this demonstration project the emphasis will be on digital finishing of polyester/cotton. These are the main fabric processes and they are considered to be most relevant (on the short term) for digital operation. Also for these fabric/chemical combinations.The polyester/cotton fabrics represent a major part (59%) of the fibres used within the EU finishing industry. Therefore the direct reproduction potential can be considered to be very significant.Not all substrate/chemical combinations can be processed with the digital finishing system. Some chemicals cannot be made jet-able, for instance due to particle size that result in blockage of the nozzles or due to crystallization of salts present in the chemical dilution. In this last situation an impregnation of the substrate with the salt up-front to digital processing will possibly be a good digital processing route. Research performed until now shows that a major part of chemicals used for finishing polyester/cotton substrate can be made jet-able. The textile finishing industry is a very capital intensive industry. For a broad range of finishing operations a broad range of installations are available that operate in batch, semi-continuous and continuous modes. Installations that are present in most finishing plants are for fabric in rope form: Winch beck, Jet, Overflow, Soft-flow and Airflow. For fabric in open-with one or more of the following machines are present: Beam, Jigger (both batch), Pad-batch, Pad-roll, Pad-jig, Pad-steam, Pad-dry and Thermosol. Due to its flexible operation (low system content and cip-system makes shift of operation easy and fast - no complex cleaning operations - no lead times and no product loss for run-in operation due to very good control of amount of chemical to be applied and distribution of dots over substrate surface) the digital finishing technology to be demonstrated in this project will be able to replace a major part of the utilization of these batch as well as (semi- )continuous machines and will lead to a significant reduction of the environmental impact associated to the use of these machines. Due to its high (industrial) speed of about 20-100 m/min and the ease and short times for shift in operation modes the digital finishing machine can economically process textiles substrate lengths between 50 m to virtually thousands of meters. The eight sequential jet beams each followed by a drying beam offers in potential the possibility to perform eight different finishing operations on a textile substrate in one machine-run. Intermediate drying (by means of infrared or other) supports drying and fixation in case "wet-in-wet" application is not feasible. However in most cases for the realisation of a good colour effect (in case of dyeing) or a significant layer thickness (in case of coating) two or more beams will be applying the same chemical. So in principle with an eight beam-machine dyeing (4 beams), coating (2-4 beams) and finishing (2-4 beams) operations can be performed in one machine run at speeds of 20-100 m/min.Environmental  problem Digitalizing the finishing process means that the dyeing, coating and finishjng can be applied with ink- jet technology with high precision, preventing "run-ins" that require a lot of substrate and chemical and lead to spillage, limiting the amount of chemical to be used due to the fact that almost all chemical will be applied to the substrate, limiting water consumption and waste water production due to fact that no baths are required and limiting energy consumption due to less water use and therefore less drying needs. Water consumption: in traditional finishing almost every operation where chemicals are applied to the substrate works with very watery chemical dilutions/dispersions. Water is the medium to transport the chemical to the fibre. In the digital process a concentrated chemical dilution is directly applied (jetted) on the substrate/fibre in the right dosage. Traditional finishing also involves a number of washing steps removing the excess of chemical. In digital finishing no or in some cases one washing step will be required. Energy consumption: between traditional processing cycles (mostly after washing but also after other wet applications) drying of the substrate takes place. In most cases the water is first mechanically forced out of the substrate, and then the substrate is thermally dried by evaporation of water. Also energy is consumed due to higher temperature application of chemicals (warm dye bath). Due to the low water content of the chemicals applied in digital operation and the fact that these chemicals are applied at room temperature significant energy consumption reductions will be realised. Also the less mechanical handling will reduce electricity consumption. Chemical usage: precise chemical dosage trough jetting of dots, no prepared baths with excess chemical to be used, lower pressure and less adsorption in the substrate-fibre all leads to less chemical consumption with digital operation compared to traditional (especially batch) operation. Not only primary chemicals will be saved, but also the utilization of secondary chemicals such as salts will be reduced. Waste water production: in traditional finishing operation most of the process water (from chemical baths, steam fixation and from washing and cleaning of equipment) will be discharged after application. These waste water streams will contain chemicals or residuals from chemicals. Since in digital finishing no baths are applied, the total water consumption is very low and the substrate is not saturated with water after treatment the waste water production is limited. The only significant discharge might be associated with the one washing step that sometimes is required after digital finishing. Due to very low system-content cleaning of the digital ink-jet system is water free and mostly the new chemical to be applied will be used leading to no or very low spillage. Solid waste production: due to high very good controllable quality (amounts to be applied) losses of finished substrate due to non-onformance will be almost zero. Also run-in operation to realise a table situation is not required. The traditional process route could be: dyeing - washing - drying - coating (two passages) - drying/curing - finishing (1 passage) and drying. In the digital process six jet-beams are utilized for dyeing (3 beams), coating (2 beams) and finishing (1beam) and after each treatment an integrated drying/fixation step (infrared drying with drying beams – chemicals within one finishing operation are applied "wet-in-wet"). Value for money: environmental cost/benefit ratio Value for money: With the new high speed digital finishing technology the full potential of digital operation from an economic as well as from an environmental point of view comes into reach. Relevant aspects determining the value for money of the proposed technology/solution are: - high speed digital ink-jet operation: for this "DSDS" will be used. This machine-lay out will enable speeds up to 20-100 m/min. - at these high speeds not only printing will be achieved (as in existing digital textile printers that operate at speeds up to 3 m/min) but also dyeing (full-font printing), coating and finishing will be possible. This is completely new and has only become feasible due to development of special chemical recipes (very fine and narrow defined particle size distributions and electrical chargeable solutions/dispersions) for digital processing and the adaptation of the nozzles size to the maximum

molecule size. - high speed drying and fixation: due to low water content of substrate (only water used to dilute

chemicals or to create a stable and jet-able dispersion needs to be evaporated) water evaporation during drying (possibly infra red or in the future ultraviolet with dedicated chemicals) is low, thus involves a very low energy consumption. - flexible operation: low system content and cip-system makes shift of operation easy and fast, no lead times and product loss for run-in operation (controlled distribution of dots over substrate 

surface). These aspects form the basis for the economical as well as the environmental potential of this

technology. When looking at the position of the textile industry and its development in the international arena it is clear that especially high tech textile applications are the future.High speed production with relatively low environmental impact can go alongside with small orders/runs for highly specialised textile products for advanced applications and just-in-time production/delivery.This is the future for the textile industry and for a major part of the textile finishing industry as figures over recent years show almost only growth in the technical/advanced textile segment. The technology certainly also has potential for the garment textile segment. When combined with currently ongoing technological developments in the garment textile industry

 the technology can contribute to a simplification of the production chain and a significant reduction of production times from raw textile substrate to ready to wear clothing. This opens potential for just-in-time production/delivery and flexible design/dessin on demand in this production chain, preventing over-production and over-stocking at trade and selling points. In this way the close location of the industry to its market again becomes a strength. From a value for money point of view digital finishing offers compared to traditional finishing techniques:  . 1. lower or equal capital cost (especially for future systems due to learning curve effects lower capital cost are expected) 2. significantly lower operational costs (due to utilization of less chemical, water and energy and expected reduction in substrate loss) 3. significantly increased production

flexibility 4. significantly decreased process times .Environmental cost/benefit ratio: for a production of 6 min meters of substrate and a given product-mix the environmental benefits and related financial savings have been calculated comparing traditional to digital finishing. The pay-back time of the investment on environment related savings is estimated to be 7 years. Other strengths, like increased production flexibility and reduced production times, will further improve economical pay-back. Added value of international approach and employment implications Employment implications It is expected that the implementation of the digital finishing technology in this project will directly and indirectly lead to the creation of employment. In the first place the implementation and investment will lead to extra employment for machine operators (at least 3 fte) and a process  engineer (1 fte). As a spin-off of this project and due to expected follow-up implementations of digital finishing process lines at other textile finishing companies it is expected that as a result of increasing orders the employment at subcontractors and other firms developing, building and marketing digital ink-jet machines for textile applications will grow. This new digital finishing technology will enable cheaper production of high-end textiles, more flexible production (planning), and faster logistics of the whole process. This can give the textile finishing industry competitive advantage in the global textile market. And last but not least the implementation and utilization of digital finishing technology can strengthen the position of textile (finishing) industry with conservation and possible creation of employment as a result. This is especially expected in the domain for high-tech textiles where this new technology can give companies a significant competitive advantage due to reduced production costs, improved production flexibility and reduced production times. Social benefits and acceptance. The project contributes to improvement of sustainability and indirectly also to an improved sustainability and awareness of the textile industry. This contributes positively to the social acceptance of the industry. The high tech digital finishing technology can also improve attractiveness of EU textile industry and therefore improve the possibility to attract new, young and highly qualified personnel (improve human capital). This might give an important and significant impulse to a sector that mainly consists of SMEs and has a relative old employee population. The digital revolution in the textile finishing sector starts now!                                                                                     {4 oktober 2007}

Imparting color to a textile is a process to decorate it. Color is the visible part of the Electromagnetic Spectrum (400 nm - 700 nm) The color can be created by colored or none colored chemical substances in a full plane or particial, visible or not visible on one side or both sides of the textile. There are also processes to improve the quality of textiles to make them appealing to the consumer. This improvement of quality can be created by chemical substances in a full plane or particial  visible or not visible on one side or both sides of the textile. Textile is any filament, fiber, or yarn that can be made into fabric or cloth, and the resulting material itself. <BR>The fabric  can be woven, knitted, tufted or non woven. The consumption of energy in the form of electricity and water is relatively high in the textile industry, specially in the pre-treatment, dyeing, coating and finishing divisions. Approx. 25 % of energy of the total textile production like, fiber production, spinning, twisting, weaving, knitting, clothing manufacturing etc. is used for dyeing. It is very important to advance energy and water  conservation in the pre-treatment, dyeing, printing, coating and finishing field. The dyeing and finishing process generally goes through repeated wet and dry operations. The development and utilization of process-specific techniques is very important. According to all known  process possibilities, we propose for example a modem factory  wherein all wet processes, like pre-treatment, dyeing, printing, coating and finishing are done continuous, in the full width up to 500 centimeters, with velocities up to 100 meters/minute. We will call it  DSDS-System. With the DSDS-System you can use the dyestuffs and chemicals which are used in the traditional textile pre-treatment, dyeing, printing, coating and finishing  processes.

The production rationalization, as time-saving, labor-saving, energy saving, water/waste water reduction, space saving with the DSDS-system could be between 70-90 %.

Craamer Textile Consulting

Visionair- Jan Craamer
Linkedin-Craamer Textile Consulting
Wappen Craamer