Tekstil Teknik Dergisi Tekstil Haberleri, Tekstil Sektörü, Tekstil Teknik
Related Articles
For more than 35 years, Retech has been developing and producing components and installations for processing of synthetic filaments mainly in the field of thermal and mechanical treatment in order to create added value for spinning customers worldwide.
Behind the nomenclature thermal and mechanical treatment there is a large amount of Know-How and technical competence. E.g. Thermal treatment goes in 2 directions, namely heating as well as active cooling. Mechanical treatment covers an even larger range, starting from a big variety of different process speeds, an extensive range of different coatings of the godet rolls which are also vital to the excellent function and superior quality of the final product.
RETECH offers complete solutions coming either as stand-alone concepts or fully integrated, as a retro-fit or upgrade of existing equipment. As the leading global partner of the textile industry in its field, RETECH Switzerland can look back on many years of experience in the world of research and development of components and installations, which are also used to significant advantage in other areas of the industry, such as solar cells.
Heated godets are since many years RETECH’s “flagship” and are used originally on drawtwisters they are now to be seen on most spin-draw and spin-draw-texturing machines running at surface speeds of 2,500 – 6,000 m/min. Although they are just as capable of transferring heat to a bundle of filaments as contact heaters, their use in the false-twist texturing process has always been prevented by the high twist in the yarn as it leaves the heated roll. The temperature range of the Retech induction heated godets is between 50°C and 250°C, this really high range gives an even higher flexibility and added value to the customer.
Based on the Energy Saving Motor (ESM) concept there are three main sizes of motor, which are available in different performances. For these types of motors there are different roll diameters in various lengths available. After defining the heated godet size, the type of heating can be decided according specific customer process data such as the material to be processed, yarn count, number of threads and wraps, process speed and temperatures, draw forces and yarn properties. In most cases the godets are heated by induction. Together with the customer on the base of process requirements Retech engineers work out the decision if one-zone or a multi-zone heating will be used and fact is that RETECH godets are capable of 6000 m/min with temperatures up to 250 °C.
Furthermore is there the definition of the interface with the machine frame. In this case RETECH also offers wide range multi functional flanges with possibilities to adjust the angle. Alternatively the godets are available with their own bearing buildings to use for a very low speed application or to use them with a belt drive to drive several godet rolls centrally.
Retech offers the customer a tailor made technical as well as financial solution and hence achieves the highest flexibility and benefit for the end-user of this godet rolls.
In line with RETECH’s credo “always 1 step ahead” they are now focused on increasing the efficiency of the heating. Basically there are 2 technologies available to control the heating.
One option is offered by using high frequency application, quite efficient but also costly because additional devices are required.
The other option is the conventional control using 50/60 Hz technology; however this can produce higher energy losses. RETECH now has improved on the common and reliable 50/60 Hz technology.
Air Bearing Separator Rolls (ABSR)
Retech has successfully implemented this technology in the market, numerous ABSR’s are in operation worldwide, size 58 x 228 mm as well as new versions e.g. 58 x 320 mm / 36 x 158 mm and 35 x 80 mm, just to mention some. The advantage of these ABSR’s is the fact that Retech rolls reduce the air consumption by around 30 % and can sustain to higher radial and axial forces.
Thanks to a complex technology Retech is able to reduce the air consumption of their latest version ABSR further, in fact the energy consumption is 1/3 less compared to conventional ABSR’s, combined with lower wear and tear.
The main reason for such improvement:
– Maximum utilization of the space available by means of individual design of all parts, considering the permanent weight and tolerances. Nano- technology is involved in order to reinforce the axial bearing.
– In order to generate a maximum pay-load and a minimum on flywheel mass combined with superior
balance exceeding 30.000 RPM it needs more than design on paper but technical detailed evidence in the field. Consistent quality control is monitored as a necessity to achieve highest quality standards in order to make this product successful in the market.
On-line tension control WIN OLT
RETECH improves quality with the on-line tension control WIN OLT. RETECH has developed a yarn tension measuring system that continuously monitors yarn tension, records yarn breaks, calculates downtimes and provides machine efficiency and quality data. This system was originally invented by Retech AG in the early 1980’s thereafter distributed in most countries in partnership with TEMCO until 2009. Subsequently Retech itself approached the world-wide market very successfully to the satisfaction of the customers.
Retech AG provides the OLT sensor itself as a standard product as well as the entire Win-OLT system. Quality control in many kind of textile processes means Win-OLT: The industry standard for high quality and optimised production.
Sustainability is becoming more and more important in every textile activity, also in spinning. Machines and components which are running for more than 2 years without any problems to the satisfaction of the customers and where spare parts are granted over years. The developments of Retech show in this direction. RETECH uses only materials which can be recycled without any exception and all new developments are based on environmental correct solutions. If the customer takes into account the cost of the whole system, a RETECH solution is cost neutral from the beginning. A cost calculation shows that energy cost of the drawing process, depending on the yarn, can be reduced between 20 and 80%. However, a lot of customer still judges the price of each component rather than the advantages of the overall system. Unfortunately, the energy consumption in production is still given too little attention. The Focus in 2015 will be to convince customers to see modifications in this angle of vision.
