The Manmade Fibers Segment of the Swiss Oerlikon Group has presented the latest development for tape production at this year’s Techtextil that took place this week in Frankfurt. The company exhibited its EvoTape and WinTape in a Virtual Reality Showroom in 3D.

EvoTape and WinTape are said to set new standards, providing greater output with the reduced deployment of energy and personnel, less waste and a faster return-on-investment (ROI).

The focus of the development work over the past few months has been on the verification of speed potentials and a lower overall draw ratio for further products. The new concept currently offers solutions for the manufacture of carpet backing, agricultural textiles and geotextiles.

Efficient tape extrusion

The EvoTape operates with a cold pre-drawing process with an approx. 1:3 ratio. In the subsequent, second drawing stage, the tapes are lighter; they take on the heat from the hot-air oven more easily. These two drawing stages are said to result in superior process stability, reaching the same tenacity values with higher speeds or superior properties at the same speed.

The splitting of the drawing process also ensures a low overall draw ratio, the company reports. As the cut width of the overall drawing is defined, this is also reduced. Consequently, more tapes can be manufactured.

More output, less waste

The automatic WinTape precision winder supplements the EvoTape concept in the take-up stage. Electronic crossing angle(s) ensure(s) perfect package build with optimum quality for the downstream further processing, according to the manufacturer.

As the tapes dwell in the yarn guide during package transfer, automatic take-up of folded tapes is possible. With two parking positions for full packages, the system configuration for carpet backing fabrics can operate for 24 hours without package transfer, hence simplifying shift work.

Carpet backing

The system configuration for carpet backing generates the familiarly high and homogeneous tape quality at simultaneously considerably higher process speeds. The EvoTape offers a process speed of 400m/min. By contrast, extrusion systems for carpet backing used to date operate at a speed of 320m/min.

The considerably superior productivity of the new EvoTape system in conjunction with the WinTape take-up unit is said to provide yarn producers with a significant expansion in capacity without substantial additional space requirements.

In this application configuration, the energy savings amount to up to 50% compared to equipment manufactured during the 1980s and 1990s, which is quite permissible for a system lifespan of 30 years and more, the company reports.

Baler twine

While the titers of carpet backing fabrics lie between 300 and 1500 dtex, the titers for baler twines are 20,000 dtex and higher. Instead of tape widths of between 0.9 and 2.5mm and thickness ranging from 35 to 45 µm, tapes with widths of between 20 and 90 mm and thicknesses of between 75 and 100 µm can be manufactured.

The focus of the process is on high tenacities for the yarn and high tenacities for the knots when tying off the bales. To achieve the high tenacities desired, the tapes are drawn at a ratio of 1:12 in currently common standard processes. The high draw ratios mean that in the case of products with 70,000dtex, for instance, only three to four tapes can be run in parallel on the system.

With the EvoTape, these draw ratios can be reduced to just the one seventh or one eighth. Lower draw ratios simultaneously also mean cutting narrower tapes, hence allowing more tapes to fit on the godets. The output of the system is virtually doubled in conjunction with the speed increase from 250 to 350m/min.

Geotextiles

The EvoTape process also showcases its advantages for geotextiles and agricultural textiles. Here, high tenacities are achieved with lower overall draw ratios as well.

For some applications, the addition of LDPE as a drawing aid can be dispensed with, additionally securing a reduction in raw material costs for this process.

www.oerlikon.com