IRO TEC: The sensitive weft thread feed

IRO TEC, the latest programmable brake for weft thread accumulators, offers highly-responsive thread tension control.

IRO TEC is the new programmable brake for weft thread accumulators. It is fitted additionally with a leaf spring brake (uni-brake) and is suitable for an extremely wide range of yarns. It provides a marked reduction in wear and ensures an excellent fabric appearance.

A perfect narrow fabric is the result of exact machine settings and precise weft thread feeding. However, in the case of wide needle looms conventional feed systems using rollers and compensation springs are unable to prevent faults entirely. Consequently, from a weaving width of 170 mm, weft thread feeding devices are employed in combination with mechanical brakes. Nonetheless, in the case of articles woven using two weft needles (Z-systems), the mechanical brake does not function and therefore the MÃœTRANS system is utilised. Unfortunately, MÃœTRANS requires very long compensation distances for the weft and numerous deflections, which leads to increased loads on the compensation springs and greater wear and tear. It is precisely these disadvantages that the new IRO TEC weft thread feed prevents.

The heart of the system is formed by a universal brake leaf, which is characterised by a large braking surface and excellent wear resistance. It can be employed in needle looms for any yarn count. The brake leaf can be opened at the side for threading, which markedly simplifies operations. Opening and closing times can be set in line with the rotation angle of the loom and the required signal emanates from an angle sensor. Furthermore, in the case of sensitive materials the braking force of the IRO TEC can be regulated individually via a potentiometer.

When in operation, the IRO TEC offers highly-responsive thread tension control. This is integrated into the weft thread accumulator (see illustration) and the reaction time amounts to around 2.5 milliseconds. The brake leaf is also suitable for reductions in thread tension peaks such as those caused when knots run through.

The Jakob Müller engineers subjected the programmable IRO TEC thread brake to extensive testing in an NF80 2/310 needle loom, using weft threads with counts of between 50 and 1,200 dtex. The results are as follows:

• Reduced compensation spring wear
• Excellent fabric appearance
• More regular weft thread feeding with constant thread tension
• Absolute parallel positioning of the weft threads in the fabric
• Improved selvedge uniformity on the warp needle side

The IRO TEC is available as an option for the S1-S5 weaving systems for the following machine types (single needle weft thread insert systems):

• NF53 2/170 and 2/210
• NFRE53 2/170 and 2/210
• NF53 2/210 VL/AL
• NF80 2/310

(For details: Jakob Müller AG Frick, 5070 Frick, Switzerland.
Tel +41 62 8655 111. Web: www.mueller-frick.com).