The Rupp Report: Breaking Boundaries

Shortly after ITMA Asia + CITME 2012 in Shanghai, The Rupp Report wrote that one of the highlights
of the event was “the announcement of cooperation between Toyota Industries Corp., Japan (TICO),
and Trützschler GmbH & Co. KG, Germany, to develop, manufacture, and market combing machines.”
(See ”
Rupp Report: Toyota´s And Trützschler’s Joint Machinery Project
,”, June 19, 2012.)
Toyota stated that “its experience in
building weaving machinery with special servo motor technology is reflected in the comber.” In the
meantime, both companies have been very active.

Different Approach

The combing machine is a key factor determining yarn quality in the spinning process. After
the draw frame process, there is no possibility to further increase the quality of the yarns to be
produced. With this combing process, the fibers become high-quality yarns. A superior and uniform
quality with reduced noil extraction can be achieved, which results in top-class yarns with added
value. A high and even quality is determined by combing movements and the batt weight.

Traditional combing machines have been working for decades more or less according to the same
principle. The driving or so-called “pilgrim” step movement is the most complex back-step movement
of the detaching rollers. The requirement of rotational reversal sets boundaries. The collaboration
between Toyota and Trützschler has led to a completely new comber concept: the new TCO 12 comber
has a different approach and delivers results that virtually have never been achieved before. With
this very new type of combing machine, one can say it is truly quite different from any other model
on the market.

The Conventional Concept

In conventional combers, the mono drive for the thin detaching rollers produces strong
torsions. As a result, vibrations and deviations in combing quality and noil volume occur between
the comb heads. The detaching rollers’ one-sided drive and the associated rotation reversal at each
nip causes strong torsional forces. The farther the combing heads are from the gear box, the more
strongly the thin axles start to distort, and, moreover, they start to swing.

This situation inevitably leads to different combing qualities by each of the eight combing
heads. The amount of combing noils and the reduction of short fibers varies considerably.
Therefore, the overall performance of the comber is also limited.

Weaving Machine Technology

The new concept of the Toyota-Trützschler Comber TCO 12 is based on two-times-two highly
dynamic synchronous servo motors, which replace the unilateral transmission. There are no cams or
elliptical gears in an oil bath gear to drive the comber. Two fully synchronized motors on each
side — four motors in all — drive the two detaching rollers. According to the manufacturers, this
design results in synchronous running and absolutely comparable motion sequences on all comb heads.
By using individual drives, the motion sequence can be precisely determined by the machine control.
Thus, for the first time, an application-oriented optimization of the piecing process is said to be
possible. This layout is based on Toyota’s weaving machine technology and is designed to provide
maximum dynamics and frequency of rotation. With this concept, the twists are reduced by 75
percent. Every machine designer is always fighting against vibrations caused by the machine drive.
With the servo drives on each side, the vibration is reduced to less than 25 percent.

Latest Drafting Technology

It seems that for the first time, a combing machine is equipped with a full-fledged draw
frame. This system is called Count Control, referring to the fact that the main target of the draw
frame is to maintain a constant sliver count on the comber. The four-over-three drafting system
with pressure bar and its drafting system geometry has been successfully applied in drafting of
comber slivers using leveler draw frames. The same-quality sensors, called Disc Monitor, are used
in the Trützschler draw frames. Both companies are convinced that such an even quality of the
sliver has been achieved for the first time using this new machine.

The fourth top roller ensures an even gentler sliver deflection at the delivery side of the
drafting system, while the adjustable pressure bar in the main draft area provides controlled
guidance. When adjusting the drafting zone widths, the top rollers are guided in the bearing blocks
of the bottom rollers. This process is said to ensure 100-percent axis parallelism for optimal
control of the fiber flow and results in a sliver evenness that has not been possible with existing
combing machines. The Disc Monitor is responsible for a consistent sliver count and optimized
sliver geometry.

Tests reflect the outcome of the new TCO 12: The Uster coefficient of variation (CV) value is
considerably below 3 percent, which corresponds to a uniformity (U%) value of 2.28. The 1m CV value
is even lower than level 1 and the 5m value is 0.23. All these values were achieved with a speed of
600 nips per minute.

Where Is The End?

Some experts will always predict that age-old spinning technology is at the end of its
evolution. When rotor spinning came onto the market, ring spinning was predicted to be out of the
market soon. Wrong. When the air-jet spinning technology became feasible, rotor spinning was
predicted to be outdated soon. Wrong. The same experts declared that along the spinning process,
there is no possibility to design a considerable improvement of the process, whether in speed or
quality. Wrong. The collaboration between Toyota and Trützschler shows a different approach and the
will to think in a different way: Combined expertise can result in uncommon products. There should
be much more to say about the new machine. Time will tell if the idea is successful on the market.

November 27, 2012