By Jürgen Müller, Head Product Group Draw Frames, Machines & Systems, Rieter
The new single-head draw frame generation is characterized by its performance: productivity increase of up to 33%, reduced energy costs, quicker lot change, outstanding sliver quality and easy, intuitive operation.
In fall 2016, Rieter introduced the new RSB-D 50 single-head draw frame for the first time to a global audience at ITMA Asia in China and ITME in India (Figure 1). The new draw frame generation excels with a multitude of innovative solutions, which reduce costs, increase quality and simplify operation and maintenance.
Energy saving drive
With the patented ECOrized drive concept, 25% of the belts and drive elements as well as the differential gear are saved compared with the previous model.
Two servo motors drive the drafting system. Unique features are the frequency-controlled drive for the suction and the individual drive for the coiler. The new drive solution for the coiler leads to straight belt tracking and a far longer lifetime (Figure 2). The quiet machine is evidence of the low abrasion.
Lower electricity costs
The new drive solution generates yearly savings of approximately €1,000 for each RSB-D 50. If the saving over the lifetime of the machine is compared with the investment, a very attractive ratio results.
As a standard feature, the draw frames are now equipped with integrated energy measuring. Should significantly increased power consumption occur, preventive maintenance can be carried out and a breakdown of the machine thus avoided.
Even tougher with power fluctuations
With a short power fluctuation, the control voltage is supplied from the drive converter. This energy store can compensate short-term voltage interruptions and reductions. The draw frame keeps running.
With longer interruptions, the draw frame with active auto-leveling shuts down in a controlled manner. The web remains in the threaded condition and allows a rapid restart.
Further optimized drafting
Conventional sliver guides in front of the drafting unit are often wrongly adjusted. The most frequent fault is non-central guidance of the sliver.
The new, patented sliver guide guarantees central guidance of the sliver at all times and therefore consistent sliver quality (Figure 3). The web width is reproducible and is set by simple swiveling of the guide elements.
Additional fiber guides in the main drafting field prevent lateral slipping of the edge fibers, which results in fewer disturbing faults in the yarn. Further, the top roller bearings are permanently lubricated and run at a lower temperature.
When processing fibers with high fiber-fiber friction, as is the case with manmade fibers, active sliver separation is necessary for a trouble-free can change. To achieve this, the motors of the auto-leveler drafting system create a thin place, which is transported below the coiler and deliberately breaks at can change.
Precise sliver coiling
CLEANcoil is the standard coiler for all fiber materials and offers maximal flexibility. The spiral coiling tube ensures coiling that is free of drafting faults, even at high delivery speeds. A honeycomb structure on the coiler underside reliably prevents deposits.
For the processing of 100% polyester, the latest development CLEANcoil-PES (Figyre 4) with a new type of coating offers unique advantages in coiling.
Even with critical polyester fibers, the cleaning cycle can be extended by at least 100%. This also leads to more consistent sliver and yarn quality (Figure 5).
The SB-D 50 draw frame without leveling and the RSB-D 50 auto-leveler draw frame produce, in practice, at a delivery speed of up to 1,200 m/min. Depending on the fiber material, up to 33% higher speeds in comparison with the previous model are possible.
The following is an example of a customer who processes combed cotton: the RSB-D 50 is operating at 650 m/min, the previous model RSB-D 45 at 480 m/min.
Despite far higher delivery speed, the sliver quality values of the RSB-D 50 achieve an equally good level (Figure 6). The yarn count (Ne 30) shows equal or even slightly better quality.
In the nine-week long-term test, the mean values of the disturbing faults on the RSB-D 50 are also remarkable. Compared with the RSB-D 45, which already achieves good quality values, the Classimat values were improved by 13% and the winder cuts by 8%.
Touch and LED displays
The SB-D 50 and RSB-D 50 use the latest control generation as well as a colored touch display with a high resolution. This allows intuitive and easy operator guidance (Figure 7).
Clear indications are of decisive importance for the operator when it concerns efficient working. Here, light-emitting diodes (LEDs), which are visible from afar and provide information on the condition of the draw frame, help (Figure 8); they simplify the operator’s work immensely.
By means of the USB interface, the data is quickly and easily transferred to other machines. Connection to the Rieter mill control system SPIDERweb is possible as a standard feature.
Frequent personnel changes or shortage of specialists are increasing problems for spinning mills.
Rieter offers a remedy by setting recommendations that appear directly on the machine display. The basis is the well-known SLIVERprofessional expert system, which is now integrated in the machine display, providing valuable technological support.
This unique tool offers setting recommendations for the entire machine after the raw material data has been entered; these can be transmitted as a data record onto other machines. In addition, SLIVERprofessional assists with the analysis of spectrogram faults such as periods and draft waves. In this way, faults are rapidly corrected and the availability of the machine is increased.
The SB-D 50 and RSB-D 50 allow, as previously, assembly on the floor, which makes flexible positioning possible.
A new option is to install the machine recessed into the floor, which means the transfer height of the can on the empty can magazine is lower and thus more convenient. The full cans are pushed out directly onto the spinning mill floor.
The RSB-D 50 keeps the unique features of the previous model, which are all patented. These include:
- Effective suction by automatically lifting clearer lips on the top rollers
- CLEANtube for sliver coiling without trash accumulations (for cotton applications)
- Sensor for exact first sliver coils, even with can plates that are too low.
With the RSB-D 50 and SB-D 50, Rieter sets another milestone in draw frame engineering for the benefit of customers. Once more, the saying prevalent amongst mill managers “Buy an RSB and you can sleep peacefully”, applies.
For more information contact:
Jürgen Müller, Head Product Group Draw Frames, Machines & Systems
Rieter Ingolstadt GmbH