Rieter

Lower labor costs due to advantages in transport and service

Index

Despite the technical possibilities available, the manual transport of cans and packages to and from highly automated rotor spinning machines still defines personnel deployment in the majority of textile mills. However, the effort involved can be reduced substantially by using large units for spinning cans and cross-wound packages, such as those supplied by several machinery manufacturers (Fig. 102*).
For example, using 18 1/2˝  cans* instead of 16˝ cans saves more than 12% of the transport movements over the long distances between the drawframe and the rotor spinning machine. Longer running times mean that large cans have to replaced less frequently. Appropriate machine design nevertheless permits space-saving layout with comparatively short transport distances. This also applies to the rectangular cans used in the context of transport automation. The filling weight of these cans is up to twice that of 16˝ cans and still some 70% higher than that of 18 1/2˝   round cans (Fig. 103).

Similarly, the effort involved in transporting the finished yarn packages can be minimized by using larger units (Fig. 103). If packages weighing 5 kg can be produced, this implies 20% less handling effort in transport, palletizing or packaging, compared with 4 kg packages. In addition to the gains in the spinning mill, the same savings in handling effort can be made in downstream processing. Added to this are savings on the corresponding number of empty tubes, for which disposable tubes are usually used. The savings here can certainly amount to some 0.05 €/kg of yarn in large installations. In combination with appropriate automation solutions this amount can be even higher.

* Can formats that fit under the rotor spinning machine in 2 rows, depending on machine type.

Personnel for setting and maintaining the machines represent a further cost block in labor costs. Optimized setting capabilities enable the necessary machine downtime and the personnel time and effort expended on this to be reduced. On machines equipped entirely or partly with infinitely adjustable inverter drives, time-consuming and usually repeated changes of gear wheels or drive pulleys with the associated machine downtime at batch changes are eliminated. Setting values for draft, yarn twist, tensioning draft, rotor and opening roller speed can be entered very easily directly at the machine control panel.

Further savings in labor costs can be made if an intelligent machine and control concept helps to simplify maintenance work and shorten cleaning operations, for example by means of:

  • operating robots of modular design;
  • easy, rapid replacement of technology components, as far as possible without tools;
  • oil-free and thus low-maintenance rotor bearings requiring little cleaning;
  • working elements that can also be replaced while the machine is running (technology components, rotor bearings, etc.).

Not all of these aspects can be quantified in terms of euros and cents, since concepts for maintenance and technical supervision of the machines vary widely between different mills. However, irrespective of the effort expended in a spinning mill, a maintenance-friendly machine concept will always have a beneficial impact on manufacturing costs.

Fig. 102 – Cost advantages per rotor spinning machine and year of large cans (18½˝ versus 16˝)

Fig. 103 – Cost savings per rotor spinning machine and year with large packages (5 kg versus 4 kg) and lower tube investment