The secret of the success of the latest generation of Lindemann scrap balers

(Web Magazine 2003)

Kurt Pessel

The fact that a growing number of customers in the recycling, automotive and non-ferrous metal industries in Europe, North and South America, Asia and Australia during the recent years have decided for Lindemann “Rapid Automatic Scrap Balers”, RAS for short, is by no means a coincidence.

It is the result of systematic procedures with in-depth market studies in the initial stages of development in order to establish what really matters to customers in the various industries and clean design work of the different engineering professions involved.

Lindemann RAS balers are much quicker, require less energy, have a higher level of availability and are unbeatable in operation and maintenance: These are some of the answers one will get when asking RAS operators why they have decided for a Lindemann baler from Metso Minerals.

Fast and economic

The RAS series is the first generation of scrap balers to operate with a peak hydraulic pressure of 350 bars. This measure means that smaller cylinders can be used at the same pressure forces – and smaller cylinders mean a lower volume of oil to move. Because fewer than 10 percent of all cylinder movements happen in the high-pressure range, 90 percent of the working movements can be made at the same drive power but at much higher speeds.


State-of-the-art high-performance driving unit of a Lindemann
RAS III baler.

In addition, the decision was made to have the hydraulic cylinders connected in series. Therefore, the returning oil from one cylinder can be used directly to speed up the advance of another cylinder working under low load conditions. An additional hydraulic oil flow separation allows to control oil flows in a manner that several cylinders can be fed at the same time.

Overall, these combined measures have helped to reduce cycle times in the new hydraulic system by up to 50 percent without increasing the power supply. This results in extremely high throughputs with a most favorable energy consumption.

Integrated and visualized

There are also highlights on the electrical side that have never been seen before in scrap balers. The infinitely variable positioning system – as opposed to the previously used proximity switches – is not affected by dirt and falling scrap. Operational disturbances, which are often due to defective proximity switches, are now a thing of the past.

The measuring system is fitted in all cylinders, and means that, for the first time ever the piston position can now be determined along the entire travel distance. This now makes it possible to control the optimum hydraulic switch positions.

This measuring system is the only one that enables a dynamic monitoring of the oil level, which offers operational safety and environmental advantages, as even low oil losses are recognized and notified.

Pre-selection option with between several bale programs, process data visualization with text formatted user guidance and online help in clear text and several languages, as well as remote diagnosis via teleservice – all features in the control and monitoring area that were not previously available with scrap balers. The energy-efficiency circuit and peak load control provide additional options for the energy-aware user.

Compact and safe

But electrics and hydraulics are not the only areas where there have been major innovations. There are also features in the mechanical area that have led to considerable improvements in maintenance and availability. For example, all the wear plates in the balers are now screwed into place and can be removed quickly and easily without first having to remove the compressors.

A special wear plate profile helps to prevent the dreaded plate jams, caused by thin pieces of metal and offcuts, which often leads to expensive operational interruptions. As an option an automatic wear monitoring system called WearCon is offered. WearCon automatically signals, well in advance, when it is time for wear plate replacement.


Comprehensive wear protection by means of wear plates with
special Lindemann profile.

Rigidity calculations with the aid of infinite elements have resulted in highly compact and therefore space-saving constructions. The idea of compact and space-saving installation – particularly important to the automotive industry – was a consistent factor in the design and arrangement of the hydraulic and drive aggregates. Attaching the hydraulic block and pipelines from the hydraulic block to the cylinders at the factory, has helped to achieve shorter installation times and problem-free commissioning.

Solutions for numerous applications

Whatever needs to be baled from a complete car chassis to aluminum foil, the RAS program contains with the triple, double and single-acting balers and bale cross-section of 600 x 600 mm down to 250 x 250 mm a variety of solutions for use in the recycling industry, automotive industry and non-ferrous metal industries.