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Predictive maintenance makes maintenance in the rubber industry more efficient

Content

July 2017

 

Lower energy consumption and a future oriented maintenance strategy: This is what the KRAIBURG GmbH & Co. KG rubber plant was aiming for when introducing a new roll mill. Predictive maintenance including the Online Diagnostics Network (ODiN) and a frequency converter from Rexroth made this possible.

From cooling hose to wiper blade: Rubber compounds play an important role both in industry and in day-to-day life. Some of these materials are produced on the roll mills at the KRAIBURG GmbH & Co. KG rubber plant. For some time, Hägglunds hydraulic radial piston motors from Bosch Rexroth have been driving the roll mills used to homogenize and roll out the rubber compounds. When KRAIBURG wanted to introduce a new roll mill into its equipment pool, the focus was on a forward-looking maintenance concept and high energy efficiency. Bosch Rexroth enabled the company to succeed in both areas.

Maintenance fit for the future

“As our roll mills run in three-shift mode almost continuously, machine availability plays a hugely important role,” explains Günther Beisser, who works in equipment planning at KRAIBURG. “Failures on a single machine ultimately delay the entire production process and thus cause extremely high costs.” To prevent this, machines are normally maintained after a certain number of operating hours. On its new roll mill, KRAIBURG wanted to find out how to do this differently and took its first step toward the maintenance method of the future.

With its condition monitoring and predictive maintenance solutions, Bosch Rexroth offers forward-looking maintenance and servicing with a range of options individually adapted to customer requirements. The possibilities cover everything from fitting the systems with intelligent sensors and components to implementation of condition monitoring for customers through to analysis of data by Bosch Rexroth. As part of service agreements and based on customer requirements, these methods are combined with regular reports and different levels of support from Bosch Rexroth service engineers.

For its new machinery, KRAIBURG uses predictive maintenance services from Rexroth including the Online Diagnostics Network (ODiN). The core idea of this service package is to carry out maintenance work before a machine stands still by using a combination of sensors, cloud-based applications, and machine learning methods. In the new machinery at KRAIBURG, sensors first record detailed data about the oil tank, pumps, motors, and electric drive. The measurements taken include temperatures, oil levels, flow rates, and pressures. The data collected is then sent to a Bosch Rexroth server, where it is analyzed using complex algorithms.

An important concern for KRAIBURG was to transmit the data using their own internal network so it was decided to use a separate system. Therefore, an independent GSM module now transmits the information gathered to the cloud, without any contact with the KRAIBURG IT infrastructure. The collected data, separately encrypted and handled for each customer, is transferred to the ODiN system. It is stored and processed on comprehensively secured Bosch servers in compliance with the Group’s very stringent data protection guidelines.

KRAIBURG uses ODiN (Online Diagnostics Network) predictive maintenance to carry out maintenance work before a downtime occurs. Magnifier

KRAIBURG uses ODiN (Online Diagnostics Network) predictive maintenance to carry out maintenance work before a downtime occurs.

 
The systems at Kraiburg run almost continuously on three shifts. Machine availability therefore plays an extremely important role. Magnifier

The systems at Kraiburg run almost continuously on three shifts. Machine availability therefore plays an extremely important role.

From cooling hose to wiper blade: Rubber compounds play an important role in both industry and day-to-day life. Materials are amongst the other things produced on the rolling mills at the KRAIBURG Gmb Magnifier

From cooling hose to wiper blade: Rubber compounds play an important role in both industry and day-to-day life. Materials are amongst the other things produced on the rolling mills at the KRAIBURG GmbH & Co. KG rubber plant.

 

Clever prediction

After installation of the new roll mill, ODiN initially collected data on all monitored components over a training phase lasting several months. Based on these signals, a machine learning algorithm determines a normal health condition for the roll mill. After the learning phase, ODiN uses a data-based model to continuously monitor the roll mill’s health index. If a single measured value moves outside the tolerance range for a short time, this does not necessarily lead to a – possibly unjustified – warning, as wear can rarely be detected with just one single signal. However, if the health index deteriorates due to changes in the data from several sensors, the system warns of a problem – even if the individual changes are within the defined limits.

The health index not only indicates the condition of the unit actually being monitored, it also identifies subtle changes in the upstream and downstream components. If movements start to take longer or require more power over time, this is a sign of wear in the mechanical or hydraulic system. In the health index reports created on a regular basis, ODiN uses machine learning to provide appropriate information and helps to create specific recommendations for action. “A major advantage of ODiN is that it means Bosch Rexroth has access to exactly the same data as we do,” explains Beisser. “It has already been very useful when we had a fault, as an engineer from Bosch Rexroth was able to look at the same data and give precise instructions, allowing us to resolve the fault ourselves without the need for an engineer to be deployed on site.”

Economical operation

KRAIBURG has achieved not only greater efficiency in maintenance, but also in operation of the new roll mill. This is because Rexroth has expanded the Hägglunds drive installed in the machine with an IndraDrive ML frequency converter. In conjunction with the hydraulic pump, it ensures that the Hägglunds drive system is always operated in the optimum efficiency range regardless of the load, which is particularly important for the roll mill at KRAIBURG because it is often not operating at its maximum rated power but at lower speed ranges. This is precisely where the intelligent combination of Rexroth technologies can increase efficiency.