Flexible condition monitoring made easy

By OEM Update Editorial December 16, 2019 12:34 pm IST

B&R Automation and Wittmann Battenfeld has developed a system for its injection molding machines which can eliminate the need for rigid service intervals without risking production downtime. Since the purchasing decisions are no longer based on a machine’s price tag alone, but on the total costs over its entire lifecycle the company decided to have a systematic conditional monitoring.

Wittmann Group one of the world’s leading manufacturers of injection molding machines, robots and peripheral equipment for the plastics processing industry. They operate a total of eight production plants in five countries and are represented at an additional 34 locations in all major plastics markets worldwide.

In the Lower Austrian town of Kottingbrunn, Wittmann Battenfeld builds injection molding machines with clamping forces ranging from 5 to 2,000 tons. Each year around 1,000 injection molding machines are produced there, 95 per cent of which are exported to customers all around the world, primarily in the EU. The lion’s share comes from the automotive industry (50 percent), medical production (15 percent) and the toy industry.

Automation specialist B&R is one of Wittmann Battenfeld’s primary suppliers. The manufacturer has installed B&R machine controls in every injection molding machine built in the last 15 years. B&R’s APROL software has been used for condition monitoring for almost three years now.

Intelligent condition monitoring for injection molders
Before switching to APROL solutions, Wittmann Battenfeld would check key sensors at scheduled intervals. Beyond continuing to use more and more sensors, what they also wanted was the ability to perform maintenance predictively. The goal was to use vibration sensing to identify potential machine and plant failures as early as possible. This would substantially reduce maintenance costs and increase availability. The right solution was found at B&R. Not only do the I/O modules reliably detect potential maintenance issues, they are also easy to configure and compatible with any controller topology.

Condition monitoring is based on vibration analysis performed locally on the modules. The results provide detailed insight into the system mechanics and allow efficiently targeted optimisation of existing processes. The injection molding machine manufacturer relies on this feature to detect contamination, such as when water gets into the oil. Although invisible to the naked eye, this kind of contamination can result in a defective pump within weeks. With an oil sensor system evaluated via APROL, this is now a thing of the past.

New opportunities with B&R’s condition monitoring system
“What has long been common practice for wind turbines and refineries was an absolute novelty for injection molding machines, and we were the first to present condition monitoring at the 2016 K trade fair,” says Dietmar Schabauer, head of technical customer service at Wittmann Battenfeld. “The greatest advantages will certainly go to customers with larger machines,” says Schabauer. “In their case, the cost of a CMS system is more easily outweighed by what is saved in prevented downtime.”

APROL for targeted analysis of measurements
Condition monitoring takes place in a three level process. The first level is the collection of measurement data. Depending on the type of data, appropriate sensors are installed at specific measuring points to transmit the actual values to the analysis systems. It is possible to evaluate vibration, torque, temperature, humidity, oil quality, flow rate or screw functionality, as well as all the data from the control cabinet. At the second level, the collected data is analysed and prepared. The heart of the CMS system is the evaluation unit, comprised of a CPU and a measuring module, which converts the measurements into analysis variables. The third level is where data evaluation and condition analysis are carried out.

It is currently possible to monitor and store around 80 different condition parameters for the machine. These values are stored on APROL servers for up to one year and can be retrieved and compared retrospectively – which is particularly helpful for service analytics. Until now, this system has been used by customers themselves as a stand-alone solution to monitor measured values on site. Wittmann Battenfeld’s long-term goal, however, is to connect its machines to the Internet and send the recorded data to the customer via the cloud. This enables them to receive notification about various machine states, such as when oil needs to be changed or service is required.

For more details, visit:
www.br-automation.com