Metal processing. Aurubis relies on FMS force measuring blocks for continuous use in demanding application.

Cold Rolling Mill in the Netherlands
In Zutphen (NL), Aurubis produces an extensive portfolio of rolled products of copper - from pure copper to high-quality specialty alloys, such as brass, copper-tin and the specialty alloy CuproBraze®.

Initial Project Phase: Replacement of existing Force Measuring Blocks
The existing force measuring technology of the five-stage roller line no longer met current process requirements; the expanding product offering demanded precise measurement of reduced material tension that was not then possible. Additional project specifications stated that the installation envelope remain unchanged and that measuring blocks must resist aggressive media (rolling emulsion consisting of water and carboxylic acid ester). The new FMS measuring blocks are designed to address a wide tension measuring range. Through extending the lower measuring range, the customer expects to achieve greater flexibility in the use of the system. The current measuring amplifiers are to be replaced by the latest generation of FMS units that include a PROFINET interface in order to achieve shorter cycle times and easy integration into the control system. The separate evaluation of the highly accurate feedback signal from each side (left & right) of the measuring rollers will be used to increase process reliability.

Goals / Solutions
Due to the very wide measuring range required, FMS was initially considering the use of the LMGZ series, size 313, force measuring bearings. However, this option would have required both major changes in the mounting configuration of the units and purge air to protect the bearings from contamination. To meet the tight specifications, FMS developed a customized measuring block based on the SMGZ series with the change from standard being the reduction of the total error from 0.5% to 0.3%. The hermetically sealed design with protection class IP67 was optimally suited for four of the five measuring roll positions, while the fifth measuring roll position utilized the LMGZ series, size 307 force measuring bearing. For data evaluation, the use of the latest dual-channel PROFINET measuring amplifier (EMGZ492.PNET) was recommended. The precise evaluation of the web tension from both ends of the measuring rollers assists the customer in optimizing the rolling process.

Result
Upon completing the installation, it was shown during the commissioning process that Aurubis was able to confirm the forecasts for measuring accuracy and range. The customer's goals have been achieved with the upgraded measurement and data acquisition arrangement.

The application of Force Measuring Blocks
Force measuring blocks from FMS are designed for use with standard pillow block bearings with assembly requiring only a few screws for an easy and quick installation. The force measuring blocks are characterized by durability, accuracy and reliability. Even narrow strip tension values at only 5% of the nominal force of the blocks are measured with high accuracy. Depending on the requirements of the application, FMS offers different models and / or options as needed. The combination of hermetically sealed measuring technology, stainless-steel housing and high overload protection make the SMGZ series and PMGZ series force measuring blocks the ideal solution for applications in chemically aggressive environments such as those found in steel and paper mills. For applications where such protection against harmful contamination is not required, the UMGZ series measuring blocks are a cost-effective alternative. With the UMGZ.P series measuring block, FMS provides a direct replacement for the Philips R 9951 series measuring block, and which are no longer available.

Functional Description
Standard pillow block bearings are mounted to the force measuring blocks, and this assembly is then used at each of the measuring roll. Thanks to this design, the replacement of a bearing or roll becomes a very quick and straightforward procedure. Depending on the type of measuring block, the installation situation, the roller weight and the wrap angle of the material web, the selection of either a horizontal or vertical block version is made. This ensures the best possible measurement of the resulting force in all cases. The force measuring blocks guarantee precise and accurate web tension measurement even with small wrap angles and heavy rollers. In situations where the standard mounting hole pattern for the pillow block bearing on the measuring block is not workable, the mounting hole pattern is adjusted as needed.  For a long service life and best measuring results, we recommend the combination of measuring blocks and digital measuring amplifiers.

Product features

• Increased stiffness, robust design
  IP 67, inert gas filled, resistant against aggressive materials, stainless steel construction
   
• For heavy rollers and high speeds
  High stiffness and robust design, overload capacity up to 10 times nominal force
   
• Precise measurement results
  In combination with FMS digital measuring amplifiers
   
• Nominal forces for every application
  From 1 kN to 100 kN
   
• Direct replacement of existing measuring blocks
  Hole patterns are available according to customer-specific dimensions