Greater flexibility in plastics production thanks to the SafetyBridge I/O system


Finishing section of the plastics plant  

In finishing, the individual products are completed and packaged

  • The core business of Chemours Netherlands B.V.s is plastics production.
  • Previously, hardwired and therefore inflexible safety controllers were used in final production and packaging.
  • I/O systems with SafetyBridge technology can be easily connected to the S7 standard controller from Siemens, completely integrated into the existing network, and operated independently of the standard controller.
  • With the new safety solution, Chemours gains flexibility and, at the same time, conformity with stringent safety guidelines.

Customer profile

Johan Sterrenburg, Chief Engineer  

Johan Sterrenburg, Chief Engineer for Electrical Systems and Instruments

In the extensive Chemours Netherlands B.V facility, around 500 employees focus on producing plastics with well-known brand names such as Teflon, Opteon, and Viton. The products are used in non-stick coatings and coolants. Established in 1959, the Chemours Group’s production site is the largest in Europe.


Packaging line in finishing  

The safety sensors and position switches are integrated into the automation solution via SafetyBridge

Each of the factories on the company premises is controlled and monitored from a central control room, into which all of the key data flows from all production processes. In finishing, where the products are completed and automatically packaged before shipping, the machines are controlled by locally installed PLCs that exchange data via Profinet or Profibus. Employees can access the process data at several operator panels that are installed at various locations, enabling them to control processes and correct errors where necessary. In the event of an alarm message, however, the process parameters are always to be adjusted centrally, from the control room.

The main process was originally controlled by its own safety controller, while in finishing and packaging, parts were hardwired meaning that inflexible systems had to be used. For this reason, those responsible set up a project for modernizing the outdated safety PLC. The project activities were aimed at finding a solution that offered greater flexibility and, at the same time, conformity with the plant operator’s stringent safety guidelines.


SafetyBridge modules installed in the control cabinet  

Version 3 LPSDO modules are installed in the packaging line control cabinet

Johan Sterrenburg, chief engineer for electrical systems and instruments at the Dordrecht facility explains. “From the very beginning of the project, it was clear that our focus needed to be on this separation between the safety system and the main control system. After we tested and evaluated all possible solution concepts, we decided to go with the Inline I/O system with SafetyBridge technology (SBT) certified by the TÜV certification body. We chose this solution because it is easy to couple to the S7 standard controller from Siemens and, at the same time, includes its own safety CPU. Therefor, the solution can be integrated into the existing network and yet be operated independently of the standard controller.”

The facilities for finishing and packaging are distributed across a large area, and now the safety sensors and position switches of all processes can be integrated into the automation solution for the first time, thanks to the decentral safety I/O system. In detail, Chemours has installed version 3 of the LPSDO (Logic Programmable Safe Output Device) module from the SBT range in both of its packaging lines. In the current configuration, up to 16 safe input or output terminal blocks can be controlled via remote access across the network. If more safety signals are required in the future, I/O modules can be added or a new LPSDO module with the corresponding I/Os can be integrated into the solution.

The logic module generates and monitors the safety protocol and processes the safety logic. For implementing the safety functions, the Safeconf configuration software contains the respective blocks, which are based on the PLCopen specification. From the point of view of the standard PLC, the SBT system is a conventional I/O module for transmitting safety packages. The Safety modules continuously monitor the content of the packages. If they determine an error, the logic module switches the system to a safe state immediately. The state data is transmitted to the central control room.


Once the safety logic has been set up, the distribution and physical location of the I/O modules in the network no longer play a role because they do not influence the safety logic. To implement or retrofit the safety logic into an existing standard controller, programmers do not need any experience or special training in the field of functional safety. All in all, with the SafetyBridge concept now implemented in the Dordrecht plant, Chemours has set up a TÜV-certified safety system that functions independently of the S7 standard controller, and yet is fully integrated into the existing plant network.


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