Integrated RFID tags in polymer injection molding

For the traceability of plastic components, if at all, they are marked with a simple code. The current methods for these codes are complex and do not offer the possibility of storing additional information. In the future, it should be possible to store important characteristic data of the injection molding process, the material properties and the component itself in the component by using an RFID tag.

• Injection molding
• PPSU high performance thermoplastic
• PA
• RFID tag
  

The current solutions that are available on the market for integrating RFID tags in plastic components consist of multi-stage processes. In some cases, the tags are attached to the component by subsequent gluing or welding. Studies already known do not allow the conclusion that economical solutions have been found for series production in plastic injection molded parts.

The company Novoplast AG is now looking for a feasible solution to integrate the tags in the injection molding process. In addition, it should be possible to process the tags with high-performance thermoplastics such as PPSU, which are processed at significantly higher temperatures and pressures than commodities such as PP or engineering plastics such as PA.

The aim of the project was to create an overview of available RFID tags, their properties and suppliers. In order to be able to read information from the RFID tags and write on them, reading and writing devices were evaluated. To ensure the stability and functionality of the RFID tags during and after the injection molding process, the temperature and pressure resistance was investigated. For this purpose, compression and injection molding tests were carried out with PA and PPSU.

Furthermore, integration possibilities of various RFID tags in injection molds were examined and concepts for their implementation were developed.

These concepts were evaluated with injection molding tests.

Simplified compression molding and injection molding tests have shown that standard RFID tags can be processed with engineering plastics up to a melt temperature of 270°C. No degradation of the RFID tags was observed. Processing with high-performance thermoplastics up to 370°C melt temperature is possible, but attention must be paid to the material composition and dimensional stability of the tags.

With the use of two giveaway injection molds, two concepts for overmolding RFID tags could be implemented. It was shown that it is possible to overmold the RFID tags in a single-stage injection molding process. The tags could be written and read with a read & write device as well as with an NFC-enabled smartphone.