Traceability is an ongoing concern for the textile industry. Technologies such as barcodes, QR codes and RFID tags have been put in place to enhance supply chain transparency, but they often fail to provide complete traceability. Researchers at the University of Borås in Sweden have developed a novel coded yarn-based tracking system that promises to overcome existing limitations and deliver improved traceability.
In the new system, intelligent yarns are fully integrated into textiles during the manufacturing stage to produce traceability tags. The coded yarns contain special optical features and, as a result, create an ‘optical stamp’ or pattern for traceability on the surface of woven or knitted fabrics. The tags are created by using a combination of coded yarns having different and distinguishable optical features, or yarn classes.
According to researchers, the coded yarns work much in the same vein as barcodes, where lines of varying widths and spacing represent digits, and a set of lines represents the full code. Similarly, a coded yarn's unique optical features represent a digit, with a sequence of coded yarns representing a complete code. The full code can be altered or controlled by changing the coded yarns’ sequence in the textile.
“Barcodes and RFIDs possess low security against copying and reproduction, which means an identical tag can easily be reproduced and placed with a counterfeit product,” the researchers explain in a technical paper published in the Journal of Manufacturing Systems. “The tracking tags are removed at the point of sale (POS). Therefore, it becomes difficult to trace back the history of a textile product after POS.”
As an integral part of the textile, coded yarns tags cannot be removed. This means that not only is traceability extended beyond POS, but it can also help in ensuring proper product care, recycling and return. Unlike RFIDs, coded yarns do not alter the feel of textiles and can be processed in textile recycling without issue.
“Since the reproduction of these tags is not easy like other tags, including barcodes and RFIDs, they can provide enhanced security to textile products from counterfeits. Further, from the economic aspect, yarn-based tags are normal textile, therefore, there is no need of special material components and in-house production in a textile industry can be done,” the researchers added.
The new technology is a step in the right direction, but more fine-tuning of the technology is needed before coded yarns are ready for market. According to researchers, further improvements are needed on tag readability — such as fixed identification marks to direct reading and decoding.