Extrusion International 2-2025

45 Extrusion International 2/2025 • The manufactured products must be biocompatible and free from impurities Regulatory requirements must also be taken into ac- count. For example, in addition to the starting material and thread structure, the thread strength is particular- ly important for tensile strength and knotting proper- ties. Their classi cation is regulated in a binding man - ner. Although suture materials are considered medical devices, the normative and regulatory requirements are regulated in the European Pharmacopoeia. In the EU and other associated countries, the decimal system is used in accordance with the European Pharmaco- poeia (EP), in which the diameter designation is metric. Although the EP classi cation is more rational, the USP (United States Pharmacopeia) is predominantly used in practice. For example: Suture material of thread size 10-0 USP corresponds to thread size 0.2 EP and has a diameter of 20 µm. From an economic point of view, it should also be noted that some of the materials used cost a good GBP 2,500 (appr. €3.000) per kilogram or more. As far as the manufacturing process was concerned, it turned out that conventional melt spinning processes were unsuitable in this case. Consequently, FET and its partners initially developed a substantially modi ed melt spinning system. After further research and de- velopment work in FET's special laboratory, which was equipped with a prototype of the Motan Colortronic material handling solution, further development of the machine and material handling for this unique process became necessary in the second half of 2012. The close cooperation between the technical teams at FET and Motan Colortronic resulted in a number of solutions that were ultimately implemented, including: A typical system for the production of biomedical yarns is described here as an example (©FET)