Extrusion International 2-2025

37 Extrusion International 2/2025 Foaming Technology in Wire & Cable Applications Promix Microcell Technology is applicable to any extrusion process where material cost is sensitive, and performance requirements are non-negotiable. The Wire & Cable industry is a regulated eld where electrical, mechanical and ageing performance is key for the successful introduction of reliable products. W hile chemical foaming of coaxial telecom cables has been applied in the past, physical foaming of a much broader range of data ( ber optical, copper) and power cable applications leads to a more cost-attractive, more sta- ble, more sustainable and better performing product. Promix Solu- tions is the leader in physical foam extrusion using environmentally friendly blowing uids like CO2 and nitrogen. The company will showcase its technology at Inter- wire USA from May 13 – 15, 2025 in Atlanta , GA at booth 539, Swiss Competence Cluster. The world of wires and cables is diverse, offering various cable de- signs. While there are limitations for foaming in high voltage power land and submarine cables due to the high electrical stresses, the many low voltage cables and data cable types show great potential to reduce material consumption in the range of 15 to 25% for jacket- ing and insulation, and even 30 to 60% for bedding and lling com - pounds. This goes hand in hand with increased cable exibility, weight reduction and an improved carbon footprint. Promix Solutions has proven its applicability in many extrusion pro- cesses, including sensor cables, ber optic cables and low-voltage power cables. A further trend towards replac- ing the environmentally critical Azo compounds used in chemical foam- ing of coaxial cables by physical foaming technology results in lower long-term costs, higher process and product stability and end-of-life re- cyclability. Cables require a super- smooth surface of their sheathing. If required, by applying a very thin skin layer extruded over the foamed jacket, cable manufacturers have additional design options to bene t from the material savings. All relevant polymeric materi- als, by means of LDPE, HDPE, PBT, EVA, Polyole n elastomers, includ - ing lled systems, and PVC have been used in combination with the Microcell Foaming Technology. Per- formance bene ts on the electrical side, i.e. improved dielectric con- stant and reduced external electri- cal interference, were realized. On the mechanical side, higher ca- ble exibility and a very stable foam - ing process resulting in narrow di- ameter tolerances are the outcome for the performance characteristics. The high-quality cell structure made with Microcell Foaming Technology permits a wide application range for wires & cables. The picture showcases an exam- ple of a sensor data cable as used in automotive (upper section), where the bedding is foamed. On the lower part an A-B jacket with a thin skin-layer highlights the potential for jacketing applications in data and power cables. Gas dosing stations for physical foaming function either on a mass- ow or pressure-controlled dosing regulation. Promix Solutions offers both types of systems, matching customer needs by applications. Besides the actual cable, micro- ducts (material savings of 10 to 15%, mono and multi-layer) and cable protection tubes (material savings of 10 to 25%, multi-layer) serving as cable infrastructure are more exam- ples enabling physical foaming to save material cost and improve their sustainability footprint. Promix Microcell Technology works for all types of extrusion pro- cesses including cables, packaging, lms, sheets and boards, pipes and pro les, blown lm and extrusion blow molding as well as thermo- forming. The technology can be ret- ro ted to existing extrusion lines as well as installed in new lines. Promix is working with a number of ma- chine builders to achieve a perfect match. Promix Solutions AG Technoparkstr. 2, 8406 Winterthur, Switzerland www.promix-solutions.com EXTRUSION TECHNOLOGY