Metallurgist, Vol. 67, Nos. 9-10, January, 2024 (Russian Original Nos. 9-10, September–October, 2023) MODELING REELING PROCESS OF CAPILLARY TUBES FOLLOWING MANDREL DRAWING S. V. Parshin, 1 P. S. Khlebnikov, 2 A. A. Fedulov, 3 N. V. Semenova, 4 and A. А. Parshina 5 UDC 621.778 The work addresses the manufacturing of capillary tubes, involving drawing on a long movable mandrel and their subsequent reeling along the outer diameter in order to extract the mandrel, resulting in fin- ished tubes of the desired quality. The two-stage finite element modeling (FEM) included varying key parameters such as tube reduction and clearance between the tube and the mandrel over a wide range. At the first stage, the permissible reduction was determined with a limit on the tolerance for the outer di- ameter. At the second stage, the occurrence of tube faceting was studied. Keywords: tube drawing, long mandrel, tube quality, acceptable facet, reeling, drawing. Capillary tubes, with an outer diameter of up to 5.0 mm and a diameter-to-wall-thickness ratio of 50 or less [1–3], have found a wide range of industrial applications, including in the chemical, food, medical, and mechan- ical engineering sectors. Due to the small size of the tubes, stringent requirements for their surface quality and geometric accuracy become increasingly critical, especially as their applications and materials become more var- ied and sophisticated [4–9]. The most cost-effective and high-performance method for producing these tubes is mandrel drawing (Fig. 1), which involves pulling a hollow billet through a die with a given hole diameter. To ensure the stability of the cross-section and reduce the wall diameter, a long mandrel, moved along with the drawn billet, is introduced. Since the finished tube is clamped tightly around the mandrel, it is necessary to carry out a reeling operation to remove the mandrel from the tube. Due to the small cross-sectional diameter and close limits on the dimen- sions of the finished product, the mandrel is extracted in several stages of reeling, complicating the process. Under incorrect operation modes, surface defects occur, leading to a violated geometry of the product. Currently, drawing mills for manufacturing capillary tubes are equipped with rolling devices based on roll- er cartridges, which allow the tube to be removed from the mandrel during elastic-plastic deformation [10]. The rollers in the cartridges can be installed perpendicular to the tube axis in the amount [11, 12] to facilitate multilateral reduction of the tube on the mandrel, which results in the altered contact between the tube and the mandrel, allowing its extraction (Fig. 2). Radial adjustment of the roller is carried out manually by pressure screws, often on the basis of the operator’s experience and evaluation. Following reeling, the mandrel is ex- tracted from the tube using a chain stripper. Ural Federal University named after the first President of Russia B. N. Yeltsin, Ekaterinburg, Russia. 1 E-mail: netskater@mail.ru. 2 E-mail: hlebnikov94@mail.ru. 3 E-mail: a.a.fedulov@urfu.ru. 4 E-mail: n.v.semenova@urfu.ru. 5 E-mail: a.a.parshina@urfu.ru. Translated from Metallurg, Vol. 67, No. 10, pp. 89–92, October, 2023. Russian DOI 10.52351/00260827_2023_10_89. Original article submitted December 3, 2022, revised article submitted January 11, 2023, original article accepted August 15, 2023. 1532 0026-0894/24/0910-1532 © 2024 Springer Science+Business Media, LLC DOI 10.1007/s11015-024-01646-0