Abstract: According to an aspect, there is provided a method for monitoring quality of loose tube fiber optic cable during manufacture in a secondary coating line. Initially, a trained machine-learning algorithm for calculating expected values of one or more quality metrics of manufactured loose tube fiber optic cable based on values of the one or more production process parameters of the secondary coating line is maintained in a machine-learning database. A computing system monitors one or more values of the one or more production process parameters during miming of the secondary coating line and calculates, in real-time during the monitoring, one or more expected values of the one or more quality metrics using the trained machine-learning algorithm with the monitored values of the one or more production process parameters as input. The computing system outputs at least the one or more expected values of the one or more quality metrics to a user device.

Abstract: Fibre material and at least one plastic material is extruded in such a way that a composite product (11) is produced. To increase the strength of the product (11) and to improve its heat resistance, the at least one plastic material of the product (11) is cross-linked in such a way that at least a surface of the wall of the product (11) is provided with a cross-linking degree higher than the cross-linking degree of an inner part of the wall of the product (11).