Polymer coextrusion head with a dual-channel nozzle

A coextrusion head for manufacturing a bicomponent polymer fiber, the coextrusion head comprising:

• a first inlet configured to receive a core polymer component;
• a second inlet configured to receive a cladding polymer component;
• a dual-channel nozzle, the dual-channel nozzle including,
• an inner channel, and
• an outer channel encompassing the inner channel, the inner channel being in hydraulic connection with the first inlet, the outer channel being in hydraulic connection with the second inlet;
• and
• a joining path establishing a hydraulic connection between the inner channel, the outer channel, and a nozzle outlet of the dual-channel nozzle, the joining path configured to bring the core polymer component and the cladding polymer component into contact with each other such that a contact layer is formed between the core polymer component and the cladding polymer component in response to simultaneously receiving the core polymer component from the inner channel and the cladding polymer component from the outer channel, the contact layer including a mixture of the core polymer component and the cladding polymer component, wherein the coextrusion head comprises at least two of the dual-channel nozzle and a hierarchical stack of channel plates, each of the channel plates comprising at least one first channels and at least one second channels, the at least one first channels establishing the hydraulic connection between the first inlet and each inner channel of the at least two dual-channel nozzles, the at least one second channels establishing the hydraulic connection between the second inlet and each outer channel of the at least two dual-channel nozzles, a number of the at least one first and second channels per channel plate being constant or increasing in downstream direction.