Namen prispevka temelji na inovativnem postopku izdelave nanokompozitov na osnovi poli(3-hidroksibutirata) (PHB) in nanofibrilirane celuloze (NFC). Raziskovalno delo obravnava pripravo koncentratnih me{anic PHB-prahu in NFC v vodni raztopini za tehnologijo ekstruzijskega me{anja. Ekstrudat koncentrirane me{anice PHB/NFC je bil nato uporabljen kot dodatek h granulirani obliki PHB pri pripravi brizganih vzorcev z razli~nimi ute`nimi dele`i NFC. V prispevku so podane dolo~ene omejitve pri predelavi tovrstnih materialov in predlagane uporabne re{itve za njihovo optimiziranje. Morfolo{ke lastnosti nanokompozitnih komponent smo raziskali z elektronsko mikroskopijo (FE-SEM), mehanske lastnosti pa z nateznim preizkusom. Morfolo{ka preiskava koncentratnih me{anic je razkrila prepleteno sestavo celuloznih nanofibril in polimernih kroglic, prĩ emer se posamezne fibrile prepletajo v obliki {ir{ih pramenov in ustvarjajo videz zamre`ene strukture znotraj polimerne komponente. Mikroskopski posnetki nanokompozitnih me{anic in izbolj{ane mehanske lastnosti izhodnih materialov potrjujejo, da je adhezivni stik med matri~no in oja~itveno komponento dose`en, porazdelitev celuloznih nanofibril po polimerni osnovi pa homogena. Nanokompoziti z visokimi ute`nimi dele`i NFC (10 % ute`nega dele`a) dosegajo pomembno ve~je vrednosti modula elasti~nosti (Et = 1720 MPa) in raztezka pri pretrgu (eb = 3,1 %) ter prenesejo vi{je pretr`ne napetosti (sM = 26 MPa) v primerjavi z referen~nim polimernim vzorcem (Et = 1340 MPa; eb = 2,4 %; sM = 20 MPa). Rezultati {tudije dokazujejo, da je ob pravilni predpripravi polimernih me{anic in optimizaciji tehnologije ekstruzijske predelave, mogo~e izdelati trdne in`ilave materiale, pri~emer dele`oja~itvene faze narekuje stopnjo izbolj{ave kon~nih lastnosti biopolimerne osnove. Klju~ne besede: nanofibrilirana celuloza, poli(3-hidroksibutirat), morfologija, mehanske lastnosti, ekstruzija, tehnologija brizganja In this paper a novel processing route for nanocomposites, based on (3-hydroxybutyrate) (PHB) and nanofibrillated cellulose (NFC), is presented. To obtain a uniform dispersion of the reinforcing filler, a PHB powder was first dispersed in water, mixed with an NFC aqueous suspension and then freeze dried to eliminate the water phase from the ensuing system. The dried batch was then extruded and added to the granulated PHB in different weight proportions. Nanocomposites with various NFC contents were subsequently produced with the injection-moulding technology. The processing limits and feasible solutions for their optimization are thoroughly described within this work. Morphological properties were investigated with FE-SEM, while mechanical properties were determined via a tensile test. SEM images showed that the PHB powder can be effectively incorporated into the mesh of cellulose nanofibrils, as clearly evident by the interlaced structure of individual fibrils with the average lateral dimensions of 69±14 nm. Improved mechanical properties and SEM observations confirmed a good interfacial adhesion and uni...