gujs part c Gazi Üniversitesi Fen Bilimleri Dergisi Part C: Tasarım ve Teknoloji 2147-9526 Gazi University 10.29109/gujsc.1747040 Composite and Hybrid Materials Polymers and Plastics Kompozit ve Hibrit Malzemeler Polimerler ve Plastikler Layer-Paused FFF-Based Manufacturing of PLA-Hemp Composites: Mechanical Behavior and Failure Morphology Katman Duraklamalı FFF Tabanlı PLA-Kenevir Kompozit Üretimi: Mekanik Davranış ve Hasar Morfolojisi https://orcid.org/0000-0001-9644-3663 Karaca Muhammet Mevlüt KARABÜK ÜNİVERSİTESİ https://orcid.org/0000-0001-8025-8236 Öztürk Fatih Huzeyfe KARABÜK ÜNİVERSİTESİ, MÜHENDİSLİK FAKÜLTESİ 12 31 2025 13 4 1431 1440 07 21 2025 09 29 2025 Copyright © 2013, Gazi University Journal of Science Part C: Design and Technology 2013 Gazi University Journal of Science Part C: Design and Technology

In this study, polylactic acid (PLA)-hemp composite samples were fabricated using a layer-paused fused filament fabrication (FFF) method, in which natural hemp fibers were manually inserted into pre-designed internal channels generated via computer-aided design (CAD). The novelty of this work lies in the introduction of a simple yet effective manufacturing approach that enables the direct integration of continuous natural fibers into the FFF process without requiring filament modification. This approach allows controlled fiber alignment and improved structural performance while maintaining the accessibility and sustainability of the FFF technique. Mechanical testing revealed that hemp fiber reinforcement increased the maximum tensile force from 1545 N to 1999 N (30%), while the displacement at maximum force decreased from 7.8 mm to 7.2 mm (8.7%), indicating a moderate reduction in ductility. Scanning electron microscopy (SEM) further confirmed the presence of fiber pull-out and interfacial separation as dominant fracture mechanisms. These results highlight the potential of the proposed method for advancing sustainable natural fiber-reinforced composites produced via additive manufacturing.

Bu çalışmada, bilgisayar destekli tasarım (CAD) ile oluşturulan önceden tasarlanmış iç kanallara doğal kenevir liflerinin elle yerleştirilmesiyle, katman duraklatmalı ergitilmiş filament imalatı (FFF) yöntemi kullanılarak polilaktik asit (PLA)-kenevir kompozit numuneleri üretilmiştir. Bu çalışmanın yeniliği, filament modifikasyonu gerektirmeksizin sürekli doğal liflerin doğrudan FFF sürecine entegre edilmesine olanak tanıyan basit ancak etkili bir üretim yaklaşımının sunulmasıdır. Bu yaklaşım, lif yönelimini kontrol edilebilir kılmakta ve yapısal performansı iyileştirirken FFF tekniğinin erişilebilirliğini ve sürdürülebilirliğini korumaktadır. Mekanik testler, kenevir lifi takviyesinin maksimum çekme kuvvetini 1545 N’den 1999 N’ye (%30) artırdığını, maksimum kuvvette yer değiştirme değerini ise 7.8 mm’den 7.2 mm’ye (%8,7) düşürdüğünü ortaya koymuş, bu durum süneklilikte orta düzeyde bir azalmaya işaret etmiştir. Taramalı elektron mikroskobu (SEM) analizleri, baskın kırılma mekanizmaları olarak lif çekilmesi ve ara yüzey ayrılmasının varlığını doğrulamıştır. Elde edilen sonuçlar, önerilen yöntemin eklemeli imalat ile sürdürülebilir doğal lif takviyeli kompozitlerin geliştirilmesi açısından potansiyelini vurgulamaktadır.

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