In material extrusion additive manufacturing, extrusion throughput and bead shape are key factors affecting deposition quality and productivity. This study investigated the effects of melt index (MI) and glass fiber (GF) reinforcement on the extrusion behavior of HDPE-based materials. Three neat HDPE materials and two HDPE+GF composites with different MI values were extruded under identical conditions, and their extrusion throughput, bead thickness, and shape stability were evaluated. The results showed that the average extrusion throughput increased with increasing MI, whereas bead thickness decreased. The HDPE+GF composites exhibited better shape stability than neat HDPE; however, brittle fracture behavior was observed under bending deformation. These findings suggest that the extrusion throughput, bead shape, and shape stability of HDPE-based materials should be evaluated in advance according to MI and GF reinforcement before applying them to material extrusion additive manufacturing.

Abstract
1. 서 론
2. 재료 및 방법
    2.1 재 료
    2.2 압출 장치 및 실험 조건
    2.3 압출량 측정 방법
3. 결과 및 고찰
    3.1 압출 비드 형상 평가 결과
    3.2 MI에 따른 평균 압출량 변화
    3.3 MI에 따른 압출 비드 두께 측정 결과
4. 결 론
후 기
References

• 우수성(Korea Institute of Industrial Technology) | Suseong Woo
• 신원종(Korea Institute of Industrial Technology) | Wonjong Shin
• 김지선(Korea Institute of Industrial Technology, Senior Researcher) | Jisun Kim Corresponding author