This paper investigates the effects of fiber alignment on the flexural strength and stiffness retention of carbon-fiber-reinforced plastic (CFRP) composites produced using a 16-head automatic tape-laying machine (Fill Multilayer) and hand-laying methods. The study compares the fiber alignment and mechanical properties of coupons made by both methods, focusing on the impact of fiber misalignment on composite performance. Key findings include: 1. **Fiber Alignment**: The Fill Multilayer machine achieved a higher degree of fiber alignment (±1.68°) compared to hand-laying (±3.45°), leading to better reproducibility and mechanical properties. 2. **Flexural Strength**: Composites made with the Fill Multilayer exhibited a higher flexural strength (1218.57 ± 78.85 MPa) compared to hand-laid samples (1116.59 ± 82.39 MPa). This improvement is attributed to the reduced fiber misalignment and better fiber orientation. 3. **void Content**: Both methods resulted in similar void content, with the Fill Multilayer showing a slight increase from 3.46% to 3.78%. 4. **Dynamic Testing**: Under cyclic loading, composites made with the Fill Multilayer showed minimal stiffness degradation (1.4% decrease in modulus after 4000 cycles), compared to a higher degradation in hand-laid samples. 5. **Conclusion**: The Fill Multilayer machine significantly improves fiber alignment and mechanical properties, making it a more reliable method for producing CFRP composites. The study highlights the importance of fiber alignment in enhancing the performance of composite materials.This paper investigates the effects of fiber alignment on the flexural strength and stiffness retention of carbon-fiber-reinforced plastic (CFRP) composites produced using a 16-head automatic tape-laying machine (Fill Multilayer) and hand-laying methods. The study compares the fiber alignment and mechanical properties of coupons made by both methods, focusing on the impact of fiber misalignment on composite performance. Key findings include: 1. **Fiber Alignment**: The Fill Multilayer machine achieved a higher degree of fiber alignment (±1.68°) compared to hand-laying (±3.45°), leading to better reproducibility and mechanical properties. 2. **Flexural Strength**: Composites made with the Fill Multilayer exhibited a higher flexural strength (1218.57 ± 78.85 MPa) compared to hand-laid samples (1116.59 ± 82.39 MPa). This improvement is attributed to the reduced fiber misalignment and better fiber orientation. 3. **void Content**: Both methods resulted in similar void content, with the Fill Multilayer showing a slight increase from 3.46% to 3.78%. 4. **Dynamic Testing**: Under cyclic loading, composites made with the Fill Multilayer showed minimal stiffness degradation (1.4% decrease in modulus after 4000 cycles), compared to a higher degradation in hand-laid samples. 5. **Conclusion**: The Fill Multilayer machine significantly improves fiber alignment and mechanical properties, making it a more reliable method for producing CFRP composites. The study highlights the importance of fiber alignment in enhancing the performance of composite materials.