The following table compares the quantitative standards and characteristics of the four primary flute types:
A-Flute: Flute height: 4.5–5.0 mm; Flute count: 34 ± 2 flutes per 300 mm. Characteristics: Offers excellent cushioning and resilience, along with high vertical compressive strength; ideal for packaging fragile items.
B-Flute: Flute height: 2.5–3.0 mm; Flute count: 50 ± 2 flutes per 300 mm. Characteristics: Features high rigidity and a smooth surface, providing strong flat-crush resistance; suitable for packaging rigid products such as canned goods and small hardware items.
C-Flute: Flute height: 3.5–4.0 mm; Flute count: 38 ± 2 flutes per 300 mm. Characteristics: Its performance falls between that of A-flute and B-flute, offering a balanced combination of both good rigidity and effective cushioning.
E-Flute: Flute height: 1.1–2.0 mm; Flute count: 96 ± 4 flutes per 300 mm. Characteristics: Thin yet dense, possessing high rigidity and an exceptionally smooth surface; ideal for high-quality printing (often used as outer packaging for electronic products).
Flute Profiles and Multi-Layer Combinations
In addition to the specifications listed above, flute types are further defined by two key dimensions: the flute profile (waveform shape) and the combination of layers:
Flute Profile (V-shape, U-shape, UV-shape): Early V-shaped profiles offered strong compressive resistance but lacked resilience (poor spring-back); U-shaped profiles provided excellent elasticity but were slightly weaker in compressive strength. Current industry standards predominantly utilize the UV-shaped profile, which combines the advantages of both; this ensures robust compressive strength while maintaining excellent bonding strength and elasticity.
Multi-Layer Structural Combinations: Single flute types are typically used in three-layer (single-wall) corrugated boards. To balance the requirements for both load-bearing capacity and cushioning, five-layer (double-wall) boards often employ combinations such as AB-flute or BC-flute configurations—for instance, utilizing the B-flute for the outer layer to provide compressive resistance, while using the A-flute for the inner layer to provide cushioning.
Corrugated cardboard carton box manufacturing machine prices
