The Influence of Perforation Shape on Fluid Intake in Sanitary Napkins

Circular Perforations: The Standard

Circular holes are the most common and the simplest to manufacture. They provide a uniform, predictable flow path with moderate capillary pressure.

• Penetration speed: Good. The circular geometry creates a stable meniscus, allowing liquid to enter smoothly.

• Anti-clogging: Moderate. The symmetrical shape is prone to blockage by gel particles or viscous fluid, as the pore can be sealed off by a single swollen SAP particle.

• Skin feel: Smooth, but the circular edges can feel slightly sharp against sensitive skin if not properly rounded.

Oval Perforations: Improved Flow and Comfort

Oval holes are elongated versions of circular perforations, providing a larger open area per pore without increasing the pore width significantly.

• Penetration speed: Excellent. The elongated shape provides a larger entry area, reducing the resistance to liquid flow.

• Anti-clogging: Good. The elongated geometry is less likely to be fully sealed by a single particle, as the pore remains partially open even when partially blocked.

• Skin feel: Softer than circular holes, as the elongated shape reduces the edge pressure against the skin.