Sanitary Napkins

A sanitary napkin consists of multiple layers designed to keep the user dry and comfortable while absorbing menstrual fluid. The core layers handle absorption and distribution, while the outer layers focus on comfort, leak protection, and securing the pad in place.

• Main layers of assembly.
• Top sheet.

The top sheet is the layer that comes into direct contact with the skin.

• Material: Made from soft, non-woven fabrics like polypropylene or polyester, or from natural materials such as organic cotton or bamboo fiber in biodegradable options.
• Function:It is designed to be hydrophilic, meaning it allows fluid to pass through quickly into the absorbent core, leaving the surface dry and comfortable against the skin. In some pads, perforated polyethylene films are used to achieve a dry, mesh-like feel.

Acquisition and distribution layer (ADL).

This optional, but common, layer sits just beneath the top sheet.

• Material:Typically made from a thermally bonded or air-bonded composite non-woven fabric.
• Function: It works to quickly move fluid away from the top sheet and distribute it evenly across the absorbent core. This prevents fluid from pooling in one spot, maximizes the pad's absorbency, and enhances protection.

Absorbent core.

This is the heart of the pad, responsible for trapping and retaining fluid.

• Material: A blend of fluff pulp (from wood pulp) and Superabsorbent Polymer (SAP).
• Function: Fluff pulp provides bulk and helps with initial fluid intake, while SAP absorbs many times its weight in fluid, converting it into a gel to lock it away and prevent backflow under pressure. This combination allows for a thinner pad with high absorbency.

Backsheet (leak-proof layer)

The backsheet is the pad's final barrier against leaks.

• Material: Often made from a waterproof material like a polyethylene (PE) film.
• Function: This layer is impermeable to liquid, preventing menstrual fluid from leaking onto clothing. Some modern backsheets are breathable, allowing air and vapor to escape for increased comfort, but remain waterproof.

Adhesive layer and release paper

These components are critical for keeping the pad in place during use.

• Adhesive: Hot-melt, pressure-sensitive adhesive is applied to the backsheet and wings.
• Release paper: A silicone-coated paper is placed over the adhesive to protect it from contamination until the user is ready to apply the pad.
• Function: The adhesive holds the pad securely to the underwear, and the release paper ensures the adhesive remains effective until use.

Wings

Found on many types of pads, wings provide extra security and side-leak protection..

• Material: They are extensions of the top sheet and back-sheet materials, with adhesive strips on the underside.
• Function: The wings fold over the sides of underwear to provide additional protection against leaks and hold the pad firmly in place.
• Variety: Available in various sizes (e.g., small, large, extra-long) and absorbency levels to suit different needs, from light spotting to heavy flow days.

Key Features:

• Soft, Breathable Top Layer: This layer, often made from materials like organic cotton or non-woven fabric, remains dry to the touch and allows air to circulate, keeping the user comfortable.
• Absorbent Core: The core's primary function is to quickly absorb and retain menstrual fluid, preventing it from reaching the top layer and ensuring a dry feeling. Modern pads use super absorbent polymers for enhanced absorption.
• Waterproof Back Sheet: Typically made from polyethylene (PE), this layer prevents menstrual blood from leaking through the pad and onto clothing.
• Adhesive Strips: These securely attach the pad to the underwear, keeping it in place and preventing it from shifting or moving during physical activity.
• Wings: Wings extend from the sides of the pad and fold around the edges of the underwear, providing extra security and preventing leaks from the sides.
• Odor Control: Many napkins include technologies to neutralize or control odors, keeping the user feeling fresh.
• Thin and Flexible Design:Modern pads are often thin and flexible, allowing for greater comfort and discretion under clothing.
• Antimicrobial Features: Some pads incorporate antibacterial surfaces to help maintain hygiene and prevent rashes.
• Customization:Napkins are available in various sizes, shapes, and absorbency levels to cater to different needs, including heavy flow, light flow, and overnight protection.