# Sanitary Napkins Raw Material Composition and Properties

Sanitary napkins are essential personal care products designed to provide comfort and hygiene during menstruation. Understanding the raw materials used in their production is crucial for ensuring quality, safety, and effectiveness. This article delves into the composition and properties of the primary raw materials used in sanitary napkins.

## Core Absorbent Material

The core of a sanitary napkin is responsible for absorbing menstrual fluid. The most commonly used materials include:

– **Wood Pulp**: A natural, biodegradable material that provides excellent absorbency. It is often blended with synthetic fibers to enhance performance.
– **Super Absorbent Polymers (SAP)**: These are synthetic materials that can absorb and retain large amounts of liquid relative to their mass. SAPs are highly effective in preventing leakage.

## Top Sheet

The top sheet is the layer that comes into direct contact with the skin. It must be soft, non-irritating, and allow for quick liquid penetration. Common materials include:

– **Nonwoven Fabrics**: Made from synthetic fibers like polypropylene or polyester, these fabrics are designed to be soft and breathable.
– **Perforated Film**: A thin, flexible plastic film with tiny holes that allow liquid to pass through while keeping the surface dry.

## Back Sheet

The back sheet is the outermost layer that prevents leakage and provides a barrier to moisture. Materials used include:

– **Polyethylene Film**: A waterproof plastic film that is lightweight and flexible.
– **Breathable Microporous Film**: Allows air to pass through while blocking liquids, enhancing comfort.

## Adhesives

Adhesives are used to secure the sanitary napkin in place. They must be strong enough to hold the pad in position but gentle enough to avoid skin irritation. Common types include:

– **Hot Melt Adhesives**: These are applied in a molten state and solidify upon cooling, providing a strong bond.
– **Pressure-Sensitive Adhesives**: These adhere to surfaces upon application of light pressure and are commonly used for the wings of sanitary napkins.

## Additives and Fragrances

Some sanitary napkins include additives for additional benefits:

– **Antibacterial Agents**: These help to reduce the risk of infections by inhibiting bacterial growth.
– **Fragrances**: Added to mask odors, though they can sometimes cause irritation for sensitive skin.

## Environmental Considerations

With increasing awareness of environmental issues, manufacturers are exploring eco-friendly alternatives:

– **Biodegradable Materials**: Such as bamboo fibers and organic cotton, which break down more easily in the environment.
– **Recycled Materials**: Using recycled plastics and fibers to reduce waste and resource consumption.

## Conclusion

The composition of sanitary napkins involves a combination of natural and synthetic materials, each selected for its specific properties to ensure comfort, absorbency, and protection. As consumer preferences and environmental concerns evolve, the industry continues to innovate, seeking sustainable and effective solutions for menstrual hygiene products.