Sanitary Napkins Raw Material Composition and Properties

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# Sanitary Napkins Raw Material Composition and Properties

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

## Core Absorbent Material

The core of a sanitary napkin is designed to absorb menstrual fluid efficiently. The most commonly used materials for this purpose include:

– **Wood Pulp**: A natural, biodegradable material that provides excellent absorbency. It is often blended with synthetic materials to enhance performance.
– **Super Absorbent Polymers (SAP)**: These are synthetic materials that can absorb and retain large amounts of liquid relative to their own 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, comfortable, and allow for quick absorption of menstrual fluid. Common materials used for the top sheet include:

– **Nonwoven Fabrics**: These are made from synthetic fibers like polypropylene or polyester. They are lightweight, breathable, and provide a smooth surface.
– **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 of the sanitary napkin, designed to prevent leakage and provide a barrier against external moisture. Materials used for the back sheet include:

– **Polyethylene Film**: A waterproof plastic film that is durable and flexible. It effectively prevents leakage and keeps the napkin in place.
– **Breathable Microporous Film**: This material allows air to pass through while blocking liquids, enhancing comfort by reducing moisture buildup.

## Adhesive

Adhesives are used to keep the sanitary napkin securely in place within the underwear. The adhesive must be strong enough to hold the napkin in place but gentle enough to avoid skin irritation. Common types of adhesives include:

– **Hot Melt Adhesives**: These are thermoplastic adhesives that are applied in a molten state and solidify upon cooling. They provide a strong bond and are resistant to moisture.
– **Pressure-Sensitive Adhesives**: These adhesives form a bond when pressure is applied. They are easy to apply and remove, making them ideal for sanitary napkins.

## Additional Components

Some sanitary napkins may include additional components to enhance comfort and performance:

– **Wings**: These are extensions on the sides of the napkin that fold over the edges of the underwear to provide extra protection against leakage.
– **Fragrance**: Some napkins are infused with a light fragrance to mask menstrual odor. However, fragrances can sometimes cause irritation for sensitive skin.

## Conclusion

The composition of sanitary napkins involves a combination of natural and synthetic materials, each chosen for its specific properties to ensure comfort, absorbency, and leakage protection. Understanding these materials helps consumers make informed choices and manufacturers to innovate and improve product quality.