Sanitary Napkins Raw Material Composition and Properties

# 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 and safety. This article delves into the composition and properties of the primary materials used in sanitary napkins.

## 1. Absorbent Core

The absorbent core is the heart of a sanitary napkin, responsible for absorbing menstrual fluid. It is typically made from a combination of the following materials:

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

## 2. 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 liquid transfer to the absorbent core. Common materials include:

– **Nonwoven Fabrics**: Made from synthetic fibers like polypropylene or polyester, nonwoven fabrics are lightweight, breathable, and soft to the touch.
– **Perforated Film**: Some sanitary napkins use a thin, perforated plastic film as the top sheet, which provides a smooth surface and quick liquid transfer.

## 3. Back Sheet

The back sheet is the outermost layer of the sanitary napkin, designed to prevent leakage and provide a barrier against moisture. Materials used include:

– **Polyethylene Film**: A thin, flexible plastic film that is waterproof and provides an effective barrier against leaks.
– **Breathable Microporous Film**: This material allows air to pass through while preventing liquid from escaping, enhancing comfort and reducing the risk of skin irritation.

## 4. Adhesive

Adhesives are used to secure the sanitary napkin in place. They must be strong enough to hold the napkin 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 adhesives are activated by pressure and are commonly used on the wings of sanitary napkins to secure them to underwear.

## 5. Fragrance and Additives

Some sanitary napkins include fragrances or additives to enhance user experience. However, these components can sometimes cause skin irritation or allergic reactions. Common additives include:

– **Fragrance Oils**: Added to mask odors, but may not be suitable for sensitive skin.
– **Aloe Vera or Chamomile**: Natural additives that can provide a soothing effect, though their efficacy varies.

## Conclusion

The composition of sanitary napkins involves a careful balance of materials to ensure comfort, absorbency, and leak protection. Understanding the properties of these raw materials helps in making informed choices and ensures the production of high-quality, safe products for menstrual hygiene.