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:

– **Cellulose Fibers**: Derived from wood pulp, these fibers are highly absorbent and provide the bulk of the core.
– **Superabsorbent Polymers (SAP)**: These are synthetic materials that can absorb and retain large amounts of liquid relative to their own mass. SAPs enhance the absorbency of the core, preventing leakage.

### Properties:
– **High Absorbency**: The core must efficiently absorb and retain menstrual fluid to prevent leakage.
– **Softness**: Comfort is key, so the core should be soft to the touch.
– **Breathability**: Good air circulation helps reduce the risk of irritation and discomfort.

## 2. Top Sheet

The top sheet is the layer that comes into direct contact with the skin. It is designed to be soft, comfortable, and quick-drying. Common materials include:

– **Nonwoven Fabrics**: Made from synthetic fibers like polypropylene or polyethylene, these fabrics are soft, breathable, and allow for quick liquid transfer to the absorbent core.
– **Perforated Films**: These are thin plastic films with tiny holes that allow liquid to pass through while keeping the surface dry.

### Properties:
– **Softness**: The top sheet should be gentle on the skin to prevent irritation.
– **Quick-Drying**: It should allow menstrual fluid to pass through quickly, keeping the surface dry.
– **Hypoallergenic**: Materials should be non-irritating and suitable for sensitive skin.

## 3. Back Sheet

The back sheet is the outermost layer of the sanitary napkin, designed to prevent leakage and provide a barrier against moisture. It is usually made from:

– **Polyethylene Film**: A thin, flexible plastic film that is waterproof and prevents leakage.
– **Nonwoven Fabrics**: Sometimes used for a softer, more breathable back sheet.

### Properties:
– **Waterproof**: The back sheet must effectively prevent any leakage.
– **Flexibility**: It should be flexible enough to conform to the body’s shape for comfort.
– **Durability**: The material should be strong enough to withstand movement without tearing.

## 4. Adhesive

Adhesives are used to secure the sanitary napkin in place. They are typically applied to the back sheet and include:

– **Pressure-Sensitive Adhesives**: These adhesives stick to the underwear when pressure is applied and can be removed without leaving residue.
– **Hot Melt Adhesives**: Used in the manufacturing process to bond different layers together.

### Properties:
– **Strong Adhesion**: The adhesive must securely hold the napkin in place.
– **Residue-Free Removal**: It should not leave any sticky residue on clothing.
– **Skin-Friendly**: The adhesive should be safe for skin contact and not cause irritation.

## 5. Release Paper

Release paper is used to protect the adhesive before use. It is typically made from:

– **Silicone-Coated Paper**: This paper is easy to peel off and does not stick to the adhesive.

### Properties:
– **Easy Removal**: The release paper should be easy to peel off without tearing.
– **Non-Stick**: It should not stick to the adhesive, ensuring easy application.

## Conclusion

The raw materials used in sanitary napkins are carefully selected to ensure comfort, absorbency, and leak protection. Each component, from the absorbent core to the adhesive, plays a vital role in the overall performance of the product. Understanding these materials