Sanitary Napkins Raw Material Composition and Properties

# Sanitary Napkins Raw Material Composition and Properties

Sanitary napkins, also known as sanitary pads, are essential hygiene products used by women during menstruation. Understanding the raw materials used in their production is crucial for ensuring quality, comfort, and safety. This article delves into the composition and properties of the primary raw 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**: This is the most common material used in the absorbent core. It is highly absorbent and helps in retaining fluid.
– **Super Absorbent Polymer (SAP)**: SAP is a synthetic material that can absorb and retain large amounts of liquid relative to its own mass. It is often mixed with wood pulp to enhance the absorbency of the core.

### Properties:
– **High Absorbency**: The combination of wood pulp and SAP ensures that the core can absorb a significant amount of fluid.
– **Retention**: The materials used in the core are designed to retain the absorbed fluid, preventing leakage.
– **Softness**: The core is designed to be soft and comfortable against the skin.

## 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 used for the top sheet include:

– **Nonwoven Fabric**: This is a fabric-like material made from fibers bonded together by chemical, mechanical, heat, or solvent treatment. It is soft, breathable, and allows for quick absorption of fluid.
– **Perforated Film**: Some sanitary napkins use a perforated plastic film as the top sheet. This material is less breathable but provides a smooth surface that can feel dry even when wet.

### Properties:
– **Softness**: The top sheet is designed to be gentle on the skin, reducing the risk of irritation.
– **Quick-Drying**: The material allows for rapid absorption of fluid, keeping the surface dry.
– **Breathability**: Nonwoven fabrics are breathable, which helps in maintaining skin health.

## 3. Back Sheet

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

– **Polyethylene Film**: This is a thin, flexible plastic film that is impermeable to liquids. It is commonly used as the back sheet to prevent leakage.
– **Nonwoven Fabric**: Some sanitary napkins use a nonwoven fabric as the back sheet, which is more breathable but less effective at preventing leakage compared to polyethylene film.

### Properties:
– **Leakage Prevention**: The back sheet is designed to be impermeable to liquids, ensuring that menstrual fluid does not leak through.
– **Flexibility**: The material is flexible, allowing the sanitary napkin to conform to the body’s shape.
– **Durability**: The back sheet is durable and resistant to tearing, ensuring the integrity of the sanitary napkin during use.

## 4. Adhesive

The adhesive is used to secure the sanitary napkin to the underwear. It is typically applied to the back sheet and is designed to be strong enough to hold the pad in place but gentle enough to be easily removed without leaving residue.

### Properties:
– **Strong Adhesion**: The adhesive must be strong enough to keep the sanitary napkin in place during movement.
– **Residue-Free Removal**: The adhesive should not leave any residue on the underwear after removal.
– **Skin-Friendly**: The adhesive should be hypoallergenic and safe for contact with the skin.

## 5. Release Paper

The release paper is a protective layer that covers the adhesive before use. It is typically made from silicone-coated paper or film.

### Properties:
– **