Sanitary Napkins Raw Material Composition and Properties

# Sanitary Napkins Raw Material Composition and Properties

Sanitary napkins are essential personal hygiene products used by women worldwide. 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 materials used in sanitary napkins.

## 1. Absorbent Core

The absorbent core is the most critical component of a sanitary napkin. It is responsible for absorbing and retaining menstrual fluid. The core is typically made from a blend of the following materials:

– **Wood Pulp**: A natural, biodegradable material that provides excellent absorbency.
– **Super Absorbent Polymer (SAP)**: A synthetic material that can absorb and retain large amounts of liquid relative to its mass.
– **Airlaid Paper**: A lightweight, highly absorbent material made from wood pulp fibers.

### Properties of the Absorbent Core

– **High Absorbency**: The core must efficiently absorb menstrual fluid to prevent leakage.
– **Softness**: It should be soft to ensure comfort during use.
– **Biodegradability**: Natural materials like wood pulp are environmentally friendly.

## 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**: Made from synthetic fibers like polypropylene, it is soft, breathable, and quick-drying.
– **Perforated Film**: A thin, flexible film with tiny holes that allow liquid to pass through while keeping the surface dry.

### Properties of the Top Sheet

– **Softness**: Ensures comfort and prevents irritation.
– **Breathability**: Allows air circulation to keep the skin dry.
– **Quick-Drying**: Prevents a wet feeling and enhances comfort.

## 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 commonly used for the back sheet include:

– **Polyethylene Film**: A waterproof, flexible material that prevents leakage.
– **Nonwoven Fabric**: Sometimes used for its breathability and softness.

### Properties of the Back Sheet

– **Waterproof**: Prevents menstrual fluid from leaking through.
– **Flexibility**: Allows the napkin to conform to the body for a secure fit.
– **Breathability**: Some back sheets are designed to allow air circulation, reducing the risk of skin irritation.

## 4. Adhesive

Adhesive is used to secure the sanitary napkin to the underwear. It is typically applied to the back sheet and must be strong enough to hold the napkin in place without causing discomfort or leaving residue. Common types of adhesive include:

– **Hot Melt Adhesive**: A thermoplastic adhesive that provides strong bonding.
– **Pressure-Sensitive Adhesive**: Adheres firmly when pressure is applied.

### Properties of Adhesive

– **Strong Bonding**: Ensures the napkin stays in place during use.
– **Residue-Free**: Should not leave any sticky residue on clothing.
– **Skin-Friendly**: Should not cause irritation or allergic reactions.

## 5. Release Paper

Release paper is used to protect the adhesive before the sanitary napkin is used. It is typically made from silicone-coated paper or film, which allows it to be easily peeled off without damaging the adhesive.

### Properties of Release Paper

– **Easy Removal**: Should peel off smoothly without tearing.
– **Protective**: Keeps the adhesive clean and effective until use.
– **Durable**: Should not tear or break during handling.

## Conclusion

The raw materials used in sanitary napkins play a vital role in their performance, comfort, and safety. From the absorbent core to the adhesive, each component is carefully selected and engineered to meet the needs of users. Understanding these materials and their properties can help consumers make informed choices and appreciate