Sanitary Napkins Raw Material Composition and Properties

# Sanitary Napkins Raw Material Composition and Properties

## Introduction to Sanitary Napkins

Sanitary napkins, also known as menstrual pads, are essential hygiene products used by women during menstruation. They are designed to absorb menstrual flow and provide comfort and protection. The effectiveness of a sanitary napkin largely depends on the quality and composition of its raw materials. Understanding the materials used in sanitary napkins can help consumers make informed choices and appreciate the technology behind these everyday products.

## Core Components of Sanitary Napkins

Sanitary napkins are composed of several layers, each serving a specific function. The primary materials used in the production of sanitary napkins include:

### 1. Top Sheet

The top sheet is the layer that comes into direct contact with the skin. It is typically made from a non-woven fabric or a perforated film. The material is chosen for its softness, breathability, and ability to quickly transfer liquid to the absorbent core. Common materials include polyethylene or polypropylene.

### 2. Absorbent Core

The absorbent core is the most crucial part of the sanitary napkin, responsible for absorbing and retaining menstrual fluid. It is usually made from a blend of wood pulp and superabsorbent polymers (SAP). The wood pulp provides bulk and structure, while the SAP enhances the absorbency by turning liquid into gel.

### 3. Back Sheet

The back sheet is the outermost layer of the sanitary napkin, designed to prevent leakage. It is typically made from a waterproof material such as polyethylene. This layer ensures that the absorbed fluid does not seep through to the user’s clothing.

### 4. Adhesive

Adhesive is applied to the back sheet to keep the sanitary napkin securely in place within the underwear. The adhesive is usually a pressure-sensitive type that is strong enough to hold the pad in place but gentle enough to be removed without leaving residue.

### 5. Release Paper

The release paper is a protective layer that covers the adhesive before use. It is usually made from silicone-coated paper or film, which allows it to be easily peeled off when the pad is ready to be used.

## Properties of Sanitary Napkin Materials

The materials used in sanitary napkins are selected based on several key properties:

### 1. Absorbency

The ability to absorb and retain menstrual fluid is the most critical property. The combination of wood pulp and SAP in the absorbent core ensures high absorbency and quick liquid transfer.

### 2. Softness

The top sheet must be soft and gentle on the skin to prevent irritation and discomfort. Non-woven fabrics and perforated films are chosen for their soft texture.

### 3. Breathability

Breathability is essential to prevent moisture buildup and maintain skin health. The top sheet and back sheet materials are designed to allow air circulation while keeping the skin dry.

### 4. Leakage Protection

The back sheet must be impermeable to liquids to prevent leakage. Polyethylene is commonly used for its waterproof properties.

### 5. Adhesion

The adhesive must provide a secure hold without causing discomfort or leaving residue. Pressure-sensitive adhesives are preferred for their balance of strength and ease of removal.

## Environmental Considerations

With increasing awareness of environmental issues, there is a growing demand for eco-friendly sanitary napkins. Manufacturers are exploring biodegradable materials and reducing the use of plastics in their products. Some brands now offer pads made from organic cotton, bamboo fibers, and other sustainable materials.

## Conclusion

The composition and properties of sanitary napkin materials play a vital role in their performance and user comfort. By understanding the different layers and their functions, consumers can make more informed choices and appreciate the technology behind these essential hygiene products. As the industry evolves, we can expect to see more innovations aimed at improving both performance and environmental sustainability.