# Sanitary Napkin Material: Composition and Properties

## Introduction to Sanitary Napkin Materials

Sanitary napkins are essential feminine hygiene products designed to absorb menstrual flow. The materials used in their construction play a crucial role in comfort, absorption, and protection. Modern sanitary napkins combine various materials to achieve optimal performance while maintaining skin health.

## Core Components of Sanitary Napkins

### 1. Top Sheet (Cover Stock)

The top layer that comes in direct contact with the skin is typically made from:

– Non-woven polypropylene (most common)
– Perforated plastic film
– Cotton or cotton blends (for organic options)

This layer needs to be soft, breathable, and quick-drying to prevent irritation.

### 2. Absorbent Core

The middle layer responsible for fluid absorption consists of:

– Fluff pulp (wood cellulose)
– Superabsorbent polymers (SAP)
– Combination of both materials

SAP can absorb many times its weight in liquid, transforming it into a gel to prevent leakage.

### 3. Back Sheet

The waterproof bottom layer is usually made from:

– Polyethylene film
– Breathable microporous film
– Biodegradable materials in eco-friendly options

This layer prevents leakage while allowing some breathability in premium products.

### 4. Adhesive Components

– Pressure-sensitive adhesive for attachment to underwear
– Release paper to protect adhesive before use

## Specialized Materials and Features

### Odor Control Additives

Some sanitary napkins incorporate:

– Activated charcoal
– Baking soda
– Antimicrobial agents

### Wing Materials

Winged napkins use elastic materials like:

– Polyurethane
– Elastic non-woven fabrics

### Organic and Natural Options

Eco-conscious products may use:

– Organic cotton
– Bamboo fiber
– Biodegradable PLA (polylactic acid) films

## Material Properties and Performance

Key material characteristics include:

– Absorption capacity (grams of fluid per gram of material)
– Wicking rate (how quickly fluid spreads)
– Retention ability (preventing fluid from being released under pressure)
– Breathability (measured in moisture vapor transmission rate)
– Softness (measured by various textile testing methods)

## Environmental Considerations

Manufacturers are increasingly focusing on:

– Biodegradable materials
– Reduced plastic content
– Sustainable sourcing
– Compostable options

The choice of materials significantly impacts both performance and environmental footprint, driving innovation in sanitary product development.