# 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 layers of specialized materials to achieve optimal performance.

## Core Material Components

### Top Layer (Cover Stock)

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

– Non-woven fabric (polypropylene or polyethylene)
– Perforated plastic film
– Cotton or cotton blends

This layer needs to be soft, breathable, and quick-drying to maintain comfort.

### Absorbent Core

The absorbent core usually consists of:

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

The SAP can absorb many times its weight in liquid, while the fluff pulp helps distribute the fluid evenly.

### Back Sheet

The back sheet is typically made from:

– Polyethylene film

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

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

## Additional Components

### Adhesive Strips

Most sanitary napkins include:

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

### Wings (in winged designs)

Winged sanitary napkins may feature:

– Additional non-woven fabric extensions
– Extra adhesive on the wings for secure fit

## Material Properties and Performance

### Absorption Capacity

Modern sanitary napkins can absorb between 10 to 50 times their weight in fluid, depending on:

– SAP concentration
– Core thickness
– Material quality

### Breathability

High-quality products offer:

– Moisture vapor transmission rates up to 3000 g/m²/24h
– Reduced skin irritation and discomfort

### Antibacterial Properties

Some premium sanitary napkins incorporate:

– Silver nanoparticles
– Plant-based antimicrobial agents
– Odor-control technologies

## Environmental Considerations

Recent developments include:

– Biodegradable top sheets from bamboo or corn starch
– Compostable back sheets
– Reduced plastic content
– Organic cotton options

## Conclusion

The material composition of sanitary napkins has evolved significantly, offering improved comfort, absorption, and environmental sustainability. Understanding these materials helps consumers make informed choices based on their needs and preferences.