Sanitary Napkins Raw Material Composition and Properties

# Sanitary Napkins Raw Material Composition and Properties

Sanitary napkins are essential hygiene products used by women worldwide. Understanding the raw materials that go into their production is crucial for both manufacturers and consumers. This article delves into the composition and properties of the primary materials used in sanitary napkins.

## 1. Absorbent Core

The absorbent core is the heart of a sanitary napkin, responsible for absorbing and retaining menstrual fluid. It is typically made from a blend of fluff pulp and superabsorbent polymers (SAP).

### Fluff Pulp

Fluff pulp is a type of wood pulp that is highly absorbent and soft. It is derived from softwood trees like pine and spruce. The fibers are mechanically processed to create a fluffy, airy structure that enhances absorbency.

### Superabsorbent Polymers (SAP)

SAPs are synthetic materials that can absorb and retain large amounts of liquid relative to their own mass. They are usually in the form of small granules that swell upon contact with moisture, turning into a gel-like substance. This property makes SAPs highly effective in locking away fluids and preventing leakage.

## 2. Top Sheet

The top sheet is the layer that comes into direct contact with the skin. It needs to be soft, comfortable, and quick-drying.

### Nonwoven Fabric

Nonwoven fabrics are commonly used for the top sheet. They are made from synthetic fibers like polypropylene or polyester, which are bonded together through mechanical, thermal, or chemical processes. Nonwoven fabrics are chosen for their softness, breathability, and ability to wick moisture away from the skin.

## 3. Back Sheet

The back sheet is the outermost layer of the sanitary napkin, designed to prevent leakage and provide a barrier against external moisture.

### Polyethylene Film

Polyethylene film is a popular choice for the back sheet due to its waterproof properties. It is a thin, flexible plastic film that effectively prevents menstrual fluid from seeping through. Additionally, it is lightweight and durable, making it ideal for this application.

## 4. Adhesive

Adhesives are used to secure the sanitary napkin in place within the underwear.

### Pressure-Sensitive Adhesive

Pressure-sensitive adhesives are commonly used in sanitary napkins. They are designed to stick firmly to fabric when pressure is applied, ensuring the napkin stays in place during use. These adhesives are typically made from synthetic rubber or acrylic compounds.

## 5. Release Paper

Release paper is a protective layer that covers the adhesive before use.

### Silicone-Coated Paper

Silicone-coated paper is often used as release paper. The silicone coating allows the paper to be easily peeled away from the adhesive without leaving any residue. This ensures that the adhesive remains effective until the napkin is ready to be used.

## Conclusion

The composition of sanitary napkins involves a combination of carefully selected materials, each serving a specific function to ensure comfort, absorbency, and leak protection. From the absorbent core to the top sheet and back sheet, every component plays a vital role in the overall performance of the product. Understanding these materials and their properties can help consumers make informed choices and appreciate the technology behind this essential hygiene product.