Blog

# Sanitary Napkins Raw Material Composition and Properties

Sanitary napkins are essential feminine hygiene products designed to provide comfort and protection during menstruation. Understanding the raw materials used in their production is crucial for ensuring quality, safety, and effectiveness. 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 menstrual fluid. It is typically made from a combination of the following materials:

– **Wood Pulp**: A natural, biodegradable material that provides excellent absorbency. It is often blended with synthetic fibers to enhance performance.
– **Superabsorbent Polymers (SAP)**: These are synthetic materials that can absorb and retain large amounts of liquid relative to their own mass. SAPs are crucial for preventing leakage and ensuring long-lasting dryness.

## 2. Top Sheet

The top sheet is the layer that comes into direct contact with the skin. It must be soft, comfortable, and allow for quick liquid penetration. Common materials include:

– **Nonwoven Fabrics**: Made from synthetic fibers like polypropylene or polyester, nonwoven fabrics are lightweight, breathable, and gentle on the skin.
– **Perforated Films**: These are thin plastic films with tiny holes that allow liquid to pass through while keeping the surface dry.

## 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 used include:

– **Polyethylene Films**: These are waterproof and provide an effective barrier against leaks. They are also flexible and comfortable to wear.
– **Breathable Films**: These allow air to pass through while still preventing liquid leakage, enhancing comfort and reducing the risk of irritation.

## 4. Adhesive

Adhesives are used to secure the sanitary napkin to the underwear. They must be strong enough to hold the pad in place but gentle enough to avoid skin irritation. Common types include:

– **Hot Melt Adhesives**: These are applied in a molten state and solidify upon cooling, providing a strong bond.
– **Pressure-Sensitive Adhesives**: These adhere to surfaces upon application of light pressure and are easy to remove without leaving residue.

## 5. Release Paper

Release paper is used to protect the adhesive before use. It is typically made from:

– **Silicone-Coated Paper**: This type of paper is easy to peel off and ensures that the adhesive remains intact until the napkin is ready to be used.

## Properties of Sanitary Napkin Materials

The materials used in sanitary napkins must possess specific properties to ensure they perform effectively:

– **Absorbency**: The ability to quickly absorb and retain menstrual fluid is paramount. This is primarily achieved through the absorbent core and SAPs.
– **Softness**: The top sheet must be soft and gentle to prevent irritation and ensure comfort during use.
– **Breathability**: Materials should allow air to circulate to reduce the risk of skin irritation and discomfort.
– **Leakage Protection**: The back sheet and adhesive must work together to prevent leaks and keep the user dry.
– **Biodegradability**: With increasing environmental concerns, there is a growing demand for biodegradable materials that minimize environmental impact.

In conclusion, the composition and properties of sanitary napkin materials are carefully selected to provide comfort, protection, and reliability. Advances in material science continue to improve the performance and sustainability of these essential hygiene products.