# Sanitary Napkins Raw Material Composition and Properties

Sanitary napkins are essential personal care products designed to provide comfort and hygiene 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 raw 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 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 provide a smooth surface.
– **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.
– **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 in place. They must be strong enough to hold the napkin in position but gentle enough to avoid skin irritation. Common types include:

– **Pressure-Sensitive Adhesives**: These are applied to the back sheet and activate upon pressure, ensuring the napkin stays in place.
– **Hot Melt Adhesives**: Used in the manufacturing process to bond different layers together.

## 5. Release Paper

Release paper is a temporary protective layer that covers 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 Raw Materials

The raw materials used in sanitary napkins must possess specific properties to ensure optimal performance:

– **Absorbency**: High absorbency is crucial for managing menstrual flow effectively.
– **Softness**: The materials must be gentle on the skin to prevent irritation and discomfort.
– **Breathability**: Good air circulation helps maintain skin health and comfort.
– **Leakage Prevention**: Effective barrier properties are essential to prevent leaks and maintain hygiene.
– **Biodegradability**: Increasingly, there is a demand for eco-friendly materials that can decompose naturally, reducing environmental impact.

In conclusion, the composition and properties of raw materials used in sanitary napkins play a vital role in their overall performance and user satisfaction. By understanding these materials, manufacturers can continue to innovate and improve the quality of these essential products.