。

# Sanitary Napkins Raw Material Composition and Properties

Sanitary napkins, commonly known as sanitary pads, are essential hygiene products used by women during menstruation. Understanding the raw materials used in their production is crucial for ensuring comfort, 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 most critical component of a sanitary napkin. It is responsible for absorbing and retaining menstrual fluid. The core is typically made from a combination of the following materials:

– **Cellulose Fluff Pulp**: This is the primary absorbent material, derived from wood pulp. It is highly absorbent and provides the bulk of the pad’s absorbency.
– **Superabsorbent Polymers (SAP)**: These are synthetic materials that can absorb and retain large amounts of liquid relative to their mass. SAP enhances the absorbency of the core, preventing leakage.

## 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 used for the top sheet include:

– **Nonwoven Fabrics**: These are made from synthetic fibers like polypropylene or polyethylene. They are soft, breathable, and allow for rapid liquid transfer to the absorbent core.
– **Perforated Films**: Some pads use perforated plastic films as the top sheet. These films are designed to be soft and allow for quick absorption while preventing the liquid from flowing back to the surface.

## 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 for the back sheet include:

– **Polyethylene Films**: These are thin, flexible, and waterproof, making them ideal for preventing leakage.
– **Breathable Microporous Films**: These films allow for air circulation while still providing a moisture barrier, enhancing comfort and reducing the risk of skin irritation.

## 4. Adhesive

Adhesives are used to secure the sanitary napkin to the underwear. The adhesive must be strong enough to keep the pad in place but gentle enough to avoid damaging the fabric. Common types of adhesives include:

– **Hot Melt Adhesives**: These are applied in a molten state and solidify upon cooling, providing a strong bond.
– **Pressure-Sensitive Adhesives**: These adhesives form a bond when pressure is applied, making them easy to use and remove.

## 5. Release Paper

The release paper is a protective layer that covers the adhesive before use. It is typically made from:

– **Silicone-Coated Paper**: This paper is treated with silicone to prevent the adhesive from sticking to it, allowing for easy removal when the pad is ready to be used.

## Properties of Sanitary Napkin Raw Materials

The raw materials used in sanitary napkins must possess specific properties to ensure the product’s effectiveness and user comfort:

– **Absorbency**: High absorbency is crucial for preventing leakage and ensuring long-lasting protection.
– **Softness**: The materials must be soft to prevent irritation and provide comfort during use.
– **Breathability**: Breathable materials help reduce the risk of skin irritation and discomfort.
– **Flexibility**: The materials should be flexible to conform to the body’s shape, ensuring a secure fit.
– **Hypoallergenic**: The materials should be hypoallergenic to minimize the risk of allergic reactions.

In conclusion, the composition and properties of the raw materials used in sanitary napkins play a vital role in determining the product’s performance and user satisfaction. By carefully selecting and combining these materials, manufacturers can produce sanitary napkins that offer superior comfort, protection, and reliability.