Sanitary Napkins Raw Material Composition and Properties

# Sanitary Napkins Raw Material Composition and Properties

Sanitary napkins are essential personal hygiene products used by women during menstruation. Understanding the raw materials used in their production is crucial for ensuring quality, comfort, and safety. This article delves into the composition and properties of the primary 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:

– **Wood Pulp**: A natural 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 highly effective in 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 polyester. They are designed to be soft, breathable, and quick-drying.
– **Perforated Films**: Some sanitary napkins use perforated plastic films as the top sheet. These films are designed to allow liquid to pass through quickly 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 for the back sheet include:

– **Polyethylene Films**: These are thin, flexible, and waterproof, making them ideal for preventing leaks.
– **Breathable Films**: Some high-end sanitary napkins use breathable films that allow air to circulate while still providing a moisture barrier.

## 4. Adhesive

Adhesives are used to keep the sanitary napkin in place within the underwear. The adhesive must be strong enough to hold the pad securely but gentle enough to avoid skin irritation. 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 are designed to stick firmly when pressure is applied, such as when the pad is pressed onto the underwear.

## 5. Release Paper

Release paper is used to cover the adhesive before the sanitary napkin is used. It is typically made from:

– **Silicone-Coated Paper**: This type of paper is easy to peel off and does not leave residue on the adhesive.

## Properties of Sanitary Napkin Materials

The materials used in sanitary napkins must possess several key properties to ensure they function effectively:

– **Absorbency**: The ability to absorb and retain liquid is paramount. Materials like wood pulp and SAP are chosen for their high absorbency.
– **Softness**: The top sheet must be soft to prevent irritation and ensure comfort during use.
– **Breathability**: Breathable materials help reduce the risk of skin irritation and discomfort by allowing air to circulate.
– **Leakage Prevention**: The back sheet and absorbent core must work together to prevent any leakage, ensuring the user remains dry and comfortable.
– **Hypoallergenic**: Materials should be hypoallergenic to minimize the risk of allergic reactions or skin irritation.

In conclusion, the composition and properties of the raw materials used in sanitary napkins are carefully selected to provide comfort, safety, and effectiveness. Understanding these materials helps consumers make informed choices and ensures the production of high-quality menstrual hygiene products.