Sanitary Napkins Raw Material Composition and Properties

# Sanitary Napkins Raw Material Composition and Properties

Sanitary napkins 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 a soft texture.
– **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 polyester. They are lightweight, breathable, and provide a smooth surface.
– **Perforated Film**: Some sanitary napkins use a thin, perforated plastic film as the top sheet. This material is highly effective in preventing backflow and 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 Film**: This is a common material due to its waterproof properties and flexibility. It ensures that the menstrual fluid does not seep through to clothing.
– **Breathable Microporous Film**: Some high-end sanitary napkins use breathable films that allow air to pass through while blocking liquids, enhancing comfort.

## 4. Adhesive

Adhesives are used to secure the sanitary napkin to the underwear. The adhesive must be strong enough to hold the napkin in place but gentle enough to be removed without leaving residue. 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

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 any residue on the adhesive.

## 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 moisture buildup, minimizing the risk of skin irritation and infections.
– **Flexibility**: The materials should be flexible to conform to the body’s shape, ensuring a secure fit.
– **Hypoallergenic**: The materials should be hypoallergenic to prevent allergic reactions and skin sensitivities.

In conclusion, the raw materials used in sanitary napkins are carefully selected to provide optimal absorbency, comfort, and protection. Understanding the composition and properties of these materials helps in appreciating the technology and innovation behind this essential hygiene product.