Sanitary Napkins Raw Material Composition and Properties

# Sanitary Napkins Raw Material Composition and Properties

Sanitary napkins, also known as menstrual pads, are essential hygiene products used by women during menstruation. Understanding the raw materials used in their production and their properties is crucial for ensuring comfort, safety, and effectiveness. This article delves into the composition and properties of the raw materials commonly used in sanitary napkins.

## Core Absorbent Material

The core of a sanitary napkin is designed to absorb menstrual fluid efficiently. The primary materials used in the core include:

– **Wood Pulp**: Wood pulp is a common absorbent material due to its high absorbency and cost-effectiveness. It is often blended with other materials to enhance its performance.
– **Super Absorbent Polymer (SAP)**: SAP is a synthetic material that can absorb and retain large amounts of liquid relative to its own mass. It is typically used in conjunction with wood pulp to improve the overall absorbency of the napkin.

## Top Sheet Material

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

– **Nonwoven Fabric**: Nonwoven fabrics are made from synthetic fibers such as polypropylene or polyester. They are lightweight, soft, and allow for rapid liquid transfer to the absorbent core.
– **Perforated Film**: Some sanitary napkins use a perforated film as the top sheet. This material is designed to be soft and smooth while allowing menstrual fluid to pass through quickly.

## Back Sheet Material

The back sheet is the outermost layer of the sanitary napkin, designed to prevent leakage and provide a barrier against moisture. Common materials used for the back sheet include:

– **Polyethylene Film**: Polyethylene is a widely used material for the back sheet due to its waterproof properties and flexibility. It effectively prevents leakage and keeps the user dry.
– **Breathable Film**: Some high-end sanitary napkins use breathable films that allow air to pass through while still preventing liquid leakage. This enhances comfort by reducing moisture buildup.

## Adhesive and Release Paper

To ensure the sanitary napkin stays in place, an adhesive is applied to the back sheet. The adhesive is typically covered with a release paper that is removed before use. Common materials include:

– **Pressure-Sensitive Adhesive**: This type of adhesive is designed to stick securely to underwear without leaving residue. It provides a strong hold while being easy to remove.
– **Silicone-Coated Release Paper**: The release paper is coated with silicone to prevent the adhesive from sticking to it before use. It is easy to peel off when the napkin is ready to be used.

## Additional Components

Some sanitary napkins may include additional components to enhance comfort and performance:

– **Wings**: Wings are extensions on the sides of the napkin that fold over the edges of underwear to provide extra security and prevent leakage. They are typically made from the same materials as the back sheet.
– **Fragrance**: Some sanitary napkins are infused with a light fragrance to mask menstrual odor. However, fragrance-free options are also available for those with sensitive skin.

## Properties of Raw Materials

The properties of the raw materials used in sanitary napkins are carefully selected to ensure optimal performance:

– **Absorbency**: High absorbency is crucial for preventing leakage and keeping the user dry. Materials like wood pulp and SAP are chosen for their excellent absorbent properties.
– **Softness**: The top sheet must be soft and gentle on the skin to prevent irritation. Nonwoven fabrics and perforated films are preferred for their soft texture.
– **Breathability**: Breathable materials help reduce moisture buildup and enhance comfort. Breathable films and certain nonwoven fabrics are used to achieve this.
– **Flexibility**: The materials must be flexible to conform to the body’s shape and movements. Polyethylene films and nonwoven fabrics provide the necessary flexibility.