# Sanitary Napkins Raw Material Composition and Properties

Sanitary napkins are essential hygiene products used by women worldwide. Understanding the raw materials that go into their production is crucial for both manufacturers and consumers. This article delves into the composition and properties of the primary materials used in sanitary napkins.

## Core Components of Sanitary Napkins

The core of a sanitary napkin typically consists of absorbent materials that quickly soak up menstrual fluid. The most common materials used are:

– **Wood Pulp**: This is the primary absorbent material. It is highly absorbent and helps in retaining fluid within the napkin.
– **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 often mixed with wood pulp to enhance the absorbency of the napkin.

## Top Layer Materials

The top layer, or the cover, is the part of the sanitary napkin that comes into direct contact with the skin. It is designed to be soft and comfortable while allowing fluid to pass through quickly. Common materials include:

– **Nonwoven Fabric**: Made from synthetic fibers like polypropylene, nonwoven fabrics are soft, breathable, and allow for quick fluid transfer.
– **Perforated Film**: Some sanitary napkins use a thin, perforated plastic film as the top layer. This material is less breathable but provides a smooth surface that prevents leakage.

## Backsheet Materials

The backsheet is the bottom layer of the sanitary napkin, designed to prevent leakage and keep the napkin in place. Materials used for the backsheet include:

– **Polyethylene Film**: This is a common material used for its waterproof properties. It prevents fluid from leaking through the back of the napkin.
– **Nonwoven Fabric**: In some cases, nonwoven fabric is also used for the backsheet, providing a softer feel while still offering protection against leaks.

## Adhesive and Release Paper

To keep the sanitary napkin securely in place, an adhesive is applied to the backsheet. The adhesive is usually a pressure-sensitive type that sticks to underwear without leaving residue. Release paper covers the adhesive until the napkin is ready to be used.

## Additional Components

Some sanitary napkins may include additional components for enhanced comfort and functionality:

– **Wings**: These are extensions on the sides of the napkin that fold over the edges of underwear to provide extra security and prevent shifting.
– **Fragrance**: Some napkins are infused with a light fragrance to mask menstrual odor. However, this is optional and may not be suitable for all users, especially those with sensitive skin.

## Properties of Sanitary Napkin Materials

The materials used in sanitary napkins are chosen for their specific properties:

– **Absorbency**: The ability to quickly absorb and retain fluid is the most critical property. Wood pulp and SAP are excellent for this purpose.
– **Softness**: The top layer must be soft to prevent irritation and ensure comfort during use.
– **Breathability**: Nonwoven fabrics allow air to circulate, reducing the risk of skin irritation and discomfort.
– **Leakage Protection**: The backsheet must be impermeable to prevent fluid from leaking through.
– **Adhesion**: The adhesive must be strong enough to keep the napkin in place but easy to remove without leaving residue.

## Conclusion

Understanding the raw materials and their properties in sanitary napkins helps in making informed choices about the products we use. Each component plays a vital role in ensuring comfort, protection, and hygiene during menstruation. As technology advances, we can expect further innovations in the materials used, leading to even more effective and comfortable sanitary products.