# Sanitary Napkins Raw Material Composition and Properties

Sanitary napkins are essential feminine hygiene products designed to provide comfort and protection during menstruation. Understanding the raw materials used in their production is crucial for ensuring quality, safety, and effectiveness. This article delves into the composition and properties of the primary materials used in sanitary napkins.

## 1. Absorbent Core

The absorbent core is the heart of a sanitary napkin, responsible for absorbing menstrual fluid. It is typically made from a combination of the following materials:

– Fluff Pulp: A highly absorbent material derived from wood pulp, fluff pulp is the primary component of the absorbent core. It is lightweight, soft, and capable of holding a significant amount of liquid.
– Superabsorbent Polymers (SAP): These are synthetic materials that can absorb and retain large amounts of liquid relative to their own mass. SAP enhances the absorbency of the core, preventing leakage and ensuring dryness.

## 2. Top Sheet

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

– Nonwoven Fabrics: These are engineered fabrics made from fibers bonded together by mechanical, thermal, or chemical processes. They are soft, breathable, and allow for rapid liquid penetration.
– Perforated Films: Some sanitary napkins use perforated plastic films as the top sheet. These films are designed to be soft and 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 plastic films that are impermeable to liquids. They provide an effective barrier against leakage and are often used in combination with breathable materials to enhance comfort.
– Breathable Films: These films allow air to pass through while blocking liquids, providing a balance between protection and comfort. They help reduce the risk of skin irritation and discomfort.

## 4. Adhesive

Adhesives are used to secure the sanitary napkin in place within the underwear. The adhesive must be strong enough to hold the napkin in place but gentle enough to avoid skin irritation. Common types of adhesives include:

– Pressure-Sensitive Adhesives: These adhesives are designed to stick firmly to fabrics when pressure is applied. They are typically made from synthetic rubber or acrylic compounds.
– Hot Melt Adhesives: These are thermoplastic adhesives that are applied in a molten state and solidify upon cooling. They provide a strong bond and are often used in the manufacturing process.

## 5. Release Paper

Release paper is a protective layer that covers the adhesive before use. It is typically made from silicone-coated paper or film, which allows it to be easily peeled away without leaving residue.

## Properties of Sanitary Napkins Raw Materials

The materials used in sanitary napkins must possess specific properties to ensure their effectiveness and safety:

– Absorbency: The ability to quickly absorb and retain menstrual fluid is crucial for preventing leakage and maintaining comfort.
– Softness: Materials that come into contact with the skin must be soft and gentle to avoid irritation.
– Breathability: Breathable materials help reduce the risk of skin irritation and discomfort by allowing air to circulate.
– Leakage Protection: The back sheet and absorbent core must work together to prevent leakage and keep the user dry.
– Biodegradability: With increasing environmental concerns, there is a growing demand for biodegradable materials that minimize the environmental impact of sanitary napkins.

In conclusion, the raw materials used in sanitary napkins play a vital role in their performance and user comfort. By understanding the composition and properties of these materials, manufacturers can produce high-quality products that meet the needs of consumers while addressing environmental concerns.