Sanitary Napkins Raw Material Composition and Properties

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# 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 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 menstrual fluid and keeping the user dry. The core is typically made from a combination of the following materials:

– **Cellulose Fluff Pulp**: This is the primary absorbent material. It is derived from wood pulp and is highly effective at absorbing liquids.
– **Superabsorbent Polymers (SAP)**: These are synthetic materials that can absorb and retain large amounts of liquid relative to their own mass. SAPs are often mixed with cellulose fluff pulp to enhance the absorbency of the core.

### Properties of the Absorbent Core

– **High Absorbency**: The core must be able to absorb and retain a significant amount of menstrual fluid to prevent leakage.
– **Softness**: The material should be soft to ensure comfort during use.
– **Breathability**: The core should allow air to circulate to prevent irritation and discomfort.

## 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 made from synthetic fibers such as polypropylene or polyester. They are lightweight, soft, and allow for quick liquid penetration.
– **Perforated Films**: These are thin plastic films with tiny holes that allow liquid to pass through while keeping the surface dry.

### Properties of the Top Sheet

– **Softness**: The top sheet must be gentle on the skin to prevent irritation.
– **Quick-Drying**: It should allow menstrual fluid to pass through quickly to the absorbent core, keeping the surface dry.
– **Hypoallergenic**: The material should be non-irritating and suitable for sensitive skin.

## 3. Back Sheet

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

– **Polyethylene Film**: This is a thin, flexible plastic film that is impermeable to liquids.
– **Nonwoven Fabrics**: Some back sheets are made from nonwoven fabrics that are treated to be water-resistant.

### Properties of the Back Sheet

– **Leak-Proof**: The back sheet must effectively prevent menstrual fluid from leaking through.
– **Flexibility**: It should be flexible enough to conform to the body’s shape for a secure fit.
– **Breathability**: While it needs to be leak-proof, it should also allow some air circulation to prevent discomfort.

## 4. Adhesive

The adhesive is used to attach the sanitary napkin to the underwear. It is typically applied to the back sheet and must be strong enough to keep the napkin in place while being easy to remove without leaving residue.

### Properties of the Adhesive

– **Strong Adhesion**: The adhesive must securely hold the napkin in place during use.
– **Residue-Free Removal**: It should be easy to remove without leaving sticky residue on the underwear.
– **Skin-Friendly**: The adhesive should be non-irritating and safe for prolonged contact with the skin.

## 5. Fragrance and Additives

Some sanitary napkins include fragrances or additives to mask odors or provide additional comfort. However, these components can sometimes cause irritation or allergic reactions in sensitive individuals.

### Properties of Fragrance and Additives

– **Odor Control**: Fragrances can help mask menstrual odors, but they should be mild and non-irritating.
– **Hypo