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 and their properties 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 primary materials used in the absorbent core include:

– **Wood Pulp**: Wood pulp is a natural material that provides excellent absorbency. It is often blended with synthetic materials to enhance performance.
– **Superabsorbent Polymers (SAP)**: SAPs are synthetic materials that can absorb and retain large amounts of liquid relative to their mass. They are highly effective in maintaining dryness and comfort.

## 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 such as polypropylene or polyester. They are designed to be soft, breathable, and quick-drying.
– **Perforated Films**: Some sanitary napkins use perforated plastic films as the top sheet. These films are designed to 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 provide an effective moisture barrier. They are also lightweight and durable.
– **Breathable Films**: Some sanitary napkins use breathable back sheets that allow air to circulate, reducing the risk of irritation and discomfort.

## 4. Adhesives

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

– **Hot Melt Adhesives**: These are thermoplastic adhesives that are applied in a molten state and solidify upon cooling. They provide strong adhesion and flexibility.
– **Pressure-Sensitive Adhesives**: These adhesives form a bond when pressure is applied. They are commonly used for their ease of application and reliable performance.

## 5. Release Paper

Release paper is used to protect the adhesive before the sanitary napkin is used. It is typically made from:

– **Silicone-Coated Paper**: This type of paper is treated with silicone to prevent the adhesive from sticking to it. It is easy to remove and ensures that the adhesive remains effective until the napkin is used.

## 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 managing menstrual flow effectively. Materials like wood pulp and SAPs are chosen for their superior absorbent properties.
– **Softness**: The top sheet must be soft to prevent irritation and ensure comfort during use. Nonwoven fabrics and perforated films are selected for their gentle texture.
– **Breathability**: Breathable materials help reduce the risk of skin irritation and discomfort by allowing air to circulate. Breathable films and nonwoven fabrics are commonly used for this purpose.
– **Leakage Protection**: The back sheet must provide an effective barrier against leakage. Polyethylene and breathable films are chosen for their moisture-resistant properties.
– **Adhesion**: Adhesives must be strong enough to keep the napkin in place but gentle on the skin. Hot melt and pressure-sensitive adhesives are preferred for their reliable performance.

In conclusion, the raw materials used in