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, responsible for absorbing menstrual fluid. It is typically made from a combination of the following materials:

– **Wood Pulp:** Wood pulp is a natural, biodegradable 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 preventing leakage.

## 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 like 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 are impermeable to liquids. They provide an effective barrier against leakage.
– **Breathable Films:** Some modern sanitary napkins use breathable back sheets made from microporous films. These films allow air to pass through while blocking liquids, enhancing comfort.

## 4. Adhesive

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 bonding and flexibility.
– **Pressure-Sensitive Adhesives:** These adhesives form a bond when pressure is applied. They are commonly used in sanitary napkins 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 coated with silicone to prevent the adhesive from sticking to it. It is easy to remove and ensures that the adhesive remains effective until use.

## 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 maintain skin health by allowing air circulation, reducing the risk of irritation and discomfort.
– **Leakage Prevention:** The back sheet and absorbent core must work together to prevent leakage, ensuring that the user remains dry and confident.
– **Biodegradability:** With increasing environmental concerns, there is a growing demand for biodegradable materials in sanitary napkins. Wood pulp and other natural fibers are preferred for their eco-friendly properties.

In conclusion, the composition and properties of raw materials used in sanitary napkins