# Sanitary Pads Raw Material Composition and Properties

Sanitary pads are essential personal care products designed to provide comfort and hygiene during menstruation. Understanding the raw materials used in their production is crucial for both manufacturers and consumers. This article delves into the composition and properties of the primary raw materials used in sanitary pads.

## 1. Absorbent Core

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

– **Wood Pulp**: A natural, biodegradable material that provides excellent absorbency. Wood pulp is often blended with superabsorbent polymers to enhance its capacity.
– **Superabsorbent Polymers (SAP)**: These are synthetic materials that can absorb and retain large amounts of liquid relative to their own mass. SAPs are crucial for 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 include:

– **Nonwoven Fabrics**: These are made from synthetic fibers like polypropylene or polyethylene. They are designed to be soft, breathable, and quick-drying.
– **Perforated Films**: Some pads use perforated plastic films that allow liquid to pass through while keeping the surface dry.

## 3. Back Sheet

The back sheet is the outermost layer that prevents leakage and provides a barrier to moisture. It is usually made from:

– **Polyethylene Film**: A thin, flexible plastic film that is impermeable to liquids. It is often embossed or textured to provide a non-slip surface.
– **Breathable Microporous Films**: These films allow air to pass through while blocking liquids, enhancing comfort by reducing moisture buildup.

## 4. Adhesives

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

– **Hot Melt Adhesives**: These are applied in a molten state and solidify upon cooling, providing a strong bond.
– **Pressure-Sensitive Adhesives**: These adhesives form a bond when pressure is applied, making them easy to use and reposition.

## 5. Release Paper

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

– **Silicone-Coated Paper**: This paper is treated with silicone to prevent the adhesive from sticking to it, allowing for easy removal.

## Properties of Sanitary Pad Materials

The materials used in sanitary pads must possess specific properties to ensure functionality and comfort:

– **Absorbency**: The ability to quickly absorb and retain menstrual fluid is paramount. This is primarily achieved through the absorbent core and SAPs.
– **Softness**: The top sheet must be soft to prevent irritation and provide comfort during use.
– **Breathability**: Materials should allow air to circulate to reduce moisture buildup and prevent discomfort.
– **Leakage Prevention**: The back sheet and adhesives must work together to prevent leaks and keep the pad securely in place.
– **Biodegradability**: With increasing environmental concerns, there is a growing demand for biodegradable materials in sanitary pads, such as wood pulp and certain nonwoven fabrics.

In conclusion, the raw materials used in sanitary pads are carefully selected to balance absorbency, comfort, and environmental impact. Understanding these materials and their properties can help consumers make informed choices and manufacturers improve product quality.