# Sanitary Pad 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 ensuring quality and safety. 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 fluff pulp and superabsorbent polymers (SAP).

### Fluff Pulp

Fluff pulp is a type of wood pulp that is highly absorbent and soft. It is derived from softwood trees and is processed to create a fluffy, fibrous material. The primary properties of fluff pulp include:

– High absorbency
– Soft texture
– Biodegradability

### Superabsorbent Polymers (SAP)

Superabsorbent polymers are synthetic materials that can absorb and retain large amounts of liquid relative to their own mass. They are usually in the form of small granules or powder. Key properties of SAP include:

– Exceptional absorbency
– Gel formation upon absorption
– Non-toxicity

## 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

Nonwoven fabrics are made from synthetic fibers such as polypropylene or polyester. They are chosen for their:

– Softness
– Breathability
– Moisture-wicking properties

### Perforated Films

Perforated films are thin plastic sheets with tiny holes that allow liquid to pass through while keeping the surface dry. They are valued for their:

– Smooth texture
– Quick-drying capability
– Durability

## 3. Back Sheet

The back sheet is the outermost layer of the sanitary pad, designed to prevent leakage and provide a barrier against external moisture. It is typically made from:

### Polyethylene Films

Polyethylene films are lightweight, flexible, and waterproof. They are commonly used for their:

– Impermeability
– Flexibility
– Tear resistance

### Breathable Films

Breathable films are microporous materials that allow air to pass through while blocking liquids. They offer:

– Enhanced comfort
– Reduced risk of skin irritation
– Improved breathability

## 4. Adhesives

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

### Hot Melt Adhesives

Hot melt adhesives are thermoplastic materials that become sticky when heated. They are favored for their:

– Strong bonding
– Quick setting time
– Non-toxicity

### Pressure-Sensitive Adhesives

Pressure-sensitive adhesives form a bond when pressure is applied. They are known for their:

– Ease of application
– Gentle adhesion
– Removability without residue

## 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. Key properties include:

– Easy removal
– Non-stick surface
– Durability

## Conclusion

The raw materials used in sanitary pads are carefully selected to ensure optimal performance, comfort, and safety. From the absorbent core to the back sheet, each component plays a vital role in the overall functionality of the product. Understanding these materials and their properties helps in appreciating the engineering and science behind everyday personal care products.