Sanitary Napkins Raw Material Composition and Properties

# Sanitary Napkins Raw Material Composition and Properties

Sanitary napkins 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 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 blend of wood pulp and superabsorbent polymers (SAP).

### Wood Pulp

Wood pulp is a natural fiber derived from trees. It is highly absorbent and provides the bulk of the absorbent core. The properties of wood pulp include:

– High absorbency
– Biodegradability
– Soft texture

### Superabsorbent Polymers (SAP)

SAPs are synthetic materials that can absorb and retain large amounts of liquid relative to their own mass. They are often used in conjunction with wood pulp to enhance the absorbent capacity of the core. Key properties of SAPs include:

– High liquid retention
– Swelling capacity
– 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 offer:

– Smooth texture
– Quick-drying surface
– Durability

## 3. Back Sheet

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

### Polyethylene Film

Polyethylene film is a lightweight, flexible plastic material that is impermeable to liquids. Its properties include:

– Waterproofing
– Flexibility
– Tear resistance

### Breathable Films

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

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

## 4. Adhesive

Adhesives are used to secure the sanitary napkin to the underwear. They are typically pressure-sensitive adhesives that provide:

– Strong adhesion
– Easy removal
– Residue-free performance

## 5. Release Paper

Release paper is a protective layer that covers the adhesive before use. It is usually made from silicone-coated paper or film, offering:

– Easy peel-off
– Protection of adhesive
– Smooth surface

## Conclusion

The composition and properties of raw materials used in sanitary napkins play a vital role in their performance and user comfort. From the absorbent core to the back sheet, each component is carefully selected to ensure optimal functionality and safety. Understanding these materials helps in making informed choices and appreciating the technology behind everyday personal care products.