Sanitary napkins, an essential item for women during their menstrual cycle, are composed of several layers, each serving a specific function. Let’s delve into the structure and materials of sanitary napkins.
Structure of Sanitary Napkins
Generally, a sanitary napkin consists of three main layers:
- Top Sheet:
This is the layer that comes into direct contact with the skin.
Materials: Typically made of ss spunbond fabric or perforated film, although cotton and heat-bonded non-woven fabric are also used.
Function: Quickly absorbs menstrual blood and directs it to the absorbent layer, while keeping the surface dry to minimize skin irritation. - Absorbent Core:
The heart of the sanitary napkin.
Materials: Primarily composed of fluff pulp, super absorbent polymer (SAP), and dust-free paper.
Function: Efficiently absorbs menstrual blood and locks it inside, preventing leakage. SAP has a strong water-absorbing capacity, transforming the liquid into a gel to effectively prevent side leakage. - Back Sheet:
The outer layer of the sanitary napkin.
Materials: Usually made of polyethylene film.
Function: Prevents menstrual blood from leaking onto clothing, and the back is coated with hot melt adhesive for easy attachment to underwear.
Materials Used in Sanitary Napkins
- Top Sheet Materials:
- Non-woven fabric: Soft, comfortable, and breathable, it is a common top sheet material.
- Perforated film: Has a microporous structure that allows for rapid liquid absorption while keeping the surface dry.
- Cotton: Skin-friendly but has relatively weak absorbency.
- Heat-bonded non-woven fabric: High softness and good absorbency.
- Absorbent Core Materials:
- Fluff pulp: Provides a base for absorption and can quickly absorb liquid.
- Super Absorbent Polymer (SAP): A super absorbent material that can absorb a large amount of liquid and form a gel.
- Dust-free paper: Enhances the strength and toughness of the absorbent layer.
- Back Sheet Materials:
- Polyethylene film: Waterproof and effectively prevents leakage.
- Hot melt adhesive: Firmly adheres the sanitary napkin to underwear.
Other Materials and Functions
- Wings: Increase the fixation of the sanitary napkin and prevent side leakage.
- Elastic side panels: Conform to the body’s curves for increased comfort.
- Additives: Some sanitary napkins contain aloe vera, vitamin E, and other ingredients to soothe the skin.