---
title: "What is a Diaper (nappy) made of?"
description: "A superabsorbent polymer that holds many times its own weight in fluid, sandwiched between nonwoven plastic layers. Every component, the material it uses, and the co"
url: https://atoneplace.net/made-of/diaper/
site: "At One Place"
---

# What is a Diaper (nappy) made of?

**What is a Diaper (nappy) made of?: A superabsorbent polymer that holds many times its own weight in fluid, sandwiched between nonwoven plastic layers.**

Superabsorbent polymer is the reason nappies became thin. Before it was introduced in the 1980s, absorbency came almost entirely from bulky wood fluff pulp; sodium polyacrylate absorbs many times more per gram and locks the liquid into a gel, so the pad shrank while holding more. The wetness indicator stripe is a simple pH- or moisture-sensitive ink printed on the backsheet. Disposable nappies are a substantial share of household waste and take a very long time to break down, but comparative life-cycle studies consistently find that the reusable-versus-disposable question turns mainly on how the reusables are washed and dried.

## Component by component

*Every material is a choice, and the third column is the constraint that drove it.*

| Part | Material | Why that material |
| --- | --- | --- |
| absorbent core | sodium polyacrylate superabsorbent polymer with fluff pulp | The polymer holds roughly thirty times its weight in water as a gel that does not release it back under pressure. |
| topsheet | perforated nonwoven polypropylene | It lets liquid pass one way and stays dry against skin, which is what prevents nappy rash from constant wetness. |
| acquisition layer | a lofty nonwoven between topsheet and core | It buys time by holding a surge of liquid while the polymer, which absorbs quickly but not instantly, catches up. |
| backsheet | polyethylene film, often microporous | It is the leak barrier; microporous versions let water vapour out so the nappy breathes without letting liquid through. |
| elastics and tapes | spandex strands and hot-melt adhesive, with a hook-and-loop or tape closure | Leg cuffs do more to prevent leaks than absorbency does, which is why fit is the usual cause of a failed nappy. |

## Other medical and personal care objects

- [Condom](https://atoneplace.net/made-of/condom/) — Dipped natural rubber latex, or synthetic polyisoprene or polyurethane for latex allergy — plus silicone lubricant.
- [Surgical mask](https://atoneplace.net/made-of/surgical-mask/) — Three layers of polypropylene, of which only the electrostatically charged middle one does the filtering.
- [Contact lens](https://atoneplace.net/made-of/contact-lens/) — A water-swollen polymer gel — and the whole design problem is getting oxygen through it to the cornea.
- [Dental filling](https://atoneplace.net/made-of/dental-filling/) — Either a mercury-silver amalgam or a light-cured resin packed with glass — and the resin shrinks as it sets.
- [Tampon](https://atoneplace.net/made-of/tampon/) — Compressed cotton, rayon or a blend, with a withdrawal cord and either a cardboard or plastic applicator.
- [Eyeglass lens](https://atoneplace.net/made-of/eyeglass-lens/) — Almost never glass — usually CR-39, polycarbonate or a high-index plastic, under several thin coatings.
- [Adhesive bandage (plaster)](https://atoneplace.net/made-of/adhesive-bandage/) — A plastic or fabric backing with pressure-sensitive adhesive, and a pad faced with a film that will not stick to the wound.
- [Artificial hip](https://atoneplace.net/made-of/artificial-hip/) — A titanium or cobalt-chrome stem, a ceramic or metal ball, and a crosslinked polyethylene socket liner that is the wear surface.
- [Syringe](https://atoneplace.net/made-of/syringe/) — A polypropylene barrel and plunger with a rubber tip seal, and a stainless steel needle on a standard taper.

## Common questions

### What is a Diaper (nappy) made of?

A superabsorbent polymer that holds many times its own weight in fluid, sandwiched between nonwoven plastic layers.

### What is the absorbent core of a Diaper (nappy) made of?

Sodium polyacrylate superabsorbent polymer with fluff pulp. The polymer holds roughly thirty times its weight in water as a gel that does not release it back under pressure.

### What is the topsheet of a Diaper (nappy) made of?

Perforated nonwoven polypropylene. It lets liquid pass one way and stays dry against skin, which is what prevents nappy rash from constant wetness.

## Related pages

- [Condom](https://atoneplace.net/made-of/condom/)
- [Surgical mask](https://atoneplace.net/made-of/surgical-mask/)
- [Contact lens](https://atoneplace.net/made-of/contact-lens/)
- [Dental filling](https://atoneplace.net/made-of/dental-filling/)
- [Tampon](https://atoneplace.net/made-of/tampon/)
- [Eyeglass lens](https://atoneplace.net/made-of/eyeglass-lens/)
- [Adhesive bandage (plaster)](https://atoneplace.net/made-of/adhesive-bandage/)
- [Artificial hip](https://atoneplace.net/made-of/artificial-hip/)
- [Pencil](https://atoneplace.net/made-of/pencil/)
- [Tennis ball](https://atoneplace.net/made-of/tennis-ball/)
- [Banknote](https://atoneplace.net/made-of/banknote/)
- [Golf ball](https://atoneplace.net/made-of/golf-ball/)
- [Paper](https://atoneplace.net/made-of/paper/)
- [Glass](https://atoneplace.net/made-of/glass/)

## Sources

- Official vendor product documentation — At One Place (/about/)