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
| 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 Dipped natural rubber latex, or synthetic polyisoprene or polyurethane for latex allergy — plus silicone lubricant.
- Surgical mask Three layers of polypropylene, of which only the electrostatically charged middle one does the filtering.
- Contact lens A water-swollen polymer gel — and the whole design problem is getting oxygen through it to the cornea.
- Dental filling Either a mercury-silver amalgam or a light-cured resin packed with glass — and the resin shrinks as it sets.
- Tampon Compressed cotton, rayon or a blend, with a withdrawal cord and either a cardboard or plastic applicator.
- Eyeglass lens Almost never glass — usually CR-39, polycarbonate or a high-index plastic, under several thin coatings.
- Adhesive bandage (plaster) 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 A titanium or cobalt-chrome stem, a ceramic or metal ball, and a crosslinked polyethylene socket liner that is the wear surface.
- 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 Dipped natural rubber latex, or synthetic polyisoprene or polyurethane for latex allergy — plus silicone lubricant.
- Surgical mask Three layers of polypropylene, of which only the electrostatically charged middle one does the filtering.
- Contact lens A water-swollen polymer gel — and the whole design problem is getting oxygen through it to the cornea.
- Dental filling Either a mercury-silver amalgam or a light-cured resin packed with glass — and the resin shrinks as it sets.
- Tampon Compressed cotton, rayon or a blend, with a withdrawal cord and either a cardboard or plastic applicator.
- Eyeglass lens Almost never glass — usually CR-39, polycarbonate or a high-index plastic, under several thin coatings.
- Adhesive bandage (plaster) 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 A titanium or cobalt-chrome stem, a ceramic or metal ball, and a crosslinked polyethylene socket liner that is the wear surface.
- Pencil Stationery and paper
- Tennis ball Sport and games
- Banknote Around the house
- Golf ball Sport and games
- Paper Stationery and paper
- Glass Building materials
Sources
- Official vendor product documentation — At One Place