What Is a Sanitary Napkin Made Of? Topsheet, Core, and Backsheet Explained

A sanitary napkin has five main layers:

1. A soft topsheet that touches the skin, usually a polypropylene nonwoven, cotton, or a perforated film.
2. An acquisition layer that pulls fluid down quickly.
3. An absorbent core of fluff pulp and super absorbent polymer (SAP).
4. A leak-proof polyethylene backsheet.
5. Adhesive with release paper.

Most pads also come in an individual wrapper.

What Are the Layers of a Sanitary Napkin?

A sanitary napkin is a layered absorbent product: each layer has one job, and the combination decides how well the pad absorbs, stays dry, and stays in place. EDANA, the European nonwovens and hygiene industry association, describes the same basic structure in its overview of menstrual products composition.

Exact materials vary by design. Two pads that look the same can perform very differently because of the choices made inside the core and topsheet.

What Is the Topsheet of a Sanitary Pad Made Of?

The topsheet of a sanitary pad is usually made of a polypropylene nonwoven, a cotton or cotton-blend fabric, or a perforated plastic film. It is the only layer that touches skin, so it shapes how soft, dry, and comfortable the pad feels.

Many topsheets are embossed with small 3D patterns. These reduce the contact area with skin and help channel fluid downward, so the surface feels drier.

What Does the Acquisition Layer Do?

The acquisition layer sits directly under the topsheet and moves fluid away from the surface quickly, then spreads it across the core. Without it, fluid can pool on the surface before the core has time to absorb it, which feels wet and increases leak risk.

This layer is usually an air-through nonwoven with an open, lofty structure. It matters most in ultra-thin pads, where the core is compact and needs help distributing fluid evenly.

What Is Inside the Absorbent Core of a Sanitary Pad?

The absorbent core of a sanitary pad is made of fluff pulp, super absorbent polymer (SAP), or a blend of both. SAP is a polymer powder that turns fluid into a gel and holds it under pressure, so it keeps the surface dry when the user sits or moves.

Fluff pulp vs. SAP

• Fluff pulp is cellulose fiber from wood pulp. It absorbs quickly and gives the pad body and softness. It holds less fluid under pressure, so pulp-heavy pads tend to be thicker.
• SAP absorbs many times its own weight and locks fluid in as a gel. More SAP allows a thinner pad with less rewet.
• Airlaid cores bond pulp and SAP into a thin, stable sheet. This is common in ultra-thin pads because the core does not shift or clump.

Thickness alone does not tell you capacity. An ultra-thin pad with a well-designed SAP core can hold as much as a thicker pulp-based pad. A thick pad with little SAP may feel wet sooner.

What Is the Backsheet of a Sanitary Pad Made Of?

The backsheet of a sanitary pad is usually a thin polyethylene film that stops fluid from reaching underwear. Better pads use a breathable microporous film, which blocks liquid but lets water vapor escape, so the pad feels less hot and stuffy.

Some backsheets are laminated with a nonwoven layer for a softer, quieter, more fabric-like feel. Wings are usually cut from the backsheet and topsheet together and carry their own adhesive strips.

What Holds a Sanitary Pad in Place?

A sanitary pad is held in place by a hot-melt pressure-sensitive adhesive on the backsheet and wings, protected by a silicone-coated release paper until use. Adhesive quality affects user satisfaction more than many brands expect. If it is too weak, the pad shifts and leaks; if it is too strong, it leaves residue on underwear.

Hot-melt adhesive also bonds the internal layers together during production. Poor internal bonding can let the core separate or clump during wear.

Are Sanitary Napkin Materials Safe?

Sanitary napkin materials are regulated product inputs, and in major markets manufacturers must document what they use. In the US, menstrual pads are medical devices. The FDA’s guidance on menstrual tampons and pads sets out what pad makers should document:

• Bleaching: pad makers should identify any bleaching process used for pad materials, such as elemental chlorine-free (ECF) or totally chlorine-free (TCF).
• Scented pads: pads made with materials without an established safety profile need premarket review.

In the EU, chemical content is controlled under REACH, so brands selling there typically ask suppliers for REACH test reports on the finished product. EDANA notes that optional components such as fragrances or odor-control ingredients are disclosed on packaging.

For a brand, the practical step is simple: ask the manufacturer for a material list and test reports for each layer. Only print claims such as “chlorine-free” or “fragrance-free” that those documents support.

How Do Materials Affect Sanitary Pad Performance?

Most sanitary pad complaints can be traced to a specific layer, which makes the material specification the fastest way to fix a product. Use this table when you review samples or customer feedback:

If you are comparing suppliers, our sanitary pad manufacturer checklist explains which material questions to ask and how to verify the answers.

How Does TianZheng Build Its Sanitary Pads?

TianZheng builds its OEM sanitary pads around four public specifications:

• Core: a 100% SAP absorbent core designed to lock in flow quickly and keep the surface dry.
• Topsheet: a 3D micro-embossed topsheet produced in-house.
• Adhesive: Henkel adhesive for secure, no-shift placement.
• Backsheet: a microporous breathable backsheet.

The standard range covers day pads (240 mm), night pads (280–330 mm), and panty liners (160 mm), and every size can be adjusted for private label projects. Core, topsheet, and nonwoven production run in-house, and finished pads are checked by inline optical inspection on dedicated production lines. You can see the full specifications on our sanitary pad manufacturing page and the production setup on our equipment page. Certificates are listed on our certification page.

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