# What is the structural composition of the material?

> Source: https://breathablefilm.com/news/knowledge-center/structural-composition-breathable-laminates/
> Author: kh_sales02
> Published: 2026-04-28
> Updated: 2026-08-28

## Key takeaways

- Kae Hwa's products are typically multi-layer functional laminates built around a core functional membrane — either a microporous PE/PP film or a monolithic TPEE membrane — that provides the primary waterproof and breathable barrier.
- This core is fused to a substrate or face fabric, such as spunbond or meltblown nonwovens for diapers and gowns, or woven fabrics for outdoor ProShell gear.
- Bonding uses solvent-free thermal or ultrasonic in-line lamination that leaves no toxic residue, and the structure can be configured as a 2L, 2.5L, or 3L build depending on the application.

## Frequently asked questions

### What is the structural composition of the material?

Kae Hwa's products are typically multi-layer functional laminates built around a core functional membrane, either a microporous PE/PP film or a monolithic TPEE membrane, that provides the primary waterproof and breathable barrier. This core is fused to a substrate or face fabric, spunbond or meltblown nonwovens for diapers and gowns, or woven fabrics for outdoor ProShell gear, using solvent-free thermal or ultrasonic in-line lamination that leaves no toxic residue, and the whole structure can be configured as a 2L, 2.5L, or 3L build depending on the application.

### Why does Kae Hwa use solvent-free lamination to bond its layers together?

Solvent-free thermal or ultrasonic lamination fuses the layers without introducing chemical adhesives, so there is no toxic residue left in the finished material — an important property for products that touch skin directly, like medical gowns and hygiene items.