Wetness Indicator Film

Wetness Indicator Film is a critical component in modern disposable hygiene products. Applied to the backsheet or acquisition layer of diapers and pads, it provides a visible color-change signal when exposed to urine or other bodily fluids. Caregivers and users can immediately tell whether a product needs changing — without unnecessary checks or premature disposal.

How Wetness Indicator Film Works

The wetness indicator film contains a pH-sensitive indicator embedded in a PE carrier layer. When urine (pH 5–8) contacts the film, the indicator undergoes a chemical reaction that shifts the visible color — typically from yellow to green to blue. The color gradient deepens with repeated wetting, providing a progressive, intuitive signal. Two formulations are available: hot-melt type (color changes upon wetting) and ink type (color fades upon wetting), allowing manufacturers to choose based on product design and production line setup.

Key Benefits

• Improved user experience: Caregivers don’t need to guess — a quick glance confirms wetness
• Reduced waste: Products are changed only when needed, not on a rigid schedule
• Enhanced brand perception: A visible, high-tech feature that differentiates your product on shelf
• High humidity resistance: Won’t trigger prematurely during storage in tropical or high-humidity environments
• Fast, clear response: Color change is visible even in dim lighting conditions

Typical Applications

• Baby diapers (tape type and pull-up pants)
• Adult incontinence briefs and pull-ups
• Feminine care pads
• Underpads and nursing pads

Loeon supplies wetness indicator film in widths up to 2,200 mm, with MOQs starting at 500 kg and lead times of 15–25 days. Custom basis weight, width, and color-change specifications are available upon request. Contact us for samples and technical support.