Consumers are often looking for products and solutions that help make their lives easier. Whether it’s simplifying a task at home or at work, they’ll remember the time and energy saved. In disposable hygiene, that task simplification is one of the things that gives products with indicators and sensors an edge in the marketplace. Wetness indicators and faecal detectors are excellent examples of adding convenience to changing time. Hot melt adhesives play a significant role in creating diaper products with these helpful design features.
First introduced in 1978, wetness indicators are very popular in disposable hygiene products today. From baby care to garments for adult incontinence, diapers that alert parents, caregivers, and wearers when they’re wet help in many ways. Their goal is:
- No more reaching into a diaper to feel for wetness
- No waking babies or patients unless a change is actually needed
- No waste from discarding diapers too soon, when the diaper is barely wet
They can even help prevent leaving a soiled diaper to become over-full and starting to leak.
Advances in disposable hygiene have, in one regard, made wetness indicators more important. With the advent of SAP (superabsorbent polymer), it may be difficult to feel when the diaper needs changing. This is even true for adult users who, due to sleep or reduced sensitivity, may not be aware of an insult.
Wetness indicators promote healthy skin and more efficient caregiving
In addition to simple convenience, indicators and sensors have other benefits. Timely changes help support better skin health. Wet skin is more susceptible to damage and irritation from prolonged exposure to urine and faeces. Over-full diapers can also result in damage from abrasion and the pressure of extra bulk. The risk to skin health is increased in older adults, as their skin tends to be less resilient, prone to irritation and secondary infections.
Indicators and sensors can also enable more efficient caregiving, especially in professional care settings. They can allow caregivers to check diapers more easily, freeing up time for other tasks. Some sensors will even notify the nursing station when a change is required, completely eliminating the need for periodic checks.
Indicators and sensors take many forms
Inks and hot melt adhesives are two common methods for applying a wetness indicator to a diaper or other disposable hygiene garment. Both rely on a visual cue to indicate wetness. Lines or patterns on the diaper may shift colours, or simply fade away when insulted. The amount of shift—and the area or length that changes—can be used to indicate the extent of the wetness.
One agent commonly used in inks and hot melt wetness indicators is primarily a pH indicator. It shifts colour from yellow to blue at higher pH levels, such as when in contact with urine or faeces.
Other methods do exist. Various types of electronic sensors can be employed in caregiving settings, and new opportunities are being explored. MIT researchers, for example, have demonstrated a new disposable “smart” diaper with an embedded RFID tag.1 Interestingly, the chips do not detect wetness directly. Instead, when the SAP absorbs an insult, it begins to act as an antenna. This allows a nearby RFID reader to sense the tag in the diaper. From there, the signal can be sent to a phone or a nurses’ station. It can also be a benefit for the patients, who may be unaware or too embarrassed to report that a change is needed.
The importance of choosing the right hot melt wetness indicator
Not all wetness indicators are created equal. You don’t want it to be activated prematurely if shipping, storage, and in-use temperatures are hot or humid. You also need to be assured that the colour changes will be sufficient to view under typical care situations. That’s why testing and data are important in selecting a hot melt wetness indicator.