In recent years, consumers’ personal and laundry care routines have been transformed. There is a demand for new concepts, not just for clothing care but also for the care that clothing provides to the skin. Consumers want clothes that not only feel fresh and clean after washing, but that continue to look like new even after many washes, retain the original color of their fabrics and never look worn. But, they are also looking for ways to protect themselves with products that are especially mild or that deliver extra caring effects for the skin and so enhance their sense of well-being.

Existing ingredients for laundry products such as fabric conditioners and dryer sheets were not able to fulfill these demands completely. Therefore, a new innovative concept based on a wet dryer sheet with special additives has been developed. This features a unique technology for depositing substances onto the fabrics, thereby changing the feel of the textiles to give a more pleasant, less rough, enhanced wellness experience.

The Benefits Of Wet Dryer Sheets
Several methods are available for the transfer of substances which benefit fabrics during or after washing: some additives, such as optical brighteners, can be transferred during the wash cycle; others, like liquid fabric softeners, can be transferred during the rinse cycle; and a third group, including regular dryer sheets, transfer the substances during the drying cycle. In chemical terms, the latter two are generally limited to cationic components, due to the high affinity that these have to fabrics. These substances mainly soften fabrics, or provide fragrance and anti-static benefits to the clothes.

With Plantatex, specialty chemical supplier Cognis has developed a special wax with skin-like properties for the drying cycle that overcomes these and other limitations. It is based on a wet dryer sheet concept impregnated with special sensory compounds or other “active ingredients.”

The fact that these ingredients are now in a liquid matrix has several obvious advantages: a) The diffusion-controlled distribution of the active ingredient during tumble drying is very uniform (as can be shown with colored additives), in contrast to regular dryer sheets which only leave substance on the fabric at the point of contact.

b) Fabrics can now also benefit from non-cationic compounds, such as non-ionic softeners, insect repellents, ultraviolet absorbers, wrinkle removers or deodorants.

c) In addition to components which are beneficial for fabrics, substances, which are subsequently transferred to the skin can also now be employed, including skin moisturizers, lipid layer enhancers, hair growth suppressants, vitamins, emollients or botanical actives.

Skin with lipid layer enhancer

Measurement: Untreated skin.

Using Wax Crystals to Improve Textile Care Plantatex, the first special active ingredient for wet dryer sheets on the market, uses a new fabric care concept called “Heat-Activated Care Crystals.” This is a wax-based dispersion that transfers wax crystals to fabrics during tumble drying. As soon as the water evaporates off of the clothes and the temperature increases, these wax crystals melt to form an even layer around the fibers, thus providing special benefits for the consumer

Clothes treated with this product have surprising sensory properties compared to regular cationic fabric softeners. While many consumers are reluctant to use regular fabric softeners due to the slimy and greasy feel of some products, the Heat-Activated Wax Crystals have a very pleasant skin feel. In addition, cationic quats’ unpleasant side-effect of making fabrics more water-repellent after treatment largely disqualifies them from use on towels or sportswear. By contrast, Heat-Activated Care Crystals make the fabrics more water-absorbent. This may sound surprising given the hydrophobic character of waxes; however, the hydrophilic properties of the treated fabric are explained by the fact that the hy drophilic parts of the dispersants are still on the wax surface. Another benefit is reduced wear and tear, due to a lubrication effect that protects the fibers and makes clothes feel much more pleasant.

Repeated washing and drying is known to cause a certain lightening in color, or graying, in the case of dark clothes. The main cause of this is microfibers fraying off the main fibers by rubbing against each other during the wash/dry cycle. After a while, these microfibers change the reflection of light in a way that makes black textiles start to look gray. However, using a wet dryer sheet containing the wax crystals avoids this effect completely, as the microfibers are “glued” back to the main fiber by the molten wax. The result is fabric that looks like new even after repeated washing and drying.

Care Crystals directly after application: before heat activation

After heat activation

Providing Textiles With Skin-Caring Properties Wet dryer sheets can also contain components that migrate from the textile to the skin. Cognis for example uses a lipid layer enhancer that contains emollients and natural lipids identical to those found in the skin. It is transferred from the fabric to the skin upon contact. Once the lipid layer enhancer has been transferred from the wet dryer sheet to the fabric, and from there on to the skin, moisturization of the skin can be shown to increase significantly, from 1 μg to 5 μg per 10 cm2. Wearing clothes treated in this way results in quantifiable and visible benefits. For example, it can be shown that skin roughness (FOITS: Fast Optical In-vivo Topometry of Human Skin) is reduced (see figures on page 19). Other techniques like MRI (Magnetic Resonance Imaging) also demonstrate an increased level of moisture in the skin.

None of these benefits can be delivered by regular dryer sheets, mainly due to the irregular way that they distribute product onto textiles and their inability to deliver it in sufficient quantities. Wet dryer sheets of the same size can hold up to 20 times more substance. Moreover, in comparison to regular rinse cycle fabric softeners, wet dryer sheets have the advantage that they can deliver any components, irrespective of their electrical charge—including substances that would normally be washed away in the rinse cycle due to a lack of substantivity.

Conclusion
Wet dryer sheets are an innovative concept for the effective transfer of substances to the fabrics, providing extra benefits that current products are unable to offer. Their special technology makes clothes pleasant to wear, protects them from wear and tear, improves color maintenance and increases moisture uptake. And wet dryer sheets can also contain skincare ingredients that provide protection for sensitive skin, enabling manufacturers to meet specific consumer needs.