Wipes: They're Not Just For Babies Anymore

By Suellen Bennett, Damian Kelly, Andy Kaziska, Mark Chandler and Cara Eaton, Croda, Inc. | April 15, 2010

In this era of convenience, the ultimate convenience item is a wet wipe. They can be used to remove make-up, to clean the toilet, to wipe down the kitchen counter or to disinfect your hands. They are incredibly portable, and after you use them, into the garbage they go. No muss, no fuss. In the personal care arena, wipes can be used for almost anything. One of the first areas where this technology was exploited was in baby wipes, where gentle cleansing was the key. Eventually, this convenient technology migrated to a multitude of other uses in personal care. There were cleansing applications like make-up remover wipes, foot freshening wipes, intimate cleansing wipes, soothing eye wipes, denture wipes and boogie wipes (yes, I’m serious!) as well as wipes for applying products such as self tanners, sunscreens, insect repellents and anti-itch creams.

One helpful fact about wipes is that they are great for air travel. You can bring them on the airplane in your carry-on bag with no repercussions at the security line. There is nothing quite as refreshing as being able to wipe airplane grime off your face with one softly scented swipe of a soothing facial wipe. Wipe technology is not just for personal care though. If you turn to household and industrial applications, wipes have become a staple product in many consumer households due to their convenience and ease of use. There are disposable wipes for everything from disinfecting counter tops and toilets to wipes designed to clean a multitude of surfaces such as glass, stainless steel and just about any other surface in the home. The formulation of wipes is quite simple. No matter the type of wipe, the beginning of the process is the development of a solution or emulsion that will be used to saturate the wipe. The solution or emulsion will have different efficacy needs based on whatever its end use may be. The second step of the process involves choosing the nonwoven for your wipe, which again will be dependent on the expected function of the wipe.

There are several challenges involved in the formulation of the solution or emulsion that is used to permeate the wipe. These challenges include cleansing or active efficacy, sensorial benefits and drainage. There is also the actual substance of the wipe to take into consideration. Do you want your wipe to pick something up or leave something behind? Do you want the wipe to feel wet or dry? Will the wipe be disposed of in the garbage or flushed down the toilet? Do you want the wipe to biodegrade? How strong does the wipe need to be for the job it is doing? A wipe used to remove make-up from a person’s face does not need to be as robust as a wipe used to clean a hard surface. However, for the purposes of this article, we will focus on the ingredients that compose the solution or emulsion used to saturate the wipe.

For cleansing, surfactants of differing strength levels are used in the solution. A baby wipe will use very gentle cleansing surfactants in comparison to a wipe used to freshen the feet or a wipe used for household applications. Sodium lauroyl sarcosinate[1] is a good example of a very gentle but very effective cleansing surfactant. Mildness is always a consideration when formulating wipes, even when intended for uses other than baby care, as these products touch the hands of the user who does not want the wipe to be caustic or drying. Di-PPG-2 Myreth-10 Adipate[2] is an extremely mild emollient ester, providing exceptional skin feel, while also reducing irritation of surfactant systems. This allows for excellent cleansing performance without causing redness or irritation to the skin, such as can be observed from classical surfactants like SLS. Beyond basic cleansing, additional functionality is now expected by consumers when using their wipe products. Therefore, products designed to enhance the performance of wipes are highly desired by formulators. To this end, Croda offers an optimized and highly active surfactant system[3], which is an anionic and nonionic blend, designed to maximize cleaning performance and ease of use in household cleaners. Due to the excellent wetting properties on both fabrics and hard surfaces, this surfactant blend is recommended as an alternative to using multiple surfactants in a wide range of cleaning products, including wipes, thereby achieving peak performance with fewer ingredients in formulation.

If makeup removal is part of the functionality required of a wipe, esters are frequently added to the emulsion to facilitate the removal of the waxy and oily components of facial makeup and to enhance performance. In addition to enhancing the cleansing performance, often the formulator will choose an ester that has a smooth or moisturizing feel on the skin. This allows for esters to provide multifunctional benefits to the formulation. For active efficacy and delivery to the skin, penetration enhancers and solubilizers can be used. Croda offers a penetration enhancer (into the top of the stratum corneum) to facilitate the efficacy of actives on the skin. We have proven its delivery ability with dihydroxyacetone and benzoyl peroxide. The INCI name is dimethyl isosorbide.[4] This ingredient also functions as a non-volatile humectant, so it will help the skin feel more moisturized. Additionally, it will enhance the make-up-removing ability of the wipe. All these features demonstrate that dimethyl isosorbide is truly a multifunctional addition to wipes.

Performance is a primary concern when formulating products for the wipes market, but this is not the only challenge. The sensorial benefits of a wipe can actually be the biggest indicator of its long term success on the market. If a cleansing wipe cleanses the skin but leaves it feeling stripped of moisture and irritated, then the consumer will look for another wipe. Myristami - dopropyl PG-Dimo nium Chlo - ride Phos phate[5] is a specialty phospholipid that contributes skin conditioning, cleansing efficacy and preservation en - hancement to wipes. PPG-3 Benzyl Ether Myristate[6], one of Croda’s patented emollient esters, has moisturization capabilities coupled with phenomenal skin spreading. It leaves the skin feeling silky and comfortable. Another important component of the sensorial experience would be the addition of botanical extracts or fragrance. The plant world offers up solutions to almost any skin ailment, so these extracts will also contribute to the efficacy part of the overall picture. Fragrance can be used to evoke so many kinds of emotions. A soft lavender fragrance used on a face cleansing wipe may bring about a feeling of calm perfect before bed, while a bracing citrus scent is perfect for a wipe used to clean up after a workout. Drainage can be a huge problem in wipes, especially those on which an emulsion is applied.

Drainage occurs when the emulsion migrates through the stack of wipes, so that most of it is on the bottom of the wipe container. This leaves dry wipes on top and extra saturated wipes on the bottom. The dry top wipes, in addition to not having enough emulsion/ solution in them for functionality, will be harder to pull off the top and will tend to rip unevenly. This is where rheology plays an important role. Emulsifiers that allow for good shear thinning upon spraying allow the emulsion to be applied easily to the wipe. If they can then thicken upon application, the emulsion will stay impregnated into the wipe and will not unduly drain. Several polymeric-based emulsifiers exhibit this interesting rheology making them perfect for usage in wipes. Many of them also contribute skin softening or moisturizing benefits, as well as some modicum of cleansing efficacy.

It’s no surprise that the hottest market trend continues to be green, and wipes are no exception. Formulating green products though has its own series of challenges, as definitions of what constitutes green vary widely, and green formulations often have a more limited range of materials from which to derive desired effects. Wipes only further complicate this issue based on the unique challenges as discussed previously. If formulators are choosing to create “green” wipes, discussions with ingredient suppliers about ingredient choice will be crucial to achieve desired performance with appropriate sensorial effects. For the past several years, wipes have been among the fastest growing product categories in a wide range of markets. Their portability and convenience, coupled with the hygiene aspect of their single usage, has made them very popular with all types of consumers. Whether you want a green hard surface cleaner wipe or a mild wipe to deliver a personal care ingredient such as a sunscreen or make-up remover, there are a multitude of raw material choices available to you as a formulator.


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