Magazine March 2011

All the Latest Information from the Textile World

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Hygiene over the years

Yoga, Pilates, Wellness, Nordic Walking, Qi Gong, homeopathy - almost everyone has heard of them these days, and this shows how radically our perception of health and relaxation has changed over the past twenty years. This change in perception has also included topics that are only indirectly related to health. An obvious example is hygiene. It is not surprising that today around 35 percent of all nonwovens produced flow into this application sector. This does not even include wipes and cosmetic articles, even if they are used for bodily hygiene. If one factors in demand for disposable wipes, the figure rises to around 45 percent. In this regard, the following analysis refers to pure hygiene articles as well as wipes and other items for bodily hygiene which are generally found under the heading of "cosmetic articles".

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Areas of application for modern hygiene nonwovens

Source: Edana

Today's areas of application for modern hygiene nonwovens are more diverse than ever before, and this trend is on the increase. Nappies are still as important as ever, and the design and structure of such disposable products is sometimes quite complex. The requirement profile of individual layers varies considerably, as shown by the following structural diagram of a typical incontinence product:

ASoft upper nonwovenPossible mixtures:
cotton, polyester, polypropylene, viscose
BRapid distribution layercellulose
CSuper absorberLong-chain and especially swellable polymers of acrylic acid
DLiquid-impermeable outer layerBreathable foil made from polypropylene and polyethylene

  • The inner layer facing the skin has to rapidly transfer liquid to the layer beneath it. The direct skin contact demands a high degree of softness.
  • The absorbing and distributing layer below transfers the liquid on to the storage area.
  • The absorbent core layer, consisting of a mixture of cellulose flakes and a superabsorbent polymer, blocks and absorbs the liquid.
  • The outer layer facing the clothing forms a moisture-proof barrier. It therefore generally consists of a polyethylene film or a breathable nonwoven-polyethylene composite that is simultaneously gentle on the skin.

Apart from nappies for babies and adults, hygiene nonwovens are also being used increasingly in women's hygiene products such as panty-liners or tampons. The same applies to various different cosmetic articles such as cotton-wool swabs or moist and dry wipes.

Materials and production methods

Typical types of fibre here primarily include cotton, rayon and cellulose, as well as synthetic fibres and various mixtures. Cellulose has excellent absorption properties, is relatively cheap and also biodegradable - a requirement that is becoming especially common in the West.

Here, nonwoven production mostly takes place by means of the air-lay method, especially since cellulose and cotton have a very short staple length. Conventional cards are also used as well, of course. The combination of different nonwoven production methods enables the production of so-called sandwich layers or compound materials. Nonwoven entanglement can of course be done in the case of staple fibres and also via the thermofixation method with the aid of chemical binders, or via waterjet hydroentanglement. The same applies to shorter-fibre cellulose fibres.

Increasing requirements placed on hygiene products

The combination of various different nonwoven production and nonwoven entanglement methods enables products with tailormade properties to be manufactured. "Tailormade" can refer to all kinds of different aspects, for example:

  • Tear-resistance
  • Filtration capability
  • Air permeability
  • Surface softness
  • Bulkiness
  • Absorbency
  • Suction speed
  • Degree of density
  • Recoverability
  • Printability
  • Skin compatibility

Often various different requirement profiles have to be combined - also when they conflict for production-related reasons, one example being a combination of high tear resistance with simultaneous softness in a product.

The advantages of hydroentanglement

Some methods of chemical entanglement have lost importance over the past few years, now that numerous products are no longer allowed to contain chemical additives for reasons of skin compatibility. Here, hydroentanglement is a perfect alternative. Without the use of chemical additives, this method is not only skin- and thus user-friendly but also highly environmentally compatible. Moreover, hydroentanglement also enables very soft products with high tear resistance to be realized.

The method of hydroentanglement is thus playing an increasingly important role, and not only for this reason. There are several more advantages over other methods, including:

  • Lower energy consumption per kilogram of raw material used
  • Less material loss
  • Minimal maintenance work
  • High production speed of up to 300 metres per minute and more
  • Large working widths of up to six metres
  • All kinds of different raw materials can be used
  • Compound materials can be produced

Trends in the hygiene market

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Demand for hygienic nonwovens continues to rise. This is also because countries far removed from the industrialised nations are undergoing a change in attitude towards disposable hygiene articles. In Europe, far more than 20 billion disposable baby nappies and around 6 billion incontinence products are sold every year. Around 40 billion hygiene products for women are sold annually in Western Europe alone. This all adds up to a total sales volume of roughly 12 billion Euros.

Modern hygiene products are being further developed all the time. A major reason for this is increasingly strict environmental compatibility legislation governing hygienic nonwovens production - also with regard to biodegradability. The needs of end users are changing, too: today's young mothers want their babies to wear a product that is not only gentle on the skin but also safe, comfortable and light. In this regard the weight per disposable nappy has been reduced by almost 40 percent since the late 1980s. In the women's hygiene sector, product weight has also been reduced by almost 20 percent over the same time period. Significant savings have also been achieved with regard to packaging material. In future this trend will have tangibly positive effects where environmental protection is concerned. The following attributes therefore sum up the trends in the hygiene article sector: lighter, safer, more discreet, more comfortable and more environmentally compatible.