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The process used to create nonwoven toxic chemical decontamination wipes, such as Texas Tech University’s Fibertech, recently received a patent from the United States Patent and Trademark Office. The process focuses on a multilayered wipe with a unique fabric structure, which can wipe liquid and vapor toxins. Also, it can be used on human skin and military equipment. This technology has been used successfully to develop products such as nonwoven decontamination wipe, Fibertech. The need for decontamination wipes, such as the kind created at TIEHH, were a top priority for the Department of Defense. The wipe that researchers tested features an activated carbon core sandwiched between an absorbent polyester layer on one side and absorbent cellulose on the other. After testing with mustard gas and other toxic chemicals, the results showed that the Texas Tech-created dry fabric out-performed 30 different decontamination products, including materials currently used in military decontamination kits. The laboratory recommended Fibertech to be part of a prototype low-cost personal decontamination system.

Moving away from spunmelt, Polymer Group Inc. PGI also makes interesting composites of nonwovens and films: the company has a proprietary continuous process for manufacturing reticulated films that have unique capabilities due to the way precision holes are imparted during the forming of the film.

Since these films can be composed of two or more layers of different polymers, the functionality can be different on either side. The films are typically individually customized and are especially popular in Asia as a component for premium, feminine hygiene products.

The company also manufactures composites of different nonwoven and/or film structures, where each structure lends separate properties or attributes to the end-product. An example is a product for house wrap, which is the result of combining an especially strong spunbond fabric with a highly engineering film. The resulting composite is strong and cheap and has excellent wind barrier properties while still allowing humidity to pass through.

Another significant development in nonwoven composites has been the structures developed by Fleissner for the wet wipes market.

Exploiting the hydroentanglement (spunlace) bonding method, the Germany-based machine builder has developed a range of composite sandwich products and technologies that allow nonwovens producers to make items as attractive costs while simultaneously moving towards meeting consumers’ concerns for their impact on the environment, in particular the desire for increased use of renewable resources.

The options available are combinations of spunbonds (S), carded webs ©, pulp (P), tissue rolls (T) and net scrims (N) in the following three-and two-layer combinations-CPC, SPC, CP, CNC and CT.

Fleissner developed these technologies having realized that with increasing raw material costs it would no longer be possible to produce nonwovens for wipes from expensive high-quality staple fibres alone, but that alternatives using cheaper raw materials were needed.

It is believed that the quality and cost advantages of the composite nonwovens produced with this technology will accelerate the move from all-staple fibre webs to pulp composites, which has already started.

There is a strong demand in the market for products with low-cost pulp layers (to provide the absorbency), combined with a spunbond layer (to give strength in both the longitudinal and cross directions) and a carded web made of staple fibres (to supply the textile hand).

Composite products are also used in many industrial applications. Johns Manville Europe introduced the company’s new CombiFil Premium for the air filtration market.

This is a multi-layer composite made of polyester spunbond and microglass air media. It combines the advantages of both technologies and allows producers to manufacture a pleated filter with high dust holding capacity and low pressure drop. Due to its high stiffness and easy pleatability, the media is self-supporting and requires no wire backing. Combinations of different polyester spunbond and microglass air media products provide customized efficiencies as high as the standards of high-efficiency particulate air (HEPA) filters.

The microglass filter media manufacturing process, heat and high-pressure air melt, draw and make fibres from the glass beads. Special process conditions allow very low fibre diameters to be manufactured, down to the micron range. The fibres are blown towards the collecting belt and deposited on a backing-typcially a light spunbond carrier. They are then impregnated with a chemical binder to form a fluty mat.

Fiberweb introduced the company’s new TopFlow product range for air filtration, which is based on composites of fine fibre meltblown (FFMB), carded staple fibre and spunbond layers.

Through combinations of these materials, bulky three-dimensional and gradient structures can be achieved, with the FFMB providing superior web uniformity and a large proportion of fibres with a diameter close to 1 m, resulting in high dust holding capacity. Additionally, the cost effectiveness of such products is guaranteed by the high production throughput that is possible with Fiberweb’s advanced technologies. apture particles within the body of the media.

Soric is again based on a polyester nonwoven and contains a pressure-resistant honeycomb cell structure, guaranteeing constant laminate thickness and resin flow.

In effect, this makes it a core material and infusion medium in one, for processes such as vacuum moulding (infusion) and resin transfer moulding.

The most important benefits of using Soric are said to be weight savings of up to 35%;excellent resin flow; constant thickness;engineering flexibility; and good mechanical properties.

In such processes, these nonwoven products are effectively acting as a flow media and increasingly they are being employed in vacuum-infused composites to allow effective spreading of the resin. The question is now, could more nonwovens also be used as reinforcements in composites, where glass is still the default, especially considering the current moves to develop parts that are constructed of single polymers.

With annual global production of around 64 million vehicles, some 1.28 Mt of nonwovens are already consumed by the automotive industry as trim and insulation, and in filtration systems. Moreover, the first use of nonwovens on the exterior of a vehicle – as sound-absorbing wheel arch liners – is also a recent and significant development. But their potential as a replacement for glass fibres in the huge composites market for automotive components and body parts represents a much bigger future opportunity.