The sale of the 1.6m-wide line, which concluded in September 2017, is to an Asian manufacturer that will use it to make polypropylene (PP) and polyethylene terephthalate (PET) filter media with basis weights in the range of 20-50gsm.
Since Nanoval began developing the technology in 2002, the company has only sold two pilot lines based on the process. The main obstacle to commercialization has been the lack of uniformity of the fabric weights, according to the company's project and quality manager Christian Gerking. However, in the later part of 2016, Nanoval was finally able to resolve this issue.
Nanoval was founded in 1987 by Gerking's father and current managing director Lüder to exploit a splitting effect caused by a particular flow of has to make small, round metal powders. Having worked on the development of nonwovens for Freudenberg in Weinheim and Kaiserlauten, Germany, during the 1960s and 1970s, Lüder Gerking also realized the potential of the technique for making fabrics.
Compared with conventional methods, the principal advantages of the Nanoval process are that it is simple, cheap and robust, and it consumes less energy and air than is needed to make an equivalent meltblown web. The process can be applied to a range of polymers including cellulose and lyocell.
In the case of cellulose, the process can operate with cheap paper pulp, including waste paper, as a raw material. However, Nanoval says the principal advantage of its cellulose/lyocell spunlaids compared with those made using staple fibers is the fineness of the continuous filaments, which have diameters below 10μm. Conventional staple fibers have a minimum titre of 1.3 dtex (diameter of 10.5μm).
Unfortunately, the productivity for cellulose fabrics is still below that demanded by potential customers; in 2017, the company succeeded in doubling the productivity to 12 kg.h-1 for each meter of working width; prospective buyers are asking for more than 20 kg.h-1.