Early Tencel History from "Regenerated Cellulose Fibres" (part 3)

Regenerated Cellulose Fibres published by Woodhead Publishing Ltd in 2001 contains a history of the Tencel development, the third extract of which appears below. (see the original for references - click here for first extract)

American Enka decided not to commercialise the process and stopped the research in 1981, probably because at that time engineering issues associated with the difficulty of avoiding exothermic reactions looked too hard to resolve economically. However when Courtaulds had demonstrated practical solutions to the many problems discovered during American Enka's early work, they (Enka that is, now part of Akzo-Nobel) re-entered the field with the continuous filament version of the lyocell process under their brand name "Newcell". The Akzo deal with Courtaulds involved their gaining access to Courtaulds technology in exchange for granting Courtaulds rights to use some of the key steps in the early patents mentioned above.Coming right up to date, Akzo Nobel acquired Courtaulds in 1998, and formed Acordis Fibres, bringing together in one company all the key lyocell technology. However, Akzo-Nobel had earlier granted a lyocell license to Lenzing, the Austrian viscose fibre maker, allowing Lenzing to enter the field with a very similar process to Courtaulds. The ensuing patent litigation between Lenzing and Courtaulds was to prove costly to both companies.
Lenzing obtained a patent in the USA for a process, some aspects of which had been operated by Courtaulds for many years, and indeed were used in production at Courtaulds Tencel® plant in Mobile. Courtaulds naturally objected,

and applied for summary dismissal of both the US and the subsequent European patent. In Europe, the Munich court would not allow the Lenzing patent to be dismissed summarily and the case went to trial. Courtaulds won, and Lenzing's European patent was disallowed with no right of appeal. In the USA, the Lenzing patent was summarily dismissed, but Lenzing appealed successfully, winning the right to another costly trial. At this point the two companies reached a settlement out of court. The lyocell patent estates of both companies were pooled, to be available royalty-free to both companies. It is perhaps worth noting that the settlement only covered patented technology. There was to be no sharing of "know-how" gained in the operation of the process, which at the time, had only been commercialized by Courtaulds.

(more to come)