Tencel Gel

Martina Opietnik of Lenzing AG, Lenzing (Austria) reviewed the development of Micro Fibre Cellulose from Turbak’s development of a nanocellulose gel in 1983, through their use in biocomposites in the 90’s and in transparent cellulose nanofibre paper in the 00’s, to their current applications in flexible organic light emitting diode displays.  Traditionally pulp is acid-degraded, beaten and homogenised to make MFC but now the lyocell process can be used to make either fibres or beads which require much less energy to convert into MFC. 

Tencel fibre gives a fibrous gel but the Tencel beads give a 3-D structure and a perfectly smooth gel.  They are both white viscous suspensions which are stable over a range of pH’s and temperature, but show thixotropic behaviour.  They also form films on drying, and can be used as coatings for films, textiles, papers and tablets.  Applications in packaging, cosmetics, food thickening, and medicines are envisaged.  In food it could also be a calorie-free fat substitute.

Asked if the coatings would be stable on polyesters, Ms Opietnik thought the gel would stick well to the surfaces of films or fibres but would have to cross-linked for durability.  Application could be by spraying.  Is the gel regarded as a fibre under the REACH regulations?  Maybe a new directive was needed to clarify this aspect.