Produced by processing woodfibre down to the smallest fibre component, nanocellulose was developed during the 1980s, but was not successfully commercialised because of the energy intensive production process involved. Sappi's patented process does not require significant energy inputs. What's more, the chemicals used in the process can be recycled easily and reused without generating large amounts of effluent.
Cellulose is the main component of plant stems, leaves and roots. Traditionally, its main commercial use was in producing paper and textiles. Nanocellulose opens up opportunities for advanced, planet-friendly solutions in place of environmentally harmful products. It currently exists in three forms:
• Cellulose Micro Fibrils (CMF)
• Cellulose Nano Fibrils (CNF)
• Cellulose Nano Crystals (CNC)
All processes involve the separation of CMF, CNF and CNC from the woodfibre.
Sappi has built a pilot-scale plant for CNF production, at the Brightlands Chemelot Campus in The Netherlands. Although designed to produce CNF, the plant will also be capable of producing CMF. Feedstock to the plant will be sourced from sustainable and certified sources.
The CNF produced by Sappi has unique morphology, and can be specifically modified for either hydrophobic or hydrophilic applications. Products produced using Sappi’s CNF will benefit from the high strength characteristics which, for example, can be translated into lighter and stronger fibre-reinforced composites and plastics in the production of next-generation lighter, fuel-efficient vehicles.
Sappi CNF could also be used in a wide range of other industrial and everyday products and devices due to its ability to improve on the properties of materials with which it is combined, for example, thickening water-based products such as paints, foods and concrete. Because of CNF’s low oxygen permeability, it could also be a future replacement for plastic films in composite packaging.
Other applications include films in lithium batteries and touch-screens. As cellulose is inherently biocompatible and bio-absorbable, there is considerable potential in biomedical applications such as wound dressings and regenerative medicine.
Among its many potential uses, nanocellulose can be used as:
• A substitute for metal materials such as high-tech spun fibres, for example in vehicle manufacture
• Antimicrobial films and water absorbent pads in medical applications
• Electronic displays
• In sensors that could help monitor structures like bridges to detect stresses
• Food packaging material that prevents oxygen entry and spoiling
• A flavour carrier, suspension stabiliser and thickener in food
• A thickener in industrial applications
• As aerogel to mop up oil spills, and
• As an additive to improve the mechanical properties of rubber, latex, thermosetting resins, soya protein and starch-based matrices.
Please click here to view our FAQs on ‘Nanocellulose’.