What are the applications of nanocellulose in packaging?

Have you ever wondered about the strength of steel? Well, you will be surprised to know that nanocellulose (NC) is 8 times the strength of steel. It is also known that NC is stiffer than Kevlar®. In addition to strength, nanocellulose has many properties that make it a sustainable and versatile material for the packaging industry.

Brief overview of the packaging industry:

The packaging industry has been using materials, based on glass, aluminium, tin and fossil-derived synthetic plastics to protect consumer goods. Owing to the growing economical and environmental concerns of these materials, alternatives are being considered. Recently, the benefits of cellulose-based packaging materials, particularly, nanocellulose, have been considered. Apparently, the prolonged use of such by-products, could help solve the unsustainability, costs and disposal challenges that the industry faces. These nano-sized particles form part of the renewable resources that can potentially solve the sustainability issues. According to a market research study published by Technavio,

“The global nanocellulose market is expected to grow at a CAGR of close to 30% during the period 2017 – 2021.”

The applications of nanocellulose in packaging:

Nanocellulose is of immense significance in the ongoing commercialization of nanotechnologies. Researchers and industrialists are therefore analysing and exploring new manufacturing processes and applications for NC. According to Gizmodo, seven incredible uses of nanocelluloses include ultimate body armor, super-flexible screens, future filters, bendable batteries, ultra-absorbent aerogels, incredibly fuel-efficient cars and biofuel. From a packaging perspective, the motivations to apply nano-scale cellulosic particles in packaging are multi-folded, as listed below: 

Edibility
Flexibility
Biodegradability
Transparency
Antimicrobial
Mechanical and barrier properties:

I. Oxygen II. Oil and grease III. Water vapour IV. Aqueous liquid

Importantly, Li and team highlighted that the packaging applications of cellulose-based nanomaterials in various industries, are technology-dependent. These technologies include: 

Layer-by-layer assembly
Electrospinning
Composite extrusion
Casting evaporation
Coating
All-cellulose composites 

Nanocellulose & the food packaging industry:

Nanocellulose, as a food packaging material in this growing sector of food and beverages exerts several purposes, such as: 

Preventing spoilage of food contents
Blocking the entry of oxygen into the food contents
Replacing the use of polystyrene-based foams
Extending food shelf-life 

Improving food quality as they can serve as carriers of some active substances, such as antioxidants and antimicrobials.

Interestingly, a new packaging technology, known as ‘active packaging’ incorporates the use of nanoparticles (e.g. nanocellulose) into polymer films to control microbial surface contamination of foods. The supply of this innovative technology is attracting much attention within the food industry due to the increasing consumer demand for minimally processed, preservative-free products. Moreover, the incorporation of nanomaterials in food packaging also help in food waste reduction as it preserves freshness of packaged food. Scientific studies are demonstrating effectiveness of the application of NC in food packaging, as exemplified by the following: 

Elimination of anthocyanins pigment leakage from blueberries during thermal processing due to coating with aqueous slurries of cellulose nanofibrils. 

Improved shelf life and quality of strawberries by applying a mixture of 1% chitosan and 5% NC. 

Nanocellulose & the paper and paperboard making industry:

In the paper and paperboard making industry, this revolutionary material, acts as an additive and a strengthening agent, which makes paper denser and stronger due to the greater surface area of NC. It also provides smooth surfaces to printing papers, improving printing quality. Owing to its optical, cost-efficient, light-weight, biodegradable and recyclable properties, transparent NC paper has gained much attention in the field of electronics (e.g. mobile phones, computers, TVs, touch sensors, solar cells, paper-based generators, etc).

In addition, an interesting study by Volkel and others has demonstrated that NC, particularly, from bacterial origin, can potentially serve as a novel stabilizing agent for paper and can be used to consolidate damaged historic papers without the application of additional adhesives. 

Conclusion:

To conclude, nanocellulose has been considered as a less expensive alternative to carbon and glass fiber for certain applications. It is also applicable as a useful material by the paper and pulp industries due to its increased absorbency property, which is beneficial for several products, such as napkins and towels. Nowadays, nanocellulose is continuously playing a vital role in the food sectors. It can also improve the environmental footprint of many of these industries by replacing synthetic or petrochemical-based materials.