Sustainability has always been a key aspect of packaging, but the importance has never been higher. Our barrier online calculator can be a very useful tool in development and implementation of more sustainable solutions.
Two of the key aspects in packaging sustainability is REDUCE packaging material and the RECYCLABILITY of the packaging. In this article, we will demonstrate how our barrier calculator can be utilized to simulate some realistic scenarios which enable you to achieve that.
Sustainability is not about finding or choosing one single, ‘correct’ route. We must consider various factors and priorities like recyclability, downgauging, resource efficiency and waste reduction. Damaging a product or food should be prevented because the environmental impact, if wasted, is much higher than the package.
Packaging optimisation and material reduction has been a main topic for the packaging value chain for decades. Changing format or material type can be one way to reduce packaging weight significantly like the change from glass to PET plastic jars or replacement of hermetic tins with retort plastic pouches. Downgauging, i.e. reducing the wall thickness or size of the packaging is another. This can still be achieved in both rigid and flexible packaging applications.
The packaging that is most easily recycled is made 100% of the same material and with no addition of colour. The best example of this is PET bottles which is recycled in large volumes. Many other packaging types are coloured with pigments like shampoo bottles or margarine tubs. Even more complex is the film and flexible packaging which often contain many different materials in different functional layers. These laminated films are highly advanced and have really pushed plastics technology to the limits resulting in very light and functional packaging. However, these are not recyclable.
That’s why the most important activity in the flexible packaging value chain these days is trying to develop monomaterial, structures that can do the same or similar job.
In the following two examples we will show how both downgauging and recyclability can be assessed and obtained and how the barrier calculator is a useful tool.
In order to reduce package weight and provide recyclable packaging, the Norner online barrier calculator enables quick simulation of the barrier performance of new packaging solution.
New mocon instruments
Norner have Mocon instruments for measurement of oxygen (OTR) and water vapour transmission rate (WVTR) which is typically carried out according to ASTM D3985 for OTR and ASTM F1249 for WVTR.
Now you can see several tutorials video with the Calculator that show how it can be a very usuful tool.
Example 1 - Packaging of food for pets
Packaging of pet food has become a major and advanced packaging segment. It involves several different formats, but we will here consider a 5kg FFS bag for dry dog food pellets.
The laminated film was analysed at Norner’s microscopy laboratory which revealed the structure to be BOPP // PE illustrated in the left figure. Here the PE film had three different layers of low density PE material including a PE plastomer in the inner layer for excellent sealing performance. The bag must be tight and since it is a dry food product the key barrier requirement is the moisture barrier.
Let us explore how oriented PE films (MDOPE) can be a technical alternative to the BOPP in the current film.
The new alternative laminate of MDOPE // PE will be monomaterial and can be classified as recyclable. We have designed the PE film with an HDPE core layer and made it 30% thinner, adding to the sustainable profile.
We use the WVTR calculator on www.barrier.norner.no to calculate the transmission of water vapour for a time period of 1 year. The new alternative has 40% better WVTR
Example 2 - Food product
Let’s consider another packed food product, a prefabricated pizza dough.
The microscopy analysis revealed that current laminate is OPET // LDPE/EVOH/LLDPE. This is also not a recyclable laminate because the OPET and PE are not compatible.
A possible recyclable alternative is a laminate of MDOPE as the top/ printing layer with a similar barrier and sealing layer. PE+EVOH is classified in most recycling streams a recyclable when EVOH < 5% of the total content.
In order to compensate for the thinner EVOH layer in the new laminate we propose to change type of EVOH from a 38% to 32% ethylene content. The new calculated OTR for the recyclable film is better!
We use the OTR calculator on www.barrier.norner.no to calculate the transmission of water vapour for a time period of 25 days for this fresh product.