What do big bag liners do?
Big Bag liners are quite literally an extra layer and barrier within the FIBC. This is used to protect the packed product even more. An FIBC itself is made from woven polypropylene, meaning more or less through which contamination can enter, the product can fall through, and moisture can pass.
Liners seal these holes, protecting the products against pests, moisture and in the case of Modified Atmosphere Packaging, even oxygen.
Depending on the needs of a customer, the liners are either separate in the bag, or they are directly attached to the FIBC – by sewing or gluing them.
The advantage of loose liners is that they can be taken out to reuse the FIBC. For bags where the liner is glued or sewed to it, this is not – yet – the case, which we’ll dive into later.
Other advantages of liners is that they can be fitted with antistatic properties, provide chemical resistance and also help with safe filling and discharging.
What are big bag liners made of?
Most liners are made with PE, eventually combined with PA and AL, but all of our liners are made to fit your needs. This is what you need to know about the different materials and the implications for use cases:
These are made from carbon-loaded polyethylene. This creates an obvious path for static to escape. This will mitigate the potential for explosions when working with dry food products such as flour or starch.
Aluminium liners are used when products require a fully leak-proof bag.
Anti-static dissipative liners
Dissipative Big Bag liners are ideal for situations where static control is crucial and can be used in cleanrooms and research fields
Opp metalized liners
Metalized oriented polypropylene (OPP) is an ultra-high barrier liner that provides maximum protection of oxygen- and moisture-sensitive products, for which shelf life needs to be increased. OPP metalized liners are a cost-effective and lighter alternative to aluminum liners
EVOH liners are used to create leak-proof bags. These liners consist of different layers made from a mix of materials to keep oxygen outside. This makes them very popular in the food industry and for products with a strong smell.
Liners and sustainability
As mentioned earlier, liners pose a sustainability challenge: when they can’t be separated from the Big Bag, the bag can’t be recycled, and given the nature of their own materials, the liners themselves are also hard to recycle.
Masterpack is fighting this in two ways: first of all, by using as little material as possible. Secondly, we are working on creating recyclable liners.
Cutting back on waste
The traditional way of creating liners is by cutting and shaping them from big tubular PE film, the so-called bottle shape liner. This is rarely exactly accurate and often needs to be tailored even more, leading to unnecessary waste material.
Masterpack does things differently. We design and fabricate PE films that are exactly the right size for our custom-made liners, so we don’t have to cut any surplus material. This saves 10 to 20 percent on waste per liner and tons of kilos on a yearly basis.
Creating recyclable liners
Liners that contain AL or PA can’t be recycled. This has been a big hurdle in making our product as sustainable as possible, but in 2021 we are launching the solution.
We have been able to replace the PA and ALU by special PE types, creating liners that have all the characteristics our clients are looking for. Tests show that protection levels are 5 to 8 times better than with the standard barrier liners. Our liners are now more sustainable than ever while still keeping your product safe.