Masterpack's Liner Guide

Posted on 20 August 2021

Everything you need to know about the liners from the future.

Any chain is only as strong as its weakest link, and for certain products, a great FIBC is just a bag without a great liner.

Liners are a vital part of the process that protects the products we use on a daily basis. It forms an extra barrier against unwanted pests, contamination, humidity, oxygen, and more.

What do you need to know about liners for FIBCs, how do they work, and what type of liners should you be using for a sustainable supply chain? We dive into the details of liners.


What we’ll cover:

  • What are Big Bag liners and what do they do?
  • What are they made of?
  • Liners and sustainability
  • How to seal liners the right way

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.

Find out what the difference is between liners and coated bags, and what works for you.


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:

Conductive liners

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.

Aluminum liners

Aluminum 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

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. Read more about our recyclable liners. 


How to seal liners the right way

Are you looking for a new supplier for Big Bags and liners? Read our blog on choosing the right liner and using it perfectly.


Want to learn more about our liners?

Are you interested in our sustainable liners or want to know more about liners in the MAP process in general? Reach out to find out more.

Want to work towards sustainable supply chain management?

At Masterpack, we are continuously working towards better ways to pack and protect products. We proudly present our newest solution: Modified Atmosphere for FIBC’s. Download our latest whitepapers:

Testing and improving your packaging (1,6MB)
Modified Atmosphere in FIBC's (6,4MB)
Pest prevention and control in bulk packaging (2,8MB)
The Modified Atmosphere Packaging Process Whitepaper

Subscribe here