Bag-in-box packaging

Packaging Professional magazine
15 Sep 2009
The bag-in-a box format, where the bag collapses as the liquid is dispensed, prevents air getting into the product to help maintain quality

Bag-in-box packaging is finding applications in beer and water packs. Mark Rose, Business Development Director of Rapak, Rugby, UK, explains

Although bag-in-box was first developed for wine packaging, the format has been adopted by many other sectors due to its ability to preserve products, extend shelf life and deliver convenience while maintaining product quality after opening. The current focus on environmental matters is leading many manufacturers to review their packaging requirements, opening up opportunities for this form of packaging.

Expanded uses

Offering bag capacities of up to 1,400 litres, high barrier films to protect the contents’ quality, and the ability to accommodate both high and low acid applications, bag-in-box is used for a variety of liquid food and drinks, including wine, fruit juices, sauces, soups, post mix syrups and milk.

Two areas in particular have seen significant developments – water and beer. In the water industry, the major attractions are convenience, product protection and taint-free packaging. Ongoing concerns about the presence of bisphenol A in certain plastic bottles has led companies to consider alternative solutions.

A further advantage is the availability of low taint films that stop polymers in the bag reacting with the product. This eliminates the possibility of the packaging affecting the water’s fresh taste. High barrier films can provide maximum product protection when the bag collapses as the liquid is dispersed. This prevents air getting into the product and helps to maintain the quality of the water once the pack is opened, inhibiting bacteriological growth.

The development of a system for beer has provided a low cost alternative to the traditional keg and is suitable for export. Beer for on-trade sales is packed and transported in stainless steel kegs from which it is dispensed. However, their size and weight makes transporting them expensive. Kegs have to be returned for re-use and many are lost in transport. These factors have restricted the export potential for many breweries.

The bag-in-box alternative has lower transport costs – containing nine hectolitres compared to a 5.4hl keg – no return costs, a longer shelf life than the usual three days after opening for the keg and longer-lasting foam on the beer. Shortages of kegs, which can occur due to the seasonability of the beer market, can also be avoided.

Beer can be packed in this way by removing the carbon dioxide after brewing. The gas is then reintroduced through a carbonator box, which is placed in each on-trade outlet between the bag-in-box and the pump head. The system can be used in all outlets that currently rely on kegs.

Other product innovations in the format include hot brewed coffee and tea in the USA. The introduction of new and enhanced technologies, such as faster aseptic filling systems, is further increasing the variety of liquid products that can be packed in bags, especially since this gives a range of sizes – the upper limit for an aseptic carton is two litres.

Antibacterial packaging

One example of aseptic technology is the Intasept system, from UK-based Rapak. It is based on double membrane technology, which guarantees the chemical-free aseptic transfer of the product into aseptic bags. This gives the security of heat-sealed closure both before and after filling, together with a sterile and fully enclosed product transfer path, meaning that the sterile product never comes into contact with surfaces or air space that have not been actively sterilised. The principle is the same for low and high acid applications.

In all market sectors there has been a growth in demand for larger sizes. The largest bags-in-boxes are ideal for foodservice and on-trade requirements, including new types of water dispensers featuring bag-in-box for home and office use, while three-, five- and 10-litre sizes are increasingly popular among consumers buying in bulk.

In terms of convenience, bag-in-box is easy to store and provides a single serve of product when required. Its large decoration area provides space for branding and impact on the shelf. Box designs can be adapted with distinctive and individual shapes that help create product differentiation, such as barrel and triangle shapes and a box in the form of a handbag.

Green bags

Packaging today has to reconcile benefits such as convenience and branding with the wider demands of the environment. Bag technology generates up to five times less waste than rigid containers, due to the empty packs collapsing fully and reducing space during disposal, and the cardboard outer being recyclable. The format is up to 80% lighter than alternative systems, so can reduce energy costs by 20% during transport.

The true environmental impact of any type of packaging can only be assessed over its entire use. Rapak commissioned UK-based packaging research association PIRA to undertake an extensive assessment and comparison of the potential lifecycle environmental impacts of bag-in-box technology with alternative liquid packaging formats. The study compared 30 pack formats and confirmed that the weight of packaging raw materials is a key element which impacts on distribution both for empty and filled packaging. The lighter weight of bag-in-box systems is therefore an important consideration.

The PIRA report stated that bag systems were environmentally competitive and in some cases superior to alternative packaging. It found that the format has excellent environmental credentials not just for wine, but for many other food and non-food market sectors.

The purpose of this lifecycle analysis project was not to prove that one format is ‘better’ than another, but to help manufacturers make the right choice for their particular product or application, given the increasing influence of environmental factors.

Further information:Rapak