Given its long history of dairy farming and production, one need goes no further than the UK for a demonstration of milk packaging best practice. Darren Dodd explains the impact food safety has had on milk packaging worldwide and the importance of integrating a tamper-evident seal into the container closure

The glass bottle was UK consumers’ preferred milk container well into the 1970s. This then gave way to lightweight, safer and easier-to-manufacture LDPE coated cardboard cartons. Later it moved to the now ubiquitous screw-capped, induction heat sealed HDPE container. While the UK has effectively pioneered the use of reliable, leak-free and secure packaging for milk containers, other developed economies have been surprisingly late in catching up.

In the United States, for example, glass may have been phased out more rapidly than in the UK in favour of coated cardboard cartons and square HDPE gallon capacity milk jugs. US dairy suppliers and retailers, unlike their UK counterparts, are latecomers to the benefits of leak-free, tamper-evident seals, particularly for HDPE milk jugs. Indeed, as US customers began to welcome the transition from glass bottle to plastic jug, the drawbacks of the latter having no secondary sealing between the container lip and the screw cap soon became apparent.

The need to seal
Leaking milk containers were accepted as par for the course. Retailers had the constant task of keeping shelves clean and accepting the complaints of consumers who, on returning home, had discovered that their milk had leaked in transit. In the shops and supermarkets, the only recourse for perennially frustrated retailers was to use costly and unsightly spill mats to soak up leakages from shelf surfaces.

Australian retailers were having similar experiences but growing consumer concern for better product safety, hygiene and the elimination of product leakage saw much wider adoption of induction heat sealing. Selig is a close observer of the Australian market and claims that, as far back as 2007, the introduction of its Lift ‘n’ Peel™ induction liner by the Australian dairy industry proved a positive selling point. Resulting in a significant sales growth for those brands that adopted the seal as a key element of their dairy packaging.

Scalable process
Canada is also seeing a trend towards induction heat sealing of milk containers following a well reported contamination incident. In June 2017 the Royal Canadian Mounted Police were called to investigate milk recalls in British Columbia when a ‘potential presence of harmful extraneous material’ was reported in unsealed milk jugs from a supplier.

Health Canada said there had been no reported illnesses associated with the consumption of these products but did conduct a food safety investigation. The dairy in question acted very promptly to improve the security of its milk packaging and, in a concerted effort to ensure best practice, has now taken the precaution of applying tamper-evident induction sealed liners to all its milk jugs.

Selig has been particularly successful in addressing the needs of the UK dairy industry. It’s easy-open induction heat seal liner provides immediate evidence of tampering. Its integral easy open, half-moon pull tab has been designed to be ergonomically easy to grip, while remaining flexible and extremely strong.

The process of applying this type of liner is, however, critical to its success. No other processing or equipment, other than an induction heating machine, is required to bond the liner. There are several key process conditions that must be met and maintained guarantee successful container sealing on a filling line. Once these process parameters have been established for a given line speed, consistent sealing integrity is assured.

Induction heat sealing is also a scalable process. Even a start-up can take advantage of this state-of-the-art liner technology, making use of new semi-automatic, even hand-held, induction machines. Induction heat sealing provides an interesting entry-level opportunity for those producers currently using milk bags or other forms of packaging. Enabling them to test market reaction, to differentiate their offering and, ultimately, to provide peace of mind for consumers.

Darren Dodd is Marketing and Service Director at Selig, a leading worldwide manufacturer of tamper evident cap and closure lining materials for use across a broad range of applications; such as food and beverage, pharmaceutical, agrochemical, cosmetics and healthcare. Selig’s comprehensive range of both one and two piece structures means that it can manage even the most challenging applications with one of its customised aluminum foil/heat seal combination products.