Selecting the best film for the job
With the popularity of PE lamination films going from strength to strength, bpi.films has introduced a guide to maximising the full potential of this versatile packaging medium
bpi.films has found a new way to add value to its customers with the launch of a concise and efficient guide to selecting polyethylene (PE) lamination films.
“Considering their numerous benefits which include exceptional sealing characteristics, impressive tear propagation strength and the ability to offer a superior moisture barrier it’s no surprise that the popularity of PE lamination films continues to go from strength to strength,” comments sales manager (speciality films) Jim Morris.
“But with an ever increasing array of products on the market, choosing the right film for a given job can prove difficult. The new guide not only helps users to quickly and accurately select the right PE film for their specific needs, it also offers advice on how to maximise the full potential of this versatile packaging medium.”
In particular, the guide urges users to consider a wide range of influencing factors before selecting a lamination film including reel profile, production techniques and specific application challenges.
“When selecting a polyethylene lamination film it’s important to consider that most lamination machines run at extremely high speeds,” continues Morris.
“In order to accommodate this pace of operation and reduce the likelihood of stoppages, a film must have a good reel profile. It’s also vitally important that these films have the correct level of slip in order to move smoothly over the machinery with reduced drag. However, if too much slip is present at the treated surface, this will lead to a poor bond strength and possible de-lamination issues. If a film employs too little slip, this will result in a low slip laminate reel that will not run effectively on high speed, automated packing lines.”
Creating an airtight seal
Another important consideration when it comes to polyethylene laminate film is its ability to create an airtight seal. To achieve this, films need to be as free as possible from ‘gels’ – small particles of highly crosslinked polymer that do not melt or flow during the heat sealing operation. If these are present in the seal area the seal itself could be incomplete. This could allow gases inside the packaging to escape and be replaced by oxygen, significantly reducing the shelf life of the packaged item. To help minimise the presence of gels, specially selected polymers should be used. Extrusion lines should be equipped with web inspection cameras to detect the presence of gels which are impossible to see with the naked eye during high-speed film production.
Given the sheer variety of packing lines and packing techniques used in the food industry, users should consider the specialist challenges of the intended application.
“It’s difficult for one film to deliver exceptional results across the board,” explains Morris. “A film might work brilliantly on a particular packing line packaging a specific food item but use it on a different one and its performance may not be as impressive. Thankfully, the versatility of polyethylene makes it easy for manufacturers to tailor the characteristics of a film to suit the nuances of a given operation. At bpi.films we offer both mono and coextruded lamination films. Different polymer types are used across the blends for these different products to provide specialist properties depending on the end use.
“We offer innovative products to address specific packaging challenges including antistatic additives for use when packaging powdery products like sugar or flour as well as anti-fog additives for use on high humidity products like cooked meat.”
The guide highlights the need to think of long-term value rather than short-term savings when selecting a film.
“Employing cheap, inferior grade polythene may offer initial savings but it can end up causing excessively disproportionate costs in the end – especially if the problems are only encountered once the laminate is on the customer’s packing lines,” concludes Morris. “This not only incurs massive costs but can also prove hugely detrimental to a company’s reputation and to customer relations. With more and more companies looking to polyethylene films to transport, protect and present their goods, it is increasingly important that they have access to all the relevant information.
“It is for this reason that we’ve launched the lamination film guide. A little insight can make all the difference between specifying a film that performs satisfactorily – and one that performs brilliantly.”
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