The packaging market can be a minefield – so many choices. So how do you choose which material to use? Which type of label shrink, stretch, glued? Which applicator?
PDC Europe offers personalised advice to anyone who asks, and today our CEO, Derek Vandevoorde, answers a few of your questions about stretch sleeves.
What are the characteristics and benefits of stretch sleeving for manufacturers?
Stretch sleeve is made from low-density polyethylene (PE) from a plastic tube that’s smaller than the container that it’s applied to. It’s stretched, the film’s elasticity ensures that it stays put on the container or product without having to use any glue. It was first used in the mid-80s, in the agrochemical sector and on petrol products, on large, simple can-like containers. The massive advances in the properties of low-density PE, with more & more elasticity, has allowed the technology to come on leaps & bounds to cater for increasingly complex shapes: concave, convex or curved. And so stretch sleeves were then developed for the drinks and milk industries.
Stretch sleeves offer a 360° communications surface. It can be white, colour dyed, with heliographic surface printing or transparent with “internal” printing (inside the sleeve) which protects the communications from the risk of erosions.
What’s more, the sleeve can withstand extreme temperatures, from -40°C to 60°C, meaning it can be used in humid and negative temperatures without any damage. In addition, stretch is an opportunity to save money on equipment and energy, as the technology doesn’t require a shrink tunnel. Not to mention the benefits in terms of recyclability. With Pes density lower than 1, the sleeve can be separated from surrounding products to be recycled.
What are the limits to sleeve technology?
It’s impossible to provide tamper-evident functions with the stretch sleeve. Also, even if stretch sleeve’s elasticity has increased hugely since the 80s, it still doesn’t have the ability to completely decorate a bottle from the neck to the foot if the shape deformations are higher than 40%. A shrink sleeve, on the other hand, adapts to up to 70% of shape deformations.
We can say that the stretch sleeve is a good compromise between a label that only covers a small part of a product, and a shrink sleeve that covers the whole product but at a much higher price point. On a similar note, both stretch and shrink sleeves need specialist printers with the technique to full the film without reducing the quality of the printing. There are only 15 or so who can do this, whereas clients often want to work with local film suppliers.
How do you fulfil the needs and expectations of manufacturers?
The sleeve industry has been confronted with “plastic bashing”, which is unjustified as a polyethylene terephthalate (PET) bottle can be recycled NINE times without losing physical properties or its transparency. It’s a light material which protects products from Ultraviolets (UV), enables a longer “use by” date and helps reduce waste. We just need to improve the access to recycling, reduce the thickness of materials and the weight of packaging.
In the UK, the milk “bottles”, made from high-density polyethylene (PEhd) are sleeved with stretch sleeves which has meant that they can reduce the thickness and weight of the container quite noticeably. The sleeve guarantees the support of the container – so the potential is huge.
Currently, the continual improvement of our machines relies on the precision of the process, in the reshaping of the sleeve in a homogenous way, releasing it at the right moment and placing it in a consistent way.
We’ve also launched SAM, an entry-priced range dedicated to large containers. Thanks to the standardisation of the sub-assemblies which their make up the machines in the range, SAM prices are 30% lower than the next model up. It means manufacturers can skip a step when equipping their plants & factories.
Beyond that we custom-engineer machines, using our 40 years of experience, to offer optimised equipment. We’ve patented our Universal Electronic Reject System (SURE) at European level. It can be installed on a sleeve applicator machine and eject fragile & unstable non-conforming products without risk of damage or fall at a rate of up to 600 cycles a minute. SURE is very compact, measuring just 30cmx30cm. There’s also HORIZON, our stretch sleeve applicator which gives the option to group containers horizontally, and our StackPack solution which groups products in a stack, one on top of the other.
Whatever the manufacturer’s specific needs, we’ll be able to offer a solution. Contact us firstname.lastname@example.org to see how our team can help you make informed choices when it comes to your packaging.
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