Load stability: how your products can be transported safely

An interview with Jelle DenDauw of ESTL Belgium.

How do you fasten a thousand coke bottles on a lorry so that they remain standing, even if the driver has to brake or swerve suddenly? It’s a typical question about load stability, and just one of the many that Jelle Dendauw deals with at ESTL, his company in Deerlijk.

Dendauw, who trained as a mechanical engineer, is a co-founder of the Belgian company ESTL and only became involved in load securement more or less by accident in 2009. The year itself is not a coincidence at all, being the year Belgium introduced new legislation on load stability.

‘Before 2009, the only actual rule was that the load should not fall off the lorry,’ Dendauw explains in his office in Deerlijk. ‘The police could only hand out a fine if the load had already fallen off the vehicle, but not if it was still dangling 1 millimetre above the road.’ The law changed in 2009, when Belgium introduced requirements for loading, meaning that loads could be checked for stability. ‘Since then, load securement is not just the lorry driver’s problem – it’s also the responsibility of those in charge of loading the lorry and the company that owns the load.’

ESTL is a KU Leuven spin-off and the loading operations came about following a scientific study carried out at the university. ‘We have a number of questions we ask when we fasten a load on a lorry: what kind of lorry is it? What does it look like? Does the vehicle have any special features? And things like: what kind of equipment is there: straps or anti-slip mats? And how much can they hold? Then there’s things like: what needs to be fastened? What is the load? And how do we need to fasten it so that it stays on the pallet?’

Dendauw has noticed that the industry is also paying more and more attention to those questions. In the past, load securement was mostly left to the driver. ‘If a load was delivered to a customer in a damaged condition, the customer would ring the carrier and the goods in transit insurance would pay for the damage.’

All that has changed now. ‘Now, people are finally beginning to realise that the issue involves the entire industry; this problem can’t simply be shifted to the last person in the chain. It’s certainly altered the dynamics.’

It means that businesses are currently taking a new look at their packaging systems. ‘If there’s any damage, the question asked nowadays is more likely to be: could those products have actually stayed where they were?’ Dendauw does not believe that it’s an ideal situation as yet. ‘But we are getting closer.’

How do you make sure the load is stable?

Load stability consists of several levels. The pallet must comply with certain conditions and the pallets need to be wrapped, packed, but the most important part is the product that is to be fastened to the pallet, particularly its shape. ‘There’s a lot of difference between coke bottles and bottles of Perrier water,’ Dendauw continues. ‘The shape is usually based on marketing decisions rather than technical requirements, although the shape affects much of the pallet’s load stability.’

He illustrates this with two extreme examples: you can load bricks onto a pallet and stack them in neat piles. The bricks really won’t break under pressure. Even so, something can go horribly wrong if you don’t wrap something round them, or if there is something wrong with the packaging. On the other hand, you can wrap the best film there is around glass jars, but if the jars aren’t strong enough, they will still break under pressure.

It is important to know that, because a lot of pressure is put on a pallet during transport. ‘It can even reach accelerations of 0.8g.’ That’s what happens if the driver has to make a very sudden emergency stop. ‘If a pallet weighing 1,000 kilos is involved in an emergency stop, 800 kilos pulls on it, so to speak. G-force comes into play in sharp turns too, and can reach up to 50 percent of the weight.’

That’s why they conduct acceleration tests at ESTL. They put a pallet on a platform and set it in motion so they can observe how all the components on the pallet shift. They can analyse the images and movements with the help of a high-speed camera. Accordingly, ESTL can make sure the shifts remain within the permissible specifications.

What happens if the pallets aren’t stable?

The most drastic instance of poor pallet stability is the loss of a load. Then there is the risk of severe damage, resulting in diminished value. Lastly, the packaging could break, which could mean that the centre of the load’s mass shifts. ‘As a result, the lorry controls the driver, instead of the other way round.’ That’s something that the police are getting better at identifying now too, according to Dendauw. ‘If a lorry overturns in a bend, but the driver wasn’t going too fast, there can only be one conclusion: the load started to shift.’

Businesses cannot easily assess pallet stability just by looking and often special tests are needed to determine the stability. ‘All too often, we see someone push against a pallet – to check whether it shifts or not – and report that it’s stable. The only thing that they forget is they pushed a few kilos against a pallet weighing a tonne.’

The importance of wrapping film is growing.

However, businesses need to spend more care on devising packaging concepts too. Dendauw believes that more and more companies are opting for ‘light-weighting’ solutions for their primary and secondary packaging. ‘This means that the integral strength of the packaging is reduced, so the role of tertiary packaging like wrapping film is becoming more important. You see, that reduction must be compensated by something else.’

The problem is the number of different several stakeholders, says Dendauw. For instance, retailers don’t want the packaging to cause a ‘nuisance’ in their stores. ‘Think of jars of spaghetti sauce on a low tray, that’s a good example. Things like that used to be wrapped in shrink film, but now people try to do without it. However, it does have an unfavourable effect on the pallet’s stability. After all, all the jars can – and want to – move independently. If you’re pragmatic about that concept, you can make a prior estimate of it.’

Businesses can have the effectiveness of their packaging systems tested. ‘They can ask us to do an acceleration test, and so on. For example, we investigate what works best for AFP customers. In fact, staff from AFP’s Research & Development Department often come to us to test a new type of film they have developed.’ Because, as Dendauw says, the film is not the most essential element, but rather a company’s last effort to ensure the safe transport of their product.

And that’s how we make sure a thousand coke bottles reach their destination in one piece.

More information: ESTL.be

Also read our article about load stability and EUMOS by Mark Juwet