Health & Safety

Plastic against metal

By Mark Nicholson

March 2020

iFlex double traffic barrier. Photo: A-SAFE

The case for flexible warehouse safety barriers

Can plastic safety barriers really match metal structures in protecting against forklift truck collisions? With the right materials, design and technology, yes, they can. What’s more, their flexible solutions offer important advantages over traditional solid defences. Mark Nicholson reports.

When the power, speed and sheer weight of a lift truck are misdirected, their potential impact on people, equipment and buildings is huge. Not surprisingly, warehouse designers have tended to rely on the strength of metal for protection. This often takes the form of steel crash barriers, railings and bollards, with bases either bolted to the floor or set within
the concrete itself.

Metal’s ongoing costs

Although undoubtedly effective, metal has side-effects which you may wish to consider when weighing up the long-term costs of different barrier options. The first is the way it reflects and transmits impact forces.

A relatively inflexible object like a metal crash barrier directs much of the collision shock straight back into the colliding vehicle. In the case of a car or van, this will result in substantial damage. A forklift may suffer some damage, but due to its more robust nature it is more likely to pass the shock on to its driver and load. This could lead to whiplash injury or a heavy fall for the driver, and damage to goods thrown from the forks.

At the same time, force is transmitted through the barrier and into the floor. In the heaviest collisions, that force is enough to break the concrete – which is expensive to repair. Less serious incidents may just dent or bend the metal. Cutting and welding to deal with structural damage is also costly, so bent and twisted but still functional metal is sometimes left unrepaired.

Here we come to a further downside of metal safety barriers: they don’t keep their looks. They may look neat and tidy when new, but scratched and worn paint, rust and accident damage soon spoil the view. If your business needs to give a good visual impression, you will have to spend regularly on refurbishing and repainting them.

Plastic-v-Metal_content_images_1.3

Not a pretty sight. Bent, rusted metal and flaking paint give a poor impression.

Flexible benefits

Instead of becoming permanently deformed themselves, or turning impact forces against the vehicle and floor, the best plastic barriers are designed to absorb and dissipate shocks. Absorption is achieved partly through plastic materials which deform temporarily under impact and then return to their original shape. They also have additional components which flex or cushion in response to impacts. Meanwhile, their whole system works together to disperse impact energy harmlessly over large areas.

Vehicles, drivers, goods and floors escape damage, and so do the plastic barriers, provided the right specification is chosen. There is no need to paint or repaint, and no rusting. What’s more, they are comparatively easy to relocate if premises are restructured.

End-to-end possibilities

The market offers an extensive choice of flexible plastic safety barriers meeting all needs. Key categories include:

  • Crash barriers – linear defensive features providing effective protection of walls, equipment and people in the areas they enclose or block off
  • Handrails – segregating pedestrians from lift trucks, sometimes in combination with crash barriers
  • Bollards – placed at strategic points such as entrances, or in high-traffic zones and other vulnerable areas; this category includes ‘goal posts’ to protect doorways
  • Racking protection – including barriers placed at rack ends and guards attached to uprights
  • Column protection – enclosing or attached to columns which support the building

A relatively inflexible object like a metal crash barrier directs much of the collision shock straight back into the colliding vehicle.

It’s not Eureka’s job to tell you which manufacturer’s products to choose, but the examples below should help illustrate the technologies available. As a starting point for your product search, it would make sense to look at A-SAFE, Boplan and McCue, which are amongst the market leaders for plastic safety barriers. Each of these manufacturers offers modular systems covering the range of barrier types above, and more, with variations to suit every specific situation.

A-SAFE

A-SAFE barriers benefit from the company’s unique Memaplex plastic material. This is produced by custom-built machinery which stretches the molecular structure of polymers and orientates their flow at the point of formation. The resulting grid structure, within which molecules are realigned, creates an inbuilt memory, allowing components to recover their shape after deforming to absorb impacts.

The barriers are connected by a patented coupling system which adds strength and absorbs impact energy in three sequential stages. As well as cushioning the force, their design dissipates energy through the barriers’ length and away from their fixing points on the floor. Examples of A-SAFE iFlex crash barrier, handrail and bollard designs are shown here.

Plastic-v-Metal_content_images_1.4

iFlex cold storage bollard. Photo: A-SAFE

Boplan

Boplan’s Flex Impact range of safety barriers is based on another high-quality, high-performance polymer which matches metal in strength but has elastic properties. Again, they are designed to absorb shocks and dissipate them through the body of the barrier.

A wide choice of modular products is offered. For instance, the Flex Impact handrail selection includes light, medium and heavy versions with varying rail arrangements. One interesting option is the TB Plus barrier, which combines the functions of a handrail and a crash barrier. Safety gates can be incorporated, encouraging personnel to stop and think before moving from a protected pedestrian zone into an area with forklift traffic.

McCue

McCue uses a variety of different materials and engineering solutions to deflect, disperse and absorb impacts. Its FlexCore bollards, offered in a range of diameters and heights, are a case in point.

First, a rotating HDPE (high-density polyethylene) cover absorbs any glancing blows. More direct impacts are absorbed by a flexible load ring and transmitted to the bollard’s core. This has a high tensile steel shaft which bends slightly to absorb heavy impacts and then flexes back unharmed. The anchoring system features a stress-relieving polyurethane damper which protects the floor from damage. Similar elements are used in McCue’s pedestrian barriers, crash barriers and other protection systems.

Although some plastic barrier systems may be higher-priced than their metal counterparts, warehouse operators must always think in terms of total cost of ownership. When you add up the costs of metal barrier and concrete floor replacement or repair after each accident, you may find plastic becomes more economical. You should also look at how much routine maintenance they will need. Then factor in the damage and injury that metal barriers may do to your forklifts, goods and drivers, and the time lost as a result. On that basis, you might decide that plastic not only looks better but makes best economic sense.

Plastic-v-Metal_content_images_1.1

iFlex double traffic barrier+. Photo: A-SAFE

Plastic-v-Metal_content_images_1.2

iFlex pedestrian three rail barrier. Photo: A-SAFE

Drive carefully!

Remember that the collisions discussed in this article are caused by poor driving. If operators drive too fast, or without enough care, they will collide with something or someone. Your first line of defence against such behaviour should be to train them well and enforce a strong safety policy. Safety barriers need to be effective, but your aim must be to avoid hitting them in the first place. Here are some tips:

  • Slow down when driving close to people, racking, other equipment and vertical building structures
  • Keep a clear distance from all the above
  • Slow down at turns
  • Look in the direction you are travelling
  • Make sure your load doesn’t block your forward view (if it does, travel in reverse – except up slopes – or ask a colleague to guide you)
  • Beware of rear-end swing when turning
Plastic-v-Metal_content_images_2

Driver error can be reduced by advances in precision steering, controlled operation and automated safety, as found on the award-winning Cat® EP14-20A(C)N(T) electric counterbalance. Nevertheless, strict safety rules, thorough training and effective physical barriers are still vital to minimising risks of collision injury and damage in the workplace.

Print