ECJ EUROPEAN Cleaning Journal

Dust, stones, rubble, leaves, paper cups, broken glass, takeaway cartons – these are just a few of the items that a sweeper has to pick up. So, what are the challenges involved in removing such a vast array of debris, asks Ann Laffeaty? And do sweepers need to be able to separate out all those different types of rubbish?

Most cleaning machines have a fairly specific job to do. A vacuum cleaner’s task is to vacuum up dust and fluff from the floor, for example. The job of a high pressure cleaner is to remove dirt and grime from walls and other surfaces using the power of water. And scrubber dryers have to deep-clean a floor and then leave it sufficiently dry for immediate use.

But a sweeper’s job is to collect up everything that happens to be in its path, then pick it up and remove it. And this could be anything. In an indoor environment such as a warehouse or factory the debris could include glass splinters, metal shavings, hazardous dust, paper waste, empty packets and coffee cups.

In an outside space such as a municipal park, road or a car park the sweeper may have to remove broken glass, cigarette ends, stones, dust, pine needles and autumn leaves. So, how does one machine cope with such a vast array of debris? And how far do these items need to be separated out before being disposed of?

Most sweepers will separate out large items of debris from the fine dust, according to Kärcher’s product manager sweepers Marian Anton. “The strong suction blower within the machine separates out the dust via a filter,” he said. “This then binds the dust so that it cannot be released back into
the environment.” The company’s Archer sweepers incorporate dust class M filters that offer a separation degree of 99.9 per cent.

While other items of rubbish are not generally separated out by the machine, a “picker” can be attached for manual use, he says. “This allows the operative to pick out large items of debris while cleaning,” says Anton.

Kärcher’s Homebase system allows the sweeper to incorporate various accessories for separating out rubbish and containing it. These include extra brooms, an additional container and a litter-picker which comes with a rubbish bag and a bin positioned on the machine.

Wet leaves present a particular sweeping challenge, says Anton. “The difficulty here lies in the large volumes of leaves involved, particularly during the autumn,” he adds. Kärcher’s leaf collection kit may be added to the company’s KM 105/100 R machine. This holds 300 litres and provides sufficient space for a large volume of leaves, though there is no separate hopper.

Fine dust hazardous

Fine dust needs to be separated from other debris since it can be hazardous to health when inhaled, and in high concentrations may also cause explosions. Kärcher’s sweepers are said to offer powerful filter systems and efficient de-dusting mechanisms for filtering or separating out fine dust from other rubbish.

When asked about the most challenging tasks for a typical sweeper, Anton asserts that this largely depends on the type of floor surface and debris involved along with the specific demand on the sweeper and its rollers.

“A standard roller brush will work well in most cases, but users may change the roller when dealing with a very specific type of debris,” he said. “If for example the surface is very smooth or a carpeted floor needs to be cleaned, a soft roller is recommended while a hard roller may be required when removing stubborn dirt from rough floors.”

New from Kärcher is the KM 85/50 R battery-powered ride-on sweeper which has a rotational speed that may be adjusted during operation to suit the type and amount of dirt involved. The collected dirt is then divided evenly between two 25- litre catch pans to facilitate the removal and transport of the debris when emptying. The machine can also be equipped with an additional side brush.

Lindhaus offers a machine for indoor use that collects the swept-up rubbish in a four-litre microfibre bag, says the company’s president Michele Massaro. “The rubbish enters the bag right after being swept up to avoid the risk of clogging,” he said. “Meanwhile, the suction controls the dust while the five-stage HEPA filter puts this machine in a different class to other mini-sweepers, which tend to be equipped with one brush and offer no suction and no filtration.”

The Lindhaus LS38 L-ion and LS38 Electric works by means of two counter rotating brush rollers which feature a low power consumption plus a high efficiency single vacuum motor, says Massaro.
The model is said to be capable or sweeping up fine dust and stones as well as paper clips and long objects such as pens and pencils.

Separating out the different categories of swept-up rubbish is an ongoing challenge according to IPC’s communications manager Gabriella Bianco. “However, today’s manufacturers are developing the most pioneering of machines that can pick up all types of debris whether it is broken glass, bulky items, small stones, leaves and scraps of paper from hard surfaces where water can’t be used,” she said.

IPC sweepers contain only one containment hopper at either the front or rear of the machine and all debris is removed by means of one main brush. “Some sweepers are equipped with filter systems for dust control and are more efficient for picking up fine dust than vacuum sweepers,” she says. “Here the debris is collected by the brooms and then brushed up to the vacuum suction.”

IPC’s 1280 ride-on sweeper has a polyester pleated filter which is said to offer good dust microfiltration results while its main brush has a V shape for the efficient sweeping of larger debris.

Collecting many different kinds of debris in one pass can be a challenge according to Tennant’s EMEA product manager Stefan Sehmke. “Each type of industry has its own distinct issues,” he said. “For example, cement factories will have to deal with fine dust as well as larger types of debris whereas logistics centres need to cope with items such as shrink wrap and wood chips. And outdoor sweepers need to be able to perform well on both dry and wet surfaces.”

Technical solutions

Tennant machines do not separate out the debris while sweeping, he says. “However, most of our sweepers have optional vacuum wands that can collect specific items of debris such as shrink-wrap in a separate hopper,” says Sehmke. “And we offer various types of sweeping brush that can be mounted under most machines.”

For example, the company’s Window Brush is designed for sweeping up bulky items and paper scraps in environments such as printing and packaging plants. And the patented Sand Wedge Brush has gaps between the bristles to enable it to perform a digging action. This is said to make it effective at removing large quantities of sand, dust, flour and other fine powders in bakeries, foundries and cement plants.

The need to manage dust is a particular issue for sweepers, says Sehmke. “Extremely fine dust creates health and safety challenges in many working environments,” he said. “Controlling fine dust is a complex task that requires good technical solutions and effective practices.” Tennant has recently added HEPA filtration capabilities to its S20 sweeper to collect and contain smaller particles.

Head of marketing for Columbus Valérie Comandré agrees that fine dust is the most challenging substance to pick up. “This is always tricky because it is difficult to remove dust without creating more dust,” she said. “And it is particularly important to remove dust in environments such as the food industry and in public places such as supermarkets, shopping malls and offices.”

She says a scrubber dryer is often used in particularly dusty areas. “However, you need to sweep first if there are also items such as steel shavings, wood splinters and other large debris to be removed,” she said.

Columbus’ sweepers are designed for use in factories, industrial units and other indoor areas and offer three levels of filtration to cope with dusty environments.

“There is also a flap for picking up larger debris, but I don’t know of any indoor sweepers that can separate out rubbish into separate containers,” said Comandré. “This is because indoor sweepers need to be very compact and there is no space for introducing a splitting system.”

So, do manufacturers consider there to be a need for separating out the different types of debris collected by a sweeper?

IPC’s Gabriella Bianco says not. “From our point of view it is more important to develop specific sweepers that are suitable for a particular application,” she said. “For example, in environments where heavy, dense debris exists such as in driveways and outdoor porches a walk-behind broom sweeper works well, whereas a vacuum sweeper is recommended for picking up bulky debris.”

Tennant’s Stefan Sehmke also feels that separation is not usually necessary. “We haven’t heard of such a requirement, but we are aware of a growing concern about the sweeping up of fine dust,” he said.

Kärcher’s Marian Anton concurs."Except for dust, we do not consider it necessary to separate out the individual components of natural debris,” he said. “However, it may make sense to collect plastic and synthetic materials first using the litter picker and to dispose of these separately.”

However, Columbus’ Valérie Comandré believes that separating out the rubbish may be the way forward. “We may not be able to make a compact machine that can do this, but it could be a possibility for larger sweepers operating in logistics areas where there is plenty of space,” she said.

“A sweeper that is capable of separating out recyclable items from the rubbish would benefit the environment. It would be good to have something like this in future.”