Working in a vacuum

24 November 2020


Julian Champkin finds that vacuum lifting is proving useful in tackling social distancing needs, in the online retail industry and beyond.

Covid-19 has affected almost every industry, and has all but destroyed some of them. Retail is one that has suffered, as fewer people enter shops. There is a flipside to that. Covid has been instrumental in hugely accelerating the already-fast growth of online shopping. If you want proof, online grocer Ocado has just overtaken supermarket chain Tesco as the UK’s most valuable retailer in terms of stock market value. It is now (September 30th) valued at £2.17bn, compared to Tesco’s £2.11bn.

Online shopping requires warehouses and delivery systems. Logistics systems can be large and very complex; at the warehouses thousands of different products have to be sorted, picked, carried, assembled into units for different destinations, and loaded onto the delivery trucks or vans. Most of this has in the past been done manually.

Covid is dealing a double-whammy to those warehouse operations. Larger or heavier parcels need two people to lift them—which cannot be done if you are socially distancing. Loading and unloading of trucks or vans has also been generally done by hand. “Even pre-Covid these were not very good solutions,” says Michael Wooster of TAWI vacuum lifting systems. “Which is why we have been bringing to market products that are geared to logistics and distribution.

“Historically, the logistics industry has kept a lot of manual handling. It has not embraced the health and safety, or the efficiency, of automation as other sectors have done. Now it is beginning to, and we have the products for that.”

One Covid-relevant product that has been developed by TAWI is a mobile vacuum lifter unit. It is designed for efficient lifting and order-picking. “It has an articulated arm with two joints and a vacuum lifter on the end,” says Wooster. “It can simply be carried on any forklift or pallet-truck and driven, or towed, around the warehouse. When you get to the lifting site, you start the vacuum pump with a push-button. Support legs automatically lower when the vacuum pump is switched on; and the articulating arm enables you to reach far into pallet racks or to the back wall of a container for the vacuum lifter to grasp the desired object. It can handle any load up to 80kg, and a wide variety of suction cups is available for lifting anything from sacks to laminate boards or tyres. A quick-coupling device lets you easily switch between cups. In contrast to most vacuum systems it runs off batteries, so it can go anywhere its transporting vehicle can go.”

A Covid-related aim, he says, is to reduce, or preferably to eliminate, two man-lifting. “Hitherto almost any flat-pack lifting has been done by two people. Now it needs to be done by one person—and we have lifting aids which allow exactly that. That is good for productivity anyway, quite apart from social distancing, and employee safety. Lift 100 tables a day and at the end of the day you will be tired. A vacuum lifter keeps going. So this is a change that will outlast Covid.”

TAWI, a Swedish company, was bought earlier this year by US company Piab. “Currently we are running in parallel,” says Wooster. “In the longer term TAWI will continue as a brand.”

The mobile order pick-up was a TAWI development. Another Covid-relevant product comes from the Piab design team, and is one which, says Wooster, may revolutionise logistics.

“It is marketed as the Vaculex ParceLift; it is a vacuum unit mounted on a frame at the end of a conveyor belt, and its purpose is to unload lorries and trucks. It is a solution to what has always been a huge sticking point in the logistics industry. Up till now, unloading has been done by people, and can involve bad posture, low headroom, and heavy or repeated movements, prime causes of back and shoulder injury. It is a global problem, that has been made worse by Covid.

“The conveyor belt is extendable from the warehouse into the back of the truck; the vacuum lifter picks up the loads, one by one, and places them onto the conveyor; and so the truck is emptied, by just one operative who does not have to lift or move anything himself. The parcels can be loose-loaded, of different sizes, shapes and weights, up to 40kg. It can be fully integrated into many types of telescopic conveyors, either factory-fitted or retrofitted at the customer’s premises. In my view, this is an industry game-changer.”

ADDITIONAL PRESSURES

“The general story about materials handling is not confined to logistics,” says Christian Viehmann, managing director of Germanybased 3i. “Many factories also have seen a reduction in the number of staff who are available. People are in quarantine, or are sick. Very suddenly there are fewer workers, but tasks still need to be done; the factories now need equipment for supporting labour. Where two people were doing a task before, that has quickly given way to one person using a device that assists in the lift. So efficiency levels have suddenly increased at a very high speed.

“It is a trend that has been happening here in Germany over many years; our workforce has been aging, and fewer young people want to do manual or lifting jobs. So this is not about replacing workers; it is about doing work for which workers are scarce. Covid has greatly speeded up that trend: it has come in much more quickly than the normal cycles of equipment and efficiency improvements.

“Our products are typically useful for tasks such as feeding material into processing machines such as presses, or moving goods in and out to feed a production line. Those tasks are suddenly lacking workers, and demand for these products has drastically and dramatically gone up—so much so that in our factory in April and May we had major capacity problems supplying the demand. One product very much asked for is our Basic lifting device, which is noiseless and operates by a simple pistol grip; it is very accurate and precise as well as quiet. We have mobile ‘lift and drive’ units as well, for lifting and tilting boxes. Around 80% are individually customised for clients, for applications like fitting batteries into cars, or installing ventilation systems in trucks. We have a wide range of gripper tools, and most loads have some kind of flat upper surface that a vacuum can get hold of, so those we can supply off the shelf.”

Italian vacuum-lift specialists Scaglia Indeva are similarly supplying Covidinspired tools that help in social distancing. Their new intelligent industrial manipulator, they say, permits exactly that. “Just one operator with an Indeva lift-assist device can safely move, tilt, turn, and precisely position a heavy load precisely and effortlessly. In situations where otherwise two or more operators must necessarily work together at close quarters it provides a safe collaborative man/machine operation.”

They too have put the vacuum lifter on wheels. Their Liftronic Mobile manipulator, introduced early this year, is safe, ergonomic and intelligent like all others in the Liftronic Series, but it can be mounted on an electric pallet truck, which means it is moveable between different workstations within the production and logistics area and can carry loads between those stations. It can lift and move bags, containers or bins and place them on a pallet or a shelf; its four-jointed arm can be bent and locked securely when the truck is being moved. It can reach to either side of the truck; the swivel joint at the end of the arm allows continuous rotation of the gripping tool. The air flow takes place inside the arm, so there are no pneumatic tubes to become twisted.

Different pick-up tools can be fitted to handle different types of load; again a quick-attach device allows changes between them with a simple release and hooking mechanism.

INDIVIDUAL ORDERS

Eurotech is another manufacturer addressing the issue of picking from many products for an individual mixed order—or, as they put it more succinctly, the challenge of batch size 1. Their new advanced order system picks items from multiple pallet positions and places them on a single customer pallet.

“Customers are increasingly calling for individual production and faster deliveries,” they say. “Orders of ever-smaller batch sizes require efficient cost-saving production and storage management.” Eurotech’s customer-specific order picking systems are designed for handling panels and other large, flat products of various formats and surfaces.

“Hand-picking large, flat items requires multiple employees. A fully automatic order picking system on the other hand offers greater efficiency and safety. Employees no longer have to carry out the hard physical work involved in hand-picking, endure less strain on their backs and avoid accidents.”

In Eurotech’s system a trolley with a vacuum lifting frame picks up the goods from prepared pallets, in any of multiple positions, and deposits them on the customer pallet. An employee operates the user interface of the system to specify source and target stations and picking volumes. To start its fully automated picking cycle, the machine requires information about which vacuum circuits to activate for the different loads. These data are stored in a database or a bar code. Picking then takes place fully automatically. The system is equipped with multiple sensors to prevent errors. For instance, it compares the weight of the panel to be lifted with previously registered data; if the weight is a match, the machine carries out its cycle. If there are deviations between the source and target weight, the cycle is interrupted, and the machine produces an error notification.

Adhesion is a common problem in handling large, flat loads such as panels. The surfaces of two adjacent panels attach to each other and become difficult to separate. Eurotech’s solution separates the loads at the corners by blowing air in through bellow suction cups on the vacuum lifting frame.

As an expansion of the system a floating vacuum lifting frame can correct misalignments of up to 50mm. Integrated linear actuators adjust the position of the lifting frame so set down loads with a maximum misalignment of two millimetres between corresponding edges. This precision protects sensitive surfaces and creates well-aligned, tidy stacks.

MAKING AN EXHIBITION

Trade fairs, which normally are the occasion for major product launches in the industry, have of course been another casualty of Covid and have not happened this year. Schmalz have responded ingeniously by hosting their own virtual trade fair online. They call it SchmalzEXPO, it is freely available to all via the company’s website, and it showcases several new products that Schmalz have introduced.

Among them is a new generation of area grippers for its vacuum tube lifters in the JumboErgo series. Named the FMP, it grips flat heavy workpieces weighing up to 140kg, and can do so even when only part of the suction area is covered.

This means that it can grip, for example, pallets or pallet-shaped objects that have open spaces on the face to be lifted. Even though some of the suction cups of the FMP are over the spaces, and exposed to air rather than being sealed by the lifted surface, its lifting power is unaffected. The FMP is ideal, say Schmalz, for safely handling sheets with cut-outs, pallets, or other workpieces with inconsistent surfaces. It also makes it easy to switch between full-surface and partly-covered gripping, as, for instance, when loading machines ergonomically and then removing the cut-outs.

Schmalz also have addressed the growth in online shopping. “In 2019, online sales grew by over eleven percent year on year,” they say. “One in three online buyers now makes several orders every week. Warehouses therefore need to optimize their logistic processes, and ergonomic and automated lifting devices, that can sort many disparate items, are in high demand.” Selecting and picking individual items from many different ones requires that they be identified, selected, and then grasped and lifted. Another Schmalz introduction, their 3D-R Vision and Handling Set, addresses this field of automated bin-picking.

A 3D camera system with digital recognition software guides a robot arm, which at its end is fitted with a new ultra-flexible vacuum cup that can grip irregularly-shaped objects at almost any orientation. The complete system can be put into operation without extensive knowledge of robotics and in less than half a day.

The vacuum for the suction tool passes through the inside of the robot arm, meaning there are no external air lines to get in the way. An optional swivel-joint module extends its reach and allows it to empty even the bottom corners of deep bins. An intelligent vacuum and pressure switch continuously monitors the gripping process to give the shortest possible cycle times.

The suction cup itself is new and interesting. The SVE is bell-shaped with a very thin, soft sealing lip; it adapts to corners, edges, and other freeform surfaces. Spray cans, for example, can be gripped reliably with high holding force and optimal sealing, and by an edge or corner as easily as by a smooth section. The gripper reliably removes workpieces from the bin, regardless of whether they have been randomly deposited or sorted in advance.

UK FIRST

Palamatic, established in 1985 by Stewart and Sue Bennison, who are still shareholders of the company, can claim to have introduced vacuum tube lifting technology to the UK. Starting with systems to handle paper and plastic sacks, in 2002 they developed a product which has extra relevance today. Repeatedly asked for vacuum tube lifters for cleanroom environments for the pharmaceutical industry, they developed the PalPharmaVac. With built-in filtration, and a fully hand-demountable design for ‘chuck-it-in-a-bucket’ cleaning regimes, it was an easy-to-use solution for operators working in full personal protective equipment and in downflow booths for clean or sterilised air. Its purpose back then was for cleanroom lifting and pouring, and for emptying expensive powders from sacks; but companies whose workers now, and for the foreseeable future, may have to work wearing PPE may well find applications for it.

Ergonomically, the lifting aid is only as good as the gantry from which it is suspended, and Palamatic also have expertise in supplying gantry systems which are individually rated for vacuum lifting units. They are available in stainless steel, which minimises internal cavities, and have flat services to prevent product buildup and to aid clean down. Two new sub ranges have recently been introduced: the Uni-LITE Series and Uni-LITE Flex Series. They differ in the strokes they can achieve to ensure the safest ergonomic application for the operator. The Uni-LITE is designed for packing and unpacking applications around waist height and conveyor height. It is designed for stroke ranges of up to 600–700mm, though it can go higher. The Uni-LITE Flex is for packing, unpacking, stacking, and de-palletising, and it has a much broader stroke range. It is also better for larger materials, where the operator prefers not to lean over.

Many of the changes brought by Covid are here to stay. The replacement of manual lifting by vacuum devices would seem to be one of them. 

Glass sealing: a vacuum lifting system from TAWI
The Basic handling system from 3i allows one-man lifting where two were needed before
Scaglia Indeva’s Liftronic Mobile, here equipped with a vacuum gripper for bags
EuroTech’s automated picking system can select from one of a number of pallets
The suction cup of the EuroTech picking system
Schmalz’s FMP flat gripper can lift pallets with open spaces