Achieving Optimum Ergonomics and Efficiency for Manual Workstations

By David Vilcek, Manager of Workholding and Assembly
Article from September 2015 issue of Today’s Medical Developments.

Laboratory technology provider Thermo Fisher Scientific has developed an ergonomically designed production line for the manual assembly of a new model series of incubators.

Health-conscious workstation design is a top priority, in addition to process and product quality.

Heracell Vios incubators for medical engineering and health research in cultivating human and animal cells are assembled in Langenselbold, Germany, where Thermo Fisher Scientific has consolidated laboratory equipment production.

A successor to Thermo Fisher Scientific’s Heracell model that sold 75,000 units in 15 years, the new series optimizes control behavior, improves protection against contamination, and facilitates operation.

The rotary module has indices which are released in 45° steps by two foot switches.

From Prototype to Production Line

To prepare for production of the Heracell Vios, Felix Pergande, technical head of production for Thermo Fisher Scientific, and Stefan Kämmerer, production resources engineer, developed a prototype of the assembly workstation in 2013. They used this workstation to develop a new series production line and a start-up plant in September 2014.

Pergande explains, “During this period of about half a year, we have had the overall responsibility for the incubator production, from organization and material procurement through to quality assurance. We industrialized production in this time. As soon as it is was well engineered, we handed it over to the incubator department.”

For the assembly workstation development, Thermo Fisher Scientific cooperated with Roemheld. Experts in assembly and handling technology, Roemheld is represented in North America by Carr Lane Roemheld of Fenton, Missouri. Roemheld, headquartered in Hessian Laubach, Germany, has been a supplier and partner for the medical engineering manufacturer since 2009.

Carr Lane Roemheld’s assembly and handling modular units consist of numerous modules that provide ergonomic object positioning for manual assembly. Horizontal and vertical rotation, tilting, lifting, placement, and movement are the basic manipulations. The units can be combined into modular systems for loads from 22 lb to 1,325 lb with manual or electrical operation.

A rotary module with media feed-ducts allows for the hydraulic, electrical, or pneumatic operation of devices held by zero-point clamping systems without complex boring.

Thermo Fisher Scientific production resources engineer Stefan Kämmerer, Manfred Parr of Roemheld and production head Felix Pergande, also Thermo Fisher Scientific (from left to right).

Focus on Ergonomics

Pergande says, “Roemheld’s consultation quality is extremely high. They dedicatedly respond to our individual requirements. In addition, their products are very reliable and can be configured according to our requirements – we do not have to buy anything ready-made.”

For the new manual assembly workstation, ergonomics were of particular significance to Kämmerer. The earlier incubator series had been assembled on height-adjustable tables, but the 40 lb units had to be moved manually without auxiliary equipment.

“For this reason, preassembly of the inner containers required a lot of handling and was physically more demanding,” Kämmerer says. This had to be improved for the production of the new series.

The inside 28″ x 18″ casing is open to the front for the 42-gallon incubator and is manufactured in Thermo Fisher’s sheet workshop. In preassembly, an employee covers all five sides with heater foils, forcing him to rotate the container several times. Apart from this, a sensor and a fixture have to be mounted. The entire process takes about 45 minutes, then insulation is attached, and the outside casing is assembled over it. The site in Langenselbold has about 150 assembly employees, eight of whom are assigned to manufacture incubators, in one or two shifts.

Four Manual Workstations

With the support of Manfred Parr, Roemheld’s assembly technology product manager, Kämmerer and Pergande designed a line of four similar assembly workstations, arranged successively. Two of them are suitable for assembling the larger incubator models.

All workstations consist of an electronic shopfloor lift module with a stroke of 8″, which can be lifted and lowered by a pushbutton. A rotary module may be released manually in steps of 45°, allowing the fitter to use two-foot switches without walking around the container.

“The prototype of the assembly workstations had only one-foot switch. In order to be able to work more efficiently, the fitters had the idea of a second foot switch; this suggestion could rapidly be implemented by Roemheld,” Kämmerer says.

After the design of the assembly workstations was completed, he ordered the components from Roemheld and assembled them. To preserve the surfaces during work, he developed a clamping device with brushes on the bearing surfaces to preserve surface finishes.

“The clear position fixation and the defined handling by means of the 45° indices noticeably reduced the risk of dents in the container,” Pergande says. Time savings and cost reduction are not high priorities in this design, though both are achieved.

To preserve surfaces during work, a clamping device with brushes on the bearing surfaces holds the inner containers.

He emphasizes that ergonomic workstation design contributes to protecting employee health since “the absence of an employee costs money, because either we cannot produce or we have to assign a replacement.”

Fewer rejects and healthier employees contribute to cost savings and enhance Thermo Fisher’s success.

“An ergonomic workstation with useful features like this is invaluable. It is good for the back, neck, and shoulders and is a noticeable relief. The body feels it immediately,” says equipment fitter Steffen Hillescheim.

Thermo Fisher Scientific intends to improve other single workstations and entire lines under lean manufacturing aspects in the future.

“This will also include the analysis of handling aspects,” says Pergande. “Since it is often inefficient to reduce wage cost by automation, we want to design our manual workstations as ergonomically and efficiently as possible.”

The standard interface conception of the modular units is helpful in this regard, because it allows for the flexible and uncomplicated planning of future workstations.