Initiating movement of a standard bicycle can sometimes be challenging, such as when peddling up steep hills. Initiating movement of an electric bicycle, on the other hand, has always been much easier. The rider either pedal-assists the motor or activates it with a throttle.

For many years, only lead-acid or nickel-cadmium rechargeable battery packs were used to power the motor. Since the 1990s, lithium-ion battery packs also have been used. Improvements in all types of rechargeable batteries—along with the “green” appeal of bike riding—have led to a surge in demand for electric bicycles.

BMZ GmbH, based in Karlstein, Germany, has made standard and custom lithium-ion rechargeable batteries, battery packs and chargers since 1994. The company produces 300 battery packs for electric bicycles every day.

In late 2010, BMZ began making battery packs that feature PCBs. The company also decided to encapsulate the packs to protect them from
moisture, dust and dirt. BMZ turned to the Hilger u. Kern-Dopag Group to meet this challenge.

The two companies had often worked together to solve several of BMZ’s previous material-dispensing challenges. Kern-Dopag designs and manufactures metering, mixing and dispensing systems for single- and multicomponent adhesives.

BMZ decided to encapsulate the battery pack with a two-component polyurethane mixed at a 100-to-20 ratio. Kern-Dopag recommended the company use an Eldomix 603 system to meter, mix and dispense the material.

A gear-pump system, the 603 is fitted with large pressure-feed vessels that allow uninterrupted production. The A component is dispensed from a 90-liter vessel, the B component from a 45-liter vessel.

Over the past 2-1/2 years, the system has lessened downtime, improved workflow and increased production and profits at BMZ, says Ingo Horstbrink, production spokesman for BMZ. He says the company is delighted with the system, which is easy to use and operator friendly.

Besides standard encapsulation, the system can be used for vacuum encapsulation, syringe filling, potting, gasketing, coating and sealing. It handles a wide range of materials, including epoxies, urethanes, silicones, polyester and acrylics.

 For more information on metering, mixing and dispensing systems, call 513-881-6370 or visit