German company, Big Drum Engineering GmbH (www.bigdrum-engineering.com) specializes in the manufacture of equipment for the filling and packaging of ice cream. Its innovative machines make it possible to produce a wide variety of ice creams (with the exception of those on a stick) with a production capacity of up to 50,000 tubs per hour.

Presentation plays a crucial role in the industrial production of ice cream. Even in large size containers, the product needs to look like a handmade delicacy. Marco Gottschalk, head of purchasing and production planning at Big Drum Engineering, knows only too well from customer enquiries.

 “In addition to quality, the presentation of a product is often the decisive factor in the decision to buy, particularly when it comes to treats such as ice cream,” says Gottschalk. “With Choice Filler, our well-known inline ice cream filling machine, we can produce ice creams in a wide variety of shapes, and decorated precisely to our customers’ requirements.”

In order to fill ice cream into large plastic or paperboard tubs so it looked more appealing, appetizing and individual, Gottschalk needed a plan. He discovered the solution to this problem in spring 2010 at the Automatica trade fair in Munich. He happened upon the brand new robot, TX90 he, at the Stäubli Robotics (www.staubli.com) stand. The demonstration showed this six-axis robot working while constantly being squirted with water, thus underscoring its suitability for use under extreme conditions. From this, the idea was born to developing the Robot Filler.

Innovative filling machine for large containers

Today, Big Drum Engineering employs the Stäubli TX90 he in its new generation of filling machines called Robot Filler. These units are designed to fill and package ice cream in jumbo containers ranging from 3.5 to 6.0 liters.

 “The filling is done by the specialist robot,” says Gottschalk.  “We can program the Stäubli TX90 he to carry out this process so that it looks like ice cream packaged by hand, for example from your local Italian parlor on the corner. We can even input different filling programs, so that the content varies slightly from pack to pack, thus accentuating the handmade look.”

The Robot Filler also scores highly in terms of flexibility. The machine can process not only different container sizes but also different packaging materials such as plastic and cardboard.

“The first two Robot Fillers have recently gone into operation in Bangkok,” says Peter Deren, electronics specialist at Big Drum Engineering. “For our customer there, flexibility was particularly important because the machines handle different types of containers, from plastic through to cardboard. Changing the programming of the machine simply requires the touch of a button, and only a few deft flicks of the wrist are necessary on the mechanical side.”

Despite the highly innovative nature of the machine, the manufacturer has given great weight to a robust yet cost-effective design. The design focuses on the essentials, with the use of sensors and other expensive equipment kept to the bare minimum. A big plus for the operator is that they get a very reliable machine at an affordable price.

The Robot Filler in operation

Via a magazine that has to be inserted manually, the empty containers are loaded automatically onto the conveyor line of the machine and carried to the filling station. After centering and locating the containers, the Stäubli robot starts the filling process. For this, the robot is fitted with a nozzle on its ‘wrist’, which is connected directly to the freezer via a hose. The freezer supplies the TX90 he with the runny ice cream mass at a pressure of eight bar.

The six-axis robot executes the filling process precisely to the prescribed program. The robot is solely responsible for supplying exactly the right quantity.

“Using the robot, we can control the filling process so precisely that, at this point, we do not require any sensors, which reduces costs and improves reliability,” says Deren.

When the container has been filled, the conveyor system moves it on to the next station. Here, a pneumatic handling device with suction pads places the lid on top. At the last station, this is then pressed down with a specified degree of pressure. The finished containers now go to be flash-frozen.

A technical challenge: The cleaning procedure

While the actual filling of the ice cream is a routine job for the robot, performed with the utmost reliability around the clock in a three-shift operation, the regular cleaning schedule presents a major challenge.

“The machines in Thailand – and in this country – are cleaned with aggressive agents and a powerful water jet, to meet the strictest criteria,” says Gottschalk. “A standard robot could not withstand this kind of cleaning process, but this presents no problem for the Stäubli TX90 he.”

The he versions are carefully designed by Stäubli Robotics to cope with the particularly harsh operating conditions under jets of water. The fully enclosed robot is designed to meet IP65 as standard, and through the use of the Stäubli excess pressure unit, this protection rating can be increased. The wrist of the machine is designed to meet IP67, and this allows it to be immersed in liquids.

The vertical cable system proved to be particularly helpful. The connections are located under the base of the robot and are thus protected from squirting water. The surfaces are treated with a particular finish which increases their resistance to corrosion and renders the casing impervious. Parts subject to particular stress are made from stainless steel. The final surface treatment is done in a high-quality finish which facilitates the cleaning of the robot.

The whole of the machine is constructed in stainless steel. The Robot Fillers have been designed strictly in line with FDA guidelines and meet the highest hygiene standards in the food sector. Their open construction ensures that cleaning is very simple. A further advantage is that the machine is very compact, takes up little production space and can be moved quickly to another location if required.

“We now have both Robot Fillers in operation and are very pleased with their performance,” says the owner in Bangkok. “The machines fully meet our expectations in terms of flexibility and quality. Also, the installation of the machines on site by employees from Big Drum Engineering went very smoothly and quickly.”