Case Study: The GRR x400 outperforms its competition in printing with polypropylene

Hürner-Funken GmbH is a fan and ventilation components company founded in 1928.  Their products are featured in the chemicals industry, semiconductor, pharmaceutical and electroplating industries.  Hürner-Funken products are made of plastic and can be used wherever fans, pipes, control flaps or volume flow regulators would corrode due to the presences of aggressive gases.  One of the typical products of the company is a central exhaust air system for energy recovery, commonly found in university laboratories. The central element of these systems is a heat exchanger made from solid plastic installed in the integrated circuit system which extracts valuable energy out of the exhaust and either heats or chills the air and feeds it out of the system.  Depending on the application of the system, they could also include filters, silencers, valves and chamber lighting for revision components.  Free-standing centrifugal fans with an optimized impeller efficiency and high efficiency motors are usually used for conveying the air.

The head of research and development, Benjamin Wolf recalls, “We have been using 3D Printing and rapid prototyping for a long time now, however, the stereo lithography equipment available at the beginning was of no use to us due to the limited selection of materials - we wanted to print with a material that would match the final product as closely as possible.” 

While completing a project with a university, Wolf came across a 3D printer for the first time. The project participants were printing prototype parts for the project on their own 3D printer and Wolf was very excited about the possibilities that could offer for their company.  They requested a market analysis report on the printer for their company's needs.  Wolf recalls, “the market analysis included the coverage of available materials, the build envelope and the price of the different devices and processes.” The clear winner of this study was the x400 from German RepRap, which according to Wolf, “stood out with the largest build envelope and an unbeatable price/performance ratio.”  Once they received the x400 printer, the developers and designers at Hürner-Funken made prototypes - both scaled down and full size models, as well as sample parts for their own in house tests and for customers.  Hürner-Funken often uses polypropylene (PP) as their principal printing material which is still considered a rather exotic material in 3D printing.  “We have been working almost exclusively with PVC and PP since 1928 and therefore have a lot of know-how about handling the material,” Wolf explains.  “Processing in the x400 with its closed build envelope is very straightforward.  Printing in PP is very important for us as the standard 3D printer material. PLA and ABS materials are not resistant to chemicals.  With PP we therefore have virtually the same material properties with the 3D printed prototype parts as in the injection molded series production.”

Because of the reliability of the x400, Hürner-Funken now manufactures specific parts using only the 3D printing process.  The ability of the x400 to print hollow or only partially filled parts was extremely important for Hürner-Funken.  “This firstly saves material and secondly also weight- a critical factor in certain applications,” says Wolf.  With prototyping, the ability to manufacture components in house is worthwhile.  “Previously, we had to wait weeks until we received prototypes from the model builder,” Wolf explains, “With the x400 this has been reduced to hours, sometimes days if we fully utilize the build envelope. You can also afford to make a reject and unusual solutions can be tried out without any problem.  The GRR x400 has established itself as an indispensable element of the development and production process.  It is extremely robust and reliable, we can produce components in the original material very quickly and economically.  We save weeks in the prototype stage and can offer our customers more solutions.  For us the x400 is a gain for the entire Hürner-Funken line.”

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