Sustainable competition

The bicycle is more popular than ever. The company Krüger Fahrrad- und Fahrradrahmenbau from Spenge-Wallenbrück also feels the significantly increased demand. The company handcrafts the backbone of every bicycle: the frame. These are coated using the wet or powder coating process - depending on customer requirements.

With a sales increase of up to 900 million euros in the Corona year 2020, the bicycle industry was considered the big non-food winner of the pandemic. This was the result of a study by the IFH Cologne trade research institute and BBE Handelsberatung. This development is also felt by the company Krüger Fahrrad- und Fahrradrahmenbau from Spenge-Wallenbrück in North Rhine-Westphalia. "Our work has always been valued. Since the Corona pandemic, however, we have been experiencing significantly higher customer demand," says Managing Director Michael Krüger. In 1967, his father Dieter Krüger founded the company as a supplier for the East Westphalian two-wheeler industry. The company grew quickly and specialized in the field of bicycle frame construction. After moving from Bielefeld to the current location, the production of complete bicycles was also started. Since 2008, the family business has been managed by Michael Krüger in the second generation.

"A bicycle consists of thousands of individual parts," he describes his work. "Making a bicycle from these individual parts is much more than just a job for us. It's a passion!" Because of this very passion for two-wheeled vehicles, Krüger is always on the lookout for the optimal solution for building the bicycle frame, which determines the character of the bicycle in terms of appearance and geometry.

"The frame is the most important part of the bicycle: it has the function of a spine and holds everything together," explains Michael Krüger. That's why the company is committed to continuously improving the quality of its products. With the help of the surface specialists from Oltrogge GmbH & Co. KG in Bielefeld, Krüger has now succeeded in optimizing internal processes while improving the sustainability of production.

Environmentally friendly addition to classic wet painting

To give the frame that special "something", a few work steps are necessary: After a primer coat as rust protection, an adhesion primer for the color shade is applied. Depending on the customer's requirements, Krüger has previously used wet paint or powder at this point. Acrylic paint is then applied in the desired color shade. Finally, a clear coat of polyester powder is applied to protect the color and frame, and the final baking of all layers takes place in a chamber oven. "In the long term, we wanted a more sustainable way to paint our frames," explains the managing director. Together with Oltrogge from Bielefeld, engineering partner in the fields of compressed air and surface technology as well as machine tools, a way was sought to make the painting process more effective and environmentally friendly. In the end, Krüger Fahrrad- und Fahrradrahmenbau decided on a new system for more effective and sustainable powder coating, especially for the application of the primer and the final clear coat.

Powder coating is a process in which paint particles are applied electrostatically to the electrically conductive bicycle frame to be coated by means of a paint gun. Krüger now uses a new Sprint manual system from Wagner for coating, which is particularly suitable for small batch sizes and frequent color changes. In electrostatic powder coating, the particles adhere to the frame due to the electrostatic charge. This is followed by the baking process in the oven, during which the paint particles fuse.

Lower costs with higher scratch and impact resistance.

Krüger benefits from the numerous advantages of the process: Compared to wet painting, powder coating is solvent- and emission-free and therefore environmentally friendly, and it also conserves resources. Powder that is not needed can be reused for the next coating process. This effectively saves costs at Krüger. In addition, powder-coated frames and components are characterized by optimum protection against weathering and corrosion, and are highly resistant to scratching and impact. Managing Director Michael Krüger is enthusiastic about the advice and the solution that Oltrogge provided: "With the new powder coating facility, we can offer bicycle frames that are sustainable and at the same time even more robust. Anyone who rides one of our mountain bikes through the mountains no longer has to worry about their paint getting scratched by small stones or the paint harming the environment."

Oltrogge GmbH & Co KG
www.oltrogge.de