Knaus Tabbert AG is a leading manufacturer of recreational vehicles. The company’s innovative designs and powerful drive systems for motor homes, caravans, and panel trucks allow for safe, comfortable, and sustainable travel.
At its German headquarters in Jandelsbrunn, Bavaria, Knaus Tabbert utilizes its comprehensive experience and know-how to continuously improve the materials and designs of its vehicles as well as new manufacturing technologies such as additive manufacturing.
Seeking faster and less expensive post processing for its 3D printed prototypes, Knaus Tabbert turned to AM Solutions, a brand of The Rosler Group, to find a better way.
From prototyping to production, Knaus Tabbert needed de-powdering and cleaning operations for additively manufactured work pieces.
“On the one hand, we are using 3D printing technology for creating prototypes. On the other hand, we are also utilizing additive manufacturing for producing standard components in volume such as the bracket for an alarm system or the hinge mechanism for the swing-out shower stall,” said Mario Meszaros, Knaus Tabbert Development Engineer.
In addition to the machinery and consumables we provide, our Customer Experience Centers enable us to demonstrate Rosler’s expertise by processing your samples with settings and requirements tailored to your needs.
Sending your work pieces to one of our 11 test centers around the world is an important step in achieving the perfect surface finishing process.
Learn what to expect from Rosler’s Customer Experience Centers and get the most out of your partnership with Rosler from Sales Representative and Interim Product Manager of Turbine Blast Equipment Zack Murray and Mass Finishing Product Manager Michael Salyers.
What to Expect as a Customer
To achieve optimal processing results, we carry out sample processing step-by-step.
With an emphasis on finding a better way, our process includes:
Blast cleaning is uniquely capable and efficient at delivering the pre-coating surface preparation required for components that must be able to withstand severe ambient conditions including heavy equipment for construction and mining, agricultural machinery, transportation and material handling equipment, and railway equipment and rolling stock.
Based in Enschede, Netherlands, the company designs and produces numerous products including placement systems for container pads. Its customers largely work within the material handling, offshore, and transportation sectors.
Like mass finishing, shot blasting is an exceptionally versatile surface treatment technology. Its applications range from general cleaning after casting and forging to shot peening and, even, cosmetic blasting for placing a fine, matte finish on the work pieces.
For shot blasting orthopedic implants, Rosler recommends mainly air and occasionally wet blasting systems. In each process, blast media is accelerated by compressed air and thrown at the work pieces through a blast nozzle, creating an extremely precise blast pattern compared to turbine blasting. Another advantage of air blasting is that it can be used with metallic, mineral as well as organic blast media.
These attributes and many more make this surface finishing method particularly useful in the medical industry.
Examples of Shot Blasting
Shot blasting is an impact system in which small metal or mineral pellets are thrown onto the surface of a work piece at speeds of 200-800 feet/second. The impact on the work piece surface produces the desired cleaning, peening, or texturing effect.
For medical applications, mainly air and wet blast systems are used which generally make a surface rougher. The smoothest finishes achieved with shot blasting are about Ra = 16-32 microinches (= 0.4 to 0.8 μm).
Unlike dry blasting that only uses a solid abrasive media, wet blasting processes use a slurry of water with the shot blasting media. This greatly cushions the impact energy on the work pieces, providing gentler, yet effective results for delicate work pieces. The achieved surface finish and appearance will also differ between wet and dry processes, even when the same media type and size are used.
With more than 80 years of experience worldwide, Rosler can supply both the machines and media best suited for your wet blasting needs.
Common Media Types
As long as it is heavier than water and not water soluble, practically any media used for dry blasting can be used for wet blasting.
It is important to consider the usefulness of the media compared to its cost. While a cheaper or longer-lasting media may be available, it may also require additional processing time to accomplish the desired surface finishing. Selecting the most appropriate media for your process requires balancing initial costs with overall results.
While highly effective in a number of applications and industries, wet blasting can be a messy process. Unlike dry shot blasting which produces dust, wet blasting generates a mix of media, dirt, and debris mixed with water mist.
If this water/particle mix is not removed properly the machine itself may be soiled to the point that it cannot be used. Mist which escapes the machine can also cause health hazards to personnel and other equipment in the area.
Rosler builds its wet blasting machines with usability and safety in mind, factoring in precautions and cleaning functions to prolong the machine’s use and ensuring a clean, safe work environment.
True to our “finding a better way…” motto, Rosler partnered with thyssenkrupp AG to create a continuous flow shot blasting operation for the fastest crankshaft forge shop in the world.
World renowned for its drive trains, chassis, and automobile manufacturing equipment, the automotive division of thyssenkrupp AG significantly contributes to the technical progress and efficiency of motor vehicles. The thyssenkrupp Gerlach GmbH plant in Homburg, Germany, is a leading partner for the development of automobile engine components, offering a full-service package ranging from component design, prototype fabrication, and full-scale production.
Developing a Solution
To improve cost efficiency at its Homburg plant and to meet all customer requirements, thyssenkrupp AG installed its high-tech “production line 19” for forged crankshafts for engines with one to four cylinders in 2016. For this line, Rosler developed an innovative shot blast equipment concept known as the Rosler RKWS crankshaft shot blasting system.
Useful in a variety of industries, this specialized form of shot blasting relies heavily on the media and water mix known as wet blasting slurry to work in tandem with the machinery in order to deliver the desired finishing results.
Rosler has extensive experience developing wet blasting systems as well as providing guidance on slurry concentrations and supplying the necessary consumables.
Andersen Steel produces agricultural equipment including grubbers, front packers, and stubble tillers equipped with vibration tines for soil cultivation. Their equipment is exposed to extreme loads, causing decreased wear life of parts including the tines.
Made using specially arched rolled steel at the company’s Poland plant, Andersen Steel tasked engineers at Rosler with finding a better way to process the tines and improve their wear life. We delivered a solution in the form of two identical machines for blast cleaning and shot peening.
Delivering a Solution
Compared to flat steel, the rounded edges of the material Andersen uses prevent small cracks from forming during the shaping process. The work pieces pass through a blast machine to remove mill scale and other contaminants before shot peening to further improve their wear resistance.
For these dual shot blasting requirements, Rosler suggested two identical Rosler RHBD 13/18 K hanger machines. Successful blasting trials in a Rosler test center helped Andersen realize the advantages of purchasing these Rosler machines by demonstrating that shot peening the work pieces doubled the uptime of the tines.
Surface preparation can account for up to 40 percent of structural steel painting and repainting jobs and the life of anti‐corrosion coatings on a steel surface largely depend on how thoroughly the surface was prepared before painting.
At Rosler, we have extensive experience evaluating structural steel surfaces for coating before and after shot blasting. This knowledge of surface preparation standards and the widely used ISO and SSPC standards guide us in developing systems to expertly prepare and repair structural steel throughout its lifespan.
Evaluating rust and mill scale pre- and post-shot blasting is a must. It is important to clearly specify the quality of the surface prior to preparation as well as the surface conditions after preparation. As a result, standards were developed to visually assess the initial surface conditions and the quality of the required surface preparation relative to the initial steel surface conditions.