Replacing a shot blasting machine for a long-time customer requires finding a better way to deliver efficient finishing in a faster, smaller, and more maintenance-friendly way. That’s exactly what Rosler delivered when Linde Material Handling (Linde) returned to us for a shot blasting upgrade.
Linde is a supplier of forklift trucks and warehouse equipment and also provides technical intralogistics solutions and services. With a sales and service network spanning more than 100 countries, the company has a global footprint.
For this particular partnership, Linde’s foundry in Weilbach, Germany, challenged Rosler to supply a new shot blasting system capable of finishing and maneuvering the counterweights it manufactures for forklifts. Our solution was a sturdy foundry version of a continuous hanger shot blast machine known as the RHBD 22/27-F.
Linde continuously strives to improve its manufacturing operations. As such, the new machines had to accomplish several goals, including faster processing, more flexible material flow, optimized utilization of available space, improved access to all critical maintenance areas, and increased overall efficiency.
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.
Due to their precision, efficiency, and economy, mass finishing and shot blasting are an indispensable part of the finishing process for a wide variety of orthopedic implants in different manufacturing stages.
These flexible machines can handle general cleaning; deburring; surface smoothing after casting, forging, stamping, machining, and heat treatment; surface preparation for polishing or coating; and the placement of the final finish on all kinds of implants and medical devices.
With an experienced partner such as Rosler, these processes are also capable of adapting to emerging trends with proper testing and processing trials.
Evolving Technology & Outlook
Orthopedic implant manufacturers are at the cutting edge of medical technology. New materials and manufacturing techniques and technologies are constantly evaluated to improve the performance and longevity of the implants and reduce the manufacturing cost. Two examples are the increased use of ceramics as base material or coating and additive manufacturing.
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.
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.
While choosing the right implant material is of utmost importance, as discussed in our previous Orthopedic Implant Series post, the significance of optimum surface treatment throughout the entire implant manufacturing process cannot be overstated. This relates not only to the right surface finish, but also total compliance with the specified tight dimensional tolerances.
The functionality of an orthopedic implant is determined by the perfect match between the various implant components. This depends, to a large extent, on the surface treatment procedure(s).
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.
As an expert in the surface finishing industry, Rosler knows that all the expertise in the world won’t do any good if the surface of the work piece is not properly prepared.
When it comes to structural steel, we receive many questions about preparation. Among the most common questions is, “How is the presence of dust on shot-blasted structural steel components evaluated?”
Understanding dust considerations and mitigation will help produce higher quality and longer-lasting structural steel components more cost-effectively and safely.
The Dangers of Dust
Blast-cleaned structural steel surfaces must be completely free of dust to ensure proper coating and painting. Residual dust will reduce the adhesion of subsequently applied coatings and, by absorbing moisture, may promote the corrosion of the blast‐cleaned steel surfaces.
The potential accumulation of dust is especially critical on horizontal surfaces, the interior of pipes, and inside structural cavities. Special inspections must be carried out to ensure that such areas are adequately cleaned and free from dust before painting.