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.
Numerous functions and calibrations factor into developing a precise and stable mass finishing process. From media and compounds to work piece characteristics and processing times, successful finishing requires each process aspect to be carefully monitored and evaluated. When it comes to process water flow rates, poor drainage from the machine can cause quality control issues as well as equipment damage and costly downtime.
While simple in their function, drains play an integral role in regulating the flow of process water out of the machine. With the exception of intentional “flooding” of the process bowl for sharp work pieces, the same amount of compound and water entering the machine must be flushed out again. Otherwise, contaminants in the form of dirt, media, metal fines, and, frequently, oil will accumulate in the process water. Since this buildup can cause the finishing process to deteriorate and even collapse, mass finishing machines must have sufficient drainage!
With more than 80 years of experience, Rosler can expertly design mass finishing technology and troubleshoot issues to protect your system for the life of the machine.
Made from plastic such as polyurethane or stainless steel material, these drains must allow process water and media debris to be flushed from the system while retaining usable media mix and the work pieces.
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).
With extensive experience in the medical industry, Rosler is an expert in designing systems and solutions for the treatment of joint reconstruction implants utilizing shot blasting and mass finishing technologies.
Our Orthopedic Implant Series continues with an overview of the stringent finishing standards for orthopedic implants.
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.
Maintaining the correct compound and water flow rate into a mass finishing machine is essential for the stability and success of a process.
If inadequate compound and water are supplied to the machine, results will be more extreme and lead to unpredictable processing times, ineffective finishing, dirty work pieces after finishing, glazed media, and, potentially, a total collapse of the process.
Excessive compound and water flow can be equally problematic. Too much water and compound will slow down the movement of media and work pieces in the machine or cause a complete stop.
For example, in rotary vibrators the typical spiral movement of the media/work piece mix will give way to an uncontrolled shaking. In centrifugal disc machines, the rotating spinner will slip under the media/work piece mix with no movement at all.
Longer processing times, poor finishing results, and even a complete collapse of the process can occur.
For the best results and stability, Rosler understands that the flow rate of compound and water into the machine must be equal to the flow rate out of the machine.
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.
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.
The Standards
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.
The dominant and widely used standards for evaluating rust and mill scale are ISO 8501‐1:2007 (based on the Swedish Standard SIS 05 59 00) and the SSPC (Steel Structures Painting Council). While different in some minor details, these standards are practically identical.
For millions of individuals, orthopedic implants provide the ability to regain mobility and reduce pain. Just as surgical skill is required to implant these artificial joints, so is skillful construction and finish of the joint components themselves.
A leader in surface finishing for medical technology, Rosler has extensive experience in shot blasting and mass finishing a wide range of medical devices from instruments to implants used specifically for joint replacement.
Our Orthopedic Implant Series continues with an overview of the most common materials used for these endoprosthetic implants.
Popular Materials
To date, the most common materials have been titanium, titanium alloys, and cobalt-chromium alloys. Both materials are very tough, resistant to corrosion, highly biocompatible, and absolutely reliable.
