Because of its many technical advantages and versatility, wet blasting is the fastest-growing segment in the field of shot blasting.
As with dry blasting, the available scope of wet blasting machinery ranges from simple, low-cost blast cabinets to sophisticated, partially or fully automated systems. Customers can choose between a wide spectrum of standard wet blasting equipment, however, for certain applications, special custom-engineered systems may offer the most efficient and cost-effective solution.
The machine type is usually determined by the processing task, the size and shape of the work pieces, and the desired degree of automation. Frequently, multi-axis robots are used for work piece handling or guiding the blast gun movement.
Rosler has extensive experience in wet blasting technology and the development of customized solutions. We have even developed the Rosler PureFinish® system for cleaning stainless steel components for the chemical, food, and pharmaceutical industries through wet blasting. This system cleans the work piece surface while facilitating cleaning, sterilization, and prohibiting bacterial growth.
Learn more about common types of wet blasting systems and examples of machine use for a glimpse into the technical capabilities wet blasting offers.
Critical aerospace components require first-class surface treatment. From engines, fuselage, wings, and landing gear to seats, gears, propellers, blades, fasteners and tanks for fuel, water, and waste, Rosler has industry experience and expertise.
While mass finishing and shot blasting methods are equally useful to manufacturers of new components and in the overhaul and repair of existing components, shot peening – a particular type of shot blasting – is especially advantageous for aerospace work pieces thanks to its ability to provide surface finishing and create internal compressive stress for improved component life.
Shot Blasting Capabilities
Rosler’s shot blasting technology meets the strict surface finishing requirements predicated by tight tolerances for safety and longevity. This impact-based process propels small metal or mineral pellets onto a work surface at speeds of 200-800 feet per second.
Desired finishes including cleaning, texturing, removal of or preparation for coating, and peening can be pinpointed to specific areas of a given work piece as well as the entirety of large, structural components.
Achieving the desired surface conditions in a mass finishing process requires the machinery, consumables, compounds, and process water to work together in a balanced manner. Independent of the other process elements, the process water itself must be evaluated for hard and soft water issues.
Rosler has more than six decades of experience designing mass finishing machinery, supplying consumables and compounds, and developing processes. Understanding the ramifications of too hard or too soft process water is a key to our success.
Classifications and Measurements
Depending on its geological source, the water used in mass finishing processes may have varying mineral content levels, specifically calcium and magnesium carbonates, bicarbonates, and sulfates. A high amount of mineral content is used to classify the water as “hard”, whereas low mineral content classifies it as “soft”.
Establishing and maintaining an effective and cost-efficient process water recycling system requires consideration of a few essential points. Without the proper compounds, additives, and monitoring, even a well-designed piece of centrifuge technology is bound to falter and, eventually, fail.
Rosler has extensive experience in mass finishing, including designing and manufacturing equipment, fine-tuning processes, and supplying the right consumables for a variety of processes. With our knowledge, preconditions and consumables can be calibrated for maximum process efficiency.
Special Recycling Compounds
Mass finishing compounds fulfill numerous tasks such as degreasing/de-oiling work pieces, burnishing/brightening surfaces, and providing a temporary corrosion protection. Above all though, the primary task of the compounds is to keep the media and work pieces clean to achieve the desired finishing goals and keep the mass finishing process stable.
Fueled by more active lifestyles and increased life expectancy,the market for knee, hip, and other replacement body jointsis on the rise. With more than $19 billion in annual worldwidesales, implants for joint reconstruction make up nearly 40 percentof all orthopedic product sales.
Thanks to significant advancements in materials and new or improvedsurface finishing technologies, today’s artificial hips andknees can last more than 20 years, giving the recipient decadesof comfort and agility.
Parts that are finished using modern mass finishingand shot blastingmethods play a key role in extending the lifespan of orthopedic implants.
Rosler has extensive experience in these processes which often include cleaning, deburring/edge radiusing, surface smoothing, post-casting surface preparation, machining, CNC grinding, and, of course, final finishing. These finishing technologies make big differences in the quality and performance of such products.
Within the food, chemical, and pharmaceutical industries, hygiene is a top priority. For safety and quality assurance, the occurrence of contamination through bacteria, proteins, or other elements must be prevented. Process plants require a defined, homogeneous, and reproducible surface for all parts that come in contact with food, beverages, chemicals, and pharmaceutical products.
Rosler delivers full compliance cleaning for stainless steel surfaces with PureFinish®, a unique wet blasting process.
What is PureFinish®?
Rosler developed this proprietary blasting process to deep-clean stainless steel components. Media specifically designed by Rosler for this environmentally friendly process remains suspended in water and is propelled onto the work piece surface with velocity.
Complete systems for blast cleaning and placing a protective coating, preservation lines are extremely useful on plates and profiles that require multiple treatments.
For example, structural steel components are commonly processed by preservation lines because they are prone to rust quickly and fail with potentially catastrophic consequences if not covered with a suitable, protective coating.
Rosler has extensive experience preparing structural steel components for use in construction, shipbuilding, and the production of all kinds of heavy-duty vehicles, trucks, railway vehicles, agricultural implements, or construction equipment. We understand the importance of applying proper surface finishing processes to these components for safety and longevity.
Offering shot blasting, painting, and more in a single source, preservation lines are a great option for a variety of industries, especially those utilizing structural steel components including steel plates, beams, round bar stock, and tubes.
Combining the direction of rotation and centrifugal force, Rosler’scentrifuge technology takes advantage of the weight difference between the liquid phase and the solids in the process water to separate “dirty” solid particles from clean, reusable process water.
The effectiveness of this technology lies in the centrifugal force that is created. For example, a modern fighter jet develops a G-force of about 10-15 while a high-speed centrifuge drum generates a force of more than 2,000 G.
The physics of centrifuge technology combined with mass finishing equipment creates efficient and ecologically sound manufacturing processes, albeit with some key limitations.
Collection by Force
The solids, primarily consisting of media and, to a lesser degree, of metal fines from the work pieces, found within “dirty” process water are heavier than the water itself. As the drum spins, heavier solids are deposited on the drum wall in the form of sludge, whereas the lighter-weight liquid remains on the inside of the drum. With the addition of special cleaning additives known as flocculants, even oil carried into the mass finishing process can be removed from the process water.
Media selection is key in any surface finishing process since these consumables are essential “precision tools” required to achieve the specified finishing results.
Whether you are developing a new mass finishing process or changing process parameters including different work pieces, process times, and requirements, partnering with an experienced expert will help you in evaluating all process parameters.
With decades of experience developing mass finishing machines and manufacturing media and compounds, Rosler is an excellent source for guidance. In some cases, pre-tumbled media may be suggested.
What is Pre-tumbled Media?
After production, some types of pre-polishing and polishing media are pre-tumbled by the manufacturer. This process breaks sharp points and corners off individual media pieces to create smoother edges.
Wet blasting can do nearly any job that is done with dry shot blasting. The defining differences are that wet blasting does so more gently and without producing dust. In addition, wet blasting can handle a small amount of oil and grease unlike dry blasting.
At Rosler, we have more than 80 years’ experience in surface finishing. While wet blasting has gained popularity recently, we’ve used this technique to provide precise, repeatable results to a number of industries over the years.
Typical Applications
With proper testing and process parameters, wet blasting can achieve numerous surface finishing goals.
A fastener with heat discoloration before versus after wet blasting.
Depending on the work piece’s starting condition and successive finishing steps, rust, scale, oxidation, road grime, grease, and oil may need to be removed. Wet blasting can accomplish a variety of cleaning applications including:
Dies and molds such as die castings and tire and glass molds.
Automotive rebuilds such as engines, transmissions, brakes, etc.
Investment castings such as boat propellers, pump impellers, housings, valve bodies, etc.
Aircraft engine rebuilds.
Various components before inspection or secondary processing.
Hydraulic components before and after wet blasting.
Work pieces with flashings and burrs must undergo deburring and deflashing. For example, firearm components require burr removal after drilling, milling, and turning. Drill bits and milling tools also require burr removal.
Despite the newest heat treatment processes, discoloration, oxidation, scale, and hard residues are found on cast and forged products as a result of manufacturing and environmental influences. Modern production methods, control and testing processes, and an uninterrupted continual processing of the cast and forged parts requires clean, light work piece surfaces.
Surface Texturing
Creating a somewhat rougher surface finish is a key step in preparation for painting, coating, and bonding with glue. Ensuring that subsequently applied coatings have a rough enough surface to adhere to improves the quality and life span of a work piece.
Examples of wet blasting applications for surface texturing include:
Preparation of automotive parts for rubber coating such as brake and engine seals.
Surface preparation to place a corrosion protection coating for screws.
Surface preparation to place a primer on airplane components such as rotor blades, stringers, and wing spars.
Orthopedic implants in which osseointegration and bone growth around the implant are encouraged. Light profiling of tibia plates, knee femorals, hip stems, and spinal implants helps promote this bone growth.
Wet blasting is ideal for stripping of paint and coatings from delicate work pieces. Processing of mineral-based construction materials such as concrete or sandstone, glass, textiles, and wood is possible with Rosler machines as well as the finishing of plastics and metals.
Landing gear includes many wet blasted components.
Shot peening is a process specially developed to improve the properties of components which are exposed to changing strains. For safety reasons, shot peening is also now absolutely necessary in the aviation and space industries. Shot peening is also essential in all industries requiring long lives for components including the automotive sector.
Wet blasting applications for shot peening are mainly used in conjunction with Almen strip N for glass beads, ceramic beads, and stainless steel shot.
Additively manufactured components before and after wet blasting.
Wet blasting is an essential technology for various post processing tasks, specifically additive manufacturing. Wet blasting cleans the 3D printed components by removing residual powder and significantly reduces their initial high surface roughness. It is capable of de-powdering and providing general surface cleaning and initial surface smoothing from Ra = 1,000 micro inches down to Ra = 40-60 micro inches (25 µm to 1–1.5 µm).
On metal AM parts the loosely sintered grains on corners are effectively removed. The wet process eliminates the worry about residual powder containment or sparking during the blasting process.
De-contamination of nuclear power plant components
Manual wet blast cabinets allows for same removal of contaminants.
Removal of small, radioactive fragments from the component surface in nuclear power plants can also be achieved through wet blasting. The process decontaminates the components to a point where they can be declassified as radioactive. Special consideration regarding the water treatment are required to meet the requirements for this application.
The Rosler Way
With a trusted partner such as Rosler, you don’t need to worry about the ins and outs of an application. Contact us to discuss your wet blasting needs and challenges and we will deliver a solution. We’ll even demonstrate results with FREE sample processing in one of our global test centers. That’s the Rosler Way.
The complete Wet Blasting Technology Series includes:
