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.
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:
When expertly combined by an experienced finishing expert such as Rosler, this method can achieve precise and repeatable results on a variety of work pieces from a wide range of industries.
A general understanding of the essential technical elements of a wet blasting machine will help you select a machine for your specific needs as well as prolonging the efficiency and life of existing wet blasting equipment.
Unlike dry blasting in which only solid abrasive media is used, wet blasting processes use a slurry in which the media is embedded in water. This greatly cushions the impact energy on the work pieces, providing gentler, yet effective results for delicate work pieces.
As the utilization of wet blasting increases, Rosler reminds manufacturers to review their traditional, dry shot blasting applications and consider if wet blasting could provide additional efficiencies, reduced costs, and better results.
Understanding the Differences
As in any surface finishing process, the starting condition of the work piece, its material composition, shape, and final finish largely dictate which finishing application is most appropriate. Understanding how the application changes the work piece is a key consideration.
Thanks to its many technical advantages and “gentle” application, wet blasting is a versatile and fast-growing segment of the shot blasting field. Achieving precise, repeatable results with any wet blasting process requires understanding both its principles and real-world uses.
With decades of experience and the latest in engineering expertise, Rosler understands how to develop efficient wet blasting machines and consumables. Learn more about wet blasting technology as we begin our five-part Wet Blasting Technology Series.
How Does Wet Blasting Work?
Wet blasting is a water-based method of shot blasting utilizing abrasives that are particularly suited for the finishing of delicate, precision-produced parts.
PureFinish® is a post-processing technique. This technique allows stainless steel to be finished to a smoother surface with a low and reproducible SRI value below 0.010. In practice, this produces a surface with a very low degree of adhesion characteristics. The PureFinish® treatment has been extensively tested by TNO. TNO, a Dutch organisation is the leading institute for Applied Scientific Research. The SRI value (Soil Retention Index) was investigated because this parameter most accurately describes the relationship between surface structure, contamination and cleanliness.
Within the food and pharmaceutical industries hygiene is a top priority, not only for safety but also to prevent contamination and to ensure the quality of the product in terms of taste, aroma and appearance. The occurrence of contamination through bacteria, proteins or other elements must therefore be prevented. Process plants require a defined, homogeneous and reproducible surface for all parts that come in contact with food, beverage and pharmaceutical products.
Over the decades researchers have searched for optimal and efficient techniques to adequately recondition the surface of stainless steel after it has been subjected to various processes. This article examines the various processes currently used and the surface conditions achieved. An independent study has shown that water jet blasting may offer the best solution in terms of both the degree of smoothness achieved and the avoidance of using chemical products.
The Aerospace Industry is a major precision manufacturing industry that justifiably employ Blast processes Surface Preparationand Finishing. The industry is identfied by several divisional disciplines and each have many applications.
Blast finishing and surface preparation are very widely accepted processes within manufacturing and service industries. Each application has its own unique reason for and why a specific treatment is required, level of performance and economic justification. Applications range from the most delicate to the most arduous and exist in almost all manufacturing industries.
Other manufacturing industries range from small newly formed entrepreneurial engineering companies with just a few employees to national and multi-national corporates, employing thousands of personnel.
Here are just a few of the many industries that justifiably employ dry and wet blast processes.
PureFinish
Within the food and pharmaceutical industries hygiene is a top priority, not only for safety but also to prevent contamination and to ensure the quality of the product in terms of taste, aroma and appearance. The occurrence of contamination through bacteria, proteins or other elements must therefore be prevented. Process plants require a defined, homogeneous and reproducible surface for all parts that come in contact with food, beverage and pharmaceutical products.
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