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.
For transmission components like gears and shafts, shot peening has become an indispensable step in the overall manufacturing process.
With the RWT swing table machine, Rosler developed a modular equipment concept that can be easily adapted to different technical requirements and offers a maximum in process stability paired with absolutely repeatable peening results and high cost efficiency. One of the numerous customers within the automotive industry utilizing the RWT is an Asian automotive supplier.
As part of a capacity expansion for minivan transmissions, this customer increased annual production to 40,000 units and decided to carry out the required shot peening operation in-house instead of subcontracting it to an external job shop.
The specifications called for a system that can handle around 560,000 single work pieces per year, including 15 different types of gears and shafts. Each work piece type required the development of a specific peening program based on drawings and various work piece materials.
Considering that automotive crankshafts weigh around
40-60 pounds and rotate approximately 100 times per second, these parts are
exposed to tremendous tensile, compressive, and shear stresses. In addition,
combustion forces and piston acceleration in an engine can also cause
Therefore, crankshafts must be made from tough,
wear-resistant materials, usually high alloy carbon steel. Typical alloying
elements are manganese, chromium, molybdenum, nickel, cobalt, or vanadium.
worldwide sales at nearly $10 billion annually, there is a high demand for
spinal implants. These implants are subject to very specific and strict surface
finishing requirements to ensure longevity and fixation to bone.
Mass finishing and shot blasting play key roles in creating the right finish for spinal implants, not only for intermediate surface treatment after forging, casting, machining, additive manufacturing, etc., but also for placing the final surface finish before implantation.
While none of these work pieces contain sand, their
surfaces may show oxidization or – in the case of ferrous metals – heavy
scale/rust caused by iron oxide.
All forms of oxidization must be removed to ensure
that subsequent manufacturing operations such as machining, coating, and
painting are economical and efficient. Poorly cleaned work pieces may cause additional
processing, premature wear on milling tools and drill bits, excessive pollution
within coolant systems, and inefficient adhesion of coatings and paint.
Traces of oxidation may also impact the work
Shot blasting and mass finishing have become indispensable technologies for surface preparation and finishing of joint reconstruction implants. Their applications range from surface cleaning, deburring, edge radiusing after forging, casting, additive manufacturing, and machining to surface preparation for different kinds of coatings, shot peening for increasing the longevity of an implant, and placing an extremely smooth, high-gloss finish on the implants before they are inserted into the body.
Are the work pieces sturdy enough to allow for somewhat more aggressive processing or must they be handled gently without any part-on-part contact?
Is batch processing possible or must it be continuous?
Which work piece handling system is best: rotary drum, troughed belt, wire mesh belt, or overhead monorail system?
Can the work pieces be handled by robot, etc.?
Rosler Metal Finishing builds shot blasting machines that are designed to expertly prepare the surface of delicate and sturdy die castings and everything in between. We can design a machine that is perfectly matched to your work piece and process.
Our Forge and Foundry Series continues with a look at the cleaning required for sand castings and the collection of removed contaminants.
Rosler Metal Finishing builds shot blasting machines that are equipped to prepare the surface of sand castings as well as collect removed contaminants for a consistent workpiece finish and the health of the utilized machine and personnel.
What design features must be considered in blast turbines used for the cleaning of sand castings?
Baked-on molding sand, sand cores, and scale/rust on the sand castings are difficult to remove and require turbines with a lot of fire power. Turbines with curved throwing blades, such as Rosler’s Gamma G series, have proven to be exceptionally effective since, compared to straight-bladed turbines, the curvature of the blades generates up to 25 percent higher throwing speeds!
Joint reconstruction implants allow millions of
individuals 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.
Our Joint Reconstruction Series continues with an
overview of the most common materials used for these endoprosthetic implants.
The most common materials used for joint reconstruction implants are currently titanium and titanium alloys and cobalt-chromium alloys. Both materials are very tough, corrosion-resistant, highly biocompatible, and have proven themselves to be absolutely reliable.