When it comes to mass finishing, amplitude and frequency require balance and careful consideration. Amplitude is a measure of movement and intensity while frequency refers to the rate of repetition.
The wrong amplitude, for example, can create lackluster finishing results and longer processing times if it is too low. If too high, it can cause unnecessary wear and tear on the machine.
Creating Vibratory Energy
Whether rotary or tub style, mass finishing vibrators always include two key components: a work bowl containing the finishing media and the work pieces.
Firmly attached to this work bowl is a vibratory drive system generating the energy to put the media and work pieces in motion. The work bowl with an attached vibratory drive system sits on a number of coil springs – in some cases on air cushions – which in turn sit on a machine base. The springs, respectively, act as air cushions allowing the work bowl to “free float” up and down within a certain distance.
Improved productivity, increased production capacity, better quality, and lower costs—a leading garden tool manufacturer tasked Rosler with developing a new mass finishing system to improve the deburring and polishing of garden shear knives.
Rosler provided a solution in the form of a tailor-made Keramo-Finish® process carried out within a double-batch centrifugal disc finishing machine. Known as the FKS 35.1 A2-So, the system includes fully automatic work piece handling and a two-stage process that deburrs and polishes stamped and laser-cut knives. Work pieces are subsequently dried in an energy-efficient rotary dryer and prepared for the next manufacturing step.
The Situation
For more than 60 years, the Gardena division of Husqvarna Group has developed a variety of gardening products and tools. The company’s broad product range includes innovative systems for irrigation, soil cultivation, and lawn, tree, and shrub care. Gardena products are used in more than 80 countries worldwide.
To ensure easy and simple handling, produce excellent cutting performance, and guarantee long service life, the Gardena’s shear components are produced with state-of-the-art manufacturing technologies. Stamping or laser cutting of the upper and lower knives followed by surface finishing is an important step.
Rosler Metal Finishing has decades of experience in the forge and foundry industries, especially when it comes to mass finishing for die-casted work pieces.
Our Forge & Foundry Blog Series continues with an overview of our top five mass finishing machines for precise cleaning of die castings.
Standard Rotary Vibrators
Media and parts are placed into a circular processing bowl in standard rotary vibrators. The energy from a vibratory motor causes the media and parts to freely tumble over each other. Some models are equipped with an internal separation device for separating the finished work pieces from the media.
Rotary vibrators can be used for batch and continuous feed processing.
The R620 Euro is one of Rosler’s standard rotary vibrator models
Rosler’s standard rotary vibrator models include the models EC, Euro, A, and R.
Ideal Work Pieces — Small to fist-sized die-castings such as shoe buckles, furniture fittings, gear shifter forks, electrical components
Innovation is at the heart of engineering. At Rosler Metal Finishing, our engineers are constantly finding a better way to help our customers meet their surface finishing needs. That’s why they developed the R 150 DL-2 rotary vibrator.
The R 150 DL-2 was an excellent choice for LINK’s new “bi-mobil” hip implant. The implant offers patients a higher degree of mobility by inserting a movable PE joint in the acetabular cup. The PE-joint in turn is clamped to the ball of the hip stem. To minimize friction and prevent premature wear, the inside of the cup requires an extremely smooth surface, which can only be achieved with a high gloss polished finish—something the R 150 DL-2 easily achieves where other surface finishing companies failed.
In addition to viewing work piece impingement as an asset, this type of mass finishing also eliminated the need for ceramic, plastic, and other types of media. The only additives required for such part-on-part finishing are water and the respective compounds.
Rosler Metal Finishing designs and manufacturers two machines specifically for part-on-part mass finishing known as WTA rotary vibrators and MK centrifugal disk machines.
The applications and benefits of each machine provide a range of part-on-part mass finishing uses for sturdy parts in bulk. Let’s compare their designs.
WTA Rotary Vibrators
Rosler developed special WTA rotary vibrators especially for part-on-part processing. These machines not only allow running the finishing/washing process, but also the subsequent drying stage in one single machine.
Fine-blanking can achieve flatness and cut edge characteristics that are unobtainable by conventional stamping and punching methods and surface finishing adds additional value.
Fine blanking is capable of combining several steps normally required by traditional stamping making this procedure a very time-efficient process. In a single step, fine blanking can produce a part which would normally require multiple operations in terms of man hours and equipment set-ups. Fine blanking is known and is a recognised method for creating component parts with fully sheared crisp clean edges, close tolerances and profile, eliminating in many cases, secondary requirements.
The production of fine blanks can be formed from various metal types of steel, non-ferrous including zinc, aluminum, aluminum alloys, copper and brass for the automotive industry and other industrial sectors.
Many companies keep the important operation of surface finishing in-house and utilise various systems such as rotary vibrators, centrifugal disk machines and waste water treatment systems. The size and shape of the parts as well as the surface finish requirements, determine which type of mass finishing system is required.
To be cost-effective, mass finishing operations for many and various fine blanked parts require the utilisation of different mass finishing technologies.
Shorter cycle times with centrifugal disk finishing
Centrifugal disk finishing systems are ideal for such applications. When it comes to intensive grinding and polishing, centrifugal disk machines are usually 10 – 30 timesmore productive. Their separation system guarantees batch integrity. However, these finishing systems are somewhat limited by the batch size. For example, a batch of relatively high quantity of parts weighing 400 kg require to be divided into several smaller batches.
Typically, for these larger production capacities, a fully automatic centrifugal disk finishing machine which processes the parts without any operator involvement all the way to depositing the finished parts into dedicated parts bins, is an ideal option. The effluent from this centrifugal disk machine can be cleaned with an effluent treatment process centrifuge after which the cleaned water and compound can be recirculated many times, to achieve considerable cost savings.
Alternatively, consideration could be given to a fully automated rotary system and possibly with several small centrifugal disk finishing machines. The effluent from all these finishing machines can be handled by a waste water centrifuge before being recycled. This allows running several surface finishing processes with optimum results and excellent cost control.
Fully automated finishing cell
Do you know the difference between standard rotary vibro bowls and high speed processing?
For the processing of larger quantities of component parts a range of high-speed rotary vibrators is an available option, with superior grinding performance and with process economics in mind.
For the processing of large quantities of component parts
In high speed rotary vibrators, (already in use at numerous manufacturers of fine blanks, stampings, folded or bent, sawn, cold and hot forged component parts), batches of 400 kg can be processed irrespective of whether a batch consists of 10 or 45,000 parts. The performance of high speed rotary vibrators is up to 60% higher than that of standard rotary vibrators which contributes to a quick payback or amortisation.
Click image to watch an automated
centrifugal disk system in operation
Post written by Sandra Banks
Personal Assistant / Digital Marketing
DL rotary vibrators allow for safe and efficient finishing of the internal channels in complex work pieces
One of the most technically challenging aspects of mass finishing is the ability to effectively treat the internal channels of precision components. This is especially true in industries which face very stringent requirements, such as; automotive, aerospace, tooling and medical. It is essential for these manufacturers to achieve precise finishing results.
Fully automatic operation produces precise and consistent results
A new specialised line of rotary vibrators that do not have an inner dome, which allows for automatic, precise surface grinding, smoothing and high gloss polishing of such specialised components. New DL vibrators allow for fully automatic and reliable treatment of such inner contours, resulting in excellent finishing results, achieved in either wet or dry operational mode. Even with extremely delicate and complex contours the dimensional integrity of the work pieces is fully maintained. Depending on the components, their original surface readings and the selected finishing process, Rz values of as low as 0.1 µm can be achieved.
In this type of machine, one or multiple work pieces may be attached to specially designed fixtures. The complete unit with the attached work piece(s) is then firmly mounted into the DL vibratory finishing system. For certain applications the loading and unloading operation can take place with a pneumatic lifting device, this eliminates the need for entirely removing the media from the work bowl when unloading the fixture with mounted part(s).
The vibratory energy is provided by two high-performance vibratory motors, placed on the outer wall of the work bowl, which is transferred to the work pieces that are mounted to the bottom of the work bowl. The intense vibration causes the processing media to flow through and around contours, internal passages or undercuts in the work pieces, without getting stuck.
Compared to standard vibratory systems, this sophisticated machine design combined with powerful vibratory motors (3,000 RPM) produces a 30% increase in processing intensity, resulting in comparably short cycle times. Adjustment of the imbalance weights and control of the motor speed, with frequency inverters, provides the ability to adapt the processing intensity to match the work pieces and the desired finishing task.
Equipment suitable for a multitude of finishing tasks
DL rotary vibrators are the perfect solution for finishing complex work pieces, such as; housings, pump or fan wheels, blisks, dies and moulds, tools, automotive wheels and a variety of other work pieces. Ensure you have sample processing trials carried out on your components so that you receive a tailor-made finishing solution, with the highest finishing quality, short cycle times and high cost efficiency.
All DL vibratory finishing systems are equipped with an easy to use control panel, which includes process timers. For wet finishing operations, compound and water are fed into the machine with a precise dosing system.
R 150/2 DL vibratory system with two external motors mounted on processing bowl
Alloy Wheel polishing has been significantly improved by optimising both the processing times and final results. These improvements have been achieved by mounting two motors on the process bowl, providing a stronger and uniform circulation of the grinding and polishing media.
Conventional machines have only a single motor in the centre and on more complex designed alloy wheels, additional machine inertia is desirable.
In the area of medical technology surface finish of work pieces is an important factor. Component surfaces must be ground, smoothed and polished without risking their required shape and functionality. The reasons for these requirements are hygiene and sterilization.
Due to newly designed industrial cutlery cleaning equipment, companies in the catering trade, i.e. event hire companies, restaurants, hotels, conference facilities and any venue catering for large events can now experience very easy ways of cleaning high quantities of all kinds of cooking and eating utensils. Continue reading Cleaning Of Cutlery In A Highly-Efficient Way→
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In this type of machine, one or multiple work pieces may be attached to specially designed fixtures. The complete unit with the attached work piece(s) is then firmly mounted into the DL vibratory finishing system. For certain applications the loading and unloading operation can take place with a pneumatic lifting device, this eliminates the need for entirely removing the media from the work bowl when unloading the fixture with mounted part(s).
