“No Contaminants < 30 µm” – A Demand Perfectly Met
Vibratory finishing with subsequent part washing represents a process combination that meets ever-increasing cleanliness specifications. By matching the right equipment these requirements can be easily fulfilled in linked, fully automatic processes as well as in stand-alone systems.
Mass finishing isn’t a term that everyone would necessarily know. Mention it to most people and you’re likely to be met with a blank stare or a look of bewilderment. Interestingly though we all come in to contact with the things it does on a daily basis. So to explain this we thought we’d take you through a day in the life of Rösler mass finishing:
Super Finishing removes the asperities that are inherent in the manufacturing process. By safely removing these microscopic peaks, the Super Finishing process leaves a much more uniform surface that reduces friction and allows for increased lubrication capability. While the dimensional integrity of the part remains intact, the result is an improved component that will operate at lower temperatures, have increased durability, quieter operation and increased time between maintenance.
Better surface properties on gear teeth and other functional surfaces are responsible for:
reducing friction and wear;
reducing operating temperature, even at high speeds;
eliminating any need for ‘run in’ time and reducing the risk of component failure at the initial stages of its life;
reduction of vibration and noise within the unit, again increasing its marketability and improving its performance;
cleaner lubricant as a result of reduced component wear producing ‘debris’ to pollute the component’s working environment (resulting again in shortening the component life span);
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.
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.
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.
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
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.
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.