As we established in Part 1 of this series, identifying and maintaining an optimal media mix is essential to realizing optimal mass finishing results. Rosler Metal Finishing understands that our equipment must work in tandem with media to provide you with the desired finishing results.
Understanding how your machine, the work pieces it is finishing, and the selected media will interact is key to delivering an optimal finish each cycle. Doing so requires understanding media consumption factors in order to maintain an optimal media mix.
What are the Factors of Media Consumption?
Media consumption and wear rates depend on ten key parameters. These rates change if even one of the parameters below change. Therefore, quoted wear rates and cut rates are relative values only.
Media usage can only be estimated, the actual consumption can only be determined by the end user under exact process conditions.
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
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.
Centrifugal (high energy disc) finishing is a mass finishing technology that allows rapid finishing of smaller, robust parts. Whereas vibratory finishing utilises a moving bowl transferring energy into the contained media (chips) and parts in this case the bowl is static and movement is caused by a rotating disk, fixed on a shaft in the base of the bowl.
Sometimes things change … including the starting condition of your parts. Worn tooling, changes in manufacturing methods or materials or investment in a new manufacturing machine can result in you no longer getting a result from your mass finishing machine like the one you have been used to and/or need. We would typically recommend a sample starting condition part is kept by the machine for reference each time parts are to be processed. Should the starting condition prove to be different often this can be accommodated in the mass finishing process itself (i.e. extended time, changes in machine speed, different media, etc…).
It is said that where a human being is involved in a process there is typically a 3% risk of error. This is because we lose focus, become distracted and invariably seek to find a way to make our lives easier. Worse still with variables such as media, water, compound, volumes of parts to be processed and process time with a mass finishing process there is often too much to tamper with!
Over time the polyurethane tub and spinner will wear. This will happen more quickly with highly abrasive process media and with sharper / heavier components and very slowly with polishing processes (providing the correct ratios of parts-to-media are adhered to).
Occasionally machines are disconnected and wired back in (following relocation, repair, etc…). When this happens machines can have the electrical phases reversed and can run backwards. Whilst the machine will process you will find the result isn’t as good as it should be.
When your process is first established a full load of parts should be calculated (be it 5,500 or even 5,000). This number of parts will be equivalent to a volume which then be added to the media to fill the machine to the correct level ensuring that all operates as it should.