Tag Archives: Centrifugal Disc Finisher

Patient-Specific Implants Call for Equally Customized Processing

Advancements in medical technology now allow for the development of Patient-Specific Implants (PSI). Specialized computer programs analyze x-rays, ultrasound, and MRI images to create surgical guides, tools, and implants tailored to the patient’s unique anatomy.

While still emerging, many medical industry suppliers have received FDA approval for PSI use. Like traditional implants, these implants must be carefully finished once created to ensure the work piece meets stringent medical safety standards while promoting patient comfort and long wear life.

The benefits of PSI use include shorter surgery times, better surgical outcomes, and cost savings.

True to its “apply innovation” tagline, Renishaw’s Medical and Healthcare Division has found great success in additively manufacturing PSI. Using CT scan-to-CAD software, one of the company’s most innovative advances is creating cranial plates using titanium powder.

When determining how to finish the implants to precise medical requirements and surgical demands, Renishaw trusted Rosler for help with mass finishing.

The Challenge



Renishaw cranial plates after polishing

Original commissioning neurosurgeon Bartolomé Oliver required the surface of Renishaw’s cranial PSI to be satin-like in order to best match the patient’s cranial contours. Renishaw Applications Engineer Andy Wescott’s job then became creating a repeatable and streamlined process to apply a satin and highly polished finish to the top of the cranial plates from their as-built condition. 

“Traditionally, post-processing these parts to a low surface roughness value was very manual and time-consuming,” Wescott said. “The post-process time for a large cranial plate was up to five hours. We needed to reduce that time and the amount of manual input because if an operator working on a part loses concentration for one second, they could burn a hole in your part.

“That makes one expensive bit of scrap.”

Finding a Better Way…

Since metal additively printed parts are now of such quality, they can be treated like any other metal part. And Rosler knows a thing or two about surface finishing metal parts, having been in the post-processing game with its mass finishing and shot blasting divisions for more than 80 years.

A more mechanized solution presented itself in the form of Rosler’s High-Energy Centrifugal Disc Finishing Machine FKS04.

Now, after a cranial plate comes out of the Renishaw AM250 machine, it undergoes only a small amount of manual operation to remove supports from printing and slightly improve the surface using a carbide burr and flap wheel.

It is then placed into Rosler’s FKS where it automatically goes through a three-step process to produce the impeccably smooth finish, reducing manual operating time to under an hour.

The clever part, which ensures repeatability on each and every part, comes from a little bit of Renishaw engineering know-how.

“We designed a tool to hold our parts in a particular orientation inside the tumbling bowl,” Wescott said. “Rather than just throwing parts into three media types and coming out with a sort of fixed part, our parts require precision. Certain features require protection from the tumbling media, so we’ve invented a tooling method that keeps parts face down in the media and only applies the surface finish where needed.”

The Rosler Way

Although there isn’t a one-size-fits-all solution for finishing, the collaboration between Renishaw and Rosler demonstrates that post-processing doesn’t have to be a grueling experience. Much like the additive manufacturing process itself, your finishing technique depends on your unique application. Contact Rosler today for help in finding a better way to meet your finishing needs.

Automation Part 7 – The Top 3 Mass Finishing and Shot Blasting Machines

Rosler understands that automating aspects of your mass finishing and shot blasting processes has never been more critical.

As we have learned during recent world events, outside factors can have a significant impact on your ability to maintain a largely manual process. Though automated mass finishing and shot blasting machinery does require some human intervention, it can often be operated with a minimal headcount and limited human contact.

In previous blogs, we have explored how an automated-first posture can help you to gain significant efficiencies, lower costs, and increase your competitive advantage. We have also looked at the balance between automation and the environment and have discussed ways that you can mitigate environmental impacts of operating automated mass finishing and shot blasting machinery.

We now conclude our Automation Blog Series with best practice examples of automated mass finishing and shot blasting machines Rosler offers and the associated accessories and components available to help in building your next-generation automated processes.

Continue reading Automation Part 7 – The Top 3 Mass Finishing and Shot Blasting Machines

Part-on-Part Mass Finishing, Part 2 – Rotary Vibrators Versus Centrifugal Disk Machines

As described in Part 1 of our Part-on-Part Blog Series, some forms of mass finishing techniques encourage part-on-part contact to achieve the desired finish. 

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.

Continue reading Part-on-Part Mass Finishing, Part 2 – Rotary Vibrators Versus Centrifugal Disk Machines

Optimal Media Mix, Part 2 – Understanding Media Consumption

As we established in Part 1 of this seriesidentifying 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.

Parameters affecting media consumption include:

Continue reading Optimal Media Mix, Part 2 – Understanding Media Consumption

Surface Finishing Technologies Add Value to “Fine Blanked” Components

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 times more 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

 

Surface Finishing Of Orthopaedic Implants And Medical Instruments

mixed-medical-images

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.

Continue reading Surface Finishing Of Orthopaedic Implants And Medical Instruments

The 9 critical points to check you get the most out of your centrifugal disc finishing machine and process

Here are 9 critical points to help you get the most out of centrifugal disc finishing:

1. Regularly Check That You Have Enough Media In Your Machine.

2. Check That The Media Condition Is Good.

3. Check You Have The Right Amount Of Water And Compound In The Machine.

4. Regularly Check Your Seal Gap.

5. Too Many Parts In The Machine.Media in machine

6. Check The Machine Is Running The Correct Way.

7. Check The Machine Tub And Spinner Are In Good Condition.

8. Check You Are Following The Process Parameters.

9. Check Your Starting Condition Is The Same.

Centrifugal (High Energy Disc) Finishing – What Is It And Why Should You Consider Using It?

 

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.

Standard FKS Machine

Continue reading Centrifugal (High Energy Disc) Finishing – What Is It And Why Should You Consider Using It?

Centrifugal Disc Finishing Tip 9. Check Your Starting Condition Is The Same

 

Sometimes things change … including the starting condition of your parts. Worn tooling, changes in manufacturing methods or mateImage 1rials 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…).

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Centrifugal Disc Finishing Tip 8. Check You Are Following The Process Parameters

 

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!

Continue reading Centrifugal Disc Finishing Tip 8. Check You Are Following The Process Parameters