Combining the direction of rotation and centrifugal force, Rosler’scentrifuge technology takes advantage of the weight difference between the liquid phase and the solids in the process water to separate “dirty” solid particles from clean, reusable process water.
The effectiveness of this technology lies in the centrifugal force that is created. For example, a modern fighter jet develops a G-force of about 10-15 while a high-speed centrifuge drum generates a force of more than 2,000 G.
The physics of centrifuge technology combined with mass finishing equipment creates efficient and ecologically sound manufacturing processes, albeit with some key limitations.
Collection by Force
The solids, primarily consisting of media and, to a lesser degree, of metal fines from the work pieces, found within “dirty” process water are heavier than the water itself. As the drum spins, heavier solids are deposited on the drum wall in the form of sludge, whereas the lighter-weight liquid remains on the inside of the drum. With the addition of special cleaning additives known as flocculants, even oil carried into the mass finishing process can be removed from the process water.
During mass finishing, the process water injected into the finishing machine is contaminated with the chemical ingredients of the compounds, fines from the grinding or polishing media, and metal fines from the work pieces.
In case of ball burnishing, when acidic or alkaline compounds are used, the process water can also contain dissolved metals or be alkaline or acidic. Or, for example, when the work pieces are covered with oil from machining or stamping operations, the water can even be contaminated with oil.
Rosler has developed a series of closed-loop, water circulation systems using centrifuge technology to remove these contaminants regardless of their origin and allow clean process water to be reused and/or safely discharged. In addition to offering more effective work piece processing, cleaning process water saves money and the environment through reduced consumption, compound usage, disposal costs, and regulations.
Before the “dirty” process water coming from a mass finishing operation can be discharged to sewage, it must be cleaned to meet the legal discharge limits for hazardous materials. Likewise, for cycling the water back to the mass finishing process, the process water must also be cleaned. Uncleaned process water would cause a mass finishing process to collapse very quickly.
Rosler has more than 80 years of surface finishing expertise. In that time, we’ve developed countless efficiencies in both the design of our equipment and the processes they support. Centrifuge technology has long been an effective and cost-efficient tool, not only for cleaning the process water, but also for reusing it for the actual mass finishing operation.
Previous Cleaning Methods
To a large extent, this technology has replaced traditional waste water cleaning methods. Until recently, the most common cleaning systems for mass finishing applications were settlement tanks and flocculation (“floc & drop”) systems.
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.
Technology has transformed almost every aspect of life and the shop floor is no exception. As explored in previous Automation Blog Series posts, Rosler Metal Finishing believes automation represents the new norm in mass finishing and shot blasting. In the face of increasing competition, manufacturing interests will continue to demand lower cost, higher efficiency, and greater flexibility from their chosen surface finishing partner.
Though it would appear that any downsides of automation are outweighed by its benefits, there’s a delicate balance to be struck when it comes to a symbiotic relationship with the world outside of the machine. Having previously discussed how human effort and ingenuity will work in harmony with automated processes, we now turn our attention to environmental considerations—namely, how automated machines used in mass finishing and shot blasting can impact the earth’s resources, and how manufacturers can mitigate that impact.
The International Institute for Sustainable Development notes that the rise of automation has thrust us into a “Fourth Industrial Revolution,” citing energy use, resource use, and ecosystems as the three most critical factors to watch as more automated processes are implemented.
These are important considerations, given that manufacturers often are targeted in headlines about waterway pollution and even global warming, but responsible manufacturing practices can help avoid the most egregious impacts and keep manufacturing operations in compliance.
Finding a solution to our clients’ needs is nothing new for Rosler, nor is combining multiple solutions into a single finishing system. Take our work with Polish brake pad manufacturer Lumag Sp. z o.o. (Lumag), for example.
When they faced the challenge of de-oiling, deburring, and surface roughening brake pad carrier plates as part of their punch press process, they turned to us for a cleaning and mass finishing solution.
Upon its founding in 1988 by Marek Zak, Lumag specialized in the production of brake linings. As the company implemented its own brake pad manufacturing technology, their products and offerings evolved. In addition to achieving enormous technological progress and applied engineering solutions, Lumag amassed a collection of machinery in need of constant upgrades and integration.
In order to meet the continuous rise of quality and safety standards for its brake pads for drum and disk brakes for commercial vehicles as well as brake pads for passenger cars and motorcycles under the trade name Breck, Lumag needed a partner with automotive expertise who could combine multiple solutions in a single system.
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.
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.
The mass finishing process creates waste water. This substance known as effluent must be properly processed for reuse or disposal. Centrifuge technology offers solutions for cleaning and/or recycling effluent.
Rosler offers a variety of options to process waste water including flocculation systems and the elimination of vibratory finishing sludge. Each type of waste has unique factors and considerations.
In order to achieve the lowest total cost of ownership and the greatest process efficiency, recycling process water used in mass finishing processes is key. Reusing water not only reduces costs in the form of less consumables used, but also enables companies to reduce their discharge and disposal fees by replacing process water less often and complying with water and waste regulations.
Waste water from mass finishing applications is often referred to as effluent and must be cleaned for recycling or discharge.
Mass finishing techniques are often used to uniformly prepare and finish work-pieces, but the compounds and liquids used to remove fines and other debris from work-pieces must be dealt with to ensure a repeatable process application. Cleaning and/or recycling waste water produced in the mass finishing process is easily achieved with centrifuge technology and provides opportunities to be more environmentally responsible and save money in the form of reduced labor and materials (cleaning agents and compounds).