Regardless of the industry, the selection of media and compounds utilized in mass finishing can elevate or hinder finishing results. The handling of effluents – used process water – also factors into a process’ efficiency and end results.
With more than 80 years of experience, Rosler understands the demands of the forge and foundry industries specifically and how to achieve precise and consistent finishing results by combining the latest technology, well-designed machines, and consumables.
This installment of the Forge & Foundry Blog Series highlights how careful media and compound selection along with proactive handling of effluents assist in producing mass finishing efficiencies.
Ingredients for Success
Media and compounds are more than just “rocks” and “soap” thrown into a mass finishing machine. Instead, these consumables are sophisticated tools that can make a mass finishing process a success or a failure.
You don’t throw your media out with the waste water, so why would you purchase new mass finishing equipment or muddle through with an inefficient process when optimization can extend the life and enhance the effectiveness of your processing equipment?
Whether a result of increased production needs or in response to poor performance, optimizing your mass finishing process is a great way to reduce operational costs and lower your equipment’s total cost of ownership.
A Proactive Approach
Revising a process to meet increased production demand is a cost-effective way to not only improve your processing times and results, but also increase and prolong your equipment’s usefulness.
Let’s say production has been steadily building over time. How do you know if it’s time to evaluate the process?
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.
Often overlooked in the manufacturing process, mass finishing can help add value in a variety of ways. Mass finishing can reduce or eliminate manual process steps, improve process consistency, increase throughput, reduce manual labor, and more.
Manufacturing or process engineers in a manufacturing plant do not have to be the expert that knows all the latest details and techniques of the finishing process. They do, however, need to have a good understanding of the basic mass finishing processes that can be applied.
Mass finishing describes a surface finishing method where parts are deburred, smoothed, polished, or cleaned using media (tumbling or vibratory), compounds (finishing soap), and specialized equipment.
Understanding how the different process components, i.e. the machine, media, compound, water, and the incoming part all interact and influence the desired part finish is important. Each of the inputs in itself has a multitude of adjustments and parameters.
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).
Machinery and media are nothing in the mass finishing world without the right compound.
A manufactured object can be designed to specifications, but if it doesn’t look and feel finished, it may be rejected. A metal alloy can be structurally perfect, but surface corrosion may make it less presentable. Process water may work well for initial cycles before contaminants wear down its effectiveness over time.
The right compound for a given mass finishing process can solve each of these problems and more.
The quality of consumables used in mass finishing is a key factor in surface processing. Using consumables with a consistent high quality is crucial to attain set surface specifications, process times, costs and to manage considerations to any environmental impact.
There are in excess of 1700 types of vibratory media consisting of various shapes, sizes and incorporating a percentage of abrasive. These are divided typically between ceramic and plastic families.
Ceramic Media Production
A ceramic media has a higher density than that of plastic media. Ceramic chips of various shapes and sizes are formed, fired and held at certain temperatures and durations; providing an infinite range of variation and capability.
A consistent, supreme quality media is extremely important for the user to obtain a uniquely stable and reproducible surface finishing result.
Ceramic media is manufactured to exacting standards, controlled in a fully-automated way.
Plastic Media Production
The manufacture of the plastic media is also totally automated.
The plastic media is of a lower density than that of the ceramic media, therefore it is suitable for a more gentle treatment of critical component parts and softer metals.
The process involves mixing, forming and curing of the media and the whole process is computer controlled and continuously monitored. This quality standard ensures a consistent wear and cutting performance, and repetitive results during the finishing process.
Surface Finishing Compounds
Compounds can be added to the vibratory process, optimising the surface specification for: degreasing, brightening, polishing, corrosion protection and producing surfaces free of stains.
Another important function is keeping the process clean. The compound continuously flushes tiny metal particulates from the chip media and other contaminants out of the mass finishing system, keeping the media active and the parts free from contamination.
Depending on the specific process, compounds will provide various options of acidity and alkalinity as a pH factor.
Despite compounds being used for many years in mass finishing applications research and development constantly progress new formulations for special applications.
The range of different compounds is broadly diversified:
Compound for mass finishing machines is an essential part of the process. There are a huge variety of compounds available and their function is to:-
Maintain the action of the media by loosening and separating metal fines from the surface of the chips and to keep them suspended in solution so that they can be carried out of the process tub.
Change the action of a media by chemical activity
Provide an aqueous solution contained water-softening ingredients, detergents for cleaning both media and component, to chemically brighten and to provide inhibitors to prevent rust on ferrous components and tarnish on all metals
Calcium () and Magnesium () are the two most common ions that are found in hard water, while iron (Fe2+), Manganese (Mn2) and Aluminium (Al3+) can also contribute to hardness.
Hardness is defined as the sum of the calcium (Ca2+) and magnesium (Mg2+) concentrations, both expressed as calcium carbonate in milligrams per litre (mg/l). Iron (Fe2+), manganese (Mn2+) and Aluminium (Al3+) can also contribute to water hardness.
The water hardness has a significant effect on the performance of compounds. Soft water will cause foam; hard water will increase the compound usage and can cause spots on component parts during drying.