Published 1/1/2020

Benefits of Recycling Vibratory Finishing Effluent

Recycling vibratory wastewater can be very advantageous and cost effective, says Dean Bell of Precision Finishing, but only if done properly.

Dean Bell, Operations Director, Precision Finishing

A: If you are paying for your water and operating large or multiple vibratory pieces of equipment, your water bill could be substantial. Recycling your wastewater could significantly reduce your operation cost. Also, if you are looking to add green technology to your manufacturing operations, recycling your vibratory waste could be an easy way to go green. Not only could you save water but proper filtering can enable you to reduce your usage of vibratory chemistry. However, you must understand that recycling isn’t as easy as it sounds and isn’t suitable for all vibratory processes.

If your vibratory process entails the use of two or more compounds and you recycle this water, it is impossible to control the quality and final finish of your parts. If, however, you are using a single chemistry in your process, your recycled water is more easily controlled, resulting in a consistent finish.

Because the vibratory process is inherently dirty, recycling this unfiltered water will result in the soils being redeposited onto your parts. This will cause serious issues such as oxidation/rusting, smutty or dirty parts. This will also create issues for post processes such as plating, anodizing, painting, and more. The dirty effluent will also “glaze” your media, thereby affecting the cut and finishing ability of the vibratory media.

Proper recycling of vibratory wastewater should entail ultrafiltration of the fine particles from the waste stream, leaving most of the chemistry behind. Using one compound enables you to control your process by adding the proper amount of chemistry to your filtered water in order to maintain a consistent finish.

Flocculation can also be used, but it needs to be closely monitored. The flocculation chemistry will mix with the vibratory compounds creating a “different” vibratory compound. This will create similar issues as previously discussed. Lastly, monitoring all recycled water is needed as the salt levels will increase in your recycling system as a rise in salt levels can create similar oxidation/rusting, smutty or dirty part issues.

Recycling your vibratory wastewater can be very advantageous and cost effective if done and monitored properly

Q: What programs should we have in place to maintain a vibratory tumbler?

A: For your vibratory finishing machine to operate efficiently and safely, you have to make sure regular inspections and maintenance are completed. Like most equipment maintenance, it is a good idea to track preventative maintenance (PM), corrective maintenance and inspections through the use of a maintenance program. The best way to drive your maintenance program is by equipment hours, as most equipment manufactures suggest certain PMs and inspections at hourly intervals.

Some vibratory equipment is installed with an automated lubricating system. Make sure this system is monitored to ensure correct lubrication. Also check the manual lubrication. Follow your equipment lubrication schedule to ensure the proper amount and type at the correct intervals. Following the manufacturer’s lubrication schedule will ensure you extend the life of your equipment’s drive system. Inspect any belts, pulleys, springs and shafts at these intervals and replace as necessary.

There are many different types of compound delivery systems. To extend the life of your compound delivery system, it is always a good idea to flush your compound system with fresh water at the end of each operation cycle to avoid buildup and residue.

The urethane liner in a vibratory machine protects the steel shell from media wear. If the machine goes unprotected, the media will work the machine walls as it does the parts, so you will want to periodically check the liner thickness to avoid compromising the machine’s integrity. You will want to check your lining for excessive wear and the easiest way to do this is by hammering a finishing nail through the lining to check its thickness. If the lining is less than ¹/₈”-¹/₄” thick, then it is time to contact your vibratory sales representative to schedule a reline.