Vibratory Tumbling Process Checklist Before Running
Regularly check machine condition and vibratory tumbling process parameters are critical. Because it makes sure consistent and stable performance. So here we made a conclusion of the 9 most important items that you need to check before running the machine. Then you can get the most out of your vibratory finishing machine with our experience.
1. Always check you have enough media in your vibratory bowl
When tumbling media (especially ceramic media and plastic media) runs over time, amount of media in vibratory finishing machine will reduce gradually. However, to keep the optimal performance of vibratory tumbling, a certain media-to-parts ratio should guarantee.
If media to parts ratio drop and exceed a certain value, the finishing performance will affect and process time may longer than expected. Besides, for a machine with internal separation, with less amount of media, parts are hard to discharge and separate completely. Especially, it will take much longer time to discharge last 25% of last parts.
The criteria that we should follow when the first time we load the vibratory finishing machine
- vibratory finishing machine with the internal separation 70% of total capacity
- vibratory finishing machine without separation deck 80% of total capacity
- trough vibratory finishing machine 90% of total capacity
2. Make sure your media in a good condition
When the vibratory tumbling process going on, media as abrasive, size will become smaller and smaller. At the same time, bulk density will be higher because of less free space between media. When the media size goes smaller, it not only takes a longer time to do the process, also smaller size media may risk lodge in parts cavity. Therefore, we have to remove undersized media when adversely affect the performance.
To replace undersized media easier, Inovatec introduces reverse screen for media separation when size bellow certain value. Also, the undersized media can be discharged at the plug and separate with a vibratory separator.
However, smaller media can use in other applications. For example, centrifugal barrel machine and centrifugal disc finishing machine for smaller and delicate parts deburring and cleaning.
3. Right amount water and compound dosing
Water and compound are also important to check before processing. Because liquid removes dirt and wear debris from parts and media surface, the whole process can keep clean and parts are protected from damage.
There are many types of chemicals available for different applications. According to performance, they can do deburring, cleaning, oxide removal as well as rust inhibition. Besides, another main function of the compound is to get the metal surface with a glossy finish.
3.1 Compound VS water ratio
It is very important to keep water and compound in a right mix ratio. Too much water means the low concentration of the compound, and this can slow down the process. However, too much compound means a higher concentration, and this will use excessive compound than the process required.
3.2 Condition of too little liquid
If we put not enough liquid in the vibratory bowl, the process will not clean very well. You can see dirty and wear debris generate from media and metal parts surround parts and media. Besides, the vibratory bowl looks very dirty.
3.3 Condition of too much liquid
If we put too much liquid (polishing compound) in the vibratory bowl, we are more likely to get lots of foam. Besides, when we put more compound than necessary, this also waste of compound and add pressure on waste treatment.
4. Regularly check our machine plug and drain
Drains allow the process water, particles, and any contaminants to be carried out of the bowl so the process can operate and perform to its optimum capability consistently. Depending on the vibratory tumbling process if unchecked drains can get blocked. Once this happens the water level in the bowl will increase, with compound added this can create foam (and mess) and the process time and surface finish will again suffer as a result. If the quantity of particles in the bowl is high then this can contaminate (and even ruin the media) as well as coating the lining of the bowl causing a loss in the drive of the media.
5. Calculate the right amount of parts process in one batch
When a vibratory finishing process is decided, loading capacity of parts and media need to calculate. We need also take into account of machine size, media to part ratio, etc to get maximum output from vibratory tumbling.
If we put too fewer parts inside the machine is expensive to process, however, if we put too many parts inside the machine will leave parts surface damaged. The right mixture ratio is based on test and error and mostly based on the experience of the engineer.
The main rule is: put as many parts as possible in your machine if you can accept the surface finishing
6. The machine should run in a right direction
Sometimes, machine electricity will shut down and machine disconnect. Our machine can run in the forward direction and the backward direction. If you find machine process tumbling not good as it should be, the movement is slow, you need to check electrical phases.
The key to check electrical phase it to see the rotary of the mass finishing machine. When you see parts and media rolls to the outer wall, then electrical phase more likely to be reverse direction. At that time you need to stop electricity, change the phase and start again. If you see parts and media rolls to inner drum, it is the right direction and you need not make any change on electricity.
7. Check if machine PU lining in a good condition
When the machine running in the long term, PU lining will wear inevitably. The high abrasive ceramic media will make the process faster. Also, parts with a sharp edge will also cut PU lining and make wearing faster. (for example surgical scissors)
When a lining wear, steel bare will expose, then media and parts will fall into the ‘hole’. At this point, the process slows down and cause more wearing to nearby PU material.
Therefore we recommend the vibratory tumbling process used to check PU lining timely. And it will be a good timing to check it when you change media or clean the bowl. Typically, the life of polyurethane stay may years if we keep good maintenance.
The thickness of PU lining is another important factor to determine the life of the machine. With thicker PU, the machine can work longer time before we can see metal bare. In case of completely wear out, the machine needs to send back to the manufacturer for relining if it is close. However, for international shipment, a PU with high thickness and durability is important to save maintenance and repair.
8. Check if your engineer follow same process parameter
There is a saying that when human involved in the production process, there is a risk of 3% error. The reason for this is that we tend to lose focus and people want to live an easier life if they can.
Moreover, people like to make the change. However, with our years of experience, when we make the standard, process parameter need to follow without any compromise. Please check all your parameter if strictly follow them. If you find everything unchanged but still not get the optimal performance, just send us an email.
The merit of the vibratory tumbling process is that you will always product the same product with all parameters the same in another day.
9. Carefully inspect if parts always start with the same condition
Keep starting condition of your parts stay same is important to keep outcome and finishing result. However, over time, your machining tools will wear, operator of your machine will change, and you will invest in new manufacturing machine. Those factors will affect surface starting condition of your parts.
As a result, we suggest keeping a reference sample indicating the starting condition. If we have some change in starting condition (for example with improving stamping machine, we have smaller burr size), we need to check and evaluate vibratory tumbling process condition again. (for example, what media to use, process time, etc).