Mass finishing from A-Z
In order to achieve the desired machining aim by means of mass finishing, the interaction of machine and process equipment is decisive. Depending on the desired machining objective and the workpiece to be machined, the following factors should be taken into account when selecting the optimum process:
- What characteristics does the workpiece have?
- Which machine is suitable with which parameters?
- Which tools, i.e. grinding tools and additives, are suitable?
Essential questions are:
- Should the workpiece be deburred?
- Should the edges be rounded?
- Should the workpiece be polished? Is the goal gloss or homogeneity?
- Are there measurable specifications (Ra, Rz, radii, etc.)?
Avatec tip: Start with sampling. Test runs with a few components to find the right parameters. A test run for the filling quantity.
Let's first take a look at the machine.
Depending on the size, weight and geometry of the workpieces to be machined, one type of machine is usually recommended. Large and heavy workpieces are best handled in a trough vibrator, while small workpieces are processed quickly and efficiently by centrifugal disc finishing. Depending on the desired throughput, there may be a different machine size in terms of useful volume.
After the machine, the choice of parameters such as speed, water supply and filling volume is up to you. A low water supply ensures shorter processing times and rougher surfaces. A higher disc speed results in higher sanding performance and more material removal at edges and on the surface. In fine processing steps such as smoothing and polishing, attention should be paid to foam formation and good embedding of the workpieces in the abrasive discs. In addition to some unchangeable parameters (maximum size of the workpieces for a certain machine type or maximum usable volume), different machining objectives can be realised with one machine type through the changeable parameters (speed, water supply and filling quantity).
There is a wide range of process media available today for mass finishing in order to achieve the desired result. First of all, it is necessary to select the appropriate abrasive (more about abrasives under C for chips). The selection of the grinding media depends on size, shape, grinding pattern, density, desired grinding effect and material, always in relation to the workpiece to be machined and the desired result.
Abrasive particles and dirt carried in with the workpieces are absorbed and removed by the compound dissolved in the water during wet processing. In addition to the task of binding and removing dirt and abrasion, a compound can also fulfil other tasks. These include, for example, degreasing, brightening the surface or providing temporary protection against corrosion of the workpiece.
Depending on the process, additives (see A for additives) can be added to the processing compound. If the workpieces to be treated are small and flat, for example, it is advisable to use adhesion release balls in the process to prevent the workpieces from sticking together (packaging).
Multi-step processing
Often the desired result cannot be achieved in one step because the required data and parameters are too different. The workpiece then has to pass through several process steps until the desired result is achieved.
A typical example when using several media is:
Step 1 - Deburring and rounding of edges
Step 2 - Grinding to obtain a homogeneous surface
Step 3 - Smoothing the surface
Step 4 - Polishing and creating a shine
Work with one media:
Step 1 - at high speed: deburring and rounding edges.
Step 2 - at low speed: smoothing the surface.
Did you know that we also offer a free sample processing in our company? This sample processing offers you and us the opportunity to determine which process equipment, processes and machines are required for your workpieces. Please contact us if you are interested!
No liability is assumed for the correctness and completeness.
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