After describing the processes of coining and cutting, plate milling and laser cutting and engraving, we would now like to explain how we carry out the tumbling technique as a finishing process.
Tumbling processes are necessary for any product that has been milled, laser cut or obtained from a mould in order to remove burrs, smooth rough edges and to polish the surfaces making them smoother and glossier. In the eyewear industry little mention is made of these processes despite them being a very important, decisive phase in the production of a high quality product.
Although this may seem a simple process, great experience is needed to perform a perfect tumbling operation. In order to obtain the best finish, the choice must be made of the most suitable technique and machinery to use according to the material, its thickness and previous manufacturing processes. But that’s not all, account must be taken of the form and resistance of the material, resulting in an infinite number of variables to be considered.
So how do we achieve this? There are two types of process, a dry and a wet one for which we use dry rotary tumblers, rotary polishers, wet and dry vibratory machines and wet rotary turbo-tumblers.
It is vital to know which type of tumblers to choose, the number of pieces to be processed and the right time needed to obtain the customer’s desired result.
The pieces are then placed in the most suitable machinery together with specific products of various types, and they are then processed by vibration, rotation or centrifugal force along with the abrasives with water, woodchips, oil or pumice powder, according to the type of material and processing time.
In particular, dry tumblers use semi-finished beech or birch woodchips cut into cubes of different sizes and mixed with oil to make them stick to the pumice powder. Wet vibrators, on the other hand, use abrasives made of polyester, ureic or ceramic products mixed with water.
In order to perform the perfect tumbling process it is not enough just to use a few woodchips, a bit of paste and then set the machine turning because, for example, since the woodchips are the product of a natural material they react in different ways on the basis of a number of factors.
It is therefore necessary for the operator to have the appropriate skills to take these differences into account in order to use the correct techniques for each component.
At D.F., you will not only find state-of-the-art machinery but also all the experience and professional skills of operators able to ensure that your designs are brought to life in the best possible way.