To guarantee a very complete and quality service, Eurogalvano also offers various types of surface preparation:
CLEANING
Grinding
In the grinding process, each piece is worked manually with accuracy and precision, initially with abrasive belts of different grits, until an appropriate level of smoothness is reached.
Polishing
Polishing allows you to eliminate all signs of grinding from the object, thus making it ready for the next galvanic step.
The metal polishing process takes place through the abrasion of cotton wheels, in special manual or automatic machines, of the objects with appropriate abrasive pastes capable of guaranteeing the desired level of surface finish.
Chemical washing
To obtain quality workmanship, therefore without imperfections, a subsequent step must be taken, namely washing. It is essential to eliminate any impurities derived from previous treatments, such as oil, metal slag, pastes, various oxidations, etc.
TUMBLING
Dry
Of considerable value, it is used on parts even in place of manual cleaning. Particularly suitable for giving a perfect surface finish to a large number of pieces of various sizes.
The tumbling process takes place by rolling the pieces in a tumbler with fine and special abrasive material to obtain a perfect finish
Wet tumbling
Vibratory finishing is the action produced by the relative movement between different elements of a mass. The mass consists of bulk pieces to be treated and a liquid solution of a chemical product.
The energy for relative motion is provided by a plant or machine. The liquid in this case allows you to cushion the blows and obtain a better finish.
Chemistry
Vibro-polishing of metals is a particular finishing process with a result comparable to “mirror polishing”, particularly suitable for small parts or materials of various sizes.
The effect is obtained through a slight vibration in contact with soft abrasive material of various sizes, together with the use of some specific chemical additives.
SANDBLASTING
Sandblasting is a mechanical cleaning, it can be used to prepare surfaces for painting, for a galvanic coating and/or to give a certain roughness.
Eurogalvano has various sandblasters for cleaning and preparing surfaces:
- Manual
- Carpet automatic
- Automatic tumbler
- Automatic in rotation
By applying different types of abrasive products such as grey, white, brown corundum, glass microspheres, steel or cast iron grains, we are able to obtain different types of finishes.
Eurogalvano is able to monitor all the roughness parameters, through the use of an instrument called a roughness tester.
The parameters most used to control the roughness of a sandblasted surface (expressed in microns) are (according to DIN 4768):
- Ra: mean roughness – arithmetic mean of the absolute values of all the crests and valleys measured along the sample section
- Rmax or Rt: maximum or total roughness – distance between the highest crest and the deepest valley measured along the sample section;
- Rz: average roughness – arithmetic mean between the 5 largest crests and the 5 deepest valleys measured along the sample section.
SATIN FINISH
It is a rather complex and delicate operation. This finish is obtained using special abrasive belts or brushes of different shapes, which have different grains and formats because the levels of satin finish can be of varied intensity.
This particular process is used to give the metal details a scratched and antiqued look.
The result has a completely aesthetic function, in fact it gives elegance to the product, however it can also have practical and functional purposes.
The satin finish can be performed both on the raw material, after grinding, and on the piece already treated in galvanic. It does not require a subsequent wash but a passage of varnish.
