The finishes offered by Estrallum are the last touch to the finished product. They offer the piece a unique aesthetic value whether it is a handle, a hinge or any other extruded aluminium component.
It is a process that enhances the extruded aluminium in its aesthetics through the following steps:
The most important phase of this process is the anodic oxidation through which a layer of aluminium oxide of controllable thickness is created, clear, colourless, porous, ultra hard and resistant. In particular, its porosity is essential to be able to create a variety of aesthetic colours. Another characteristic of the oxide is that it develops from the surface of the piece inwards, by a few microns, leaving the dimensions of the piece itself practically unaltered. It is not a coating but a chemical and structural transformation of the substance itself through which the piece is made.
By acting on the electrochemical parameters it is possible to create suitable thicknesses and dimensions of the pores of the oxide in order to obtain an adequate protective layer which will then be enhanced with a colour.
The final fixing phase allows the coloured pigment to be blocked inside the pores and to seal everything in order to obtain an aesthetic, resistant and long-lasting finish.
It is a process of adding a coloured protective layer used to acquire aesthetic value. Consequently, the final dimensions of the painted piece will be different from the initial ones.
The painting system essentially consists of an overhead conveyor to which the pieces being processed are attached to be moved, in order, through the pre-treatment tunnel, the drying oven, the painting cabin and then back into the oven for the final polymerisation.
The pieces are hung on the chain by means of dedicated hooks and/or conductive rocker bars.
The process begins with a chemical pre-treatment to which the pieces are subjected to remove traces of oil from previous mechanical processes (nanotechnological degreasing) and to prepare the surfaces to receive the powder coating (passivation). A good pre-treatment is a guarantee of excellent adhesion of the coating to the substrate.
The powder used is mainly an epoxy-polyester resin, i.e. a hybrid mixture of polyester and epoxy resins which combines some of the characteristics and properties of the starting substances: it has a high level of hardness, resistance to heat and to many chemical substances but it is recommended for indoor use due to low UV resistance.
The pre-treatment is followed by the actual painting which consists of dispensing the powder, using dedicated guns which, due to the electrostatic effect, is deposited on the surface of the pieces. The final polymerisation takes place in the oven at an average temperature of 200°C at which the resin melts, is distributed on the surface of the piece and, as it cools as it exits the oven, solidifies creating a hard and resistant protective coating.
The use of powders of various colours gives the desired aesthetic effect to the coating.
Like powder coating, chrome plating gives protection and a prestigious aesthetic appearance. Furthermore, aluminium surfaces are not immune to wear. As such, it is necessary to apply treatments that improve their characteristics and performance. Hence the need to chrome the aluminium, an essential action to preserve its beauty and durability over time. For these reasons, we make use of suppliers who can also offer this type of finish.
