OFB

The main Trasmetal quality in over 60 years of existence has always been that of searching for alternative technical solutions that allow the limits of machines and equipment for surface treatment and finishing to be overcome. 

It is therefore based on this philosophy that Trasmetal directed its efforts towards a technical solution able to overcome the fisical limits of traditional electrostatic equipment.

The result was the opportunity of creating a type of electrostatic distributor with the following characteristics:

• The basic idea is that the Trasmetal electrostatic distributor, vertically movable,  has a fluidised alimentation tank located on the ground to which the powder, through an apposite pump, is transferred to the OFB distributor. This tank allowa the powder itself to be drawn, loaded and delivered so as to eliminate any negative effect linked to the variable distance of the distributor from the ground. This solution allows the lack of thickness homogeneity caused by the equipment to be overcome, considering the high vertical travel.

• The distributor is equipped with a large number of closely arranged electrodes, and a continuous powder distribution slot that would avoid the effects of discontinuous distribution along with the related interference between the flakes of powder caused by traditional equipment. This solution, by allowing continuous-flake powder emission, allows the lack of homogeneity on the horizontal axis to be overcome.

• The materials used, the shape and the dimensions selected were to protect the distributor from erosion caused by the abrasive effect of the powder; this would allow preservation of the distributor characteristics over time, minimising costs due to maintenance and spare parts.

• The amount of powder distributed by each single distributor is comparable with that of over a dozen traditional devices, with a consequent reduction of both the variables that need to be managed to control the workpiece as well as the maintenance operations of the line itself.

The shape that was to be attributed to the new distributor from the very start was circular, with a distribution slot on the entire circumference and a radial arrangement of the electrodes. It was also decided to use the disks in pairs, while the materials were moved on the two sides around them along a characteristic “double omega” path. This choice was based on the double objective of maximising the exposure time of the profiles and avoiding the use of complicated and difficult to maintain rotating hooks and it was really useful for the Al estrusi profile covering. The result was the possibility of powder coating vertically suspended profiles at speeds (and therefore productivity) far greater than those ever reached by systems equipped with traditional electrostatic equipment.