Euroimpianti

Published 02-08-2011

Introduction

Euroimpianti is proud to present the first automatic plant in the world that paints three-dimensional items with UV-curing powder coatings.

Aimed at production of items as electric motors, hydro-pneumatic pumps, pneumatic pistons and similar items that can be painted fully assembled, without damaging the electrical components inside, thanks to a UV curing process that involves only a superficial heating of 90 ° - 100 ° C.

Powder coating has been used for more than 50 years with great economic and ecological improvements.
Its application technology has continuosly developed, reaching a level that nowadays allows obtaining colour changes in only 90 seconds.

On the contrary, since then, powder coating polymerization has always been carried out in ovens with hot air, whose temperature can vary from 130°-140°C up to more then 200°C: always with remarkable operating costs due to the continuous increase in prices of methane gas for heating purposes.

Powder manufacturing engineers have long been searching for suitable solutions to reduce, as much as possible, the percentage of incidence of coating energy costs.
For example: considering the cost of the powder coating oeration as 100, 57% comes from the consumption of methane gas for oven heating and power to move the plant.

The plant

The technology of powder coatings with hot-air hardening has been used since the ‘60s, a while ago, and it is well-know all over the world. The UV polymerization technology is less known: it also offers other specific advantages compared with traditional process:

• Improved surface look, as powder coating melting with IR lamps and the following curing are performed in different phases, one after the other
• The system is extra-compact and needs a lot less space for the plant
• Reduced energy consumption thanks to limited melting and curing time (only 3 minutes)

The process

The main technical features of the application and curing operations by means of UV lamps can be schematized as follows:

• Nanotechnology-based pre-treatment (in case with the application of corrosion-resistant primers)
• Application and recovery of powder coatings in a traditional booth
• Powder coating meltin in the first part of the oven by means of IR lamps
• Powder coating curing in the UV area
• Cooling
• Unloading of coated motors and immediate packaging

Powder coating curing in the IR oven

Powder coating curing is a very important aspect for the surface quality of the manufactured item: it must be as quick as possible, uniform and at 90°C-100°C, by using a high number of infrared rays for a time of 2.5 minutes.

Powder coating curing in the UV oven

Raw materials, powder coating formulation and the combination of UV lamp types are interconnected one to the other. The lamps are built-in in the oven, so that all surfaces are exposed to the same curing level without causing over-curing of the manufactured goods (some tenths of seconds).

Cooling

The cooling time is very short, as the surface temperature equals only 90°C - 100°C.
Temperature reduction, to reach the temperature that allows handling the electric motor, equals about 4-5 minutes with cooling at room temperature.

Conclusions

Electric motors, hydro-pneumatic pumps, hydraulic pistons and other assembled manufactured goods are perfectly compatible with UV powder coating polymerization technology.
The whole curing time in the oven, by means of UV lamps, lasts only 3 minutes, with the conveyor that moves at 5-7 minutes, as well.
The advantages of UV powder coatings, therefore, can be summarized as follows:

• extra-compact coating plant
• application of a single layer
• less rejects
• resistance to chemical agents and surface hardness

This is an excellent technical result, which has been obtained at industrial level and for the first time by Euroimpianti in collaboration with Akzo Nobel Powder Coatings, as well as with the insistence of Anver.
Now, it is foreseen that also customers coaters requests for technological innovation can be satisfied, mainly concerning the reduction in energy consumptions at the plant and in investments: a significant step forward in the world of industrial coating.

This system installed at the showroom Euroimpianti is available to customers who would like to approach themselves the reality of UV powders and discover its advantages.