Schubert Techincal Services

ATE Simple Paint

The ATE Simple Paint System, designed for optimising and improving the performance of electrostatic and non-electrostatic, mixed air and air mix spray guns. Manual, robotic and through-feed automatic systems can all be connected whether applying water or solvent based materials.

Designed as a simple retro-fit, the Simple Paint can be installed very quickly with a minimum of fuss. Just a simple connection into the main compressed air line prior to the pump.

Simple Paint One with one column for a maximum of 3 air mix guns.
Simple Paint Two with two columns for 4 to 8 air mix guns.

The Simple Paint System will give you the following advantages:-

Elimination of static charge build-up and ‘faraday cage’ effect.
Reduction in paint/lacquer usage.
Reduction of solvent content.
Improvement of surface finish (no orange peel effect).
Lowering of pump pressures.
Oil, grease and contamination removed from compressed air.
Less over-spray.
Fewer rejected products.

Technical Explanation

There have always been solutions and products presented to the wet and powder finishing sectors for improving the spray process and which attempt to resolve application and environmental problems.

Many problems or application limitations in the sectors are caused by the static charge which is created during the application process.

This is a factor that directly influences the entire finishing process, but which unfortunately is completely left out of the consideration since the static charge or “staticity” is not visible to the human eye:

Analysis

Any friction between two or more bodies produces a static charge: for example, the friction of a pen on a sweater, the “shock” when you get out of the car, and so on.

In the coating process there is friction that creates low levels of static charges that disturb the application of the coating product (paint or lacquer).

More specifically there are two moments when such charges are generated:

- the friction of the coating when it is atomised, passing through the nozzle of the spray-gun (small density charges are created on the tip of the spray-gun that contaminate the gun and the hand of the operator with the coating)

- the friction of the atomised coating being forced onto the surface of the piece during application (this friction generates a larger amount of static charge).

This staticity “charges” the particles of the coating, influencing their deposit and flow on the product surface: the coating follows the behaviour of the electrostatic field.

Staticity is a form of energy or magnetism that, as it is created, has to be discharged.

During the coating process, the particles of the coating discharge the accumulated staticity onto grounded bodies (pieces to be coated) or in areas near them (metal spray booth, operator and objects) where there is a lower concentration of static charges.

The consequences can be seen on the piece to be coated as well as on the operator and the coating equipment.

On the piece subjected to the coating

On a piece the static charge accumulates:
- in the corners or in hidden zones, creating a barrier that repels the coating, making it difficult for the coating to penetrate and deposit. To cover the most difficult points the operator has to use a higher air pressure and product (but the higher the spraying pressure, the greater the bounce of the coating), or he has to go over the area more than once.
Giving the minimum coating thickness in a critical point, too much coating is applied to nearby areas. Thus sagging or running occurs.

- a part of the coating that does not flow over the piece, does not ‘free drop’ onto the floor under gravity, but rather returns back onto the piece (it tries to ‘roll over’ from below, because it is charged and therefore attracted by the piece, something that creates the problem of coating bouncing back onto the surface).

On the operator and the coating environment

A part of the staticity discharges:
- Onto people (because humans conduct), something that produces rebounds of coating on the gun and on the operator
- In the spray booth, because its structure attracts coating particles, thereby producing an excess of overspray (and consequently dispersion of the coating product).
- In automated applications (where the spray-guns work in an enclosed steel structure) the rebound of the coating generates additional problems of contamination of the product with fine parts of coating material.

Product Solution

Eliminating staticity during coating processes means intervening directly at the origin of many existing problems and providing operators with more stable and secure results, as well as making large financial savings.

From a practical viewpoint, a spray process environment without static charge means:
- less interference with the process of transferring the coating onto the piece.
- less coating waste, thus lower coating cost.
- more coating arriving on the surface of the piece.
- much better quality end product.
- a reduction in polishing times.
- reduction of VOC’s to atmosphere (less solvent needed).
- lower working pressures mean lower compressed air costs.

Only available in the UK and Eire through Schuberts – Where Experience Counts!