how to obtain an always efficient paint gun

magnetika — Thu, 24 Jun 2021 14:47:11 +0000

Davide Pironi, Sales and Business Manager of spraycolor® advises us on maintaining the efficiency of spray guns for industrial painting.

Here is how to keep the painting quality high, saving on both wear and consumption, for the benefit of your company and the environment.

What must the worker take into consideration?

The answer is as simple as it is essential … the nozzle and the air head are the fundamental cornerstones of your spray gun.

Keep in mind that a clean or dirty air head (head) affects the final spray quality by around 60/70%.

To guarantee that each nozzle and spraycolor® production head give the best results over time, we use only selected raw materials and an established production process.

The great precision and repeatability of CNC machines allow to obtain a constant flow rate (ml/min) and a resistance to wear throughout the life of the component.

To get the most out of your paint gun, you must first make sure that the size of the nozzle and the desired spray pattern are correct.

If you aim either of these two factors in the wrong direction you will have a strong negative impact on the workmanship and the paint will likely accumulate or be sprayed unevenly.

First look at the chemical you will be spraying.

Heavier coatings such as resins or polyurethane-based products will require a larger gun nozzle size.

Lighter ones such as fixatives and anilines will favour smaller diameter nozzles.

For example, primers to create thick bases will be sprayed with a diameter starting from 1.2 – 1.5 mm up to 1.7 mm to allow the smooth application of the product.

On the contrary, low viscosity chemicals can be sprayed with diameters between 0.8 and 1.0 mm.

The most accurate choice between one diameter and the other will depend on the amount of product we need to spray.

Low quantities such as 80-150 ml/min can be painted with a diameter of 0.8 mm while if you were to want 150-200 ml/min the 1.0 mm diameter would be the better choice.

How to keep the “heart” of the paint gun clean?

Air head: we recommend removing the head from the spray gun and immerse it in a detergent solution, possibly hot and NOT ACID at the end of each work cycle.

It is a simple operation and possible when the operator stops the system in the evening.

Any type of detergent is sufficient since the spraycolor® air caps are surface treated to endure and last over time.

Before resuming the production cycle, blow the air head with compressed air for about 10/20 seconds and reassemble it on your spray gun.

! WARNING !

Nozzle: prolonged machine downtime during the painting phase can often cause blockages resulting from the sedimentation or solidification of chemical product inside the tube of the system and gun nozzle.

We therefore recommend that you finish each painting cycle (even if of short duration) by washing the circuit, possibly with water at a minimum of 30° C.

L'articolo how to obtain an always efficient paint gun proviene da Automatic Spraygun - spraycolor.

The transfer efficiency in an industrial spray gun

magnetika — Mon, 02 Nov 2020 17:15:06 +0000

Often when looking for industrial paint spray guns you do not properly focus on the aspect of the transfer with consequent waste of sprayed product.

WHAT IS THE TRANSFER EFFICIENCY?

It is simply the ratio expressed as a percentage between the product actually deposited on the surface and the total product sprayed. The higher this percentage, the less paint is wasted in “overspray”.

HOW CAN YOU SAVE THEN DURING THE PAINTING PHASE?

First we must carefully evaluate the surface that we are going to treat, wood, leather and fabric are very porous materials while for example ceramic, stainless steel, iron are absolutely not.
During this phase, the pressurised paint with which we use our professional paint guns will impact on the product creating a rebound that will turn into a mist and dry powders.

These represent waste that must be purified and disposed of, creating an unnecessary economic burden.
For example, think of having to spray a layer of Teflon on a stainless steel pan, it will be much more difficult than applying a light resin on a hide for furniture, therefore you will need to find the right gun that is able to transfer the product without generating excessive mist to be purified.

In the case of several spray guns working simultaneously on large lines or industrial plants, we must check that the same quantity of paint to be sprayed arrives on each single piece, and if necessary install flow regulators for spray guns.

IS LOWERING THE OPERATING PRESSURE IN INDUSTRIAL PAINTING SUFFICIENT TO GUARANTEE SAVINGS?

No, lowering the operating pressure too much will affect the spraying capability and finish of the paint, especially on very compact surfaces such as ceramic.
However, today’s technology allows us to choose “how” to transfer according to the processing we have to perform.
In fact, there are HVLP, LVLP, traditional pressure or volumetric pressure spray guns, each of them able to transfer the sprayed product to optimize the transfer efficiency as much as possible.
In the industrial process, even just a few percentage points can translate into huge economic savings.

HOW DO YOU CHOOSE THE RIGHT PAINT GUN TECHNOLOGY?

The ideal solution would be to test in your own field accompanied by a specialized spray gun technician, if this is not possible, here are some useful tips to make your choice.
HVLP spray guns, short for High Volume Low Pressure, take advantage of the large amount of incoming compressed air to obtain a high-performance finish at low operating pressures, 1.5/2.5 bar.
These are suitable for all types of products to be sprayed including glues and resins (simply choose the appropriate size of needle and nozzle).
Volumetric spray guns exploit the same principle as above and bring these results to extreme values such as operating pressures of just 0.4/0.9 bar.
They require an adequately dimensioned air system and are ideal for large production lines.
Finishing quality slightly lower than HVLP.
LVLP spray guns, short for Low Volume Low pressure, require just a few litres of incoming air and are able to obtain an excellent finish, the product is delivered in a completely uniform and delicate manner.
Particularly suitable for spraying low density products at operating pressures between 1.5 and 2 bar.
“Softpressure” paint guns, patented by us, is a segment of guns that is intermediately placed between a traditional and an LVLP paint gun, in fact it allows traditional finishes at lower operating pressures (2 / 2.5 bar).
Traditional spray guns allow an adequate finish with standard operating pressures between 3 and 4 bar and enjoy a lower transfer efficiency than other product categories.

L'articolo The transfer efficiency in an industrial spray gun proviene da Automatic Spraygun - spraycolor.