Why Use an Airless Sprayer

Manual spraying has been around for a long time. With the rapid change of the times, the technology of spraying has also evolved. The most popular method in the spraying industry now is airless spraying.

Let's learn more about airless spraying today. After reading this article, you will know why the airless spraying method is the best choice for you by comparing it with other spraying methods.

 

Achieve Maximum Coverage with a High Flow Rate Airless Sprayer

3 Spraying Delivery Methods

First, let's learn about the 3 main types of spraying delivery methods, including airless spraying.  

1.Air spraying and Its Disadvantages

The first spraying delivery method is air spraying. Through the compressed air will paint from the container to the spray gun (commonly used compressed air pressure of 0.4 ~ 0.6MPa), the paint in the tip and the air mixed and dispersed into droplets, sprayed to the surface of the coated object, the formation of a uniform distribution of the coating. Since compressed air is sprayed along with the paint, this method is called “air spraying”.

The efficiency of this method is much higher than that of traditional brush and roller coating, and the thickness of the coating is more uniform. However, this method also has some disadvantages:

1. Because compressed air is used to atomize the paint, the spray can trap moist, cold, oily air, which can affect the quality of the coating.

   
   

2. Coating waste is greater than with brushing and rolling because some of the coating is dispersed by spraying, especially when operating outdoors in windy conditions.

   
   

3. It is not possible to spray high solids and high viscosity coatings, and expensive thinners must be added to reduce the viscosity in order to achieve the coating. This not only requires multiple sprays to achieve the desired coating thickness, but also causes aerosol backwash, resulting in uneven coatings in corners and recesses.

   
   

4. Outfits with dosing cups and suction canisters or double hoses add weight to the gun, increasing the operator's physical exertion, and the time it takes to continually add paint is not economical.

As you can see, air spraying is not a perfect option.

2.High Volume Low Pressure (HVLP)and Its Disadvantages- Special Air Spraying

High Volume Low Pressure (HVLP) air spraying is based on the principle of using a large amount of compressed air and a small amount of atomizing pressure (10 to 19 psi) to atomize the paint, thereby increasing paint utilization and reducing mist dispersion.

Although HVLP systems also use compressed air, they are different from standard air spray systems. With an HVLP sprayer, a turbine delivers a large volume of air at a much lower pressure to atomize and spray the fluid. Typically, the air pressure at the equipment air cap must be equal to or less than 10 PSI to be called HVLP.

This system is designed for small, fine finishing jobs because it offers the highest quality professional finishes with minimal overspray and unsurpassed accuracy.

However, it is important to note that while HVLP can increase paint utilization up to 65%, there are still two major problems:

1. Inability to Atomize High Viscosity Paint: Since HVLP uses high air volume and low air pressure to atomize paint rather than the high atomizing pressure of conventional air spraying, HVLP has limitations on the viscosity of paint when spraying.

   
   

2. Increase in investment cost: Compared to the air consumption of 8~17 cfm for traditional air spraying, the air consumption of 12~25 cfm for HVLP is much larger, which requires the use of a larger air compressor. This requires the use of a larger air compressor. As a result, the investment will be greatly increased.

And these two problems have greatly limited the widespread use and development of HVLP in the coating industry. This has led to research into alternative methods.

 

The Technology of Airless Spraying.

3.Airless Spraying

The third type of spraying is airless spraying. This method differs from the first two in that it requires neither a compressor nor a turbine.

Airless spraying using compressed air (also available motor or oil pump) for power, drive the high-pressure pump will be sucked into the paint and pressurized to 7.5 ~ 30 MPa, through the high-pressure hose and gun, and finally sprayed by a special tip. At this time, the high-pressure paint is rapidly expanding, colliding with the air at a speed of 100 m/s, atomizing into very small droplets, sprayed onto the surface of the workpiece, forming a uniform coating film to achieve the purpose of spraying.

Since the sprayed paint is not mixed with compressed air, and the paint is pressurized to a very high pressure, it is called “high-pressure airless spraying”, or airless spraying for short.

This method is highly efficient, suitable for a wide range of materials including high viscosity coatings and requires no dilution, and is available at a wide range of prices. It makes up for the shortcomings of the previous two methods and is the fastest and most versatile way to achieve professional spraying results.

Below I will present a detailed table comparing airless sprayers to other spraying methods, including traditional manual methods.

Airless sprayers have obvious advantages over other spraying methods

There are certain reasons why airless sprayers have become the most popular spraying method on the market. The following table provides a specific comparison between airless spraying and other spraying methods:

Construction method\comparison content	Hand Brush	Roller Coating	Air Spraying	High Pressure Airless Spraying
Working efficiency	35-50㎡/hour	45-60㎡/hour	200-300㎡/hour	400-500㎡/hour
Applicable Coatings	Low viscosity coatings	Low Viscosity Coatings	Low Viscosity Coatings	Various Viscosity Coatings
Coating surface quality	Brush marks particles residual bristles	Roll marks particles	Insufficiently dense coating consistent color over large areas	Excellent surface quality smooth and dense coating consistent color over large areas
Coating adhesion	The paint is not easy to reach the wall void resulting in the coating is not dense enough poor adhesion	The paint is not easy to reach the wall void resulting in the coating is not dense enough poor adhesion	Due to the air bounce and air in the void to form vortex holes and other effects so that the paint is difficult to penetrate into the void and wall bite is poor poor adhesion	Paint can go deep into the pores of the wall the paint film and the wall to form a mechanical bite good adhesion
Service life of coatings	short	short	Moisture in the compressed air affects the quality of the coating film resulting in a shorter coating life	Fully reflects the performance of high resin content coatings with long life and good scrub resistance
Transfer efficiency/material utilization	Uneven thickness generally between 30-200 microns low utilization rate	Uneven thickness generally between 30-200 microns low utilization rate	Paint thickness is uniform but thin need to spray more degrees rebound phenomenon is serious and due to the air atomization resulting in paint mist flying around low material utilization rate	Uniform thickness easy to control a spray thickness of up to 30 microns high utilization of materials
Convenience of construction	Lightweight tools but constant dipping is required on site	Lightweight tools but constant dipping is required on site	Need to connect the air compressor poor maneuverability need to add material frequently low efficiency	Easy to carry easy to clean equipment on-site contamination
Construction environment	Not flying apart but dripping	Not flying apart but dripping	Flying around and poor operating conditions	Fewer flyaways better operating environment
Applicable occasions	The quality of the finish is not very high and small areas are painted	The quality of the finish is not very high and small areas are painted	Higher finish quality required larger areas to be painted	High quality of finish larger and larger areas to be painted

It can be seen that, in every respect, airless sprayers have a very comprehensive superiority over other spraying methods. Within the right budget, the airless spraying method is the optimal choice.

Conclusion

To conclude, airless sprayer has the advantages of efficient spraying, uniform coating, high quality surface, versatile adaptability and environmental protection and energy saving. It can cover large areas quickly, is suitable for a wide range of coatings and application scenarios, and deep penetration improves adhesion, while its user-friendly design and easy operation make it the ideal choice for achieving professional spraying results. For more information or if you have further questions, you can contact HVBAN.