In essence, an HVLP gun remains to be an air spray gun because it utilizes air as its primary atomization force. Equally HVLP and traditional air spray guns use the identical two elements of compressed air, force and volume but in numerous portions. The tension, which happens to be Usually mentioned with regards to lbs for each sq. inch or PSI and volume, which is famous with regards to cubic feet for each moment, are equally necessary for either gun to operate.
Originally HVLP guns where by designed to use exceptionally substantial volumes of CFM that were produced by turbines in lieu of compressors. These turbines delivered, occasionally, hundreds of CFM but hardly any tension. So that you can keep on being competitive with the turbine HVLP guns, the manufacturers of the traditional air spray guns quickly found out how to transform their guns to HVLP utilizing compressed air as an alternative to turbine air. Today HVLP guns are as frequent as the old traditional guns.
HVLP technological know-how proved that in the event you made use of a lot of volume of air as opposed to a great deal of strain like regular guns did, you might not simply atomize coatings and also accomplish that extra successfully. The effectiveness improvement was typically connected to The reality that the atomized paint particles traveled in a slower speed than paint particles that were atomized with higher air tension. We seek advice from this attribute as spray particle velocity. The upper the velocity in the paint particle the decrease the performance can be.
I prefer to make use of the analogy of the tennis ball as well as a cement wall. The paint particle is agent from the atomized paint particle as well as wall represents the substrate remaining coated. The tougher you throw the ball in opposition to the wall, the even more the ball bounces through the wall. For the duration of air spray atomization the paint particle can journey at speeds bigger than thirty toes for each 2nd or FPS. If the exact coating is atomized with HVLP technologies, the FPS drops to 10 to 23 FPS. The slower the particle velocity, the fewer get better and over spray, the more economical the technology will probably be.
In combination with spray particle velocity, One more attribute that impacts guns that use lots of quantity of air like HVLP is air damming. Here I like to make use of the analogy of the 2′ higher by two’ broad by two’ deep box and blocks which can be one’ large by one’ vast by 1′ deep. Within this circumstance the box is The within of a cabinet as well as blocks signify a cubic foot of air from the gun. Test to assume these blocks of air as they exit the spray gun and enter the box. Any time you spray in to the box you will be filling it Using the blocks of air. The inside spot of your box can only maintain 8 cubic feet or eight blocks, however the gun you happen to be employing is putting out 20 cubic feet for every minute or 20t blocks per moment.
The result is the fact in seconds you might be putting a lot of blocks in the box and those further blocks are avoiding you from Placing in additional blocks and they are spilling out all over. The volume of air has got to go somewhere mainly because it ordinarily are not able to pass through the item you are attempting to spray. The large quantity of air from your gun is preventing extra air and most significantly, the coating from getting into the box. This is often an example of air damming and the higher the quantity of air the more damming you will get.
Besides air damming There’s the condition of air turbulence. Turbulence final results from sudden changes in wind path and velocity. This results in the plane to bounce and shift fast in Instructions that aren’t meant. Anyone that has at any time flown within an airplane or jet has most likely seasoned it initial hand. Since the atomizing air exits the spray gun it starts to connect with the coating and also the bordering air in the ambiance developing turbulence. Also, the air and coating communicate with the substrates’ geometry producing eddies and currents which incorporate for the turbulence. All guns develop their particular turbulence during atomization but guns with high atomizing pressures or superior volumes of air will develop much more turbulence than guns that use low pressures and very small volumes of air.
So Besides these qualities which are shared by regular air spray, HVLP, LVLP and RP guns, a single also needs to realize the advantages and limits of HVLP. For the most part the advantage is lessened coating use as HVLP is demonstrated to increase ones’ transfer efficiency. In essence transfer efficiency is than % of paint solids that leave the spray gun for the duration of atomization that really turn out over the substrate rather than during the spray booth filters, booth partitions or perhaps the booths floor. Some companies have witnessed coating price savings for each sq. foot of up to 50% while some may perhaps only see savings of fifteen to 20%. Much depends on your coating, your atmosphere, your finishers And exactly how very well your typical gun was create to start with.
As for the limitations, HVLP guns use significantly far more CFM than standard guns. Therefore you may more than likely be having to pay more for electric power to operate your compressor at greatest or you may perhaps ought to enhance to a bigger compressor at worst. Even though the All round atomization of HVLP has enormously enhanced, atomization quality could be negatively influenced by superior viscosity and or high movement costs. Most states require that HVLP guns be limited to 10 psi with the air cap for the reason that pressures greater than that begin to decrease the guns’ performance significantly. So In the event your material is viscous or If you’re working large movement charges you might be hampered by this 10-psi Restrict or through the declining efficiency should you exceed 10 psi.