" " wisno wood furniture finishing: H.V.L.P. air spray gun in the wood furniture finishing

Monday, December 20, 2010

H.V.L.P. air spray gun in the wood furniture finishing

H.V.L.P. (air) spray gun is one of spray gun type which has been widely used in the wood finishing industry. H.V.L.P. spray gun is the air spray gun that is modified to produce better transfer efficiency. In the H.V.L.P. spray gun, the material atomization is set in a low pressure, by this way the dust spray generated will be less and thus the more material will attached and coat the surface. The H.V.L.P. spray gun will increase the efficiency of material transfer up to (30%-60%). (see the types of spray equipment).
The H.V.L.P. spray gun for wood finishing has been used many years ago, before the L.V.L.P. gun was developed and popularized. The L.V.L.P. spray gun as the newest development of this  equipment is offering lot of benefits but still cannot fully substitute the H.L.V.P. spray gun. Each of them has their own advantages and disadvantages and our job as finishing person is to recognize them and then choose the best suit equipment according with our need.
As a simple guide, the H.V.L.P. spray gun can produce better material atomization then the L.V.L.P gun. It is better choice for the application of finishing materials which has relatively low viscosity.

To find the comparison between the air spray, H.V.L.P. and L.V.L.P. can be seen in the table below:


Type of spray gun         working viscosity (NK 2 cup)     volume compressed air     atomization

Air spray                         up to 22 second                           300 liter per minutes          perfect 


 H.V.L.P.                           up to 14 second                          500 liter per minutes           perfect


L.V.L.P.                             up to 18 second                           200 liter per minutes          good


The uses of H.V.L.P. spray gun

H.V.L.P. spray gun is widely used in the wood finishing industry. The fact is this tool could work well for most of the finishing material for wood finishing. Stain, glaze and wash coat can be applied with this equipment with satisfy result. There some peoples uses H.V.L.P. to coat the clear coating and base coat and happy with the result despite of the fact that this equipment is not too suitable. The materials with a high viscosity such as thick sealer, top coat or base coat can not be applied with this equipment. They are always needed to be more reduced to fulfill the viscosity required of the H.V.L.P equipment. This of course can reduce the thickness of the coating layer. To produce the required thickness we require more coating application that will result in waste of time and energy. For thick materials, the air spray, airless gun or even the L.V.L.P. gun are more suitable since they can produce a thicker coating with less layer.
The H.V.L.P. as well as the air spray and L.V.L.P. is simpler and much cheaper compared to the airless spray gun. The H.V.L.P. spray gun is available in the model of cup gun or installed with the pressure port or a low pressure diaphragm pump.

Tips in the uses of H.V.L.P. spray gun
  •   Use the appropriate finishing material.
Each types of equipment have its specification, the choosing the right equipment with the right materials is essential to produce the optimal results. H.V.L.P, spray gun will work well for materials with relatively low viscosity. With almost perfect atomization and better transfer efficiency, this tool is a good choice for application of many finishing materials such as wood stain, glaze and wash coat.
The finishing materials of high viscosity such as sealer, top coat, base coat, water based paint, should be applied by using the more suitable tools. Currently the finishing equipment industry already provides many types of spray equipment such as air spray gun, airless spray gun or L.V.L.P which are can be chosen with more optimum result.
  •  The proper spray gun setting.
To meet the optimal results, high transfer efficiency and the best atomization, this tool is need an appropriate adjustment. The air pressure is needed to be set at the low pressure, (maximum 2 bar). If the air pressure is too high, it will work as an air conventional spray gun so that the expected savings were not obtained. This tool will consume more volume compressed air, since that the uses H.V.L.P gun in lot amount should consider the compressor’s capacity.
  •  The movement of the spray gun.
This tool will indeed result in fewer dust spray but it will layer less material. To produce a fairly thick coating as the air spray gun it needs slower movement or more overlapping. To get use with this spray gun we may require time to know and understand the setup and adjustment of this equipment. The nozzle and tip with a larger size is often used than the conventional air spray gun to produce a coating in a similar result.

 

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