Slide 1
What is electrostatic spray?Electrostatic coatingis a
manufacturing process that employscharged particlesto more
efficiently paint a workpiece. Paint, in the form of either
powdered particles or atomized liquid, is initially projected
towards a workpiece using normal spraying methods, and is then
accelerated toward the workpiece by a powerfulelectrostatic charge.
Process provides excellent "wrap" of coating around the part, even
on sides opposite the spray gun.HistoryDeveloped in 1938 by Harold
Runsburg to improve spray depositionLead to achieve material
transfer efficiency levels of up to 98% and significant reductions
in overspray, resulting in dramatic cost savings and reduced VOC
emissions in a wide range of applications, in many different
industriesImportancesWidely used in automobile and aircraft
industriespest control in agricultureElectrostatic Spraying.How Its
Done.PreparationsThe materials wanted to be coat is cleaned to bare
metal.SandpaperBench grinderPreparations is different for different
materials.
SprayingSet up
Spraying
SprayingTribo charging gun
By increasing the flow speed of the powder and constricting the
spray gun bore an electrostatic charge is imparted to the powder
particles and no powerful electric fields and lines of force
develop between the spray gun and the object.Electrons are
discharged to the ground
Finishing Metal are placed in an oven and heated to temperatures
that range from 160 to 210C (depending on the powder).To obtain the
final solid, tough, abrasion resistant coating.NEGATIVE
POSITVEsmall electrode, which createshigh voltage electricity
paint particles travel at a slow speed through they become
negatively charged.
DISADVANTAGE1. Strict safety precaution
Explosion and FireAn electrical charge or spark can easily
ignite flammable liquids. Paint thinners and cleaners are highly
flammable.Heat StressBreathing masks, hair caps and special
anti-static clothing can keep you safe from most electrostati c
spraying dangers. Electrostatic ChargeBefore any painting starts,
all equipment must be checked and properly grounded within 10 feet
if not chances for a shock increase. PollutionPaint solvents are
atomised once sprayed and become volatile organic compound vapours
(VOCs) that at high concentrations these vapours can cause
headaches, drowsiness if inhaled and also cause skin exposure.
(VOCs) areorganic chemicalsthat have a highvapor pressureat
ordinaryroom temperature.
11DISADVANTAGE2.The Faraday Cage EffectLower density of field
lines will occur on interior corner Friction charging = no high
voltage that generate free ions or produce electric field. friction
charging of powder particles depends on each particle being rubbed
against the barrel of the spray gun.
ADVANTAGE1. No Overspray(Cost Effective)The primary advantage is
an increase in transfer efficiency. (45% - 90%).2. Fast DryingThe
electrostatic paint cures completely overnight allowing to resume
with no interruption.3. DurableElectrostatic paint creates a strong
bond comparable to powder coating. 4. Go Green!Painting process
releases less paint particles into the air giving it distinct green
advantages.5. Factory FinishAchieve the professional look needed to
be successful with electrostatic painting.
