Installation

 

60

 

 

 

 

 

 

cup

50

 

Typical high-solid paint

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

#1 Zahn

 

 

Typical enamel paint

 

 

 

40

 

 

 

 

 

 

with

 

 

 

 

 

 

 

 

 

 

 

 

 

viscosity:

30

nU1

 

 

 

Typical spray

 

 

 

 

 

 

 

 

 

 

 

viscosities

 

Apparent

 

nU2

 

 

 

 

 

20

 

 

 

 

 

 

 

 

 

 

 

 

 

 

10

 

 

 

 

 

oC

 

15

25

35

45

55

65

 

(60)

(80)

(100)

(120)

 

(140)

(oF)

 

 

 

Temperature

 

 

 

 

FIG. 10: Effect of Temperature on Viscosity

The chart in FIG. 10 shows the effect of temperature in reducing two fluids to a sprayable viscosity, between 20 and 34 seconds using a No. 2 Zahn cup.

Note that temperature has more of an effect on high solid fluids than on thin enamels. That is, for the same 10° temperature rise, the viscosity of the high solid fluid is reduced more than the enamel. This means the high solid fluid is temperature sensitive, and you need to take this into consideration when planning your system.

Once the fluid is reduced to about 34 on the chart, vis- cosity reduction begins to level off and temperature will not significantly improve sprayability (it only uses more energy).

309524N

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Image 13
Graco 309524N important safety instructions Effect of Temperature on Viscosity