Calculating powder requirements

[Intel55]

OK, I am curious, how do you calculate how much powder is required?

Slow day and I was wondering what the calculation would be for this:

a roll
150" long
12" in diameter

thickness is to be .008 - .01.
how many pounds of powder would be required?
DJ Hybrid
for the total surface area (excluding the top and bottom areas)
2 Pi rh + 2Pir^2
2(3.145)(6)(150) + 2(3.145)(6)^2
5661+226 = 5887?
Thanks

[Gordon]

Hi Intell55

Powder product data or technical bulletin should provide powder required data in form of lb/sqft/0.001" or kg/sqm/0.1mm.

Lets assume tech bulletin states 0.11 lb/sqft/0.001"

Work out job surface area in sqft = dia x Pi x length = 12"/12 x 3.1416 x 150"/12 = 39.27 sqft.

So 0.11 x 39.27 = 4.32 lb/0.001" for job
for 0.008" thickness 8 x 4.32 = 34.56 lbs

Bear in mind, account for wasted spray at either end of shaft

It is worth recording actual results for specific powder and set-up. Working from experience tends to be far more accurate than from manufacturers data (It does not always do what it says on the tin ) .

[Gordon]

Hi Intell

Sorry, I seem to have missed the final part of your post. Yes if you include the flat end faces add on 2 x Pi x radius sqd to surface area + any overspray.

[hvofhamid]

Hi Intell

Sorry, I seem to have missed the final part of your post. Yes if you include the flat end faces add on 2 x Pi x radius sqd to surface area + any overspray.

hi all
when you spray not all your powder is coating the subsrat,you loose so much.
a simple way to calculate is to know ,how many time take your coating and as you know how many grammes you use per minute,you will be fixed.
best regards

[Gordon]

hi all
when you spray not all your powder is coating the subsrat,you loose so much.
a simple way to calculate is to know ,how many time take your coating and as you know how many grammes you use per minute,you will be fixed.
best regards

Just to make things clear:

Powder required data takes account of the powders deposit efficiency, it is not the same as powder feed rate. What it does not take account of is when you are spraying off the job. As I said before, knowledge from past experience of spraying a particular powder in similar conditions is best, but there are many times we have to make estimates with new powders or processes without the benefit of doing trial runs first.

[Intel55]

Thanks for the reply!