Converting grams coating weight to coating thickness in mils

Does anyone have any thoughts on how to convert grams of coating weight per square foot to mils of coverage per square foot? Thank you in advance. Jim

[JohnS]

Originally Posted by Jim-T

Does anyone have any thoughts on how to convert grams of coating weight per square foot to mils of coverage per square foot? Thank you in advance. Jim

*You'll never find the reference data to work in mixed units. Do it in metric then convert final answer if needed.

*You need the density of your coating. If it is like a paint where volatiles evaporate you need the final density for dried product. Note that densities expressed in g/cm³ (or g/mL), kg/L, or t/m³ are numerically equivalent

If you have weight in g/m², divide by density in g/cm³ to get volume in cm³ applied per m².

The weird units of cm³/m² reduce to µm as follows:
cm³/m² x 1 m²/10000 cm² x 10mm/cm x 1000 µm/mm = µm

So a coating weight in g/m² divided by the dry coating density in g/cm³ directly gives you a coating thickness in µm.

What would be 100sq.meter compare to mil

Does anyone know how much will be zink coating in 20 microns thickness in gram sq.m?

[JohnS]

Originally Posted by Unregistered

Does anyone know how much will be zink coating in 20 microns thickness in gram sq.m?

I assume the coating is the same density as metallic zinc, 7.14 g/cm³.
(It could be lighter if the coating has any porosity.)

The volume, 20 µm thick, applied to 1 m³ is
100 cm x 100 cm x 20E-4 cm = 20 cm³
20 cm³ x 7.14 g/cm³ = 142.8 g

As this is applied to 1 m², it is 142.8 g/m²

What would be the conversion from oz to grams for fabric? Sounds so trivial, and one that any respectable unit conversion calculator can handle, but there must be another trick because the numbers a straight conversion produces is absurd.

For example, a "5oz PU coating on 1640 Denier nylon".

A Denier cloth is roughly 0.28 microns per Denier, so 1640 is 460 microns, or 0.46mm.

As the coating is in ounces, than I assumed the spec means 5 oz per square foot. Converting 5 oz to metric gives 141 grams. There are 10.7 square feet to a square metre. So converting to metric, 5 oz would be 141*10.7/1.2 grams per metre, or 1500 grams per metre. Taking a density for polyurethane elastomer of 1.2 g/cm3, 1500 grams per metre would be a 1260 micron thick coating (rounding).

This is an absurd number for the coating thickness, because the coating is a thing flexible film, hardly noticeable on the fabric.

[JohnS]

Originally Posted by Fabric user

What would be the conversion from oz to grams for fabric? Sounds so trivial, and one that any respectable unit conversion calculator can handle, but there must be another trick because the numbers a straight conversion produces is absurd.

For example, a "5oz PU coating on 1640 Denier nylon".

A Denier cloth is roughly 0.28 microns per Denier, so 1640 is 460 microns, or 0.46mm.

As the coating is in ounces, than I assumed the spec means 5 oz per square foot. Converting 5 oz to metric gives 141 grams. There are 10.7 square feet to a square metre. So converting to metric, 5 oz would be 141*10.7/1.2 grams per metre, or 1500 grams per metre. Taking a density for polyurethane elastomer of 1.2 g/cm3, 1500 grams per metre would be a 1260 micron thick coating (rounding).

This is an absurd number for the coating thickness, because the coating is a thing flexible film, hardly noticeable on the fabric.

As fabric (in Customary units) is usually sold by the square yard, I would guess the 5 oz spec is really 5 oz/yd², not 5 oz/ft², thus about 170 g/m², or about 140 µm. That still seems thick, but does it make more sense?

You need to pin down the "5 oz" spec. That guess that it is per square yard is only a guess.