Metric nomenclature has been confusing many sellers and users of composites and since 95% of the world’s population understands and functions in metric terms (as opposed to English Units of measure) this may be helpful:

FUNCTION ENGLISH UNITS METRIC

1. Roving Measurement Yards per pound Grams per 1000 meters 207 Yield = 2400 TEX
Yield = 496200 divided by TEX TEX = 496200 div. by Yield

2. Roll goods area weight: All roll goods in the U.S are measured by ounces per square yard, except chopped strand mat and continuous strand mat, which are measured by ounces per square foot. The metric per unit weight for all roll goods is the same, grams per square meter.
Oz / yd2 x 33.9 = grams / m2 24 oz woven roving = 800 grams/m2
Oz / ft2 x 305 = grams / m2 18 oz woven roving = 600 grams/m2
Grams / m2 x .029493 = oz / yd2 1.5 oz mat = 450 grams/m2
Grams / m2 x .003277 = oz / ft2 3 oz mat = 900 grams/m2

3. Length 1” = 25.4 mm 1” = 2.54 cm
3 mm = 1/8” 6 mm = ¼”
12 mm = ½”
19 mm = ¾”
25 mm = 1”

4. Weight 1 metric ton = 1000 kg = 2,205 lb.
Pounds = .4535 x kg
Kg = 2.205 x lbs.

5. Filament Diameter: The U.S. glass fiber industry makes this even more confusing by measuring filament diameter in English Units, then matching up with a letter; and thus, you have a “G” filament or a “K” filament. The remainder of the World measure in micrometers, shortened to microns. In the reinforced plastics world we only deal with filament diameters ranging from 9 microns to about 33 microns.

NEED A REPLACEMENT FOR E-GLASS CONTINUOUS STRAND MAT?

E-glass continuous strand mat is in limited supply and is controlled by Owens Corning and Vetrotex. What are the alternatives to a high priced product (distribution price approximately $1.60/lb.) and one that is limited by supplier?
Take a look at the EMK series of Stitchmat products made by CPIC! This product line includes a number of combination (woven roving – mat) products and hidden in the line are a series of products made of mat only and bound together by knit yarn. The nomenclature is EMK followed by one three-digit number ranging from 300 to 900. The numbers represent the weight of the mat in grams per square meter.

• EMK 300 = 1 oz/ft2
• EMK 450 = 1.5 oz/ft2
• EMK 600 = 2 oz/ft2
• EMK 900 = 3 oz/ft2

This is not a product that will replace continuous strand mat in every process but it is ideal for those that are using a continuous strand mat in an RTM process and quite possibly in pultrusion.

“G” filament = 0.00035” = 9 microns “L/M” filament = 0.00059” = 15 microns
“H” filament = 0.00039” = 10 microns “M” filament = 0.00063” = 16 microns
“I” filament = 0.00043” = 11 microns “M/N” filament = 0.00065” = 17 microns
“J” filament = 0.00047” = 12 microns “S” filament = 0.00088” = 22 microns
“K” filament = 0.00053” = 13 microns “T” filament = 0.00093” = 24 microns