close box The applications which
can use this mineral are
highlighted. Please select
one to learn more.
Product Benefits
Technical Details

Milled E-glass (glass (amorphous silica) consisting of SiO2, Al2O3, CaO, MgO, B2O3, F2, Na2O, K2O, Fe2O3) is produced from an industrial E-glass side stream. Milled E-glass can be characterised by:


  • ‘Green’ attributes, as a product of an industrial side stream.
  • Relatively high Mohs hardness of 6.


Advantage over quartz and cristobalite and certain feldspar grades: free of labelling, milled E-glass grades can be used as an alternative when labelled grades of other mineral fillers are no longer permitted or wanted.


Basic properties

Property Value Unit
Moisture 0.2 [%]
pH 9 [-]
Hardness (Mohs) 6 [-]
Refractive index 1.57 [-]
Colour (D65/ 10°) L* 93 [-]
L.O.I. 0.5 [%]
Density 2.6 [kg/ dm3]


Product overview

Grade D50





[g/ 100 g]

G25 12 41 22
G75 31 130 15


Production location Portafill G

Portafill G is the brand name for Sibelco’s milled E-glass product.



  • Burnish resistance: due to its hardness of 6 on Mohs scale, milled E-glass provides good burnish resistance (low tendency to become glossy when rubbed).
  • Ease of tinting: due to the combination of refractive index, brightness and colour, paints including fine milled E-glass particles provide excellent reproducible colour results when working with tinting systems.
  • Gloss control: the gloss level of an interior coating can be regulated by selecting the appropriate grade of milled E-glass.
  • Scrub resistance: due to its hardness of 6 on Mohs scale, milled E-glass improves the wet-scrub resistance of interior decorative paints.
  • Stain resistance: milled E-glass acts as a supporting mineral filler in stain resistant coatings.
  • Abrasion resistance: due to its hardness of 6 on Mohs scale, milled E-glass will increase the coating’s resistance to wear.
  • Clarity: due to its fairly low refractive index, milled E-glass becomes transparent when combined with certain binder systems.

Sibelco © 2024