Mermet's Low emissivity metallised fabrics, M-Screen Ultimetal (MSU), Screen Nature Ultimetal (SNU) and Satine Low-E, were developed by taking three well-established fabrics and adding the latest high-performance metallised coatings.
Woven glass fibre screen shading fabrics
Mermet has been weaving glass fibre cored screen shading fabrics for roller window blinds over 50 years. The dimensional stability and inertia (it does not stretch, does not burn, does not absorb) of the glass fibre already produces some of the best shading fabrics available.
Large panels can be made that do not stretch, require few joints, and lie flat and offer the additional benefits brought with fine yarns; external through vision and diffuse distribution of incoming natural light.
External and internal shading
Externally located shading provides the best levels of heat and light control, but where external installations are not practical, internal shading must be used.
Before metallisation became available, fabric colour was going to determine performance, meaning a choice between good heat control OR good light control; light, reflecting, colours give better heat control while darker, absorbent, colours the better glare control.
Metallic reflective coatings improve heat control
Shiny, reflective metallised coatings were initially trialled to improve heat control but found to not be much more reflective than a conventional fabric in white. But on open weave materials, light transmission values were found to be dramatically reduced irrespective of base fabric colour.
A shading fabric for an internal roller blind could be chosen that had great levels of Solar Reflectance(Rs), good glare control with low Visible Light Transmittance (Tv) and had the bonus of giving the option to choose an internal face colour for asthetic purposes.
A Mermet open weave screen fabric window blind can be chosen with an internal face colour in white, black, cream or grey without largely effecting its performance.
Metallised fabrics have low emissivity
But the metallisation of the fabrics face can provide another, initially unsought, benefit: low emissivity.
Emissivity is a material’s ability to radiate surface heat (thermal energy).
The fabrics generally used for window shading have high emissivity; they present little or no barrier to the passage of thermal energy letting up to 90% (0.90) pass. This means that a standard roller blind fabric when covering the window does not have any real beneficial effect on the insulation of the window.
Low emissivity will however produce significant improvements to the insulating properties of the roller blind, keeping expensively generated heat in the room at night and over the winter.
Mermet low emissivity fabrics
Mermet offers 3 fabrics with Low Emissivity:
- Satine Low-E fabric has metallised, low-e (15%) coatings to both faces of the well-established robust Satine 5500 fabric.
- SNU, the Ultimetal version of Screen Nature has a low-e (10%) coating to the pvc free, fossil fuel free, 90+% glass fibre screen fabric.
- MSU, the Ultimetal coated version of the popular M-Screen internal fabric with emissivity down to 5% (0.05) and a patented coating.
De Leeuw, the parent company of Mermet UK, has staff perfectly placed to explain, design, and quantify shading solutions using these new generation Mermet fabrics.