The light diffusers are available in different materials, namely acrylic (pmma/Plexiglas®), polycarbonate (lexaan®/makrolon®) and PETG (vivak®). These plastics are having different material characteristics, so there is always a diffuser that is suitable for your application. The diffusers are on stock in various thicknesses, light transmissions, shape and surface.
Acrylic is having the best light technical characteristics. Therefore, the starting point for the selection of material is always to choose acrylic. Acrylic has a very high light transmission and is completely 100% colourless. It is UV stable, colour proof, temperature resistant to 80ºC, quite rigid, resistant to many chemicals and 100% recyclable. The fire rating of acrylic is E according to EN13501.
We advise to use polycarbonate light diffusers when the diffuser has to be impact resistant or when fire certification Bs1d0 is necessary. Polycarbonate is having a high resistance to temperatures up to 120ºC and barely knows any thickness tolerance. Polycarbonate is less rigid and can therefore be cold bended. Polycarbonate is not UV stable, but many polycarbonate light diffusers are UV proof produced.
PETG has the advantage that in case of fire less toxic gases are released than in the case of polycarbonate. That is why PETG can only be used at airports for example. Another major advantage is that PETG is food grade certified, can be warm bended and the maximum user temperature is 70ºC.
Standard diffusers are also known as classical opal sheets. The standard diffusers are having a light transmission of 30% and are price-favourable.
Professional diffusers are having a high light transmission (30%-60%) and still has a good diffusion. These sheets are also price-favourable. Especially when you look at the output of the sheets.
Advanced diffusers are optimized diffusers with the very best characteristics. The highest light transmission combined with still excellent diffusion. This combination means high efficiency. Advanced diffusers are truly the best diffusers with a matching price.
The light transmission is the amount of light that is measured on the other side of the light diffuser then where the light source is situated. With other words, the percentage of light that is transmitted through the sheet.
Diffusion is light scattering. The most common requirement for light diffusers is that the dots of the LEDs should not be visible anymore. But that’s not enough. The light surface must also be even. More about this, you can read the question: “How can I illuminate light diffusers evenly?”
The efficiency of the light diffusers is the amount of light transmission multiplied with the diffusion. The higher the number, the more efficient is the diffuser. This is our goal, a maximum possible light transmission and the greatest possible diffusion.
The half-value angle has to do with how broad the light is radiating. For example, in case of advertising, advertising must always be observed properly. Then you want the half-value angle to be as large as possible. But in lighting, we just want the light to come where we want it to be. This means a limited half-value angle. The half-value angle is also important when determining the UGR value (unified glare rate). This is a standard that certain lighting needs to meet. Some of our diffusers contribute to achieving the right UGR standard.
The UGR value (unified glare rate) is a measure of direct glare from light fixtures. A standard which needs to be met for certain lighting. Some of our diffusers contribute to achieving the right UGR standard.
Since there are so many different applications and so many different light sources with a very diverse range of light spectra, angles of egress and temperatures, we have put together a broad range of diffusers with disparate characteristics and properties. Nearly every application comes with its own requirements. With our collection, we want to offer you the desired flexibility. We have light diffusers in stock in sheets, tubes and round rods.
The core rule for a simple solution with about 30% light transmission is that the distance between the light sources (led strips, for example) is equal to the distance from the light sources to the diffuser sheet.
However, for an optimal solution, we refer to our very thorough documentation “Select the right light diffuser” (Sied Kooistra, 2013) and “Even backlighting with LEDs is easy” (Sied Kooistra, 2017).
By placing a diffusing thing between the observer and the light source. The diffuser should be chosen in a given situation is absolutely not just to answer as there are quite a lot of issues that need to be considered: type of light source, beam angle, spacing, placement, desired light output requirements regarding impact resistance, fire behavior, indoor or outdoor application, serviceability and how long it takes. It is a field of study.
For this project, a beautiful counter was made of our light diffuser sheets for the BSH headquarters in Hoofddorp. Light diffusers of acrylic can be produced in various thicknesses and in small volumes. This makes it possible to use light diffusers in constructive applications.
Cast acrylic light diffusers have the best light technical properties, are UV-stable, optically pure, color-fast and easy to fabricate. In addition, all acrylic sheets are fully recyclable! The most environmentally friendly choice in light diffusers is the PyraLed4 Greencast® version. This is the first opal sheet made from 100% recycled acrylic.
Looking for an opal sheet with hardly any thickness tolerance? Then opt for the opal sheet made of extruded Plexiglas. If it is important that the opal sheet is impact resistant and has a fire certification, choose a polycarbonate opal sheet.
Diffuser sheets in 15 or 20 mm thickness offer sufficient strength for a construction such as a counter. Philips Lighting, Mediapark Hilversum and BSH Hoofddorp have created beautiful luminous counters from our acrylic light diffusers. The PyraLed3 is an excellent example of this. But also very suitable for luminous floor parts or bridges that must be able to withstand weight.
In addition to structural applications, its thicker opal sheets such as the PyraLed3 and the OPY3 can be used very well where the diffuser is close to the LED. PyraLed3 has a particularly good diffusivity so that the LEDs remain invisible, even when the sheet is placed close to the LED. A good example of this are the chandeliers of the Rijksmuseum. The OPY2 has a good diffusivity, but also a high light transmission!
PyraSied has a wide variety of cast acrylic opal sheets with various characteristics and properties. Choice of different light transmissions, surface structures and thicknesses. Every application has different requirements and with our different opal sheets we offer the desired flexibility. Looking for a standard 30% opal sheet type, choose type M2006, which we have in stock in 3 to 10 mm thickness.
Luminaires, bar and counter fronts, lettering / signing, decors, displays, light diffusers, furniture, reactors, partitions and store presentations.
For inspiration, check out our Acrylic community. This contains various applications with acrylic.
Light diffuser / opal sheets made of cast acrylic can be cut, milled, laser-cut, warm bend, glued, drilled, faceted, polished and matted and printed. For more information about fabricating acrylic sheets, check out our fabrication page.
Plexiglas®, Versato®, Altuglas® and Astariglas® are brands of the plastic acrylic (PMMA).
More than 35 years of experience in performance plastics
We deliver quickly, cut-to-size and always from our own stock everywhere in Europe
We are plastic specialists and provide customized services for all, both serially tailored to your supply chain and one-offs
We develop new design and colour collections annually and guide customer-specific acrylic production for projects