Optical silicones are used in the manufacture of primary lenses with multi-segment LED light sources for Adaptive Driving Beam (ADB), with the aim of improving safety for drivers and road users.
Adaptive Driving Beam technology allows drivers to keep their high beams on at all times, as the system automatically adjusts the intensity according to changing traffic and road conditions.
Conditions of darkness or poor lighting increase the likelihood of a collision. Driving in the dark accounts for 25% of all car journeys, but poses a real risk that requires constant vigilance.
| Potential solutions | Limitations / Disadvantages |
| Increase road lighting | Reflect and reflections, necessary infrastructures |
| Increasing the use of drivers’ headlights | Glare and anxiety for the drivers in front |
| ADB: Adaptive driving beam | Long-distance visibility without causing discomfort, distraction or glare |
LED lighting for roads and motorways
The optical silicone and silicone adhesive used in the LED module offer high resistance to UV rays and external impacts.
It is important to note that PDMS-based materials are permeable to volatile organic compounds (VOCs), thereby preventing contamination of the LED chip or its phosphor layer which converts the light.
Outdoor applications in the automotive sector
In the design of an LED lighting module for emergency vehicles using two optical LSRs, the specially designed transparent lens was moulded from SILASTIC MS-1002 mouldable silicone.
This lens was then co-moulded with SILASTIC MS-0002 mouldable silicone to form the housing. The result was an LED module with:
- a compact footprint with “maximised light output”;
- exceptional resistance to damage such as stone chip impact;
- improved sealing performance to prevent water ingress;
- high stability against UV rays and photothermal effects to prevent lens yellowing.
Properties of SILASTIC™ mouldable silicones for optical applications
The SILASTIC™ range comprises a variety of mouldable silicones designed to meet the requirements of optical and automotive lighting applications. The table below compares the key physical, mechanical and optical properties of the products, making it easier to select the most suitable solution for your design requirements.
| SILASTIC™ MS-0002 Moldable Silicone | SILASTIC™ MS-1001 Moldable Silicone** | SILASTIC™ MS-1001 Moldable Silicone** | SILASTIC™ MS-1003 Moldable Silicone | SILASTIC™ MS-4002 Moldable Silicone | SILASTIC™ MS-4007 Moldable Silicone | SILASTIC™ MS-2002 Moldable Silicone | |
| Color | Translucent | Optically clear | Optically clear | Optically clear | Optically clear | Optically reflecting | White clear |
| Viscosity (part A), cP | 148 000 | 20 000 | 40 000 | 52 000 | 50 000 | 28 000 | 695 000 |
| Viscosity (part B), cP | 145 000 | 9 000 | 18 000 | 37 500 | 21 000 | 9 500 | 565 000 |
| Viscosity (mixed*), cP | – | 14 000 | 26 250 | 42 300 | 25 000 | 10 500 | – |
| Working time at 25°C (pot life), hours | 48 | 30 | 48 | 48 | 48 | 48 | 48 |
| Specific gravity, kg/l | 1,14 | 1,05 | 1,07 | 1,05 | 1,08 | 1,08 | 1,44 |
| Durometer, Shore A | 65 | 87 | 72 | 51 | 84 | 70 | 84 |
| (psi) | 1 300 | 1 740 | 1 625 | 800 | 1 700 | 1 700 | 1 250 |
| (MPa) | 9,0 | 12,0 | 11,2 | 5,5 | 11,7 | 11,7 | 8,6 |
| Elongation, % | 270 | 50 | 80 | 325 | 60 | 100 | 65 |
| Linear CTE, ppm/°C | 280 | 250 | 275 | 325 | 250 | 270 | 210 |
| Luminous transmittance*** | 75% à 450 mm87% à 760 mm | 92% à 10 mm90% à 25 mm84% à 50 mm76% à 100 mm | 90% à 10 mm84% à 25 mm75% à 50 mm59% à 100 mm | 92% à 10 mm89% à 25 mm85% à 50 mm77% à 100 mm | 93% à 10 mm90% à 25 mm86% à 50 mm79% à 100 mm | 93% à 10 mm91% à 25 mm87% à 50 mm80% à 100 mm | N/A |
| Refractive index (nD,589-3 nm) | N/A | 1,418 | 1,413 | 1,409 | 1,417 | 1,413 | N/A |
| Abbe number, a.i. | N/A | 48 | 52 | 51 | 52 | 51 | N/A |
| Dielectric strength | 500 | 736 | 584 | 508 | 711 | 650 | 525 |
| Dielectric strength (kV/mn) | 19,7 | 29 | 23 | 20 | 28 | 25,6 | 20,7 |
| Volume resitivity, ohm,cm | – | – | 1.00E+18 | 1.00E+16 | 1.00E+14 | 1.00E+14 | 3.00E+15 |
| Agency listing | UL94UL94 746A | UL94UL94 746AAMECA | UL94UL94 746AUL746C(f1)(f8)AMECA | UL94UL746AUL 746C(f1)(f8) | UL94UL746AUL 746C(f1)(f8) | UL94UL746AUL 746C(f1)(f8) | UL94UL746AUL 746C(f1)(f8) |
* mix ratio 1:1
** CV grade
*** Weighted total transmittance between 360 and 780 nm according to CIE Colorimetry 15:2004
Find out more about SILASTIC™ mouldable silicone solutions
Adaptive Driving Beam technology is helping to improve road safety by combining intelligent lighting systems with advanced optical materials. Thanks to their optical transparency, UV resistance, durability and moulding flexibility, SILASTIC™ mouldable silicone solutions are well suited for demanding automotive lighting applications, including LED lenses, housings and integrated optical components.
If you would like to learn more about SILASTIC™ products and identify the most suitable solution for your application, contact the experts at MD Poland. Our team can help you select the right material from the SILASTIC™ portfolio and provide technical support for automotive, optical and industrial projects.
