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The SILASTIC™ Moldable Silicone allows refraction, reflection and diffusion in many forms.

Publié le 2021-02-11

More freedom in designing your lighting with optical silicones SILASTIC™ Moldable Silicone

High performance injection molded optical silicones for lamps and luminaires :

Imagine your LED lighting options without the limitations of traditional glass and plastic lighting. With the unsurpassed features and performance of SILASTIC™ Modular Silicones (moldable silicone) you can imagine and create the brightest innovations in LED lighting.

Innovative designs currently impossible to achieve with optical plastics and glass are now possible.

Moldable silicones are suitable for a wide range of applications, including secondary lenses, light pipes, micro-lens arrays, light guides and other optical components.

DOW's moldable optical silicones offer good resistance to ultraviolet (UV) exposure, optical yellowing and scratch resistance - compared to polycarbonate (PC) plastics and polymethyl methacrylate (PMMA). Due to their chemical skeleton, the silicones are heat resistant and particularly well suited to handle the increasing temperatures of the new high-power LED lighting systems.

SILASTIC™ Moldable silicone versus other optical solutions :

SILASTIC™
Moldable Silicone
PCPMMAGlass
Light transmission 94% 88-99% 93% 95%
Refractive index 1,42 1,58 1,49 1,52
UV resistance High Low Medium High
Chemical resistance Medium Medium Low High
Service temperature maximum (°C) >150 120 90
Yellowing* Low High High Low
Micro detail replication High Low Medium Low
Ability to mold large and thick parts High Low Low
Minimum thickness** <0,5 mm 2 mm 2 mm -
Draft angle (manufacturing)** <0° 1 to 2° 1 to 2° -
Weight Low Medium Medium High
Flexible material — integration High Low Low Low

The benefits of optical silicones at a glance:

  • Flexibility and reproducibility to obtain complex optical shapes
  • Possibility to add fine surface features
  • Physical and optical performance in demanding environments (high humidity and UV exposure ( UL746 C(f1))
  • Excellent optical properties without yellowing
  • Proven performance with high throughput and less downtime
  • Mechanical strength
  • Lighter than other traditional materials

Optical performance

SILASTIC injectable optical silicones offer refraction, reflection and diffusion of light in many forms:

  • Excellent optical clarity and light transmission combined with resistance to heat, UV and environmental degradation allows these silicones to offer higher light density, low scattering and long term performance.
  • The long-term stability of optics made with SILASTIC™ silicones has been proven in accelerated aging tests up to 12,000 hours at 150°C, as well as in tests using artificial sunlight (UV A and B) combined with heat (65°C).
  • Highly versatile, these two-component silicone materials allow you to explore more complex designs, while simplifying the manufacturing process and reducing costs. With low viscosity before curing, Dow's optical silicones make injection molding of complex shapes easier than with plastics or glass. Silicones require very little injection pressure compared to thermoplastics.


Depending on the needs of your application, these silicones will allow you to produce flexible and soft or firm and resistant components.

The flexible material is easily demolded, even with complex shapes and undercuts.

Fine details, surface finishes and micro-scale optical structures can be molded, and no secondary polishing will be required.

Discover the characteristics of SILASTIC optical silicones and ask for your sample :

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

(psi)

(MPa)

65

87 72 51 84 70 84

1 300

1 740 1 625 800 1 700 1 700 1 250

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 mm
89% ) 760 mm

92% à 10 mm
90% à 25 mm
84% à 50 mm
76% à 100 mm

90% à 10 mm
84% à 25 mm
75% à 50 mm
59% à 100 mm
92% à 10 mm
89% à 25 mm
85% à 50 mm
77% à 100 mm
93% à 10 mm
90% à 25 mm
86% à 50 mm
79% à 100 mm
93% à 10 mm
91% à 25 mm
87% à 50 mm
80% 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.
Dielectric strength
N/A
500
48
736
52
584
51
508
52
711
51
650
N/A
525
Dielectric strength (kV/nm) 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 UL94
UL94 746A
UL94
UL94 746A
AMECA
UL94
UL94 746A
UL746C(f1)(f8)
AMECA
UL94
UL746A
UL 746C(f1)(f8)
UL94
UL746A
UL 746C(f1)(f8)
UL94
UL746A
UL 746C(f1)(f8)
UL94
UL746A
UL 746C(f1)(f8)

*mix ratio 1:1
**CV grade
*** Weighted total transmittance between 360 and 780 nm according to CIE Colorimetry 15:2004

More information

Need information on moldable silicones or SILASTIC™  ? Contact our technical department on +33 426 680 680 or fill in our Contact form.

In addition you can download LED Lighting product selector guide by DOW :