Sikasil® AS-787 SL

Sikasil® AS-787 SL

Self-levelling potting compound for electrical components

Sikasil® AS-787 SL is a 2-component, non-corrosive, fast-curing silicone potting agent, for encapsulation of electronic parts.  

  • Short non-flow time with excellent flow properties
  • Good heat dissipation
  • Superb dielectric properties
  • Excellent adhesion to most photovoltaic substrates
  • Outstanding performance under harsh environment conditions
  • Low volatility
  • UL® certified: UL94 V-1, HWI 3, HAI 0, RTI ≥105°C
 
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PRODUCT BENEFITS

  • Short non-flow time with excellent flow properties
  • Good heat dissipation
  • Superb dielectric properties
  • Excellent adhesion to most photovoltaic substrates
  • Outstanding performance under harsh environment conditions
  • Low volatility
  • UL® certified: UL94 V-1, HWI 3, HAI 0, RTI ≥105°C
 

Areas of Application

The self-leveling and fast curing potting agent Sikasil® AS-787 SL can be used for encapsulation and protection of electronic components which may have to withstand harsh environmental conditions. Originally designed for junction box potting in the photovoltaic industry. This product is suitable for experienced professional users only. Tests with actual substrates and conditions have to be performed to ensure adhesion and material compatibility.  

Product Details

Typical Product Data
Properties

Sikasil® AS-787 SL (A)

Sikasil® AS-787 SL (B)

Chemical base

2-component silicone

Color (CQP001-1)

mixed

White

Translucent

White

Cure mechanism

Polycondensation

Cure type

Neutral, alkoxy

Density (uncured)

 

mixed

1.3 kg/l

1.0 kg/l

1.2 kg/l

Mixing ratio

A: B by volume

A: B by weight

10:1

13:1

Viscosity (CQP029-6)

at 0.89 s-1

20 Pa·s

1 Pa·s

Consistency

Liquid

Application temperature

ambient

5 ─ 40 °C

Snap time (CQP554-1)

12 minutes A

Non-flow time (CQP070-2)

19 minutes A

Shore A hardness (CQP023-1 / ISO 7619-1)

30

Tensile strength (CQP036-1 / ISO 527)

1.0 MPa

Elongation at break (CQP036-1 / ISO 527)

130 %

Volume restivity (DIN IEC 60093)

1014 Ω·cm

Electrical strength (DIN IEC 60243-1)

20 kV/mm

Relative permittivity (DIN VDE 0303 Part 4:1969-12)

3.5 F/m

Comparative tracking index CTI (DIN EN 60112)

600 V

Thermal conductivity (DIN 52612)

0.2 W/m·K

Thermal resistance (CQP 513-1)

4 hours

200 °C

Service temperature (CQP513-1)

-40 ─ 150 °C

Shelf life

12 months B

CQP = Corporate Quality Procedure

A) 23 °C / 50 % r. h.

B) storage below 25 °C
Technical Information

CURE MECHANISM

Sikasil® AS-787 SL starts to cure immediately after mixing the 2-components.
The speed of the reaction depends mainly on the temperature, i.e. the higher the temperature the faster the curing process. Heating above 50 °C could lead to bubble formation and is therefore not allowed.
The product may also be used in confined spaces but the outgassing by the curing process needs to be considered.
The mixer open time, i. e. the time the material can remain in the mixer without flushing or extrusion of product, is significantly shorter than the snap time indicated above.

Application

Application Information

Surface Preparation

Surfaces must be clean, dry and free from grease, oil and dust. Surface treatment depends on the specific nature of the substrates and is crucial for a long lasting bond.

Application

Before processing Sikasil® AS-787 SL both components have to be mixed homogeneously and air-bubble-free in the correct ratio as indicated with an accuracy of ± 10 %. Most commercially available metering and mixing equipment are suitable. For advice on selecting and setting up a suitable pump system, contact the System Engineering Department of Sika Industry.
Consider that the B-component is moisture-sensitive and must therefore only be exposed briefly to air.

Removal

Uncured Sikasil® AS-787 SL can be removed from tools and equipment with Sika® Remover-208 or another suitable solvent. Once cured, the material can only be removed mechanically.

Hands and exposed skin have to be washed immediately using hand wipes such as Sika® Cleaner-350H or a suitable industrial hand cleaner and water.

Do not use solvents on skin.

 

Overpainting

Sikasil® AS-787 SL cannot be overpainted.

Application Limits

To exclude materials influencing Sikasil® AS-787 SL, all materials such as gaskets, setting blocks, sealants, etc., in direct and indirect contact have to be approved by Sika in advance.
Where two or more different reactive sealants are used, allow the first to cure completely before applying the next.
Sikasil® AS-787 SL may only be used for serial application after a detailed examination and written approval of the corresponding project details by Sika Industry.