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BLUESIL ESA 7250 A

BLUESIL ESA 7250 A

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Optically clear, high-strength 2K-Pt silicone potting compound for electronics potting, optoelectronics — mixing ratio 10:1.

Optically clear, high-strength 2K Pt silicone potting compound (Shore A 52) for electronics potting, optoelectronics and photovoltaic cells

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  • Networking type
  • Number of components
  • consistency
  • Mixing ratio
  • UV resistance
  • Paint has hardened
  • Self-leveling
  • Viscosity uncrosslinked (mPa·s)
  • Electrical insulation
  • Potting time (min)
  • Food contact
  • Suitable for medical use
  • Tensile strength (MPa)
  • Elongation at break (%)
  • Tensile strength (N/mm)
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Silicone ESA BLUESIL 2K silicone ELKEM Swiss bearing addition platinum base component 1:1 silicone gel electronic encapsulation optically clear

 
General Terms and Conditions.

Shipping usually within 1 to 3 business days
(availability will be confirmed after ordering)

. Express logistics. Fast and reliable within Switzerland & Europe.

Shipping from Swiss warehouse within 24 hours. Batch certificate. Invoice within 30 days (B2B). Technical support.
Shipping & Delivery

Usually 1 to 3 working days

Availability will be confirmed after order receipt.

Express logistics within Switzerland & Europe.

General Terms and Conditions →

Product data

Internal reference: 40-7250A

HS code: 39100000

Internal reference: 40-7250A
HS code: 39100000

BLUESIL ESA 7250 A
BLUESIL ESA 7250 A
Bluesil Elkem Silicones SKU 40-7250A​

Bluesil ESA 7250 A & B is an optically clear, high-strength 2K Pt silicone potting compound (Shore A 52) for electronics potting, optoelectronics and photovoltaic cells.

This product line comprises 2K polyaddition silicone elastomers with optical clarity for electronics encapsulation, optoelectronics, and photovoltaic cells — defined refractive index, high transparency. ESA 7250 is tailored to specific industrial applications — the most important properties and areas of application are listed below.

High strength + optically clear

Bluesil ESA 7250 combines outstanding mechanical properties (6.2 MPa tensile strength, Shore A 52) with optical clarity. 10:1 mixing ratio, 4-hour pot life, refractive index 1.406 — a proven industry standard for optoelectronics and high-performance potting.

ESA 7250 in numbers
Visually clear
Transparent
Shore A 52
hardness
6.2 MPa
Tensile strength
4 h
Potting time

What distinguishes ESA 7250

Visually clear
Direct view of encapsulated components — suitable for visible connections.
High strength (Shore A 52, 6.2 MPa)
Robust vulcanizate — protects mechanically stressed components.
Low-viscosity mixture
4,000 mPa·s — easily degassable and pourable.
Long potting time (4 hours at 23°C)
Careful processing even with large volumes.
Definitive refractive index
n=1.406 — suitable for optical applications with index jump.
Top heat resistance
+200 °C for short periods, suitable for many industrial applications.

What is the ESA 7250 used for?

Electronic potting
Potting of electronic components with high mechanical protection.
Optoelectronic connections
Optical fiber encapsulation with index jump.
Photovoltaic cells
Insulation and protection of solar cells.
Mechanical-optical components
Where transparency AND mechanical strength are required.
Industrial sensors
Encapsulation of high-performance sensors.
LED potting
High-performance LEDs with clear optics.
Data sheets & safety data sheet
Full TDS and SDS in DE, EN, FR — view or download directly.
To the documents →

processing

1
Prepare component
Position the component cleanly and dry in the encapsulation mold. Align the optical axes.
2
Mix A & B
10:1 or 1:1 (see comparison table). Low-viscosity mixture — easily degassed.
3
Degas
30–50 mbar vacuum — important for bubble-free optics.
4
Shed
Pour slowly into the mold — refractive index 1.40 makes the material optically clear.
5
Curing
24–48 h at 23 °C or accelerated with heat up to +150 °C.

Recommended accessories

Bluesil Inhibitor 3
Pot life extender for polyaddition silicone systems (Pt-Cure).
View product →
Bluesil Primer PM 820
High-performance primers for polar plastics (PA, PES, ABS, PP) and composites.
View product →
Bluesil Primer 131
Universal adhesion promoter for stainless steel, aluminum, PMMA and many metals.
View product →

Important instructions

Mixing & Dosage
Stir A and B thoroughly before each use. Use precise dosage in the specified ratio (see table above) — ideally by weight. Incorrect dosage will result in incomplete cross-linking.
Degassing
Degas the mixture under a vacuum of 30–50 mbar. The material expands 3–4 times, then contracts back to its original size after 5–10 minutes. Interrupt the vacuum several times for better degassing.
Avoid inhibitors
Polyaddition silicones are inhibited by: sulfur-vulcanized rubber, tin-catalyzed RTV, amine epoxides, and PVC with tin salts. If in doubt, conduct a preliminary test.
Application advice
SILITECH will advise you on the optimal RTV variant for your application — substrate, hardness, pot life, mechanics. Contact us with your specific application details.

ESA 7250 compared to related RTV products

Networking system, mechanics, and processing times side by side — all values ​​from the official Elkem TDS. “— " = not specified in the datasheet.

ESA 7250
Current product		 RTV 141 →ESA 6110 →RTV 8352 LV →
Networking system2K Polyaddition (Pt)2K Polyaddition (Pt)2K Polyaddition (Pt) Gel2K Polyaddition (Pt)
Mixing ratio10 : 110 : 11 : 11 : 1
ColorOptically clear, colorlessTransparent, colorlessVisually clearWhitish
Shore A hardnessA 52A 50Gel (Penetration 250)A 55
Elongation at break115 %120 %—78 %
Tensile strength6.2 MPa6 MPa—2.3 MPa
Tear resistance4 kN/m———
Potting time4 h4 h50 min (Std) / 5 min (QC)130 min
demolding time24–48 h24–48 h120–180 min8 h
Mixed viscosity4,000 mPa·s4,000 mPa·s1,200 mPa·s2,200 mPa·s
Main applicationElectronic pottingOptoelectronic connectionsElectronic encapsulation (potting)Electrical Engineering Encapsulation
Topics & Application Areas
Key terms related to this product. Also useful for our search and filters.
Silicone ESA BLUESIL 2K silicone ELKEM Swiss bearing addition platinum base component 1:1 silicone gel electronic encapsulation optically clear

Technical data for BLUESIL ESA 7250 A

All 19 product information 8 Further properties 1 Physical properties 3 Electrical properties 1 Curing values ​​1 Product approvals 2 Mechanical properties 3
Product information
Manufacturer Elkem Silicones
Mixing ratio 10 : 1
Networking type Addition (Platinum)
Number of components 2K (two-component)
consistency Flowable
Mixing ratio 1:1
brand Bluesil
Container 1 kg, 2.5 kg, 5 kg, 25 kg
Other features
UV resistance Yes
Physical properties
Paint has hardened Transparent
Self-leveling Yes
Viscosity uncrosslinked (mPa·s) 4
Electrical properties
Electrical insulation Yes
Curing values
Potting time (min) 4
Product approvals
Food contact No
Suitable for medical use No
Mechanical properties
Tensile strength (MPa) 6.2
Elongation at break (%) 115
Tensile strength (N/mm) 4

For binding values, please refer to the technical data sheet (TDS) in the "Documents" tab.

Documents and datasheets

Click on a document for a preview or the download icon for a direct download.

Technical Data Sheets (TDS) 1
Bluesil ESA 7250 A E5 - Technical Data Sheet EN.pdf
653 KB
Safety Data Sheets (SDS) 4
Bluesil ESA 7250 A E5 - Safety Data Sheet DE.pdf
241 KB
Bluesil ESA 7250 A E5 - Safety Data Sheet EN.pdf
335 KB
Bluesil ESA 7250 A E5 - Fiche de Sécurité FR.pdf
440 KB
Bluesil ESA 7250 A E5 - Scheda di Sicurezza IT.pdf
433 KB

Frequently asked questions about ESA 7250

Practical questions regarding processing and design — answered by SILITECH.

Bluesil ESA 7250 A & B: Optically clear, high-strength 2K Pt silicone potting compound (Shore A 52) for electronics potting, optoelectronics, and photovoltaic cells. Main applications include electronics potting, optoelectronic connections, and photovoltaic cells.

Polyaddition crosslinking is a two-component silicone chemistry using a platinum catalyst. Component A contains the platinum complex, and component B contains the SiH crosslinker. When mixed, the components crosslink without releasing reaction byproducts—no shrinkage due to outgassing, excellent dimensional accuracy, and low linear shrinkage. Important: Polyaddition silicones are inhibited by various substances—sulfur-vulcanized natural rubbers, tin-catalyzed RTV silicones, amine-catalyzed epoxy resins, and tin-stabilized PVC. In case of doubt, a preliminary test should be carried out.

Thoroughly stir components A and B before each processing step. Measure precisely according to the mixing ratio specified in the TDS (see comparison table above) – ideally by weight. Mix with an electric or pneumatic agitator at low speed (minimize air entrainment). Degas the mixture under vacuum (30–50 mbar) – the material will expand 3–4 times its original volume, bubbles will escape, and the material will settle back after 5–10 minutes. Then slowly pour into the mold from the lowest point to avoid air entrapment. For polyaddition systems, avoid contact with inhibitors (sulfur-based rubber, tin-based RTV, amine epoxides, PVC with tin salts).

Store in the unopened original container in a dry, cool place — typically between +5 and +30 °C, see TDS for exact values. Store components A and B separately; seal airtight after opening. Polyaddition systems are insensitive to moisture, but should be stored in a cool place to maintain pot life. Consult the Safety Data Sheet (SDS) before use.

The comparison table above lists related RTV products with different hardnesses, pot lives, or application profiles. If you are unsure which product is best for you, we would be happy to advise you — contact SILITECH with details of your application (substrate, desired hardness, processing time, mechanical requirements, and durability).

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Product specifications

Product information
Container 1kg or 2.5kg or 5kg or 25kg
Manufacturer Elkem Silicones
Mixing ratio 10 : 1
Networking type Addition (Platinum)
Number of components 2K (two-component)
consistency Flowable
Mixing ratio 1:1
brand Bluesil
Other features
UV resistance Yes
Physical properties
Paint has hardened Transparent
Self-leveling Yes
Viscosity uncrosslinked (mPa·s) 4
Electrical properties
Electrical insulation Yes
Curing values
Potting time (min) 4
Product approvals
Food contact No
Suitable for medical use No
Mechanical properties
Tensile strength (MPa) 6.2
Elongation at break (%) 115
Tensile strength (N/mm) 4
Keywords
Keywords
Silicone ESA BLUESIL 2K silicone ELKEM Swiss bearing addition platinum base component 1:1 silicone gel electronic encapsulation optically clear
processing
Viscosity of mixture1,200 mPa·s
Viscosity Comp. A1,000 mPa·s
Viscosity Comp. B1,200 mPa·s
Pot life at 23°C40.0 min
Physical & Thermal
Density (23°C)0.98 g/cm³
Temperature resistance (duration)-50 to 200 °C
Peak temperature (short-term)200 °C
Electrical characteristics
Dielectric constant ε (1 kHz)2.8
Dielectric strength23.0 kV/mm
Contact resistance1e+15 Ω·cm
Loss factor tan δ0.001
storage
Shelf life in original packaging12 months
Storage temperature-10 to 30 °C

Documents and datasheets

Safety Data Sheets (SDS) and Technical Data Sheets (TDS) are available for download: