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Description for Dow Sylgard 170 Silicone Elastomer
A two-part, 1:1 mix, black, general purpose encapsulant with good flowability, long working time and flame resistance, low viscosity.Brand Sylgard Chemical Resistance Good Application Type Potting, Encapsulant 1 Part or 2 Part 2-Part Material Form Liquid, Silicone elastomer Industry Relays, General purpose, Sensors, Electrical PCB system assembly applications, Transformers, Connectors, Amplifiers, High voltage resistor packs, E-Mobility Solutions, Smart Meters, Insulation, Smart Home Devices, Headlamp assemblies, Electronics Manufacturer Dow Chemistry Versatile, Polydimethylsiloxane silicone elastomer, Solvent-free Cure Method 2-Part Cure, Heat accelerated cure, Room temperature cure Cure Temperature (°C) 25, 70, 85, 100, 25 Room temperature Cure Time (min) 1,440, 25, 15, 10, Rapid Viscosity (cPs) Low, 2,135, Good flowability Color Black, Dark Gray Ozone Resistance Ozone resistance High Temperature Resistance (°C) 200 Low Temperature Resistance (°C) -45, -55 Volume Resistivity (O) 5.6E + 17 (ohm *cm) Stress Relief Stress relief Key Specifications Mil-Spec (United States Military Standard): PRF-23586F (Grade B2): MIL1 Spec tested to MIL-PRF-23586F, UL (Underwriters Laboratory), ULC (Underwriters Laboratories of Canada), NFPA (National Fire Protection Association): UL 94: UL 94 V-0 -
Technical Data for Dow Sylgard 170 Silicone Elastomer
Overview
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Chemical Resistance
- Chemical Resistance - Good
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Application Type
- Pottant / Encapsulant - Potting, Encapsulant
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1 Part or 2 Part
- 2-Part
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Material Form
- Elastomer - Silicone elastomer
- Liquid
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Industry
- Smart Meters
- Smart Home Devices
- E-Mobility Solutions
- Headlamp - Headlamp assemblies
- Electronics - Relays
- Sensors
- Printed Circuit Board (PCB) - Electrical PCB system assembly applications
- Transformers
- Connectors
- Amplifiers
- Voltage Resistors - High voltage resistor packs
- Power Supplies
- Industrial - Industrial controls
- General Purpose
- Insulation
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Chemistry
- Solvent-Free
- Other - Versatile
- Silicone - Polydimethylsiloxane silicone elastomer
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Application Method
- Dispenser - Automated mixing and dispensing, Manual mixing
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Cure Method
- Room Temperature / Air Dry - Room temperature cure
- Heat - Heat accelerated cure
- 2-Part Cure
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Color
- Black
- Gray - Dark Gray
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Key Specifications
- Mil-Spec (United States Military Standard) : PRF-23586F (Grade B2) : Type I, Class II, QPL - MIL1 Spec tested to MIL-PRF-23586F
- UL (Underwriters Laboratory), ULC (Underwriters Laboratories of Canada), NFPA (National Fire Protection Association) : UL 94 : V0 - UL 94 V-0
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Brand
- Sylgard
Specifications
Cure Specs
Cure Temperature (°C) 25, 70, 85, 100, 25 Room temperature Test Method Cure Time (min) 1,440, 25, 15, 10, Rapid Test Method Viscosity (cPs) Low, 2,135, Good flowability Test Method Linear Shrinkage (%) Minimal shrinkage Work / Pot Time (min) 15, Long Test Method Mix Ratio 1:1 (by volume), 1:1 (by weight) Material Resistance
Flame Resistance Flame resistance Ozone Resistance Ozone resistance UV Resistance UV resistance Environmental Resistance Environmental resistance High Temperature Resistance (°C) 200 Low Temperature Resistance (°C) -45, -55 Moisture/Humidity Resistance Moisture/humidity resistance Conductivity
Dissipation Factor 0.00200, 0.00020 Test Method Dielectric Strength (V/mil) Good, Durable, 472 Test Method Dielectric Constant 2.54, 2.50 Test Method Thermal Conductivity (W/m°K) 0.277 (btu/hr ft °F), Moderate Volume Resistivity (O) 5.6E + 17 (ohm *cm) Test Method Hardness
Stress Relief Stress relief Shore A Hardness 47 Test Method Flexibility Flexible Other Properties
Coefficient of Thermal Expansion (CTE) 275 (ppm/°C) Test Method Flash Point (°F) 213.8 Business Information
Shelf Life Details Shelf life is indicated by the “Use By” date found on the product label. For best results, Dow Corning silicone encapsulants should be stored at or below 25°C (77°F). Special precautions must be taken to prevent moisture from contacting these materials. Containers should be kept tightly closed and head or air space minimized. Partially filled containers should be purged with dry air or other gases, such as nitrogen., Shelf life is indicated by the “Use Before” date found on the product label. Refer to the product label for storage temperature requirements. Shelf Life Type From date of manufacture Shelf Life (mon) 24 Not Good For
Don't Use For Unsaturated hydrocarbon plasticizers, Curing agents, Other organometallic compounds, Polysulfides, Other sulfur containing materials, Some solder flux residues, Chemicals, Organotin, Silicone rubber containing organotin catalyst, Polysulfones Don't Use With Certain materials, Sulfur, Plasticizers -
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Best Practices for Dow Sylgard 170 Silicone Elastomer
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Surface Preparation
In applications requiring adhesion, priming will be required for many of the silicone encapsulants. For best results, the primer should be applied in a very thin, uniform coating and then wiped off after application. After application, it should be thoroughly cured prior to application of the silicone elastomer. Additional instructions for primer usage can be found in the information sheets specific to the individual primers.
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Mixing
These products are supplied in a 1 to 1 mix ratio, which is very robust in manufacturing environments and allows for some process and dispense equipment variation.
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Deairing/Degassing
In most cases de-airing is not required.
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Curing
Thoroughly mixed Dow silicone encapsulants may be poured/dispensed directly into the container in which it is to be cured. Care should be taken to minimize air entrapment. When practical, pouring/dispensing should be done under vacuum, particularly if the component being potted or encapsulated has many small voids. If this technique cannot be used, the unit should be evacuated after the silicone encapsulant has been poured/ dispensed. Dow silicone encapsulants may be either room temperature (25°C/77°F) or heat cured. Room temperature cure encapsulants may also be heat accelerated for faster cure.
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Testing
If a substrate or material is questionable with respect to potentially causing inhibition of cure, it is recommended that a small scale compatibility test be run to ascertain suitability in a given application. The presence of liquid or uncured product at the interface between the questionable substrate and the cured gel indicates incompatibility and inhibition of cure
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Removal
REPAIRABILITY In the manufacture of electrical and PCB system assemblies devices it is often desirable to salvage or reclaim damaged or defective units. With most non-silicone rigid potting/ encapsulating materials, removal or entry is difficult or impossible without causing excessive damage to internal circuitry.
Dow silicone encapsulants can be selectively removed with relative ease, depending on the chosen remove method and technique and repairs or changes accomplished, and the repaired area repotted in place with additional product. To remove silicone elastomers, simply cut with a sharp blade or knife and tear and remove unwanted material from the area to be repaired. Sections of the adhered elastomer are best removed from substrates and circuitry by mechanical action such as scraping or rubbing and can be assisted by applying Dow OS fluids to swell the elastomer. Before applying additional encapsulant to a repaired device, roughen the exposed surfaces of the cured encapsulant with an abrasive paper and rinse with a suitable solvent and dry. This will enhance adhesion and permit the repaired material to become an integral matrix with the existing encapsulant. Silicone prime coats are not recommended for adhering products to themselves.
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Cure Temperature Test Methods
Cure Temperature | Cure Time Test Method |
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25°C | These values are not intended for use in preparing specifications. |
70°C | Heat Cure, These values are not intended for use in preparing specifications. |
85°C | These data were collected on 50-100 gram samples of a lot believed to be typical and should be used as initial estimates of cure times. Times will vary slightly from batch to batch and can be longer or shorter due to thermal mass of your parts and your heating ramp rate. Pretesting is recommended to confrm adequate cure for your application, For primerless adhesion products, cure time is based on time to reach durometer. Full adhesion may take more time at the cure temperature |
100°C | Heat Cure, These values are not intended for use in preparing specifications. |
25°C Room temperature |
Cure Time Test Methods
Cure Time | Test Method |
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1,440 min | These values are not intended for use in preparing specifications. |
25 min | Heat Cure, These values are not intended for use in preparing specifications. |
15 min | These data were collected on 50-100 gram samples of a lot believed to be typical and should be used as initial estimates of cure times. Times will vary slightly from batch to batch and can be longer or shorter due to thermal mass of your parts and your heating ramp rate. Pretesting is recommended to confrm adequate cure for your application, For primerless adhesion products, cure time is based on time to reach durometer. Full adhesion may take more time at the cure temperature |
10 min | Heat Cure, These values are not intended for use in preparing specifications. |
Rapid |
Viscosity Test Methods
Viscosity | Test Method |
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Low | These values are not intended for use in preparing specifications. |
2,135 cPs | These values are not intended for use in preparing specifications. |
Good flowability | These values are not intended for use in preparing specifications. |
Work / Pot Time Test Methods
Work / Pot Time | Test Method | Temperature |
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15 min | These values are not intended for use in preparing specifications. | 25°C |
Long | These values are not intended for use in preparing specifications. |
Dielectric Constant Test Methods
Dielectric Constant | Test Method |
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2.54 | 100 Hz, These values are not intended for use in preparing specifications. |
2.50 | 100 kHz, These values are not intended for use in preparing specifications. |
Dielectric Strength Test Methods
Dielectric Strength | Test Method |
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Good | |
Durable | |
472 V/mil | These values are not intended for use in preparing specifications. |
Dissipation Factor Test Methods
Dissipation Factor | Test Method |
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0.00200 | 100 Hz, These values are not intended for use in preparing specifications. |
0.00020 | 100 kHz, These values are not intended for use in preparing specifications. |
Volume Resistivity Test Methods
Volume Resistivity | Test Method |
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5.6E + 17 (ohm *cm) | These values are not intended for use in preparing specifications. |
Shore A Hardness Test Methods
Shore A Hardness | Shore Hardness Test Method |
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47 | These values are not intended for use in preparing specifications. |
Coefficient of Thermal Expansion (CTE) Test Methods
Coefficient of Thermal Expansion (CTE) | CTE Test Method |
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275 (ppm/°C) | Linear CTE (by TMA), These values are not intended for use in preparing specifications. |