IRS 3071 Polyurethane Potting Compound, Flame Retardant Encapsulating Compound

IRS 3071

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About IRS 3071 Polyurethane Potting Compound

IRS 3071 is a semi-rigid, room temperature curing, flame retardant and thermally conductive polyurethane potting compound. Specifically designed for the cost effective encapsulation of a variety of low to medium voltage electrical and electronic applications, the material is medium viscosity, flame retardant to UL94 V-0 at 6mm and has excellent adhesion to a wide range of substrates. IRS 3071 is resistant to UV, water based cleaning chemicals, motor oil, lubricants and most dilute acids and alkalis.

Features & Benefits

  • Non-toxicIRS 3071 Polyurethane flame retardant potting compound twinpack
  • Flame retardant to UL94 V-0 at 6mm
  • Excellent adhesion
  • Thermally conductive
  • Economical
  • RoHS & WEEE compliant
  • Long pot life
  • Cured at room temperature or with heat


Specification Mixed Resin Hardener
Colour Black Black Amber
Specific gravity (g/ml) 1.65 1.72 1.24
Viscosity m.Pa.s @ 25°C 6,000 19,000 200
Mix ratio 8.4:1 (weight)
6.1:1 (volume)
Pot life 20 minutes (150g @ 25°C)
Gel time 40 minutes (150g @ 25°C)
Cure schedule Minimum cure:
24 hrs @ 20°C
4 hrs @ 60°C
2 hrs @ 80°C
Full cure:
1 week
4 hours
2 hours
Operating temperature range -40 to +125°C
Flammability UL94 V-0 @ 6mm
Shrinkage 0.5% by volume
Shore hardness A90
Thermal conductivity 0.75 W/mK
Coefficient of linear expansion 60-80 ppm/°C
Volume resistivity 1210 ohm-cm
Surface resistivity 12-1410 ohm
Dielectric strength 16 kV/mm
Relative permittivity 3.2 @ 50KHz
Water absorption 0.54% (after 30 days @ 25°C)
Elongation at break ~ 30%
Comparative tracking index > 600
Glass transition temperature (Tg) -10°C


Safety Data Sheets
For the latest SDS for this product, please e-mail

Other Information

See how IRS 3071 works as part of a real application in this Potting Compound Case Study:

Potting a pressure-resistant device for deep sea fishing

Utilising a combination of optically clear Opti-tec 4210 and opaque IRS 3071 into their product, SNTech was able to protect their innovative ‘Pieces Deep’ fishing lights from 100 bar pressures at depths of 1000m, without sacrificing light performance.

STOPFREEZE IRS 3071 potting compound case study Potting compound protects trace heating system thermostats

The development process of STOPFREEZE’s COMBI and KIT products required a method of protecting the IP67 waterproof in-line thermostat with integral LED indicators from water ingress and physical damage in its outdoor situation.

Potting compound goes under the sledge hammer at Tough Tracker

A flame retardant polyurethane potting compound enabled the protection of electronics and a resistance to high impact shock and extreme conditions.


All Downloads

Filename Size Download
Potting compound goes under the sledge hammer at Tough Tracker 1.11MB
Potting compound protects trace heating system thermostats 0.26MB
Case Study - Opti-tech 4210 & IRS 3071 - SNTech 0.57MB

Ordering Information

IRS 3071 is available in twinpacks or in bulk.

IRS 3071 twinpack

The twinpack sachet is a clear film sachet, with the resin and hardener separated by a removable clip and rail divider. Click here for twinpack mixing instructions.

In kit form, resin and hardener are provided in separate containers to the correct ratio. In most cases pour the hardener into the larger resin container and use it as a mixing vessel. Stir well using appropriate mixer until homogeneous.

Part number Description
IRS3071-1KG Polyurethane potting compound – 1000 gram twinpack
IRS3071-5KG Bulk kit – 5kg
IRS3071-25KG Bulk kit – 25kg

For optimal results, store away from strong oxidising agents, strong acids, water, alcohols and amines. Store in a cool, well-ventilated area. Keep container tightly closed. Keep in original packaging.


Next Steps

Our technical sales team are on hand to discuss your application requirements. Click here to get in touch.

Find out more information on how to purchase.

  • Last updated: February 2022
  • Version: 5.0

Statements, technical information and recommendations contained herein are based on tests we believe to be reliable but they are not to be construed in any manner as warrantees expressed or implied. The user shall determine the suitability of the product for his intended use and the user assumes all risk and liability whatsoever in connection therewith.