IRS 3071 Polyurethane Potting Compound, Flame Retardant Encapsulating Compound

IRS 3071

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About IRS 3071 Polyurethane Potting Compound

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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
Shelf life 12 months


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


As of 24 August 2023, adequate training is required before industrial or professional use of this product.

Other Information

See how IRS 3071 works as part of a real applications in these potting compound case studies:

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.

Application Insight – Potting Industrual LED Beacons

Encapsulating miniature PCB’s in various signalling devices for industries including logistics, oil and gas, rail, security, process control and public transport.

Application Insight – Bonding Lithium Battery Systems for Motorsport

Bonding lithium-ion cells into bespoke battery packs for motorsport.

All Downloads

Filename Size Download
IRS 3071 Product Data Sheet 0.13MB Download
Case Study - Potting compound goes under the sledge hammer at Tough Tracker 1.11MB Download
Case Study - Potting compound protects trace heating system thermostats 0.26MB Download
Case Study - Potting a pressure-resistant device for deep sea fishing 0.57MB Download
Application Insight - Motorsport Battery Packs 0.14MB Download
Application Insight - Potting Industrial LED Beacons 0.12MB Download

Ordering Information

IRS 3071 twinpack

IRS 3071 is available in twinpacks or in bulk.

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
Click here to buy on
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.


Let’s start by talking about your application

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  • Last updated: January 2024
  • Version: 5.3

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.