Urethanes in LED Encapsulation – PT 2

In our previous blog “Urethanes” we discussed the advantages of urethane adhesives and applications when they are advantageous. One particular application that urethanes excel in is LED encapsulation. When high temperature resistance is not necessary, urethanes can be implemented in place of silicones. Urethanes work more efficiently in low temperature applications and are easily utilized for electronic packaging. Another major benefit when working with urethanes is that they protect stress sensitive electronic devices, as well as act as a barricade against water.

Polyurethanes are often utilized for their flexibility, shore hardness variances and short pot life. Polyurethanes are also perfect for delicate electronic components as they can act as shock absorbers. They are water resistant which makes them great resources for marine applications.

Polyurethanes & LEDs

LED lighting has become increasingly common, you may find them in illuminated furniture, surrounding cabinetry or concealed in room to produce indirect lighting. Two-component potting solutions are used to protect LEDs (polyurethane or silicone).

In order for an LED encapsulation to be working at an optimum performance, it should be potted with polyurethane or silicone products. This also protects the LED from mechanical damage, moisture or any other environmental disturbance. Two part potting systems allows the adhesive to be processed on fully automatic mixing machines.

light diffusing urethane

Top LED Light: Potted with Entex 53071 – Light Diffusing Bottom LED Light: Potted with Entex 53061 – Not Light Diffusing

Both space and time are saved when LEDs are casted with potting and silicone materials. The chosen sealant can greatly influence the properties of the emitted light. There will be a greater light dispersion and clear casting that does not interfere with the emitted light. Polyurethane-based optical casting protects from yellow which is generated from UV radiation by aliphatic isocyanate.

Urethane LED encapsulants can be used as a tool to control light emitting from the LED. These products can be made to be light diffusing if the application calls for it. See the video (or photos) below for the difference between a light diffusing and not diffusing urethane.

When designing LED lights and lighting systems, the casting material should first be determined. Resin Designs offers clear, ridged or flexible, urethane LED Encapsulants that can be light diffusing:

  • Entex 53051: Crystal Clear, UV stable, encapsulants. This material is ridge (Shore D75) and non-light diffusing.
  • Entex 53061: Flexible version of Entex 53051.
  • Entex 53071: A light diffusing version of Entex 53061.

Contact us to create custom LED encapsulants for your application.