Clear encapsulation ideal for LEDs

Opti-tec 4200 is an encapsulant/potting compound and adhesive. This optically clear polyurethane is ideal for use in electronics or electrical equipment which incorporates LEDs or other items where high transparency and aesthetics are important. Its clear, non-yellowing, hard setting properties will be appreciated in outdoor signage, illumination projects, e.g. pathways, swimming pools or fountains and in large public installations. It can be used for protecting photovoltaic and solar panel projects.

Opti-tec 4200 features excellent non-yellowing colour stability, due to the incorporation of both UV resistant base materials and the addition of UV stabilizers and antioxidants. It may be used for a range of applications from high value LED panels to decorative giftware (e.g. flower impregnation). It is also an excellent resin for the doming of badges, labels and decals.

Further important features include its hard set which enables it to resist impacts and mechanical loads better than silicones. It is also easy to mix, with very low viscosity, excellent penetration/air release, low shrinkage and low exothermic properties. Opti-tec 4200 is available in a convenient side-by-side double syringe cartridges, twin pack sachets and bulk packaging.

Optically clear silicone encapsulants

LED, photovoltaic (PV) and other light sensitive devices require UV stable, non-yellowing encapsulants for protection and improved light transmission. The table below shows a range of addition cure silicones which are temperature and moisture resistant, non-yellowing and UV stable.

Product	Hardness	Viscosity mPas	RI	Mix Ratio
OPT7020	40	4500	1.40	10:1
ACC Q-Sil 218	59	3000	1.40	10:1
ACC Q-Sil 222	59	2200	1.40	10:1
ACC QLE1102	45	1000	1.40	1:1
ACC Q-Gel 300	Gel	1000	1.40	1:1
ACC Q-Gel 301	Gel	2000	1.40	1:1
ACC Q-Gel 310	Gel	1000	1.40	1:1
ACC Q-Gel 311	Gel	1000	1.40	1:1
ACC Q-Gel 900	Gel		1.43	1:1
ACC Q-Gel 910	Gel		1.47	1:1
ACC Q-Gel 920	Gel		1.49	1:1
ACC Q-Gel 92-14-1	Gel	650	1.515	1:1
ACC Q-Gel 92-16-1	Gel	2820	1.539	1:1
ACC Q-Gel 92-18-1	Gel	5690	1.549	1:1

Of special note is ACC Q-Sil 222 which is self bonding to a wide range of substrates without the use of a primer.

These materials are technically well suited to the following applications

• LED potting


• Outdoor signage, displays and lighting


• PV module manufacture


• PV concentrator cell manufacture


• Sealing aviation displays

Check out our range of silicones from ACC and Opti-tec.

Bonding optical couplets

A question from the DYMAX blog:

We have to manufacture a component which is comprised of two individual parts molded from acrylic (PMMA) that have slightly different additives. The parts have concave and convex surfaces which fit onto each other. We want optical coupling between these two surfaces. Can we place one piece as an insert and mold the other over it? Is there some other, better method to achieve the same effect?

One common technique to bond couplets together as described is to mold both acrylic lenses separately and then bond them together with an optically clear adhesive. There are optical grades of adhesives that have excellent adhesion to acrylic, are designed to be transparent to most visible wavelengths, possess low shrinkage, stress, and viscosity for easy dispensing and alignment, and then cure uniformly and evenly under the proper light source. The real benefit is that you can optically align the lenses together while the adhesive is wet, and then cure on-demand.