OLS-1211 | Liquid Encapsulant - Two part Epoxy

Harmonization Code : 3907.30.00.90 |   Polyacetals, other polyethers and epoxide resins, in primary forms; polycarbonates, alkyd resins, polyallyl esters and other polyesters, in primary forms : Epoxide resins : Other
Main features
  • Epoxy potting compound
  • Better anti blue and UV resistance
  • Encapsulation of LED lamps and displays

Product Description

OPTOLINQ OLS-1211 is a two-component (Part A & Part B), low halogen, optically clear epoxy casting compound designed for the encapsulation of LED lamps and displays. Part A is an epoxy resin while part B is primarily a modified curing agent.

OPTOLINQ OLS-1211 offers excellent bonding properties to a wide range of substrates and good resistance against heat aging, cold and thermal shock. Additionally, this epoxy encapsulant features over then 99% visible light transmittance and low light decay. It has much better UV resistance and antiblue properties than OLS1000.

OPTOLINQ OLS-1211 has been developed for applications that will not be exposed to temperatures above 125°C but it can pass the SMD reflow process at 260 °C. It has been used extensively for low-power LED encapsulation, automatic LED casting, and potting of large optoelectronic modules. It can be colored and diffused by the addition of specific dye and diffusing concentrates.

Product Family
5 kg
Part A Part B

Catalog Product

Unlike other products we offer, the products listed on this page cannot currently be ordered directly from the website.

Technical Specifications

General Properties
Refractive index
Refractive index
The refractive index determines how much the path of light is bent, or refracted, when entering a material. It is calculated by taking into account the velocity of light in vacuum compared to the velocity of light in the material.

The refractive index calculation can be affected by the wavelength of light and the temperature of the material. Even though it is usually reported on standard wavelengths it is advised to check the TDS for the precise test parameters.
Work life @25°C
Work life @25°C
Work life is the amount of time we have to work with a material until it is no longer able to be easily worked and applied on a substrate.

It is based on the change in viscosity and it can rely on the application requirements.
4 hours
Physical Properties
Viscosity is a measurement of a fluid’s resistance to flow.

Viscosity is commonly measured in centiPoise (cP). One cP is defined as
the viscosity of water and all other viscosities are derived from this base. MPa is another common unit with a 1:1 conversion to cP.

A product like honey would have a much higher viscosity -around 10,000 cPs-
compared to water. As a result, honey would flow much slower out of a tipped glass than
water would.

The viscosity of a material can be decreased with an increase in temperature in
order to better suit an application
1,100 mPa.s
Chemical Properties
Water Absorption 0.3 %
Mechanical Properties
Hardness is a dimensionless quantity. There is no direct relationship between measurements in one scale and their equivalent in another scale or another hardness test.
Durometer (Shore D) 85
Thermal Properties
Coefficient of Thermal Expansion (CTE)
Coefficient of Thermal Expansion (CTE)
CTE (Coefficient of thermal expansion) is a material property that is indicative of the extent to which a material expands with a change in temperature. This can be a change in length, area or volume, depending on the material.

Knowing the CTE of the layers is helpful in analyzing stresses that might occur when a
system consists of an adhesive plus some other solid component.
Coefficient of Thermal Expansion (CTE), α1
Coefficient of Thermal Expansion (CTE), α1
CTE α1 (alpha 1) is the slope of the Coefficient of thermal expansion in a temperature range below the Glass transition temperature (Tg).

It explains how much a material will expand until it reaches Tg.
60 ppm/°C
Coefficient of Thermal Expansion (CTE), α2
Coefficient of Thermal Expansion (CTE), α2
CTE α2 (alpha 2) is the slope of the Coefficient of thermal expansion in a temperature range above the Glass transition temperature (Tg).

It explains the extent to which a material will expand after it passes Tg.
183 ppm/°C
Gel Time
Gel Time
Gel time is the time it takes for a material to reach such a high viscosity (gel like) that it is no longer workable.

It is usually measured for different temperature conditions and even though it does not refer to full cure it is advisable to never move or manipulate the material after it reached its gel time since it can lose its desired end properties.
Gel Time @ 160°C / 320°F 125 sec
Glass Transition Temperature (Tg)
Glass Transition Temperature (Tg)
The glass transition temperature for organic adhesives is a temperature region where the polymers change from glassy and brittle to soft and rubbery. Increasing the temperature further continues the softening process as the viscosity drops too. Temperatures between the glass transition temperature and below the decomposition point of the adhesive are the best region for bonding.

The glass-transition temperature Tg of a material characterizes the range of temperatures over which this glass transition occurs.
127 °C

Additional Information

Operating instructions

We recommend to process the product in a clean room at room temperature with a relative humidity lower than 35%.

  1. Preheat Part A to 50-55°C for 2 hours, making sure that you adjust this to the external temperature. Do not preheat for more that 24 hours.
  2. Mix part A with the diffusion agent and the pigment and stir well. Afterwards add Part B in a 100:100 ratio.
  3. To ensure that all the entrapped air bubbles are removed after mixing, the mixture of Part A and B should be done in a vacuum and degassed at 0.1MPa for 10-15 minutes.
  4. Clean and dry the glue injection tool. Use it within 90minutes in room temperature and under tightly sealed conditions, ideally in a vacuum.



It is advised to cure in two stages to reduce thermal stress.

  • The mixture should be cured in the oven within 30 minutes after dispensing.
  • The oven should be already preheated to the curing temperature.
  • After the initial cure is finished the post curing should be carried out within 2 hours, ideally in the same oven.

Cure Schedule

  • 1hour @ 130-135°C + 6-8hours @ 130-135°C
  • 1hour @ 125-130°C + 6-8hours @ 130-135°C
  • 1hour @ 105-120°C + 6-8hours @ 130-135°C


Using Additives

Optolinq OLS-1211 can be mixed with diffusing agents or color pastes to achieve customer-specific purposes.

Recommended quantity of various diffusing agents and color pastes:

  • OPC-R Red Color Paste: 0.1-0.5% by epoxy weight
  • OPC-B Blue Color Paste: 0.1-0.5% by epoxy weight
  • OPC-G Green Color Paste: 0.1-0.5% by epoxy weight
  • ODF-090 Diffusing Agent: 3-5% by weight (LED lamps), 4-8% (LED displays)

For example, ODF would be 100 : 100 : 3~5 for LED lamps


Storage and Handling

OPTOLINQ OLS-1211 is supplied in 5Kg cans and should be kept in a cool and dry place (40% – 75% humidity) away from direct sunlight or temperature extremes. It should not contact any acid and alkali substances. Consult the Safety data sheet for the handling of this product

The product comes in fluorinated drums. Please keep it at 0-30° and use it within the shelf life .After the Can is opened, the unused product should avoid prolonged contact with air. Try to tightly seal the package to ensure its stable performance.

Shelf life at 0-30°C:

Part A: 6 months

Part B: 3 months


Data Ranges

The data contained herein are reported as typical values and/or range values based on actual test data and are verified on a periodic basis. They are reference values and not guaranteed specifications.