| After dispensing, encapsulants are cured at room temperature or
by heat, depending on the specific product being used (see the Encapsulants Family Data Sheets for curing details of individual products).
These encapsulants will cure in thin or thick section and can cure when
confined. Encapsulants can be inhibited by certain materials due to the
type of catalyst used, resulting in poor or incomplete cure. For more
specifics, please refer to the Gels and Encapsulants Processing
Tutorial. |  |
For best results, units to be encapsulated or potted should be clean of
grease, oil and other surface contaminants. Common cleaners for substrate
preparation include Dow Corning’s line of OS Fluids, isopropyl alcohol, toluene
and acetone.
 | A room temperature cure process can be used for most of the
standard encapsulants. After being mixed and applied, the encapsulant is simply
allowed to cure at ambient room conditions. Most products will require several
hours to cure or need to be left undisturbed overnight. Room temperature curing
processes are more appropriate for low to medium volume production
applications. There are a few encapsulants that are designed for rapid
room temperature processing. Refer to the Encapsulants Family Data Sheet for typical curing times of individual
products. |
For standard encapsulants, a separate priming step may be required for good
adhesion to the substrate to with stand temperature cycles. Primerless
encapsulants are available but require heat to cure. For more information
on selecting the right Dow Corning Primer for your substrate and material and
for application guidelines, please refer to “ Dow
Corning ® Brand Primers, Prime Coats and Adhesion Promoters”.
| For any of the heat curing encapsulants, heating
will accelerate the cure rate. For the Standard Encapsulants, heat
acceleration occurs at any temperature above room temperature. For
Self-Priming Encapsulants, cure and the development of adhesion are not
achieved until the material is heated above 100°C. Higher temperatures
will result in faster cure. Limitations on cure speed are generally
dependent on the temperatures that the unit and components are able to
withstand. Heat curing can be done in a batch or conveyor oven. |
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