Utility Development Corporation

Sealathane High Performance Castable Polyurethane Elastomers

Sealathane 55D Polyurethane Elastomer is designed to provide the easiest processing of all heat cured elastomers currently available on the market. Sealathane 55D is compatible with all processing methods including both compression and injection molding. Sealathane 55D can also be used as an adhesive for plastic and metal bonding, providing an outstanding bond to all surfaces.

Sealathane 55D has been specially designed to allow for room temperature mixing and extended pot life when used with the supplied curative system. Sealathane 55D gives the end user the ability to work with the polyurethane at room or slightly elevated temperatures and obtain uniform mixes that can be degassed without the threat of curing.

Sealathane 55D is supplied as a low viscosity liquid polymer allowing for easy mixing of curative and resin. There is little exotherm experienced when mixing giving the end user the ability to mix large batches of polymer for later use, eliminating the need for expensive automated mixing machines. The mixture can then be deaired under vacuum either at room or a slightly elevated temperature to remove air introduced during the mixing process. The degassed system can then be molded and rapidly cured at temperatures above 250^oF. Use of Sealathane 55D will provide superior performance, reduce processing time, and reduce overall costs.

Sealathane 55D is available in various colors such as white, black, gray, green, red, and blue. Sealathane 55D can also be supplied as a more electrically conductive version by the addition of conductive fillers.

Sealathane 55D is supplied in 1 gallon and 5 gallon kits, containing both the resin and curative..

Typical Properties:

Processing Guidelines

Step 1: Heat the Polymer

Sealthane 55D may crystallize during prolonged storage. If crystallization occurs heat the polyurethane to reduce the viscosity and bring the polymer back to its normal working conditions. Use of a forced air oven and temperatures not to exceed 140^oF are recommended for thawing.

Step 2: Mix the curative

Add the desired amount of curative to the mixing vessel and mix with a large spatula. Mix thoroughly, scraping the sides of the container, to ensure a uniform and homogenous mix.

Step 3: Degas the Mix

Place the mixed system inside a vacuum oven for deairing. To ease the de-airing process, the oven may be heated to a temperature not to exceed 120^oF. It is recommended that the container placed in the vacuum be two to three times larger than the volume of the mix. Pull vaccum until air is removed from the system.

Step 4 Apply Polyurethane Mold Release

Apply a proper amount of mold release onto the molding surface. Sealathane 55D will stick to most metals and requires mold release to remove a finished part. Failure to use mold release will cause sticking to the mold. Stoner E236 Urethane Mold Release has shown good results. The end-user should test any mold release on a small scrap piece before molding.

Step 5 Pour into Mold

The deaired mixture can be poured or injected into a mold for curing. The mold does not need to be pre-heated, but a preheated mold will hasten the curing cycle

Step 6 Cure and Demold the Part

The mixture will need to be cured for an adequate amount of time to build up enough green strength to remove from the mold. UDC recommends 25 minutes at 250^oF, but complex shapes and large sizes will require more time. Once the polymer has built up enough strength it may be removed from the mold.

Step 7 Post Cure

In order to obtain optimum properties Sealathane 55D should be post cured at 200^oF for 8 hours.

For more information about our Sealathane castable resin systems, please email or call at (973)994-4334.