ST-512 Vari-Gel Injection Resin

ST-512 Product profile summary
STRATATHANE ST-512 Vari-Gel Injection Resin is an MDI-based hydrophilic polyurethane mixed with water at the work site to form a single injection material with a very short gel time which will handle large amounts of water. ST-512 reacts with water to gel at any temperature above freezing and will accommodate seawater and high concentrations of minerals. The resultant gel is chemically stable and non- biodegradable. The ST-512 backbone is similar to ST-504 but has been optimized to produce a strong rapid-setting gel.

Stratathane ST-512 contains no measurable amount of TDI as performed by the Modified Analysis for Diisocyanates. ST-512 is non-flammable, non-carcinogenic, and non-corrosive as defined by 40 CFR and as described in the NIOSH Pocket Guide for Hazardous Materials.

ST-512 is often used when heavy flows of cold water must be stopped, when a water-reactive gel with a closely controlled set time is needed, and where a flexible seal is preferred. ST-512 is injected directly from the container by blending the polymer with water in the desired ratio using twin stream pumping equipment. During injection, ST-512 mixes with water, expands slightly as it gels for some water ratios, and fills the leak path with a tight seal that is strong, chemically stable and which immediately stops water entry.

The expansive nature of ST-512 at certain water:resin ratios is a significant feature in its ability to stop water leakage. Depending on conditions at the leak site, the end product state desired for the ST-512 may vary from a soft to a very dense gel. Normally, the ratio of water to resin will be about 10:1, but up to about 15:1 is quite usable. The viscosity of the solution after water is added is not much greater than that of water itself. If the injected area contains water, ST-512 either displaces the water or incorporates it into the gel mass as it sets.