Premature Cure Indication for QwikSeal® Pre-Sealed Fastener Technology; Topic #DLA08-01

Systems and Materials Research Corporation (SMRC) has developed a proprietary process called QwikSeal for pre-coating fasteners with cure-blocked sealant, then overcoating the pre-applied sealant with a moisture-impermeable size coat. QwikSeal is designed to replace the current “wet installation” process where sealant is mixed and applied to each fastener at the point of installation, and which is time-consuming, messy, wasteful, and inconsistent. In Phase I, SMRC developed premature cure indicators (PCIs) using selectively-tuned molecular probes that change color on exposure to specific reactive groups on the sealant resin, providing a very early and direct sign of sealant cure state. Successful PCI development could clear the way for large-scale entry of QwikSeal into the aerospace marketplace through PPG Aerospace, SMRC’s commercialization partner. Three dyes have been selected for further development in Phase II: each one changes color only in the presence of the appropriate reactive groups, exhibits an obvious color change, and is readily detected by the naked eye in ambient light. Activities in Phase II will focus on ensuring the long-term stability and accuracy of the PCI, synthesis scale-up, incorporating the PCI into the QwikSeal system, and maximizing the shelf life of the QwikSeal sealant.