A polyurethane reaction profile is not a pass/fail lab record. It is a time-based fingerprint of how your polyol, isocyanate, catalyst, water, surfactant, and machine settings interact. Read it as a process signature, and it…
Jiacheng Dai 
What Is Reaction Injection Molding (RIM)? Reaction injection molding (RIM) is a closed-mold polyurethane process that meters two or more low-viscosity reactive liquids into a high-pressure mixing head, mixes them by impingement, and injects the…
Jiacheng Dai 
Pinholes in polyurethane parts rarely announce themselves as a materials crisis; they show up as small surface voids, disappear after a tooling change, and then return with the next supplier lot or the next humidity…
Jiacheng Dai 
A wheel that looks dense on the outside can still fail the first time it reaches its rated load — because the real defects are formed before the mold closes. Cast polyurethane wheels live or…
Jiacheng Dai 
Polyurethane spray application atomizes a metered, heated two-component polyurethane system through a spray gun onto a substrate, where the A-side (isocyanate) and B-side (polyol or amine resin) mix under high pressure and react within seconds.…
Jiacheng Dai 
Most sandwich panel defects—voids under the metal facing, density drift near the edges, poor adhesion after thermal cycling—are locked in before the board reaches the saw. The line amplifies what metering, mixing, and laydown have…
Jiacheng Dai 
Most PU sole problems are created before the first drop of mix reaches the mold. A slightly cold polyol, a drifted metering pump, or a mold that loses temperature at the edge can produce the…
Jiacheng Dai 
Polyurethane potting compounds rarely fail at the dispense head. They fail in the field months later, when thermal cycling has worked a crack into a solder joint, or when moisture found a path through an…
Jiacheng Dai 
Most sealant failures on a production floor do not begin with the polyurethane. They begin with a joint that moves more than expected, a substrate that was not primed, or a one-component bead that was…
Jiacheng Dai A polyurethane adhesive rarely fails because the chemistry is mysterious. It fails because one property — open time, green strength, elongation, or moisture resistance — was matched to a brochure number instead of the real…
Jiacheng Dai 
