rtexer

The Problem: MHR was recently involved in troubleshooting a RIM machine that was showing erratic flow rates on the ISO line. (It's always the ISO line, isn't it?). The machine is set up with a variable speed frequency drive that controls the motor speed, and hence the pump flowrate, based on the measured flowrate and the desired target flowrate. The actual flowrate was varying significantly due to the inaccurate readings from the flowmeter. The flowmeter in question was a gear style...

Calibrating two streams at a time offers major advantages, and many RIM manufacturers are not aware it is possible to calibrate with both streams running at the same time.

The Importance of Orifice Sizing Orifice sizing is vital for achieving the best mix quality of two-part polyurethane foam in a Reaction Injection Molding (RIM) operation. Several factors influence the overall injection pressure of your system, and the orifice is the final point before mixing takes place. Each polyurethane chemical supplier provides a datasheet detailing the ideal injection pressure for your specific chemistry. Other critical considerations include the chemical temperature and...