PROCESS

• Two liquid reactants - polyi socyanate component and resin mixture - are held in separate temperature controlled feed tanks equipped with agitators. From these tanks, the polyol and isocyanate are fed through supply lines to metering units that precisely meter the reactants, as high pressure, to the mixhead.
  
• When injection begins and valves in the mixhead open, the liquid reactants enter a chamber in the mixhead at pressures between 1,500 and 3,000 psi where they are intensively mixed by high-velocity impingement.
  
• From the mix chamber, the liquid flows into the mold at approximately atmospheric pressure and undergoes an exothermic chemical reaction, forming the polyurethane polymer in the mold.
  
• Shot and cycle times vary, depending on the part size and the polyurethane system used.
  
• An average mold for an elastomeric part may be filled in one second or less and be ready for demolding in 30- 60 seconds.
  
• Special extended gel time polyurethane RIM systems allow the processor to fill very large molds using equipment originally designed for molds with smaller volumes.