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Liquid injection molding II. Mechanical design and characterization of a RIM machine
Author(s) -
Malguarnera Salvatore C.,
Suh Nam P.
Publication year - 1977
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.760170210
Subject(s) - hydraulic accumulator , gear pump , materials science , accumulator (cryptography) , ball valve , volumetric flow rate , mechanical engineering , molding (decorative) , polyurethane , discharge pressure , distillation , composite material , pressure head , peristaltic pump , ball (mathematics) , mechanics , engineering , computer science , chromatography , chemistry , mathematical analysis , physics , mathematics , algorithm , gas compressor
A unique liquid injection molding machine for polyurethane was designed and built to process a large quantity of polyurethane in a short period of time. This machine has a continuously variable flow rate. Using inexpensive, low capacity gear pumps, 5 gallon hydraulic accumulators were charged with fluid components. The fluid can be pumped into the accumulators at low pressure followed by nitrogen gas addition to the bladders to raise the fluid pressure, or the charging pumps can pump up the accumulators against an existing pressure. The two components were then discharged under pressure through linkage activated ball valves and mixed together in a mixing chamber. The system provided for a very low pressure loss during discharge, resulting in high fluid velocity. Extremely high flow rates were possible: approximately 1440 lb/min at 2500 psi, a pressure less than the maximum possible system pressure. This system delivers large flow rates of high quality urethane while still maintaining its simplicity, light weight, and relative low cost.