Siemens SIMATIC 505 - Plastic Injection Molding Machine Control Points, Machine Configuration; Injection, Pack and Hold, and Plasticate Profiles for Output Configuration

Installation and Startup
3-4
Machine Configurations (continued)
Mold
Hopper
Heater bands melt
pellets to liquid plastic
Screw motor
Injection ram
Ram
position
sensor
Clamp
actuator
Mold
position
sensor
0–10V
0–10V
Clamp end
of machine
Water circulates
to cool and solidify
plastic in mold
Injection end
of machine
Pressure control valve
Pressure
Transducer
System
pressure
Flow (velocity)
control valve
0–10Vdc
Flow signal
0 +10Vdc output
0 2000psi
UP
PU
System
pressure
Pressure
transducer
0 +10Vdc output
0 2000psi
Figure 3-3 Plastic Injection Molding Machine Contr ol Points, Machine Configuration 3
T able 3-1 Injection, Pack and Hold, and Plasticate Pr ofiles for Output Configuration 3
Velocity
Calculation
Pressure
Calculation
Resultant Operation for Output Configuration 3 Only
Open loop Open loop Open loop ram velocity setpoint
Open loop Closed loop Closed loop hydraulic pressure output
Closed loop Open loop Closed loop hydraulic flow output
Closed loop for
inject and pack and
hold profiles
Closed loop for
inject and pack and
hold profiles
If hydraulic pressure < pressure setpoint, then closed
loop output flow; if pressure > pressure setpoint, then
closed loop output pressure
Closed loop for
plasticate profile
Closed loop for
plasticate profile
If current step pressure setpoint ≥ 32000, then closed
flow profile is executed for the step; otherwise, a closed
loop pressure profile is executed
Note: See input/output configurations, T able 3-2.