Page 11 - Injection Molding Advanced Troubleshooting Guide
P. 11
XII Contents
11 Hot Runners ............................................... 95
11.1 Hot Runner Advantages ....................................... 95
11.2 Heaters and Thermocouples ................................... 95
11.3 Hang Up Areas .............................................. 96
11.4 Hot Drop Tips ................................................ 96
11.5 Drooling, Stringing, and Sprue Sticking .......................... 97
11.6 Freeze Off ................................................... 97
11.7 Orifice Size .................................................. 97
11.8 Leakage .................................................... 98
11.9 Zones and Wiring ............................................ 99
11.10 Hot Runner Troubleshooting ................................... 99
12 Cavity Balance ............................................. 101
12.1 Flow Length ................................................. 103
12.2 Flow Diameter ............................................... 103
12.3 Shear ....................................................... 103
12.4 Cooling ..................................................... 105
12.5 Venting ..................................................... 106
12.6 Clamp Pressure .............................................. 106
12.7 Cavity Fill Balance Study . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
12.8 Artificial Balance ............................................. 108
12.8.1 Family Molds ......................................... 109
13 Cavity Instrumentation ..................................... 111
13.1 Cavity Pressure Technology .................................... 111
13.2 Cavity Thermocouples ........................................ 118
13.3 Process Documentation ....................................... 121
13.4 Process Control .............................................. 122
13.5 Additional Monitoring Options ................................. 123
14 Mold Cooling ............................................... 125
14.1 Mold Cooling Importance ...................................... 125
14.2 Water Flow .................................................. 126
14.3 Documentation .............................................. 127
