Molding Window
Why Determine a Molding Window?Why Determine a Molding Window?
Determine if the part will fill Is pressure low enough?
Small molding window indicates the part will be difficult to produce
May suggest additional gates to reduce pressure Change part design to improve filling
Increase wall thickness
Analysis Inputs RequiredAnalysis Inputs Required Finite Element model
Cavity-based analysis On the part model, no runners
Analysis sequence, Molding Window Material Injection location Process settings
Injection molding machine Mold temperature Melt temperature Injection Time All can be defined but
normally defaults are used
Analysis GuidelinesAnalysis Guidelines
In the Advanced dialog, the parameters that control the molding window size can be set Feasible molding window limits Preferred molding window limits
Results AvailableResults Available
Results Summary Zone 3D XY Graphs
Quality Injection pressure Minimum flow front temperature Maximum shear stress Maximum cooling time Maximum shear rate
Recommended Mold Temperature : 95.00 CRecommended Melt Temperature : 270.00 CRecommended Injection Time : 0.6653 s
Interpreting the ResultsInterpreting the Results
Basic procedure for viewing results Results summary file
• Look at recommended conditions Zone plot
• Get a sense of the size of the molding window Quality XY plot
• Set X axis to Injection time, & set mold and melt to recommended• Decide to keep recommended or determine alternative conditions
Injection pressure XY• Set X axis to Injection time, & set mold and melt to conditions used• Check if pressure is too high
Minimum flow front temperature• Set X axis to Injection time, & set mold and melt to conditions used• Determine injection time of a 0ºC, 10ºC and 20ºC temperature drops• Decide on injection time to use
Check remaining plots for problems
Results Summary FileResults Summary File Review the results summary file for the
recommended molding conditions Becomes basis for
viewing results Compare to
temperatureranges analyzed
Zone PlotZone Plot
Use cutting plane tool for manipulating
Turn on all 3 planes Make Active (move) the
planes to see window Look for window size
More green the better When done turn off all
planes
Quality PlotQuality Plot
Set X axis to time in result properties Set mold and melt to recommended Decide if recommended conditions are
practical In middle of the range? Move mold and melt
sliders to see effect onquality
Pick mold and melt to use Query max quality for
time
Injection pressureInjection pressure
Set X-axis to injection time Make sure pressure not too high
Most machines the design limit should be 80 MPa Check at specific conditions by query
• Pick on curve to find injection time
Minimum Flow Front TemperatureMinimum Flow Front Temperature
Set X-axis to injection time Query graph to find the flow front temperature equal
to the melt temperature This will be the injection time where the quality is the
highest Query to find 10ºC & 20ºC
temp drops Represents good window 10ºC the middle 20ºC the end
Check Remaining PlotsCheck Remaining Plots
Check to make sure no problems are present In particular make sure the shear stress is below the
design limit in the database
Shear Rate Cooling Time
Shear Stress
Material Use Honeywell Plastics, Capron 8333G HS
Gate locations Center gate
Design Criteria 2-plate tool Determine optimum
processing conditionsfor the given gate location
Practice, CoverPractice, Cover
Optional modelsOptional models Cell Phone
Material• PC+ABS, Bayer AG Bayblend FR 2000 V-0/1.6
Design Criteria• Determine which gate location is best, center or end gate
Door Panel Materials
• ABS, Bayer AG Novodur L3FR• ABS, GE USA Cycolac T-XC 30001
Design Criteria• Determine which material is going to work best
QUESTIONS?QUESTIONS?