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?