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Ø Ø Alpha1 Ø alpha2
) ) (LTEC)
alpha2 (mm/C)
alpha1 (mm/C)
Ø
E1
E2
ØE
E1
E2 E1
Ø Ø
E1 E1
E2 E2
E2
Ø Ø
Impact Strength
Chapter 3
Ø Ø Ø
-
Melt
Melt
VS.
80
Optimal Fill
Maximum Injection Pressure (MPa)
Cartridge Heater
Shut-Off Pin
Heater
Gate
Melt Cavity Melt
Melt
/
Material
ABS, SAN Acetal Acrylic Cellulosics Ionomer Nylon Polycarbonate Polyester Polyethylene Polypropylene PPO Polysulfone Polystyrene PVC
650 640 630 620 610 600 590 5000 650 640 630 620 610 600 590 5000
0.075” thickness
10000
15000
20000
10000
15000
20000
Injection Pressure (psi)
Injection Pressure (psi)
Thanks!
Ø Under packing
Twisted shape
Ø
Pack Time
Shrinkage
Ø
Ø
Shrinkage Melt Temperature
Ø
Ø
Shrinkage
Ø
Mold Temperature
Warm
Ø
Ø
Cold
Chapter 5
Ø Ø Ø Ø Ø
Gates
Weld lines
High resistance to flow Viscosity (Pa-s) Material Water Viscosity 10-1 10 Polymer 10,000 Glass 1020 Shear Rate (1/s)
Increasing temperature
Low resistance to flow
High MFV
Hale Waihona Puke Baidu
Low MFV
time = t1
time = t2
/
Ø Ø Ø Ø Ø
Higher Pressure
Lower Pressure
Chapter 4
Ø
Shrinkage
Ø
Pack Pressure
Ø
Warpage
Ø
Pack Pressure
Ø Over packing
(Dome Shape)
Better Design
Shrinkage
Wall Thickness
High Shrinkage
High Cooling Rate Low Crystallization Level
Low Cooling Rate High Crystallization Level
Warped Part
Ø Ø Ø
Injection Molding Process
(Cure Time)
X
=
Chapter 2
Ø Ø
Amorphous
Ø Ø
Semi-crystalline
v , , v , “ ”
Frozen Layer
Mold Wall
Fountain Flow Region
Mold Wall
Ø Ø
Ø
Ø
Uniform Molecular/Fiber Orientation Less Part Warpage
Chapter 6
Higher Pressure
Lower Pressure
Shrinkage Gate Diameter/Thickness
3
Nozzle Frozen Layer
Chapter 1
22
Sec.
1 9 10 2
Hopper Barrel
Screw Mold
“
”
“
”
Screw is applying a specified pressure to the polymer melt in order to pack more plastic into the cavity. Also called “compensation stage”.
Lower Pressure
Melt Temperature (F)
650 640 630 620 610 600 590
,
5000
10000
20000
Injection Pressure (psi)
0.100” thickness Melt Temperature (F) Melt Temperature (F)
Low MFR Material
W
High MFR Material
W
Higher Pressure
Lower Pressure
Ø Ø Ø
Thin-Wall
Ø
Inj. Pressure and Clamp Force
PMMA
Hi Viscosity
PP
Low Viscosity
Ø
PP
Low MFR
Ø Ø Ø
Cooling CoolingTime Time~ ~
2 (Heaviest (HeaviestWall WallThickness) Thickness)2 Thermal ThermalDiffusivity Diffusivityof ofthe theMelt Melt
Original Design
60
Time Range
40
20
0
4
8
12
16
20
Fill Time (sec)
Ø
Higher Pressure
Lower Pressure
Constant Speed
Ram Speed % Ram Speed %
Profiled Speed
Stroke %
Stroke %
MFA @ time = t1 MFA @ time = t2
Max. Flow Length (in)
20 15 10 5 0 0.020
0.040
0.060
0.080
0.100
0.120
Part Thickness (in)
Ø Ø Ø
Ø Ø
More Cooling & Drag Force Less Cooling & Drag Force
Higher Pressure
Thick Part
Warped Part
Uniform Thickness
Ø Ø
Thin Part Thick Part
Higher Pressure
Lower Pressure
GE Plastics/PC Lexan 101 Melt temperature: 624(F)
25
Pressure (psi) 22050 17985 13923 9863
Diameter (mm.)
4.7 - 9.5 3.1 - 9.5 7.5 - 9.5 4.7 - 9.5 2.3 - 9.5 1.5 - 9.5 4.7 - 9.5 4.7 - 9.5 1.5 - 9.5 4.7 - 9.5 6.3 - 9.5 6.3 - 9.5 3.1 - 9.5 3.1 - 9.5
Max. Flow Length (in)
20 15 10 5 0 0.020
0.040
0.060
0.080
0.100
0.120
Part Thickness (in)
Ø
Ø Ø
Ø
Ø
Core Shaft
Ø Ø Ø Ø
Ø Ø Ø
Not Recommended
Ø Ø Ø
Ø Ø
Ø
Non-uniform Molecular/Fiber Orientation More Part Warpage
Ø
Rib
ü ü ü
Ø
Ø
Chapter 8 CAE MoldFlow
Moldflow (CAE) 1976 CAE Moldflow
MF/Flow MF/Cool MF/Warp MF/Stress MF/Shrink MF/Optim MF/Gas MF/Fiber MF/Midplane MF/Tsets
Diameter (in.)
0.187 - 0.375 0.125 - 0.375 0.312 - 0.375 0.187 - 0.375 0.093 - 0.375 0.062 - 0.375 0.187 - 0.375 0.187 - 0.375 0.062 - 0.375 0.187 - 0.375 0.250 - 0.375 0.250 - 0.375 0.125 - 0.375 0.125 - 0.375
specific volume;T–
temperature
Specific Volume
∆ν
B
Specific Volume
Increasing Pressure
Crystallization Phase A
A
∆ν
B
Temperature
PVT
Temperature
PVT
Ø alpha1 ( alpha2 (
< 8
(Runner Balance analysis)
(Family mold)
(Din)
(φ )
Dia.
Taper Angle
φ
( Shape Factors)
A
(deq) = 2 Shape Factor =
p
A
=
pd
b
A
θ
deq
a
Chapter 7
Ø Ø Ø Ø Ø Ø
Ø Ø Ø
Fill Time (sec)
Ø Ø “thermal diffusivity”
Change Cooling Time
k α = ρ ⋅Cp
Thermal Conductivity (k) Specific Heat (Cp) Density (p)
PVT
Ø p– Ø Ø Ø
pressure;
v–
Ø Ø
Flow Length
Long Flow Length
Short Flow Length
Higher Pressure
Lower Pressure
GE Plastics/PC Lexan 101 Melt temperature: 624(F)
25
Pressure (psi) 22050 17985 13923 9863
) ) (LTEC)
alpha2 (mm/C)
alpha1 (mm/C)
Ø
E1
E2
ØE
E1
E2 E1
Ø Ø
E1 E1
E2 E2
E2
Ø Ø
Impact Strength
Chapter 3
Ø Ø Ø
-
Melt
Melt
VS.
80
Optimal Fill
Maximum Injection Pressure (MPa)
Cartridge Heater
Shut-Off Pin
Heater
Gate
Melt Cavity Melt
Melt
/
Material
ABS, SAN Acetal Acrylic Cellulosics Ionomer Nylon Polycarbonate Polyester Polyethylene Polypropylene PPO Polysulfone Polystyrene PVC
650 640 630 620 610 600 590 5000 650 640 630 620 610 600 590 5000
0.075” thickness
10000
15000
20000
10000
15000
20000
Injection Pressure (psi)
Injection Pressure (psi)
Thanks!
Ø Under packing
Twisted shape
Ø
Pack Time
Shrinkage
Ø
Ø
Shrinkage Melt Temperature
Ø
Ø
Shrinkage
Ø
Mold Temperature
Warm
Ø
Ø
Cold
Chapter 5
Ø Ø Ø Ø Ø
Gates
Weld lines
High resistance to flow Viscosity (Pa-s) Material Water Viscosity 10-1 10 Polymer 10,000 Glass 1020 Shear Rate (1/s)
Increasing temperature
Low resistance to flow
High MFV
Hale Waihona Puke Baidu
Low MFV
time = t1
time = t2
/
Ø Ø Ø Ø Ø
Higher Pressure
Lower Pressure
Chapter 4
Ø
Shrinkage
Ø
Pack Pressure
Ø
Warpage
Ø
Pack Pressure
Ø Over packing
(Dome Shape)
Better Design
Shrinkage
Wall Thickness
High Shrinkage
High Cooling Rate Low Crystallization Level
Low Cooling Rate High Crystallization Level
Warped Part
Ø Ø Ø
Injection Molding Process
(Cure Time)
X
=
Chapter 2
Ø Ø
Amorphous
Ø Ø
Semi-crystalline
v , , v , “ ”
Frozen Layer
Mold Wall
Fountain Flow Region
Mold Wall
Ø Ø
Ø
Ø
Uniform Molecular/Fiber Orientation Less Part Warpage
Chapter 6
Higher Pressure
Lower Pressure
Shrinkage Gate Diameter/Thickness
3
Nozzle Frozen Layer
Chapter 1
22
Sec.
1 9 10 2
Hopper Barrel
Screw Mold
“
”
“
”
Screw is applying a specified pressure to the polymer melt in order to pack more plastic into the cavity. Also called “compensation stage”.
Lower Pressure
Melt Temperature (F)
650 640 630 620 610 600 590
,
5000
10000
20000
Injection Pressure (psi)
0.100” thickness Melt Temperature (F) Melt Temperature (F)
Low MFR Material
W
High MFR Material
W
Higher Pressure
Lower Pressure
Ø Ø Ø
Thin-Wall
Ø
Inj. Pressure and Clamp Force
PMMA
Hi Viscosity
PP
Low Viscosity
Ø
PP
Low MFR
Ø Ø Ø
Cooling CoolingTime Time~ ~
2 (Heaviest (HeaviestWall WallThickness) Thickness)2 Thermal ThermalDiffusivity Diffusivityof ofthe theMelt Melt
Original Design
60
Time Range
40
20
0
4
8
12
16
20
Fill Time (sec)
Ø
Higher Pressure
Lower Pressure
Constant Speed
Ram Speed % Ram Speed %
Profiled Speed
Stroke %
Stroke %
MFA @ time = t1 MFA @ time = t2
Max. Flow Length (in)
20 15 10 5 0 0.020
0.040
0.060
0.080
0.100
0.120
Part Thickness (in)
Ø Ø Ø
Ø Ø
More Cooling & Drag Force Less Cooling & Drag Force
Higher Pressure
Thick Part
Warped Part
Uniform Thickness
Ø Ø
Thin Part Thick Part
Higher Pressure
Lower Pressure
GE Plastics/PC Lexan 101 Melt temperature: 624(F)
25
Pressure (psi) 22050 17985 13923 9863
Diameter (mm.)
4.7 - 9.5 3.1 - 9.5 7.5 - 9.5 4.7 - 9.5 2.3 - 9.5 1.5 - 9.5 4.7 - 9.5 4.7 - 9.5 1.5 - 9.5 4.7 - 9.5 6.3 - 9.5 6.3 - 9.5 3.1 - 9.5 3.1 - 9.5
Max. Flow Length (in)
20 15 10 5 0 0.020
0.040
0.060
0.080
0.100
0.120
Part Thickness (in)
Ø
Ø Ø
Ø
Ø
Core Shaft
Ø Ø Ø Ø
Ø Ø Ø
Not Recommended
Ø Ø Ø
Ø Ø
Ø
Non-uniform Molecular/Fiber Orientation More Part Warpage
Ø
Rib
ü ü ü
Ø
Ø
Chapter 8 CAE MoldFlow
Moldflow (CAE) 1976 CAE Moldflow
MF/Flow MF/Cool MF/Warp MF/Stress MF/Shrink MF/Optim MF/Gas MF/Fiber MF/Midplane MF/Tsets
Diameter (in.)
0.187 - 0.375 0.125 - 0.375 0.312 - 0.375 0.187 - 0.375 0.093 - 0.375 0.062 - 0.375 0.187 - 0.375 0.187 - 0.375 0.062 - 0.375 0.187 - 0.375 0.250 - 0.375 0.250 - 0.375 0.125 - 0.375 0.125 - 0.375
specific volume;T–
temperature
Specific Volume
∆ν
B
Specific Volume
Increasing Pressure
Crystallization Phase A
A
∆ν
B
Temperature
PVT
Temperature
PVT
Ø alpha1 ( alpha2 (
< 8
(Runner Balance analysis)
(Family mold)
(Din)
(φ )
Dia.
Taper Angle
φ
( Shape Factors)
A
(deq) = 2 Shape Factor =
p
A
=
pd
b
A
θ
deq
a
Chapter 7
Ø Ø Ø Ø Ø Ø
Ø Ø Ø
Fill Time (sec)
Ø Ø “thermal diffusivity”
Change Cooling Time
k α = ρ ⋅Cp
Thermal Conductivity (k) Specific Heat (Cp) Density (p)
PVT
Ø p– Ø Ø Ø
pressure;
v–
Ø Ø
Flow Length
Long Flow Length
Short Flow Length
Higher Pressure
Lower Pressure
GE Plastics/PC Lexan 101 Melt temperature: 624(F)
25
Pressure (psi) 22050 17985 13923 9863