Presentation for understanding simulation for blow molding process

1. Applications of Simulation in Blow Molding
Dr. Karel Kouba
Dr. John Perdikoulias
Dhaval Harsora

2. About B-SIM®
• Blow molding simulation software
• Developed by Dr. Karel Kouba in Czech Republic.
• Originally released in 1992 - over 25 years of success!
• Accurate
• Non-Isothermal, Visco-Elastic (K-BKZ material model)
• Easy-to-use
• Fast project set-up
• Fast, stable solvers
• Efficient mesh refinement
• Versatile
• Extrusion blow molding
• Stretch (injection) blow molding

3. Partial List of B-SIM® Customers

4. • Can be used to Optimize
• Polymer and tool material
• Part design
• Tool design
• Parison size and shape
• Parison programming (extrusion BM)
• Rod height (stretch blow molding)
What can you do with simulation?

5. • Can be used to Optimize Polymer material
What can you do with simulation?
ABS HDPE

6. • Can be used to Optimize Polymer material
What can you do with simulation?
ABS
Thickness – 1.33 mm to 4 mm
HDPE
Thickness – 1.48 mm to 4 mm

7. • Can be used to Optimize Tool material
What can you do with simulation?
HTC 500 W/m^2/K HTC 50 W/m^2/K
ABS

8. • Can be used to Optimize Tool material
What can you do with simulation?
HTC 500 W/m^2/K
ABS
Temperature – 149.9°C to 159.8 °C
HTC 50 W/m^2/K
ABS
Temperature – 154.1°C to 159.8 °C

9. • Can be used to Optimize Part Design
What can you do with simulation?
Initial Run Optimized Part Design
Thickness Profile Optimization

10. • Can be used to Optimize Part Design
What can you do with simulation?
Uniform Thickness Non-Uniform Thickness
No Pressure area

11. • Can be used to Optimize Tool Design
What can you do with simulation?
Tool A Tool B

12. • Can be used to Optimize Tool Design
What can you do with simulation?
Tool A Tool B

13. • Can be used to Optimize Parison Size & Shape
What can you do with simulation?
Circular Parison Elliptical Parison

14. • Can be used to Optimize Parison Size & Shape
What can you do with simulation?
Circular Parison Elliptical Parison

15. • Can be used to Optimize Parison programming
What can you do with simulation?
Initial Run Optimized Run

16. • Can be used to Optimize Rod height (ISBM)
What can you do with simulation?
Long Rod Short Rod

17. • Can be used to Optimize Rod height (SBM)
What can you do with simulation?
Long Rod Short Rod
Incomplete forming

18. Predict
• Thickness distribution
• Web and wrinkle formation
• Stress distribution
• Cooling time
What can you do with simulation?

19. • Can be used to Predict Thickness distribution
What can you do with simulation?

20. • Can be used to Predict Web & wrinkle formation
What can you do with simulation?

21. • Can be used to Predict Stress distribution
What can you do with simulation?

22. Stretch Blow Molding
Optimization - Example 1
• Optimization task:
• Find suitable initial preform thickness profile to obtain
almost uniform thickness on the final product (bottle)

23. Stretch Blow Molding
Optimization - Example 1
Initial and optimized preform thickness profile

24. Stretch Blow Molding
Optimization - Example 1
Final thickness profile comparison
0
0.5
1
1.5
2
2.5
3
0 100 200 300 400 500 600
Arc length (mm)
Thickness(mm)
Initial
Optimized

25. Stretch Blow Molding
Optimization - Example 2

26. 0
0.5
1
1.5
2
2.5
3
0 50 100 150 200 250 300
Arc length (mm)
Thickness(mm)
Start
Step 3
Step 6
Step 9
A B
Stretch Blow Molding
Optimization - Example 2
• Automatic optimization results - the final thickness
distributions:

27. 0
1
2
3
4
5
6
0 50 100 150
Arc length (mm)
Thickness(mm)
Original
Optimized
A B
Stretch Blow Molding
Optimization - Example 2
• Original and optimized preform initial thickness
profile:

28. Stretch Blow Molding
Optimization - Example 3
• How the plug final position influences the final
product thickness profile ?

29. Stretch Blow Molding
Optimization - Example 3

30. 0
0.5
1
1.5
2
2.5
3
0 50 100 150 200 250 300
Arc length (mm)
Thickness(mm)
210 mm
220 mm
230 mm
240 mm
A B
Stretch Blow Molding
Optimization - Example 3
• Final thickness profiles for different final positions
of the plug:

31. Extrusion Blow Molding
Optimization - Example 1

32. 0
0.2
0.4
0.6
0.8
1
1.2
0 20 40 60 80 100 120 140 160
Arc length (mm)
Thickness(mm)
Start
Step 3
Step 6
Step 9
A B
Extrusion Blow Molding
Optimization - Example 1
• Automatic optimization results - the final thickness
distributions:

33. 0
0.2
0.4
0.6
0.8
1
1.2
0 10 20 30 40 50 60
Arc length (mm)
Thickness(mm)
Start
Step 3
Step 6
Step 9
A B
Extrusion Blow Molding
Optimization - Example 1
• Automatic optimization results - the final thickness
distributions:

34. 0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
0 20 40 60 80 100 120
Arc length (mm)
Thickness(mm)
Original
Optimized
A B
Extrusion Blow Molding
Optimization - Example 1
• Original and optimized initial thickness profile of
the parison:

35. 0
0.2
0.4
0.6
0.8
1
1.2
1.4
0 5 10 15 20 25 30 35 40 45
Arc length (mm)
Thickness(mm)
Original
Optimized
A B
Extrusion Blow Molding
Optimization - Example 1
• Original and optimized initial thickness profile of
the parison:

36. Extrusion Blow Molding
Optimization - Example 2
• Parison extrusion optimization using AWT (Axial
Wall Thickness control)

37. The axial wall thickness
(AWT) control enables to
adjust the annular die gap
along the length (axis) of
the extruded parison. The
adjusting is achieved by
hydraulic shifting of a
conical core part (mandrel)
in the die.
Extrusion Blow Molding
Optimization - Example 2
• AWT (Axial Wall Thickness control)

38. The maximum value
(100%) specified in the
AWT control settings
corresponds to the
maximum opening of the
extrusion die.
To get the minimum
thickness, setting must be
0%.
Extrusion Blow Molding
Optimization - Example 2
• AWT (Axial Wall Thickness control)

39. Extrusion Blow Molding
Optimization - Example 2
• AWT optimization results - Final thickness

40. Extrusion Blow Molding
Optimization - Example 2
• AWT optimization results - Optimized extruded
parison

41. Extrusion Blow Molding
Optimization - Example 2
• AWT optimization results - Original and optimized
AWT settings

42. Extrusion Blow Molding
Optimization - Example 2
• AWT optimization results - Optimization progress

43. Extrusion Blow Molding
Optimization - Example 3
• Parison extrusion optimization using PWT (Partial
Wall Thickness control)

44. PWT controls allow to vary the
circumferential wall thickness
distribution dynamically over the
parison length. Two servohydraulic
actuators deform the dynamic
flexible deformable ring by pushing
and pulling, so that the required
parison wall thickness is achieved
at every desired point,
circumferentially and axially
Extrusion Blow Molding
Optimization - Example 3
• PWT (Partial Wall Thickness control)

45. • PWT optimization - Final thickness
Initial
Final
Extrusion Blow Molding
Optimization - Example 3

46. • PWT optimization - Final thickness
Initial
Final
Extrusion Blow Molding
Optimization - Example 3

47. • PWT optimization - Final thickness
Initial
Final
Extrusion Blow Molding
Optimization - Example 3

48. Extrusion Blow Molding
Optimization - Example 3
• PWT optimization - optimized extruded parison

49. Extrusion Blow Molding
Optimization - Example 3
• PWT optimization - optimized PWT settings

50. Case studies
• Water tank design
• Windshield Wiper Container

51. B-SIM example (extrusion BM)
• Desing optimization of water tank
Courtesy of Reinold Hagen Stiftung, Germany

52. B-SIM example (extrusion BM)
• Optimization task
• The minimum required final wall thickness is 0.8 mm.
• The tank has to fit into the space in the car

53. B-SIM example (extrusion BM)
• CAD model

54. B-SIM example (extrusion BM)
• Design step 1
• Resulting in a large web

55. B-SIM example (extrusion BM)
• Design step 2 - dividing plane modified
• Web was eliminated
• New results enable to analyze min. thickness

56. B-SIM example (extrusion BM)
• Design step 3 - critical areas analysis
• Areas with the critical thickness determined
• Along the border wall thickness 0.8 mm, a trim line is
assigned, design modified

57. B-SIM example (extrusion BM)
• Design step 4 - new design verification
• Simulation results - the minimal thickness is above 0.8 mm

58. B-SIM example (extrusion BM)
• Windshield Wiper Container - thickness profile
optimization

59. Optimization results
B-SIM example (extrusion BM)

60. Windshield Wiper Container :
Machine Parameters Setting (AWT control)
B-SIM example (extrusion BM)

61. Windshield Wiper Container : Final thickness verification
B-SIM example (extrusion BM)

62. Thank you!
Questions?
Dr. John Perdikoulias
jp@compuplast.biz
Dhaval Harsora
dh@compuplast.biz