Influence of injection molding parameters on warpage

Transcription

1 Influence of injection molding parameters on warpage Janez Turk, Marko Kolenc, Hella Saturnus Slovenija 9. Forum Operativne Odličnosti,

2 Agenda Part 1: Introduction of the company. Part 3: Case study. Part 2: Theoretical buildup. 2

3 Part 1 Introduction of the company Opel Insignia LED headlamp Renault Twingo headlamp Renault Traffic headlamp BMW mini (FL + DRL + PO) Porsche Macan Basic (PO + DI) VW Golf A7 R Line (FL + CO) 3

4 Part 2 Theoretical buildup Introduction to warpage Pack pressure and global shrinkage Pack pressure and local shrinkage Manipulation of warpage 4

5 Origin of warpage 5

6 Effect of packing pressure value Value of global shrinkage is determined by pressure at transition temperature. Pressure induces compression which counters thermal contraction 0.66% 0.54% 0.44% Molten Solid 30 MPa 45 MPa 60 MPa 6

7 Flat pack pressure End of fill end of equilization 7

8 Falling packing pressure End of fill Equilization End of pack 8

9 Sharp rise in packing pressure 0 s 1.5 s 2.5 s 9

10 Two different features 1.25 mm 0.75 mm 2 mm <2.0 s 2.5 s 3.0 s 10

11 Complex geometry 0 s 2.0 s 2.5 s 3.0 s 11

12 Part 3 Case study Situation briefing From simulation to the machine What about cooling? Packing pressure profile Machine hydraulic response time Produced parts 12

13 Foglamp Cover Lens CAD: wall thickness Wall thickness ratio to avoid sink marks. Material: Polycarbonate. DD mesh. Initial simulation: Results of warpage with default simulation parameters Warpage problem was Identified Direction of warpage was also problematic (assambly process) 13

14 Production vs. simulation I Initial process parameters set in production We align the parameters of production and simulation. Deflection: Comparison between produced part and simulation result 3D SCAN SIMULATION Good matching between simulation and reality. Deflection amplitudes on produced part are lower. 14

15 Influence of cooling Looking for improvements with adjusting mold temperatures. 30 C temperature difference between FS and MS. Coolant temperatures Deflection No potential for improvement. 15

16 Influence of packing phase, simulation Deflection With pack profile we were not only able to decrease warpage, but also to change its direction. 16

17 Production vs. Simulation II Optimised packing profile from simulation was used in production. Deflection: Comparison between produced part and simulation result 3D SCAN SIMULATION Parts is predeformed. Difference between reality and simulation has increased. 17

18 Machine hydraulic response time Default settings Packing profile 0.01s Deflection results with several machine hydraulic response time 0.01s 0.10s 0.10s 0.50s 0.50s We can see big influence on warpage results. 18

19 Final produced parts Conclusions Packing pressure is big contributor to deflection result. Packing pressure can change direction of warpage. With complexity of the packing profile (injection parameters) gap between simulation and reality is increasing. Accuracy of simulations is influenced by many factors Final optimisation should be done in production. 3D scans of produced parts 19

20 Thank you for your attention Questions? 20