Plastics 4.0. Engineering Passion Seite 1

Transcription

1 Plastics 4.0 Engineering Passion Seite 1

2 Engineering Passion Seite 2 APC plus Adaptive Process Control

3 Engineering Passion APC plus Resilient processes, even at high recyclate concentrations Hans Malinowski, Competence Forum, Munich,

4 Seite 4 Product quality and it s influencing factors Potential causes for an instable process Changing ambient conditions -- Seasons -- Day & Night -- Temperature & Humidity Changing flow resistances - Mold venting - Cooling & Tempering - Non-return valve / Hot-runner Changing material quality - Batch variations Additives / Masterbatch - Recyclate / Moisture The human factor - Availability - Qualification - Method Overcautious settings - Pressures - Temperatures - Times

5 Seite Product quality and it s influencing factors Potential causes for an instable process Plastic material (up to feed zone) Plastic material Variation of the plastic quality (batch fluctuations) Purity degree Polluted greenware/ foreign particles at material charge Humidity Variable moisture content Additives/ reinforcements Quality variations (batches) at masterbatch, recyclate, fibers, fillers Mixing Discontinuous mixing of virgin material and additives Machine Injection Non-return valve Delayed closing of Non-return valve Injection, drive Deviating injectioncurves (actual-values) Holding pressure, drive Deviating holding pressure curves (actual values) Mold tempering Parameter modification of mold tempering and mold cooling Melt temperature Parameter modification of heating zone temperatures Manual settings Injection Parameter modification of injection profile, profile steps Holding pressure switchover Variation of switchover point, stroke-dependent, pressure-dependent Holding pressure Parameter modification of holding pressure profile, profile steps Air draft Local cooling on surfaces through open gates or doors Ambient conditions Solar irradiation Local warming on surfaces through radiant heat CAUSE Ambient air humidity Changes in air humidity, winter, summer, thunderstorms Room temperature Changes in air temperature, winter, summer, internal cooling load Fluctuating melt viscosity Non-return valve Delayed opening of non-return valve Material dwell time Unequal material dwell times due to cycle time fluctuations Back pressure, drive Deviating back-pressurecurves (actual-value) Plasticizing rotation speed Deviating plasticizing rotation speed Heat balance in plasticizing unit Displacement of thermal equilibrium from out-/inside / through cycle time fluctuations Convection at plasticizing unit Increased loss of heat (cooling down) at the cylinder surface Plasticizing cylinder heating Deviating cylinder temperature, control system Mold venting Worse venting due to contamination of the mold parting surface Hot-runner shut-off nozzle Discontinuous opening/ closing characteristics Heat balance in mold Displacement of thermal equilibrium from out-/inside / through cycle time fluctuations Convection at mold Increased loss of heat (cooling) at the mold surface Hot-runner heating Deviating hot-runner temperature, control system, fixed mold half Cooling, tempering Deviating mold cooling temperature, control system Availability QA Delayed quality control (night) due to limited QA-personnel Availability set-up man Delayed parameter adjustment due to limited set-up personnel Motivation Delayed intervention in case of process deviation, unclear responsibility Qualification QA Insufficient qualification for difficult decisions Qualification set-up man Set-up man (operator) is unable to stabilize the process, missing skills Fluctuating flow resistance Fluctuating melt pressure Machine Plasticizing Mold Person

6 Seite 6 The set-up man determines the target process Pressure progression during the injection process Non-return valve is closed Melt is compressed Changeover point Compression phase Injection pressure reference curve Filling phase Holding pressure phase Shot weight Cavity pressure reference curve

7 Seite 7 Deviations in material viscosity are not compensated Conventional: Constant changover point (holding pressure) Non-return valve is closed Injection pressure actual curve Changeover point Viscosity MFI: 11 Injection pressure reference curve p MFI: 6 Risk: Shrink marks Cavity pressure reference curve Shot weight Cavity pressure actual curve

8 Seite 8 Deviations in material viscosity are not compensated Conventional: Constant changover point (holding pressure) Non-return valve is closed Injection pressure actual curve Injection pressure reference curve Changeover point Viscosity MFI: 11 MFI: 19 Injection pressure actual curve Cavity pressure actual curve p Shot weight Risk: Flashes Cavity pressure reference curve

9 Seite 9 Compressibility delays form filling Pressures and velocities during the injection process & Injection pressure 3 4 Velocity flow front Velocity screw Cavity pressure

10 Seite 10 Compressibility delays form filling Pressures and velocities during the injection process & Injection pressure 3 4 Velocity flow front Velocity screw Cavity pressure

11 Seite 11 Compressibility delays form filling Pressures and velocities during the injection process & Injection pressure 3 4 Velocity flow front Velocity screw Cavity pressure

12 Seite 12 Compressibility delays form filling Pressures and velocities during the injection process & Injection pressure 3 4 Velocity flow front Velocity screw Cavity pressure

13 Seite 13 Compressibility delays form filling Pressures and velocities during the injection process & Injection pressure 3 4 Velocity flow front Velocity screw Cavity pressure

14 Seite 14 The compressibility depends on the plastic material Compressibilität of various plastics PP PC PA 6 PA6 GF60

15 Seite 1 APC plus learns the reference process The set-up man determines the target process Non-return valve is closed Start of melt flow in cavity Constant changeover point V Schußgewicht

16 Seite 16 Without APC plus no detection of viscosity deviations Conventionel: Constant changover point (holding pressure) Constant changeover point p V Schußgewicht Too less melt volume in the cavity

17 Seite 17 APC plus corrects viscosity deviations in the same shot Adaptive process control with APC plus Adapted changeover point p p V Schußgewicht Perfect melt volume in the cavity

18 Seite 18 Increase of recyclate propotion with APC plus Example of application on a CX Machine BluePower Vario Drive SPX 10 sprue picker Ejector coupling Quick change system for mold APC (Adaptive Process Control) CX mm Application Crown wheel Mold 4-fold cold runner Material PA 66 GF30 Shot weight 47,9 g Part removal falling parts Sprue removal SPX10 sprue picker Cycle time 1 sec Recyclate proportion 0 % gradually increased to 100%

19 Seite 19 Influence of recyclate proportion on the part weight Praxis example: Increase of recyclate proportion with and without APC plus Part weight in g 39,3 Influence of recyclate proportion on the part weigth with and without APC PA66 GF30 Part weigth APC Part weigth Position Viscosity Viscosity 32 39, , ,20 26 Variation of part weight: 39,1 39, Schußgewicht 39,0 20 0,187 g 0,480 % 39, ,030 g 0,077 % With APC plus 6 times lower part weight variation 38, , , , % 10% 20% 30% 40% 0% 60% 70% 80% 90% 100% Recyclate proportion in % Schußgewicht

20 Seite 20 APC plus compensates different share of recyclate Effectiveness of APC plus 20 % Recyclate 40 % Recyclate Shot weight Adaption Changeover point Adaption Without APC plus With APC plus Without APC plus With APC plus Crate 8 x 2 liter application: crate 8 x 2 liter / shot weight: 217 g / material: PE HD / cycle time: 37,7 s

21 Seite 21 Adaptive process control Potential benefits with APC plus 0 Zero-defect production Easy to handle Your benefit: - Significantly lower reject rates - Constant high part quality Your benefit: - Reduced downtime costs - Easier to use and faster ramp-up Reduce material costs Your benefit: - Enormous cost reduction potential - Increase of recyclate proportion APC COGS Energy & cycle time saving APC plus stabilises the processes and maximize profits

22 Engineering Passion APC plus Resilient processes, even at high recyclate concentrations Hans Malinowski, Competence Forum, Munich,