WORKSHOP P I M. Powder Injection Moulding

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Darleen Lane
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1 WORKSHOP Mikkelissä ke P I M Powder Injection Moulding

3 Definition of PIM PIM MIM Injection moulding of metal powders Wittmann Group Injection moulding of powders CIM Injection moulding of ceramic powders KIRSCH Edmund /

4 PIM process Powder Binder Mixing Pelletizing Feedstock Injection Moulding Green Part Debinding Brown Part Sintering Finished Part

5 PIM process Advantages of PIM realisation of complex shapes reproducible quality and economical production of high numbers high quality standard clean production and nearly no waste

6 PIM process Material characteristics high shrinkage (around 15%) jetting high thermal conductivity separation of powder and binder multi step process abrasive Rules as in plastics injection moulding - but some more.

separation of powder and binder multi step process

7 Typical PIM materials Metals Fe-Alloys steels (316L, 42 CrMo 4,...) hard metals (WC/Co) non ferrous metals (Titanium, Tungsten) Ceramics: Al 2 O 3, ZrO 2 SiC, SiN, AlN

8 Binder systems Polyolefin- / wax mixtures Thermoplastics Other: Thermoset, Agar,...

9 Binder Requirements for mixing low viscosity of binder components good adhesion to the powder good wetting ability for a homogenous mixture with a low shear rate chemical stability no migration of binder components storage stability low energy requirements

a homogenous mixture with a low shear rate chemical stability

10 Binder Requirements for debinding simple and complete debinding non-toxic and no corrosive end products low ash content low metallic residues after debinding decomposition temperature higher than injection moulding temperature selective debinding of particular binder components is possible

residues after debinding decomposition temperature higher than injection

11 PIM process Powder Binder Mixing Pelletizing Feedstock Injection Moulding Green Part Debinding Brown Part Sintering Finished Part

12 Injection moulding machines for PIM conventional PIM special PIM processes and highest precision Micro Injection Moulding

13 Injection moulding machines for PIM Standard machine + MIM Package

14 Machine characteristics for PIM MIM Package: 03.G04 Wear and corrosion resistant screw and barrel in lieu of standard 93.D21 Screw in special geometry for processing MIM 93.E63 special Shut off ring with reduced outer diameter for processing MIM

15 Machine characteristics for PIM Wear mechanisms feeding zone (solid granules) transition zone (solid granules + high viscous flow) melt (viscous flow)

16 Machine characteristics for PIM Wearing on a Standard plastic screw Zylinder Materialfluss (After 1 year production with PIM material)

17 Machine characteristics for PIM Highly abrasion resistant materials Conventional Steel Special Steel Grade abrasion resistant

18 Machine characteristics for PIM MIM Package: execution of nozzle and nozzle head for screw tip cleaning from front side

19 Machine characteristics for PIM barrel change from the front side on small machines Quick barrel change in EcoPower with cleaning position option

20 Machine characteristics for PIM Electrical or fluid heater bands bar Periodical up and down in temperature leads to inconsistent cavity pressure => for low-temperature (<100 C) binder systems fluid heater bands are recommended Shot no. Max. Cavity Pressure Switch over pressure Max. Injection Pressure

low-temperature (<100 C) binder systems fluid heater bands are recommended 0 1 4 7 10 13 16

21 Machine characteristics for PIM MIM Package: 04.A42 Front side gate safety system for manual part removal incl. clearance of ejector and core pull movements

22 Machine characteristics for PIM Options recommend : Pressure sensor at the noozle Temperature sensor at the noozle Pressure sensor at mould for cavity pressure

23 Machine characteristics for PIM Options recommend : Vacuum pump

24 PIM Process Defects To avoid this problems you need knowledge of all steps in the process

26 PIM process Quality monotoring VISION SYSTEM: PowerVision Control center integrated in machine controller Thickness Measurement Weight Measurement

27 Injection process Simulation of the filling phase W-Cu Al 2 O 3 Quelle/Source: ARCS

28 Injection process Simulation of the filling phase t F =0.01s t F =0.02s t F =0.04s t F =0.06s t F =0.08s t F =0.15s

29 Injection process Simulation of the filling phase position of the pressure transducer in the machine die Catamold 316LA 0,55 s 0,67 s 0,69 s 0,75 s (filling time) Mold Filling Study with Moldflow Plastics Insight TM

30 Injection process Simulation of the filling phase 1. WHAT IS PRACTICABLE? 3D-flow simulation with Moldflow Plastics Insight TM (MPI TM ) Assumption of a homogeneous one phase melt flow Consideration of the jetting phenomenon is feasible PIM-feedstock has to be wall-adhering Prediction of the weld lines is feasible 2. WHAT IS IMPRACTICABLE? Modelling of the multi-phase-flow Modelling of the particle flow Modelling of the phase separation behaviour (geometry, material and process condition influence on phase separation)

31 Mould design wear resistant platens and inserts for cavity walls big and round shaped runner systems to avoid separation of powder and binder part removal manually or by a robot system Design rules Type Draft angle 0,5-2 Wall thickness 1,3 6,5 mm Webbing 0,5 0,7 x wall thickness Radius 0,4 0,8 mm

32 Testing tool wedge structure (Quelle/Source: IFWT, Vienna; IMM, Mainz)

33 Tolerances Tolerances for PIM parts Type Average Max. achievable Main dimension 0,1 mm 0,04 mm Dimensions 0,3% 0,05% Weight 0,4% 0,1% Hole diameter 0,1% 0,04% Subdivision distances 0,3% 0,1% Angles 2 0,1 Flatness 0,2% 0,1% Parallelity 0,3% 0,2% Roundness 0,3% 0,3% Rectangularity 0,2% / 0,3 0,1% / 0,1 Rouhness 0,3 m 0,01 m Density 1% 0,2%

34 Separation of powder and binder too much binder too much powder too much binder

35 Runner systems good: round shapes bad: angular shapes are causing separation of powder and binder

36 Damage during ejection (Quelle/Source: IFWT, Vienna; IMM, Mainz)

37 Automation Damage during ejection can be avoided by an especially designed robot system

38 Turnkey solution Machine Automation with robot along the machine

39 INSIDER solution ALL-IN-ONE insider solution Space-saving design Reduced robot cycle time Easy access in spite of integration No separate safety barriers CE label SHORT DISTANCES for pick and place

40 Turnkey solution Machine Robot Automation Laser cutting

41 Practice

42 Practice

43 PIM parts Quelle/Source: Fa. Schunk Sintermetall GmbH

44 PIM parts blades

45 PIM parts Cover for electronic Medical parts

46 Micro precision parts Definition for micro precision parts: 1. parts with normal dimensions 2. tolerances in the range of micrometers 3- values: shot volume: ±0,002 cm 3 sintered dimension: ±0,005 mm (±0,01%) milling heads out of hard metal (Courtesy: Seco Tools AB)

47 CIM parts multicomponent Wittmann Group KIRSCH Edmund /

48 Micro PIM / MIM + CIM article: material: mold: art volume: shot size: application: meander MIM 1-cav, 2-platen gating 0,010 cm³ / 10 mm³ 0,065 cm³/ 65 mm³ micro mechanic article: material: mold: part volume: shot size: application: gear MIM 1-cav, 3-platen gating --- cm³ / --- mm³ --- cm³/ --- mm³ micro mechnic article: material: mold: part volume: shot size: application: test bar MIM 1+ 1-cav, 2-platen gating 0,00045 / 0,00015 cm³ / 0,45 / 0,15 mm³ 0,10265 cm³/ 102,65 mm³ tests Photos: Battenfeld, Taisei Kogyo CO.,LTD, Horst Scholz GmbH & Co. KG, FZ Karlsruhe

49 Micro PIM / MIM + CIM material: steel 316L part weight: 9mg

50 MicroPower The standard machine for high-precision and micro injection molding All-electric standard injection molding machine Extendable to a production cell - modular and flexible Designed for short cycles Optimal for clean-room and medical applications Modest space requirements and reduced Optimized Injectionprocess

51 MicroPower - Injection unit 2-step plunger injection Plunger diameter 5 mm or 8 mm Injection speed up to 750 mm/s Injection pressure up to 3000 bar Shot volume max. 4cm 3 Advantages: High process stability and reproducibility Easy and good access Easy maintenance Fast material change Optimized back pressure monitoring

52 Standard single step system Downscaled standard technology cold material slug micro parts sprue Disadvantage: Large melt cushion, less accuracy Deviations in shut-off of check ring Thermal separation of sprue and melt cushion creates each cycle a cold material slug in the nozzle tip Long flow length melt 1 mg shot weight needs only 0,0056 mm stroke on a 14 mm screw No process control of small parts, IMM controls sprue Large sprue and material waist

53 MicroPower two step system Split plasticizing and injecting Dosing function on the plasticizing screw sprue no cold material slug melt Advantage: molded part High accuracy by direct melt pressure sensor Shut off function combined by injection plunger FIFO (first in - first out) Injection of thermal homogeneous material No cold material slug Smallest melt cushion Very short flow length Shot volume below 50mg possible Photo: Wittmann Battenfeld

55 Thank you for your kind attention. Wittmann Battenfeld GmbH Wiener Neustädter Strasse Kottingbrunn Austria

Injection molding equipment

Injection Molding Process Injection molding equipment Classification of injection molding machines 1. The injection molding machine processing ability style clamping force(kn) theoretical injection volume(cm3)