20140513 APP Seminar China
Compounding Highly Filled Compounds with Twin Screw Extruder Gavin Wang Head of Sales Coperion (Nanjing) Machinery Co., Ltd. APP Seminar I Manila & Hanoi I 2015-05-26/28 I Page 2
Product range ZSK series STS series CTE / CKY series APP Seminar I Manila & Hanoi I 2015-05-26/28 I Page 3
Product range Specific torque (Md/a 3 ) Tailor-made ZSK Mc 18 Made in Germany 18 Standardized STS Mc 11 assembled in Coperion Nanjing (for world market) 11.3 CTE PLUS manufactured in Coperion Nanjing 5.5 (7.2) APP Seminar I Manila & Hanoi I 2015-05-26/28 I Page 4
Design criteria of the ZSK D o = Outer diameter D i = Inner diameter a = Centerline distance D o D o / D i = Diameter ratio determines shear, degassing and powder intake M d / a 3 = Specific torque determines power density and filling degree D i a n = Screw speed determines shear and mixing D o / D i = 1,5 to 1,6 M d / a 3 11,0 Nm/cm 3 n 800 min -1 APP Seminar I Manila & Hanoi I 2015-05-26/28 I Page 5
ZSK evolution of torque and volume ZSK Standard D o / D i = 1,22 M d / a 3 = 5,0 Nm/cm 3 ZSK variable D o / D i = 1,44 M d / a 3 = 5,0 Nm/cm 3 Increase of free volume (100%) and of specific torque ZSK Supercompounder D o / D i = 1,55 M d / a 3 = 8,7 Nm/cm 3 ZSK MEGAcompounder D o / D i = 1,55 M d / a 3 = 11,3 Nm/cm 3 ZSK MEGAcompounder PLUS D o / D i = 1,55 M d / a 3 = 13,5 Nm/cm 3 ZSK Mc 18 D o / D i = 1,55 M d / a 3 = 18 Nm/cm 3 Increase of free volume (additional 40%) Increase of torque Increase of torque ZSK MEGAvolume D o / D i = 1,80 M d / a 3 = 8,7 Nm/cm 3 ZSK MEGAvolume PLUS D o / D i = 1,80 M d / a 3 = 11,3 Nm/cm 3 APP Seminar I Manila & Hanoi I 2015-05-26/28 I Page 6
Cross section of twin screw extruder (shear & elongation, dispersion & distribution) APP Seminar I Manila & Hanoi I 2015-05-26/28 I Page 7
ZSK Mc 18 shear rate.. γ minimum = 0,9 γ average.. γ maximum = 30 γ average. Shear rate γ = Velocity (v) Height (h) APP Seminar I Manila & Hanoi I 2015-05-26/28 I Page 8
ZSK Mc 18 reduced shear rate Low feed rate Constant screw speed barrel Q 2 Q 1 h Q 2 Higher feed feed rate rate barrel Q 1 screw screw Shear rate = f(speed / h) Shear rate = f(speed / h) Average value Average value SEI (kwh/kg) Rate kg/h) APP Seminar I Manila & Hanoi I 2015-05-26/28 I Page 9
ZSK Mc 18 New powder density 18 Nm/cm³ Torque increase Average shear rate decrease Degradation decrease Product quality improvement Reduced specific energy Output increase with constant product quality Increase screw speed APP Seminar I Manila & Hanoi I 2015-05-26/28 I Page 10
Technical features of STS Mc 11 Optimized die head with braker plate Multi-key screw shafts Gear box (from Europe) Bibbygard safety clutch (UK) AC/DC Motor Profile steel baseframe (Engineered in Germany) Wear and/or corrosion protection for barrels and screw elements STS side-feeder SS hose with flexible connection TOUCHmaster control panel (option) for easy operation APP Seminar I Manila & Hanoi I 2015-05-26/28 I Page 11
STS Mc 11 new features Specific torque (Md/a³) increased from 10 Nm/cm 3 to 11.3 Nm/cm 3 Maximum screw speed increased from 800 rpm to 900 rpm 25% more throughput increase with torque and screw speed increase STS Mc 11 first time within the legendary ZSK MEGAcompounder patent owned by Coperion Gearbox shared with ZSK Mc 18 for medium torque applications Using European gearboxes only Piston type solenoids for robust design APP Seminar I Manila & Hanoi I 2015-05-26/28 I Page 12
STS Mc 11 new features Base frame by FEM (Finite Element Method) design, with increased stiffness, high lifetime for smooth running and vibration damping leads to increased safety factor Whenever necessary STS screw shaft material is upgraded in order to meet the higher torque requirements Screw shaft coupling redesigned now similar to ZSK Mc 18 coupling Die heads redesigned for easy cleaning (similar to ZSK 26 Mc 18 die head) for certain sizes for masterbatch application Easy clean hopper and insert for masterbatch application APP Seminar I Manila & Hanoi I 2015-05-26/28 I Page 13
Less product stress on STS Mc 11 Specific energy [ kwh/kg ] 0.22 0.21 0.20 0.19 - ~ 5 % - ~ 4.5 % 400 600 900 Screw speed [ rpm ] STS STS Advanced STS Mc 11 APP Seminar I Manila & Hanoi I 2015-05-26/28 I Page 14
Fiber reinforcement - PA6 + 30% GF STS 50 Mc 11 : 25% max. throughput increase 900 800 STS Mc 11 Throughput [kg/h] 700 600 500 STS Advanced 400 400 500 600 700 800 900 Screw Speed [1/min] APP Seminar I Manila & Hanoi I 2015-05-26/28 I Page 15
ABS compounding STS 65 Mc 11 : 25% capacity increase 1400 Capacity at 85 % torque [kg/h] 1200 1000 800 600 400 200 0 STS65 Advanced STS65 Mc11 APP Seminar I Manila & Hanoi I 2015-05-26/28 I Page 16
STS Mc 11 new base frame Base frame by FEM (Finite Element Method) design, with increased stiffness, high lifetime for smooth running and vibration damping leads to increased safety factor Steel profiles welded, manufactured by CNC in-house in Coperion Engineered by Coperion Stuttgart Higher reliability and better alignment APP Seminar I Manila & Hanoi I 2015-05-26/28 I Page 17
STS Mc 11 new base frame APP Seminar I Manila & Hanoi I 2015-05-26/28 I Page 18
STS Mc 11 new base frame APP Seminar I Manila & Hanoi I 2015-05-26/28 I Page 19
STS Mc 11 new gearbox Specific torque upgraded from 10 Nm/cm 3 to 11.3 Nm/cm 3 Shared with ZSK Mc 18 for medium torque applications Coperion branded Using European gearboxes only Higher safety factor Longer bearing life time APP Seminar I Manila & Hanoi I 2015-05-26/28 I Page 20
Barrels Manufacture with German Heller CNC machine center to achieve high manufacturing precision and quality APP Seminar I Manila & Hanoi I 2015-05-26/28 I Page 21
Barrels Pre-heated in Furnace from Germany before welding to avoid stress and afterwards crack and leakage in future. Welding the barrel at high temperature, to avoid stress. APP Seminar I Manila & Hanoi I 2015-05-26/28 I Page 22
Screw elements Advantages: High precision of element profiling Better elements conformity High productivity German DMG CNC for Screw Elements APP Seminar I Manila & Hanoi I 2015-05-26/28 I Page 23
Screw elements APP Seminar I Manila & Hanoi I 2015-05-26/28 I Page 24
Manufacturing of CTE PLUS gearbox housing APP Seminar I Manila & Hanoi I 2015-05-26/28 I Page 25
Inspection of CTE PLUS gearbox housing APP Seminar I Manila & Hanoi I 2015-05-26/28 I Page 26
Zeiss 3-dimension inspection center Dimension check range up to micron level (measuring accuracy is 1.4 micron) Special designed temperature sensor can offer extremely reliable temperature compensation to ensure the precision Inspection data of every single barrel is around 80 items Inspection data of every CTE gearbox housing is around 40 items Zeiss 3-dimension Inspection Center APP Seminar I Manila & Hanoi I 2015-05-26/28 I Page 27
Inspection and tuning for screw shaft alignment APP Seminar I Manila & Hanoi I 2015-05-26/28 I Page 28
Final assembly alignment check Final assembly alignment check for STS with Faro Final assembly alignment check for CTE with Faro APP Seminar I Manila & Hanoi I 2015-05-26/28 I Page 29
Facts and figures STS extruder installed (2004 2012, FY2013, FY2014) 18.0% 2.4% 0.4% 14.2% 65.1% Asia Europe America Middle East Africa STS extruders installed in the world: 501 sets APP Seminar I Manila & Hanoi I 2015-05-26/28 I Page 30
Highly filled with CaCO3 PP + 70%CaCO3 LLDPE + 75%CaCO3 LDPE + 85%CaCO3 LDPE + 84%CaCO3 LLDPE + 80%CaCO3 APP Seminar I Manila & Hanoi I 2015-05-26/28 I Page 31
Mixing mechanisms in twin screw extruders Dispersive Mixing = Break up agglomerates and aggregates Distributive Mixing = Distribution of primary particles Shear stress Elongational stress Do radial velocity axial velocity Dt APP Seminar I Manila & Hanoi I 2015-05-26/28 I Page 32
Cross section of twin screw extruder (shear & elongation, dispersion & distribution) APP Seminar I Manila & Hanoi I 2015-05-26/28 I Page 33
Working principle of kneading blocks. S W M T K There are the following relations: W --> --> M T S --> M --> K W... staggering angle S... width of the disk T... transporting effect K... dispersive mixing (kneading, shearing) M... distribuitive mixing APP Seminar I Manila & Hanoi I 2015-05-26/28 I Page 34
Working principle of kneading blocks. APP Seminar I Manila & Hanoi I 2015-05-26/28 I Page 35
How to achieve very good dispersion? Dispersion requires for shear stress, but too high shear stress will over compress the particles and generate the agglomerate and degradation With high torque machine, filling degree can be increased, then average shear rate will be reduced Increase the screw speed Split feeding Special design screw elements for helping dispersion Optimization of screw design Gentle Shear! APP Seminar I Manila & Hanoi I 2015-05-26/28 I Page 36
Highly filled Premix - Setup 1 2 3 4 5 1 Polymer pellets/powder 2 Filler 3 Additives 4 High speed mixer 5 Volumetric feeders 6 ZSB side feeder 7 STS Mc 11 Twin screw extruder 8 Venting 9 Vacuum 10 Water ring pelletizer 11 Centrifugal dryer 5 11 6 9 8 8 10 7 APP Seminar I Manila & Hanoi I 2015-05-26/28 I Page 37
Highly filled - Premix Disadvantage: Polymers and CaCO 3 filler will be over compressed at solid form before melting under the high shear stress, which will generate agglomerates that hardly break later on High wear in the melting zone High cost and energy consumption if pulverize the polymer High labor cost and dust pollution with high speed mixer Low automation Advantage: Plasticizer and lubricants will get pre-molten in the high speed mixer, which will wet and incorporate the CaCO 3 powder. Thus the bulk density will be increased, then further the output increase APP Seminar I Manila & Hanoi I 2015-05-26/28 I Page 38
General layout for compounding of highly-filled Split Feed 1 2 3 5 7 1 Polymer pellets 2 CaCO 3 powder 3 Additive powder 4 atmospheric vent 5 CaCO 3 powder 6 atmospheric vent 7 CaCO3 powder 8 Vacuum degassing 9 STS Mc 11 twin screw extruder 11 Diverter valve 12 Water ring pelletizer 9 4 6 8 11 10 APP Seminar I Manila & Hanoi I 2015-05-26/28 I Page 39
LDPE / LLDPE + 80 % CaCO 3 * Split Feed * Throughput depends on raw materials and formulation PP + 70%CaCO3 LLDPE + 75%CaCO3 LLDPE + 80%CaCO3 Very good output and quality at 80% CaCO3 reached on STS APP Seminar I Manila & Hanoi I 2015-05-26/28 I Page 40
Highly filled CaCO 3 compounds Filling Degree > 80 % requests a very good processing Know-How together with a suitable formulation for highest throughput. Feeder layout & arrangement, screw configuration, temperature profile and processing parameters are essential. Coperion started to focus on these formulations many years ago and initiated internal trials (also with customers). In the meantime machines specifically configured for these highly filled polymers are successfully in operation. APP Seminar I Manila & Hanoi I 2015-05-26/28 I Page 41
Questions? Thank you! 20140513 APP Seminar China Gavin Wang Gavin.Wang@coperion.com