Polymer Engineering (MM3POE)

Transcription

1 Polymer Engineering (MM3POE) THERMOPLASTIC COMPOSITES Thermoplastic Composites 1

2 Contents Introduction Short Fibre Materials Properties Manufacturing processes Applications Long Fibre Materials Properties Manufacturing processes Applications Thermoplastic Composites 2

3 1. Introduction MATRIX THERMOPLASTIC POLYMERS REINF- ORCEMENT SEMI FINISHED Platelets/ Short fibre Glass mat Continuous fibre Pellets/ Granules GMT sheet COMPONENT Prepreg sheet Commingled yarn/fabric Thermoplastic Composites 3

4 2. Short Fibre Reinforced Thermoplastics (SFRTPs( SFRTPs) Most TP resins can be combined with fibres/fillers to enhance properties for injection moulding/ extrusion eg. stiffness, strength, impact, heat distortion thermal expansion, friction & wear Reinforcement comes in two forms - fibrous & mineral: l Aspect ratio, a = l/d d Thermoplastic Composites 4

5 2. SFRTPs Moulding compounds supplied as pellets in two forms: Fibrous reinforcement (eg. glass, carbon, Kevlar): Improved mechanical & thermal properties Higher cost & processing difficulties Anisotropic & non-uniform material properties Mineral reinforcement (eg. mica, clay): Enhanced performance eg. mech. props, dimensional stability Often at lower cost BUT similar processing difficulties Thermoplastic Composites 5

6 2.1 Glass reinforced thermoplastics Table 1: Mechanical and thermal properties of SFRTPs Material Density Kg/m 3 ABS 30% glass 1280 (+230) Acetal 30% glass 1630 (+210) PC 30% glass 1430 (+230) PBT 30% glass 1520 (+210) HDPE 30% glass 1170 (+220) PP 30% glass 1120 (+210) PS 30% glass 1280 (+210) Tensile Strength MPa 100 (+59) 134 (+73) 128 (+66) 134 (+75) 69 (+51) 67 (+43) 93 (+45) Flexural Modulus GPa 7.6 (+5.4) 9.7 (+6.9) 8.3 (+6.0) 9.7 (+7.4) 6.2 (+4.8) 3.8 (+2.6) 9.0 (+5.9) Impact Strength kj/m (-3.0) 1.8 (+0.5) 3.7 (+1.0) 2.5 (+1.3) 1.1 (+0.7) 3.0 (+2.6) 1.0 (+0.55) HDT o C 104 (+13) 163 (+53) 149 (+20) 221 (+167) 127 (+88) 146 (+89) 102 (+20) Thermal Expansion 10 6 / K 16 (-37) 22 (-23) 13 (-24) 12 (-41) 27 (-33) 20 (-20) 19 (-17) Thermoplastic Composites 6

7 2.1 Glass reinforced thermoplastics Tensile Strength of SFRTPs 30% glass Base resin Tensile Strength (MPa) Flexural Moduli of SFRTPs 30% glass Base resin 0 ABS Acetal PC PBT HDPE PP PS Flexural Modulus (GPa) ABS Acetal PC PBT HDPE PP PS Thermoplastic Composites 7

8 2.1 Glass reinforced thermoplastics 120 Creep at 40 C for PA 66 (10MPa load) Data from Bayer AG Durethan Range % Short term modulus Time (hours) 35% glass 0% glass Thermoplastic Composites 8

9 Carbon/Aramid Aramid/Long Fibre Table 1: Mechanical and thermal properties of SFRTPs (contd) Material Density Kg/m 3 PEK 30% glass 1530 (+230) PEK 30% carbon 1420 (+120) PEEK 30% glass 1490 (+170) PEEK 30% carbon 1440 (+120) PES 30% glass 1600 (+230) Nylon % glass (+250) Nylon % glass (+430) Nylon 66 (Verton) % glass (+430) Tensile Strength MPa 170 (+65) 225 (+120) 157 (+65) 208 (+116) 140 (+56) 180d/115c (+95/+55) 200d/155c (+115/+95) 230d/165c (+145/+105) Flexural Modulus GPa 9.0 (+5.3) 17.9 (+14.6) 10.3 (+6.7) 13.0 (+9.4) 8.4 (+5.8) 8.7d/5.5c (+5.8/+4.4) 12d/9.6c (+9.1/+8.5) 15.8d/11.2c (+12.9/+10.1) Impact Strength kj/m (+2.0) 8.0 (+1.0) 10.0 (+2.0) 9.0 (+1.0) 9.0 (+1.0) 9d/12c (+3/-10) 11d/13c (+5/-9) 27d/37c (+21/+15) HDT o C 358 (+172) 360 (+17.4) 315 (+155) 315 (+155) 216 (+13) 245 (+145) 250 (+150) 261 (+161) Thermal Expansion 10 6 / K Thermoplastic Composites 9

10 2.4 Mechanical properties of SFRTPs Mechanical properties of SFRTPs depend on: Fibre length (aspect ratio) Fibre volume fraction Fibre orientation σ Thermoplastic Composites 10

11 2.4 Mechanical properties of SFRTPs If fibres are parallel to loading, then: where E V E (1 V ) E max V f 1 f f = fibre volume fraction f E f, E m = fibre & matrix (polymer) moduli The correction factor, η 1, is given by: tanh(na) 1 1 = E (short) na E (contin.) m where a = aspect ratio and n depends on fibre distribution and fibre & polymer properties: n E f 2G m ln(2r / d) Thermoplastic Composites 11

12 2.4 Mechanical properties of SFRTPs Correction Factor Fibre Length Correction Factor Glass/Nylon, 30% Vf a = Fibre Length (mm) 1 n 1 E f n = d = 22 m tanh(na) na 2G m ln(2r / d) Thermoplastic Composites 12

13 2.4 Mechanical properties of SFRTPs Thermoplastic Composites 13

14 2.4 Mechanical properties of SFRTPs If fibres are parallel to loading, then: E V E (1 V ) E max 1 f f f m In reality fibres are NOT parallel to loading, so that: 2D random E 8 3 Emax 3D random E 1 Emax 5 Thermoplastic Composites 14

15 2.5 Processing of SFRTPs INJECTION MOULDING is by far the most important process In comparison to base polymers, SFRTPs can lead to: Increased wear on moulding equipment Anisotropic material properties Higher melt viscosity Thermoplastic Composites 15

16 2.5 Processing of SFRTPs 800 Viscosity at 25 s -1 for PA 66 Data from Bayer AG Durethan Range Viscosity (Pa s) o C 200 o C Glass fibre content (% mass) Thermoplastic Composites 16

17 2.6 Applications of SFRTPs AIR-INTAKE SYSTEMS Compared to metal manifolds: Metal - machining after casting Surfaces rougher than composites Lower mass of composite (up to 50%) Lower thermal conductivity, so faster warm-up & reduced emissions Composite manifolds offer ~ 3% add. power due to improved air flow Manufacture of hollow parts: Lost-core technique or 2 part, vibration welding General Motors' Vortec 4200 Inline six-cylinder engine features a robust air intake manifoldmade by Montaplast of North America, Inc. using DuPont Zytel glass-reinforced nylon Thermoplastic Composites 17

18 2.6 Applications of SFRTPs Verton glass/pp door module for Mazda 6 Carbon/nylon 66 injection moulded mountain bike wheel Thermoplastic Composites 18

19 2.6 Applications of SFRTPs Glass/PEEK rocket ignitor Carbon/PEEK pump impellor Thermoplastic Composites 19

20 3. Long/Continuous Fibre Reinf. Thermoplastics (LFRTPs( LFRTPs) For medium/high performance, long fibres are needed for required mechanical properties Long/continuous fibre thermoplastics have been developed as alternatives to thermosets Disadvantages of thermosets Matrix brittleness Ingress by solvents Limited shelf life Slow curing cycle Advantages of thermoplastics Toughness Resistance to chemicals Unlimited shelf life High volume production Recycling of scrap Repair of damaged structures Disadvantages of thermoplastics High viscosity High temperature processing Thermoplastic Composites 20

21 3.1 GMTs and LFTs Glass Mat Thermoplastic (GMT) random fibre (chopped/ continuous swirl ) mat melt impregnated with thermoplastic resin Table 2: Properties of Quadrant Plastic Composites glass/pp GMTs Material C100 F23 M f 23% chopped fibre B100 F30 M f 30% chopped fibre B100 F40 M f 38% chopped fibre G100 F40 M f 40% continuous fibre C100 UD45 M f 23% chopped/22% UD Density Kg/m 3 Tensile Strength MPa Flexural Modulus GPa Impact Strength kj/m 2 HDT o C Thermal Expansion 10 6 / K /46 9.6/ /40-50 PP < Thermoplastic Composites 21

22 3.1 GMTs and LFTs Direct Long-Fibre Thermoplastic (LFT-D) fibre (glass) strands and polymer combined & extruded directly to produce an alternative to GMT Thermoplastic Composites 22

23 3.1 GMTs and LFTs - Applications VEHICLE FRONT ENDS Fatigue (70 million cycles) Dynamic loading up to 100 o C Attachment pts (moulded inserts) Parts integration Cost & weight reductions VW Golf front end - GMT 3.7kg (35% lighter than Steel) Thermoplastic Composites 23

24 3.1 GMTs and LFTs - Applications SEAT STRUCTURES Strength, stiffness & toughness Parts integration, moulded inserts Rear impact protection Audi TT rear seat back 3.5 Kg incl steel frame & carpet Integral seat belt support Thermoplastic Composites 24

25 3.1 GMTs and LFTs - Applications BATTERY TRAYS Support battery weight Chemical resistance (battery acid) BMW battery tray <1 Kg incl. integral inserts Dimensional stability (-30 to +80 C) Thermoplastic Composites 25

26 3.2 Continuous Fibre Reinforced TPs Best mechanical properties are achieved with CONTINUOUS FIBRES (ideally aligned) UD tapes & laminates Woven fabrics Thermoplastic matrices can be combined with aligned fibres by: Film stacking Hybrid (commingled) yarns Powder impregnation Also: polymerisation control (eg. APC-2) Thermoplastic Composites 26

27 3.2 Continuous Fibre Reinforced TPs Material Twintex 1/1 V f 35% glass/pp Plytron 1/1 V f 35% glass/pp Twintex 1/1 V f 50% glass/pet Plytron UD V f 35% glass/pp Twintex UD V f 50% glass/pp TEPEX 101 1/1 V f 47% glass/pa66 CETEX /1 V f 50% glass/pei TEPEX 201 1/1 V f 48% carbon/pa66 CETEX T300 1/1 V f 50% carbon/pei Schappe Techs. 1/1 V f 56% carbon/pa12 SUPreM IM7 UD V f 60% carbon/peek Cytec APC-2 UD V f 63% carbon/peek Table 3: Properties of aligned fibre composites Density Kg/m 3 Tensile Strength MPa Flexural Modulus GPa Impact Strength kj/m 2 HDT o C Thermal Expansion 10 6 / K /11 21/ /- 32/ service temp service temp /68 120/ service temp /82 138/ service temp Thermoplastic Composites

28 3.2 Continuous Fibre Reinforced TPs VT Halmatic 6.7m rigid inflatable boat Vacuum formed using woven glass/pp Twintex Peugeot 806 bumper - woven glass/pp Twintex combined with GMT Thermoplastic Composites 28

29 3.2 Continuous Fibre Reinforced TPs APC-2 Williams Formula 1 gear selector APC-2 Apache helicopter horizontal stabiliser Thermoplastic Composites 29

30 3.2 Continuous Fibre Reinforced TPs Airbus A380 Glass/PPS wing fixed leading edge ( J-nose ) Stork Fokker Thermoplastic Composites 30

31 3.3 Mechanical properties of LFRTPs Longitudinal Modulus (GPa) E V ) E 1 0V f E f (1 0 ai cos 4 2D Random f i m 0/90 UD 0/+-45/90 +/ Fibre Volume Fraction (%) Thermoplastic Composites 31

32 3.4 Processing of LFRTPs Industrial hot flow compression moulding facility for GMT/LFT Thermoplastic Composites 32

33 3.4 Processing of LFRTPs Compression moulding simulation for automotive front end Thermoplastic Composites 33

34 3.4 Processing of LFRTPs Vacuum bag Bleeder Vacuum Connector Release film Frame Tool Sealant Twintex Vacuum consolidation for commingled thermoplastic composites ( Thermoplastic Composites 34

35 3.4 Processing of LFRTPs transfer frame control pyrometers shaped rubber tool rapid transfer device accumulators moving bolster blank holder to apply membrane stresses textile sheet for forming emitters reflectors heated composite rigid lower tool formed part infra-red oven fast acting hydraulic press Matched mould forming for aligned thermoplastic composites (M.D. Wakeman- Fig in Design & Manufacture of Textile Composites, ed. A C Long, Woodhead Publishing Ltd 2005) Thermoplastic Composites 35

36 4. Summary 10 Specific Strength (MNm/kg) PP PA66 PA66/glass SFRTP GMT/LFT Twintex/ Plytron PEEK/carbon SFRTP Aluminium/ Titanium alloys Steel APC-2/SUPreM UD APC-2/SUPreM TEPEX 1/1 carbon/pa Specific Stiffness (MNm/kg) Thermoplastic Composites 36