Radiation Curing: Coatings and Composites

Transcription

1 Radiation Curing: Coatings and Composites Anthony J. Berejka, Ionicorp+, USA Daniel Montoney, Strathmore Products, USA Marshall R. Cleland, IBA Industrial, Inc., USA Loïc Loiseau, IBA Industrial, Belgique Polyray 2009 Universite de Reims 19 mars 2009 Reims, France

2 Industrial Electron Beam Markets WIRE CABLE TUBING SURFACE CURING SERVICE OTHER TIRES SHRINK FILM >1400 high current EB manufacturing installations

3 Electron Beam Parameters Voltage = Electron Penetration = Thickness Penetrated Amperage = Beam Current = Exposure Intensity Kilowatts = Megavolts x Milliamps kw = MV x ma

4 EB Market Segments Require Different Energies Market Segment Surface Curing Shrink Film Wire & Cable Sterilization Composites Electron Energy kev kev MeV 3 10 MeV 10 MeV Typical Penetration 0.4 mm 2 mm 11 mm 38 mm 24 mm

5 kev Development Unit 1.5 m 0.9 m 1.5 m

6 Low-voltage EB Pilot Line 300 kev self-shielded EB unit for crosslinking film or surface curing

7 Low-voltage EB Equipment 300 kev self-shielded EB unit for crosslinking film or surface curing

8 Industrial Electron Beams 2.7m 6.6m 1.6m 3.0m 10 MeV, 200 kw 5 MeV, 300 kw

9 X-ray Conversion

10 X-ray Depth of Penetration 80 Dose (kgy) Depth in cm x density, g/cc 10 MeV electrons 5 MeV X-Rays 7.5 MeV X-Rays

11 Unipolis 10 MeV EB/X-ray Facility

12 RDI Studies late 1960s Walter Brenner and Marsh Cleland 5 July 2005

13 Brenner-Campbell Conclusions

14 Surface Tension Tests Control of water = high contact angle EB formulation = low contact angle

15 Surface Tension Tests 55 Contact Angle Surface Tension, dynes EB curable coating binders

16 VARTM with HDPE Platens Carbon fiber twill sealed in between platens

17 VARTM with PC/HDPE Platens Wetted carbon fiber Carbon fiber twill sealed in between platens

18 EB/X-ray Cured Sample

19 Solubility EB/X-ray Cured Samples Gel content, % X-ray cured EB cured ~2g resin sample immersed in methylene chloride for ~16 hours Dose, kgy

20 EB Coating Flexibility Mandrel Bend 0-T Bend

21 Toughness Testing 123 cm Falling tup impact testing: Eight ply carbon fiber composite matrix with impact additive

22 Toughness/Impact Testing Four ply carbon fiber composite and aluminum test panel of comparable thickness: impacted at 13.6 N-m

23 Properties Six Ply Carbon Fiber Reinforced Composites X-ray cured Initial fracture Izod in mold at 24 kgy of matrix Impact bis-phenol-a diacrylate 6.8 N-m 901 J/m matrix system no impact additive bis-phenol-a diacrylate 15.8 N-m 1043 J/m matrix system with impact additive

24 Developing Molecular Structures Molecular weight, Mn, and molecular weight between crosslinks, Mc, is important

25 Developing Molecular Structures Conventional bis-phenol-a diacrylate Multiple suppliers, used in radiation curable coatings

26 Microphase Understanding Intra-molecular impact additive Inter-molecular impact additive

27 Microphase Understanding Intra-molecular impact additive Inter-molecular impact additive SEM to same µm scale

28 Microphase Understanding SEM µm scale amine cured epoxy AFM nano scale gel UV cured epoxy diacrylate

29 Thermal Analysis Resin Systems X-ray cured at 20 kgy DSC Tg TMA Tg bis-phenol-a diacrylate 54 C 66 C (Mn = 452) ethoxylated b-p-a diacrylate C (Mn = 572) diluted acrylated epoxy-phenolic 92 C 69 C

30 Dynamic Mechanical Analysis

31 Dynamic Mechanical Analysis Used by Charlesby for EB cured styrene-polyesters

32 Dynamic Mechanical Analysis 75 Peak tan δ, C Effect of X-ray dose on peak tan δ on coating binder/matrix materials

33 Dynamic Mechanical Analysis tan δ 42 C Binder/matrix X-ray cured in mold to 60 kgy

34 Dynamic Mechanical Analysis tan δ 34 C Eight ply carbon fiber X-ray cured in mold to 20 kgy

35 Pragmatic Tests: TMA TMA in compression mode

36 EB XL PE Creep Resistance Deformation, mm (TMA constant load at >Tm) Time, seconds EVA Tm = 72 C under constant load at 100 C 200 kgy 150 kgy 100 kgy 50 kgy 15 kgy

37 Heat Deflection Test 1.82 MPa 100 mm 13 mm Temperature increased a 2 C/minute under constant load

38 Heat Deflection Test Six ply composite X-ray Heat cured in mold at 24 kgy Deflection bis-phenol-a diacrylate >180 C matrix system no impact additive bis-phenol-a diacrylate >180 C matrix system with impact additive Test ended at 180 C = maximum temperature of heating bath

39 X-ray Curing Studies Initial X-ray curing carbon fiber composite in the mold

40 Deep-drawn Fiber Composite

41 X-ray Curing Composites in the Mold

42 X-ray Cured Motorcycle Fender

43 X-ray Cured Sports Car Fender

44 Conclusions + Materials development intended for coatings work can be transformed into use as the matrix system for fiber reinforced composites + Tests conducted using low-energy EB can be scaled up to higher energy and X-ray curing + X-rays facilitate curing in the mold which can be used for large sized products

45 Conclusions + Some properties developed for coatings are of benefit when binders are used as matrices: Surface wetting = adhesion Flexibility = impact resistance + Binders and matrices for EB/X-ray curing should be intentionally designed polymers + Fundamental insights into materials should be tempered with pragmatic testing