JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - 44

FEATURE g…/… Turbine blade bonding “Wind Energy” (not per mass) of an adhesive, but also the rheology (flow characteristics) of the product. These factors may significantly affect the shape and size of the adhesive bondline and the amount of "squeeze out" or material wasted by inadvertent flow away from the desired position. Choosing the right adhesive in terms of both density and flow can reduce the total weight of adhesive in a typical blade by as much as 50-100 kg. As blade makers push larger stretched blades onto existing unchanged turbine platforms to pick up lighter winds, keeping blade weight low in this way can be critical. The overall mould cycle time in blade component manufacture has been significantly improved. Assembly of the basic components – such as sparcaps, shear webs, shells and roots – has been the main focus of most development work to reduce these cycle times and achieve higher output. The heating and cooling processes used to speed the curing cycle can lead to severe thermal variation in the adhesive joints between the components, resulting in built-in stresses which may be large, especially in the often thick bondlines used in rotor blade assembly. These stresses can affect lifetime fatigue performance. Rotor blade manufacturers, quite rightly, have a long wish-list of expectations for their adhesive. The combination of required properties is a constant trade-off between cure progression for strength, shrinkage stresses caused by heat and exotherm, and the ability to achieve correct thermal resistance which is often expressed as a glass transition temperature (Tg). Such fast heating and cooling also requires a tough adhesive to prevent thermal cracking, a property that usually reduces Tg. This becomes particularly important in large blade production since dimensional variations in the moulding of 30-50m long composite components that are supposed to fit together can require gluelines to make up the gaps which may be considerably thicker than necessary. Careful consideration is given to these thicker regions that will show even higher cooling shrinkage stresses. Size matters Blade economics is increasingly dominated by transportation costs as blades get bigger. So it is inevitable that sophisticated modular designs with mid-length in-field joints be employed before long, allowing blades to be delivered in transportable pieces. While mechanical joints have many practical advantages for site assembly, the management of stress concentration at these joints has helped design larger areas of adhesive bonded joint. Anyone having burst a button on a shirt will appreciate the need to avoid point loads in a fatigue situation! Even mechanical fittings will have to be bonded to the composite at some point, as is the case for many blade root studs today. The challenge of making this field-practical also involves trade-offs in adhesive design, though it will be financially rewarding if solved by blade producers and adhesive engineers working together at design stage. Design Even before an adhesive is applied to a manufactured component, the assembly joint design is a critical (and often overlooked) factor to success, and blade design is no exception. Everyone knows adhesives work best if peel stresses are kept away from the joint. Nonetheless, this is not a simple task and localised joint design for leading edge, spar cap and other joints can have a dramatic effect. It is often an area where most adhesive suppliers expect the customer’s designers and manufacturing engineers to provide their own solutions. With its raceboat and wind blade engineering pedigree, Gurit is lucky to be one of the few adhesive manufacturers with a large structural engineering service capable of recommending adhesive joint profile designs to optimise component structure whilst integrating production gains – providing the integrated solution. Through careful design of the structure and its joint elements and by giving consideration to the production process, overengineering can be avoided and material consumption, time and energy can be employed in blade production as efficiently as possible to avoid waste. A green approach, if you like, to producing an ecological product. Contact: peter.george@gurit.com More information: www.gurit.com The cross section of a blade. For many blade manufacturers who have had to avoid brittle adhesive cracking, the preferred option has been to address the cracking risk by lengthening cure cycles to obtain lower thermal stresses. This unnecessarily reduces the productive turnaround speed of the mould. Choosing toughened adhesives like Gurit’s Spabond 340 has minimised this need for longer cycles, thus restoring production capacity and opening up the possibility to review further cycle improvements. Keeping an eye on weight problems The high volumes of adhesive used in turbine blade assembly raise another issue in adhesive choice, namely consumption. It is vitally important to consider not only the cost per volume 44 jec composites magazine / No49 June 2009
http://www.gurit.com

Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #49 - June 2009

Cover
Index
Contents
- NEWS WORLDWIDE -
CompaniesMergers and acquisitions /Opening/Development /Partnership
3B: a high-quality fibreglass supplier
DK Composites: a player that has made a name for itself
Agenda of events
Equipment Innovative robotic solutions for fibre placement
- BUSINESS -
Market survey Indian distributors of raw materials for composites
Trends Subcontracting in aviation: a rapidly changing sector
Niche market Composites conform to creation
Human capital NCC: a global source for commercialization, manufacturing acceleration and incubation
- FEATURE -
Market 2009-2013: no slow-down in global wind developments
Design Composite wind turbine blade design: leveraging aerospace advances
Reinforcement New composite hybrid reinforcements for the wind turbine industry
Resins Advanced epoxy technology for wind turbine blades
Foam Breakthrough in structural PET foam core materials
Adhesive Turbine blade bonding
Production Automated blade production for wind energy plants
UT scans to ensure blade quality
Application An innovative composite wind turbine: for homeowners and professionals
- USERS’ PLATFORM -
Composites in the world - An astonishing chair
 - “Light car - Open Source”
The Greenbirdproject: 203 km/h just using wind
Lightweight hand-launched glider
Successful partners Innovative architectural cladding
Application GRP pipe system for Cancéropôle stormwater network
Composite system has capital solution for park odours
Composite drives team in first zero-emission race
- KNOW-HOW -
Materials Fibre-reinforced cores
Release agents Mould release system for the marine industry
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - Cover
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - 2
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - 3
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - 4
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - Index
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - Contents
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - 7
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - CompaniesMergers and acquisitions /Opening/Development /Partnership
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - Pub1
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - Pub2
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - 3B: a high-quality fibreglass supplier
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - 10
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - DK Composites: a player that has made a name for itself
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - 12
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - 13
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - Agenda of events
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - 15
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - Equipment Innovative robotic solutions for fibre placement
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - 17
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - 18
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - - BUSINESS -
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - Market survey Indian distributors of raw materials for composites
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - 21
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - Trends Subcontracting in aviation: a rapidly changing sector
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - 23
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - Niche market Composites conform to creation
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - 25
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - Human capital NCC: a global source for commercialization, manufacturing acceleration and incubation
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - 27
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - 28
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - - FEATURE -
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - Market 2009-2013: no slow-down in global wind developments
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - 31
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - 32
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - 33
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - Design Composite wind turbine blade design: leveraging aerospace advances
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - 35
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - Reinforcement New composite hybrid reinforcements for the wind turbine industry
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - 37
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - 38
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - Resins Advanced epoxy technology for wind turbine blades
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - 40
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - 41
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - Foam Breakthrough in structural PET foam core materials
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - Adhesive Turbine blade bonding
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - 44
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - Production Automated blade production for wind energy plants
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - 46
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - UT scans to ensure blade quality
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - Application An innovative composite wind turbine: for homeowners and professionals
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - 49
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - 50
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - - USERS’ PLATFORM -
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 -  - “Light car - Open Source”
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - Lightweight hand-launched glider
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - Successful partners Innovative architectural cladding
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - 55
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - Application GRP pipe system for Cancéropôle stormwater network
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - Composite system has capital solution for park odours
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - Composite drives team in first zero-emission race
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - - KNOW-HOW -
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - Materials Fibre-reinforced cores
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - 61
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - 62
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - Release agents Mould release system for the marine industry
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - 64
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - 65
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - 66
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - 67
JEC COMPOSITES MAGAZINE - Issue #49 - June 2009 - 68
https://www.nxtbook.fr/newpress/jeccomposites/jcm2007_135
https://www.nxtbook.fr/newpress/jeccomposites/jcm_2020_Q1_Innovation_Report
https://www.nxtbook.fr/newpress/jeccomposites/jcm2005_Special_Issue3
https://www.nxtbook.fr/newpress/jeccomposites/jcm2005_134
https://www.nxtbook.fr/newpress/jeccomposites/jcm2003_133
https://www.nxtbook.fr/newpress/jeccomposites/jcm2001_132
https://www.nxtbook.fr/newpress/jeccomposites/jcm1911_Special_Issue2
https://www.nxtbook.fr/newpress/jeccomposites/jcm1911_131
https://www.nxtbook.fr/newpress/jeccomposites/jcm1909_130
https://www.nxtbook.fr/newpress/jeccomposites/jcm1907_129
https://www.nxtbook.fr/newpress/jeccomposites/jcm1905_128
https://www.nxtbook.fr/newpress/jeccomposites/jcm1903_Special_Issue1
https://www.nxtbook.fr/newpress/jeccomposites/jcm1903_127
https://www.nxtbook.fr/newpress/jeccomposites/jcm1901_126
https://www.nxtbook.fr/newpress/jeccomposites/jcm1811_125
https://www.nxtbook.fr/newpress/jeccomposites/jcm1810_124
https://www.nxtbook.fr/newpress/jeccomposites/jcm1808_123
https://www.nxtbook.fr/newpress/jeccomposites/jcm1807_122
https://www.nxtbook.fr/newpress/jeccomposites/jcm1805_121
https://www.nxtbook.fr/newpress/jeccomposites/jcm1804_120
https://www.nxtbook.fr/newpress/jeccomposites/jcm1803_119
https://www.nxtbook.fr/newpress/jeccomposites/jcm1802_119-Supplement_Innovation_Report
https://www.nxtbook.fr/newpress/jeccomposites/jcm1801_118
https://www.nxtbook.fr/newpress/jeccomposites/jcm1711_117
https://www.nxtbook.fr/newpress/jeccomposites/jcm1710_116
https://www.nxtbook.fr/newpress/jeccomposites/jcm1708_115
https://www.nxtbook.fr/newpress/jeccomposites/jcm1707_114
https://www.nxtbook.fr/newpress/jeccomposites/jcm1706_113
https://www.nxtbook.fr/newpress/jeccomposites/jcm1704_112
https://www.nxtbook.fr/newpress/jeccomposites/jcm1703_111
https://www.nxtbook.fr/newpress/jeccomposites/jcm1701_110
https://www.nxtbook.fr/newpress/jeccomposites/jcm1611_109
https://www.nxtbook.fr/newpress/jeccomposites/jcm1610_108
https://www.nxtbook.fr/newpress/jeccomposites/jcm1608_107
https://www.nxtbook.fr/newpress/jeccomposites/jcm1607_106
https://www.nxtbook.fr/newpress/jeccomposites/jcm1605_105
https://www.nxtbook.fr/newpress/jeccomposites/jcm1604_104
https://www.nxtbook.fr/newpress/jeccomposites/jcm1603_103
https://www.nxtbook.fr/newpress/jeccomposites/jcm1601_102
https://www.nxtbook.fr/newpress/jeccomposites/jcm1511_101
https://www.nxtbook.fr/newpress/jeccomposites/jcm1510_100
https://www.nxtbook.fr/newpress/jeccomposites/jcm1509_99
https://www.nxtbook.fr/newpress/jeccomposites/jcm1507_98
https://www.nxtbook.fr/newpress/jeccomposites/jcm1505_97
https://www.nxtbook.fr/newpress/jeccomposites/jcm1504_96
https://www.nxtbook.com/newpress/jeccomposites/jcm1503_95
https://www.nxtbook.com/newpress/jeccomposites/jcm1501_94
https://www.nxtbook.com/newpress/jeccomposites/jcm1412_93
https://www.nxtbook.com/newpress/jeccomposites/jcm1410_92
https://www.nxtbook.com/newpress/jeccomposites/jcm1409_91
https://www.nxtbook.com/newpress/jeccomposites/jcm1406_90
https://www.nxtbook.com/newpress/jeccomposites/jcm1405_89
https://www.nxtbook.com/newpress/jeccomposites/jcm1404_88
https://www.nxtbook.com/newpress/jeccomposites/jcm1403_87
https://www.nxtbook.com/newpress/jeccomposites/jcm1401_86
https://www.nxtbook.com/newpress/jeccomposites/jcm1311_85
https://www.nxtbook.com/newpress/jeccomposites/jcm1310_84
https://www.nxtbook.com/newpress/jeccomposites/jcm1308_83
https://www.nxtbook.com/newpress/jeccomposites/jcm1307_82
https://www.nxtbook.com/newpress/jeccomposites/jcm1305_81
https://www.nxtbook.com/newpress/jeccomposites/jcm1304_80
https://www.nxtbook.com/newpress/jeccomposites/jcm1303_79
https://www.nxtbook.com/newpress/jeccomposites/jcm1301_78
https://www.nxtbook.com/newpress/jeccomposites/jcm1212_77
https://www.nxtbook.com/newpress/jeccomposites/jcm1210_76
https://www.nxtbook.com/newpress/jeccomposites/jcm1208_75
https://www.nxtbook.com/newpress/jeccomposites/jcm1207_74
https://www.nxtbook.com/newpress/jeccomposites/jcm1206_73
https://www.nxtbook.com/newpress/jeccomposites/jcm1204_72
https://www.nxtbook.com/newpress/jeccomposites/jcm1203_71
https://www.nxtbook.com/newpress/jeccomposites/jcm1201_70
https://www.nxtbook.com/newpress/jeccomposites/jcm1111_69
https://www.nxtbook.com/newpress/jeccomposites/jcm1110_68
https://www.nxtbook.com/newpress/jeccomposites/jcm1108_67
https://www.nxtbook.com/newpress/jeccomposites/jcm1107_66
https://www.nxtbook.com/newpress/jeccomposites/jcm1105_65
https://www.nxtbook.com/newpress/jeccomposites/jcm1104_64
https://www.nxtbook.com/newpress/jeccomposites/jcm1103_63
https://www.nxtbook.com/newpress/jeccomposites/jcm1101_62
https://www.nxtbook.com/newpress/jeccomposites/jcm1011_61
https://www.nxtbook.com/newpress/jeccomposites/jcm1010_60
https://www.nxtbook.com/newpress/jeccomposites/jcm1009_59
https://www.nxtbook.com/newpress/jeccomposites/jcm1006_58
https://www.nxtbook.com/newpress/jeccomposites/jcm1005_57
https://www.nxtbook.com/newpress/jeccomposites/jcm1004_56
https://www.nxtbook.com/newpress/jeccomposites/jcm1003_55
https://www.nxtbook.com/newpress/jeccomposites/jcm1001_54
https://www.nxtbook.com/newpress/jeccomposites/jcm0911_53
https://www.nxtbook.com/newpress/jeccomposites/jcm0910_52
https://www.nxtbook.com/newpress/jeccomposites/jcm0909_51
https://www.nxtbook.com/newpress/jeccomposites/jcm0907-08_50
https://www.nxtbook.com/newpress/jeccomposites/jcm0906_49
https://www.nxtbook.com/newpress/jeccomposites/jcm0904_48
https://www.nxtbook.com/newpress/jeccomposites/jcm0903_47
https://www.nxtbook.com/newpress/jeccomposites/jcm0901_46
https://www.nxtbook.com/newpress/jeccomposites/jcm0811_45
https://www.nxtbook.com/newpress/jeccomposites/jcm0810_44
https://www.nxtbook.com/newpress/jeccomposites/jcm0809_43
https://www.nxtbook.com/newpress/jeccomposites/jcm0807_42
https://www.nxtbook.com/newpress/jeccomposites/jcm0806_41
https://www.nxtbook.com/newpress/jeccomposites/jcm0805_40
https://www.nxtbook.com/newpress/jeccomposites/jcm0803_39
https://www.nxtbook.com/newpress/jeccomposites/jcm0801_38
https://www.nxtbook.com/newpress/jeccomposites/jcm0712_37
https://www.nxtbook.com/newpress/jeccomposites/jcm0710_36
https://www.nxtbook.com/newpress/jeccomposites/jcm0709_35
https://www.nxtbook.com/newpress/jeccomposites/jcm0707_34
https://www.nxtbook.com/newpress/jeccomposites/jcm0706_33
https://www.nxtbookmedia.com