JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 61

Single-step preforming
The laminate fabrics for the shell and stringers of the FRP roof can be manufactured using warp-knitting machines with multiaxial weft insertion. Enhanced fabrics with locally adjusted drapability and local reinforcements require an extended machine functionality, which is illustrated in this section. Warp-knitted non-crimp fabrics Non-crimp fabrics (NCF) are defined as drawn parallel layers of reinforcing threads or tows. They can be produced economically on warp-knitting machines with multiaxial weft insertion (Fig. 6). The loose fibre layers are connected with warp-knitting yarns by loop formation [5]. The warp-knitting elements and loop formation are described in references [6] and [7].

Fig. 7: Pattern discs (left), electro-mechanical guide bar (middle) and locally adjusted stitch type (right)

Varying stitch types during production require an adjustment of the yarn run-in from stitch course to stitch course. To adjust drapability locally, a computer-controlled beam control is also integrated [ 11]. Locally adjusted thickness Local reinforcements are placed on the loose fibre layers between the weft insertion systems and warpknitting unit. Prefabricated textiles Fig. 8: Endless (up) and finite (down) reinforcement or unidirectional fibre layers can be supplied in endless or finite form by means of feeding modules (Fig. 8). The feeding modules can lay down several parallel reinforcements with the same length at a time. Several modules can be arranged in a row to produce multi-layer textile structures [12]. Cutting and stacking unit Conventional winding of multiaxial warp-knitted NCF with high layer setup or local reinforcements can lead to deformation or damage of the textile structure. This can be avoided by cutting the NCF into pieces, stacking them and compensating the Fig. 9: Winding (left) and stacking (right) of NCF with local reinforcements local reinforcements (Fig. 9). A conveyor belt system is used to stack the individual pieces. The movement of the belt system can be divided into four phases (Fig. 10), which are described on next page. Carrying: the tailored NCF is transported at constant speed by a transport chain. It is cut out of the transport chain by diamond disc blades and subsequently separated No73 June 2012

Fig. 6: NCF (left) and warp-knitting machine with multiaxial weft insertion (right)

The drapability, thickness and width of the fabrics produced using state-of-the-art machines are constant. Drapability can be defined as the adaption of a semi-finished laminar material on curved three-dimensional surfaces [8]. In a subsequent preforming process, tailored NCF with locally adjusted properties such as drapability and local reinforcements provide benefits such as simplified handling, reduced handling steps and reduced scrap. Locally adjusted drapability Stitch length, stitch type (underlap of the guidebar lateral to process direction) and yarn run-in have an impact on the drapability of NCFs. A greater stitch length, a larger underlap and a higher yarn run-in of the warp-knitting yarns increase the formability of the material while complicating handling [ 9, 10]. A locally adjusted stitch length requires major modifications in the machine software and hardware. Therefore, this possibility was not considered. The underlap is predetermined by the movement of the guide bar, which is mainly driven by pattern discs. An electro-mechanical guide bar provides the possibility to change the underlap locally. The machine manufacturer, LIBA Maschinenfabrik GmbH, Naila, Germany, modified the machine operating system and produced the hardware (Fig. 7) [ 11]. An NCF with locally adjusted stitch type is shown in Fig. 7.

/ jec composites magazine 61



JEC COMPOSITES MAGAZINE - Issue #73 - June 2012

Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #73 - June 2012

Cover
Edito
Point of view: core material
Contents
Agenda of Events
COMPANY & BUSINESS
- In Brief
- Reinforcement
- Book launch
APPLICATIONS
- Railway
- UAV
- Electric vehicule
MARKET
- Human ressources
- Sandwich
SPECIAL JEC ASIA 2012
- Floor plan
- Conferences
- JEC Asia Innovation Awards Programme
- Innovation report
- Country guest of honour: Malaysia
- Reinforcement
- Wind energy
RESEARCH & DEVELOPMENT
- Design
- Automation
TECHNOLOGY & INNOVATIONS
- Reinforcement
- UPR
- Mirco-pultrusion
- Pultrusion
- Injection
- Certification
Index
In the world
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - Cover
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 2
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - Edito
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - Point of view: core material
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 5
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - Contents
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 7
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - Agenda of Events
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - - In Brief
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - - Reinforcement
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 11
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - - Book launch
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 13
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - - Railway
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 15
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - - UAV
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - - Electric vehicule
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 18
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - - Human ressources
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - - Sandwich
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 21
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 22
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 23
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - - Floor plan
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 25
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - - Conferences
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 27
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 28
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 29
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - - JEC Asia Innovation Awards Programme
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 31
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 32
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 33
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - - Innovation report
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 35
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 36
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 37
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 38
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - - Country guest of honour: Malaysia
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 40
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 41
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 42
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 43
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 44
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 45
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 46
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 47
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - - Reinforcement
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 49
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 50
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - - Wind energy
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 52
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 53
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 54
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - - Design
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 56
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 57
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 58
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - - Automation
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 60
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 61
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 62
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 63
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 64
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 65
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - - Reinforcement
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 67
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - - UPR
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 69
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 70
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - - Mirco-pultrusion
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 72
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 73
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - - Pultrusion
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 75
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - - Injection
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - - Certification
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 78
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 79
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 80
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - Index
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - In the world
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 83
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 84
https://www.nxtbook.fr/newpress/jeccomposites/jcm2107_141
https://www.nxtbook.fr/newpress/jeccomposites/jcm2105_140
https://www.nxtbook.fr/newpress/jeccomposites/jcm2103_139
https://www.nxtbook.fr/newpress/jeccomposites/jcm-experts-digest-additive-manufacturing-2020
https://www.nxtbook.fr/newpress/jeccomposites/jcm2101_138
https://www.nxtbook.fr/newpress/jeccomposites/jcm2011_Special_Issue4
https://www.nxtbook.fr/newpress/jeccomposites/jcm2011_137
https://www.nxtbook.fr/newpress/jeccomposites/jcm2009_136
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