3D woven spacer fabrics in sports applications. Glass fiber reinforced snowboards

Transcription

1 3D woven spacer fabrics in sports applications Glass fiber reinforced snowboards Conference Composites without borders, Moscow Stefan Fenske, Benedikt Wendland, Marcel Haeske, Thomas Gries Institut für Textiltechnik der RWTH Aachen University (ITA), Aachen, Germany Reference: Snowboard_saut_et_tremplin.jpg

2 Outline 1) Presentation of the ITA 2) Motivation 3) 3D woven spacer fabrics an introduction 4) Materials and methods 5) Results & Conclusion 6) Outlook 2 Reference: Snowboard_saut_et_tremplin.jpg

3 Outline 1) Presentation of the ITA 2) Motivation 3) 3D woven spacer fabrics an introduction 4) Materials and methods 5) Results & Conclusion 6) Outlook 3

4 raw materials: natural fibers, polymers,... semi-finished textiles & products application fields The unique position of ITA Comprehensive textile process chains mobility building & living health technology and competence fields energy 4

5 public Strictly confidential ITA Facts and Figures Staff: 100 Scientists 55 Service personnel 190 Graduate research assistants 50 Students majoring in textile technology each year Fundamental Research ca. 30% Subsidy ca. 4% Research and development Publicity and third party funded research Academic and industrial education Industry-Related Public Funding ca. 35% Industrial Funding ca. 31% Development and transfer Direct industrial research Further education partially public Budget: ca. 14,3 Mio. 5

6 Outline 1) Presentation of the ITA 2) Motivation 3) 3D woven spacer fabrics an introduction 4) Materials and methods 5) Results & Conclusion 6) Outlook 6

7 Motivation Snowboarding is very popular New snowboard technologies can be a very lucrative market! State of the art in snowboard construction: many different layers, often with a wooden core High demand of lightweight snowboards, fabricated in an automated production process Typical Snowboard Build-Up 7 Source:

8 Motivation Snowboard materials are required to withstand high mechanical tensions and forces Glass fibers exhibit appropriate mechanical properties Objective: Production of a snowboard made of glass fiber reinforced plastics (GFRP) with a 3D woven spacer fabric as textile structure 3D woven spacer fabric 8 Source:

9 Outline 1) Presentation of the ITA 2) Motivation 3) 3D woven spacer fabrics an introduction 4) Materials and methods 5) Results & Conclusion 6) Outlook 9

10 Woven fabrics - Overview Consist of two or more orthogonal intersected yarn systems: Warp yarns Weft yarns 5000 years old principle Total production: approx. 30 million tons woven fabrics/year Advantages for reinforcement applications Cost-effective manufacturing High reproducibility Good process-ability Excellent formability Plain Weave Twill Weave Satin Weave 10

11 Classification of 3D woven fabrics 3D - woven fabrics Integral fabrics Distance fabrics Hollow cellular fabrics Circular and tubular woven fabrics Contour fabrics Hybrid woven/knitted fabrics Distance fabrics with interlocking yarns Distance fabrics with plane interlocking 3D - contour weaving method Contour fabrics on conventional weaving looms Multilayer fabrics 3D - orthogonal - fabrics 3D - woven 3D - fabrics Multiaxial fabrics Circular weaving Multiaxial 3D orthogonal circular weaving Tubular fabrics Tubular nodal fabrics 11

12 3D woven spacer fabrics specifics Additional yarns in the z-direction Good compression characteristics due to pile yarns Mechanical properties can be adjusted by changing the pile binding and outer structures Machinery requirements include a simultaneous multiple weft insertion and an adjusted shedding system Main applications are structural composites and cushioning Not suitable for carbon in the z- direction Pile yarns Warp direction Production direction Weft direction Weft yarn Warp yarn 12

13 Production of 3D woven spacer fabrics Principle of carpet weaving, but without cutting of the pile yarns Two separate sheds are formed to produce two ground fabrics one at the top and one at the bottom Two weft shots are inserted simultaneously by rapiers Warp healds Double Rapier Weft yarn Pile yarns Pile healds Warp yarn 13

14 Outline 1) Presentation of the ITA 2) Motivation 3) 3D woven spacer fabrics an introduction 4) Materials and methods 5) Results & Conclusion 6) Outlook 14

15 Materials Specification spacer fabrics: Warp direction: E-Glass 136 tex, 10 threads/cm Weft direction: E-Glass 136 tex, 10 threads/cm Pile direction: E-Glass 68 tex, 50 connections/cm² Metal insert integration by cutting the spacer fabric and a portion of pile yarns Insert with screw thread Cut pile yarns Cut spacer fabric 15

16 Methods Production with manual hand lay-up Not possible to apply pressure to pile yarns of spacer fabrics Production of two series of materials for insert pull-out tests 1 st NCF on bottom in order to increase mechanical stability 2 nd NCF on top in order to protect the weakened area where the insert is put in 1 st series: Non-Crimp Fabric (NCF) only at the bottom Weft direction Spacer fabric NCF at bottom 2 nd series: Reinforcing NCF at bottom and on top NCF on top Spacer fabric NCF at bottom Warp direction 16

17 Methods Insert pull-out tests conducted according to DIN ISO Test direction: warp Since variation of pile yarn height is only possible in said direction Top traverse Universal Testing Machine Sample with insert Bearing roll Bottom plate 17

18 Outline 1) Presentation of the ITA 2) Motivation 3) 3D woven spacer fabrics an introduction 4) Materials and methods 5) Results & Conclusion 6) Outlook 18

19 Force [N] Results Maximum pull-out force is about 2000 N Shear strength in the pile yarn area is low. Failure happens in pile yarn area! Failure of pile yarns Failure of pile yarns Serie 2.Serie Displacement [mm] 19

20 Conclusion Production of composites is challenging Parallelism between ground fabrics difficult to achieve with hand lay-up Pile yarn configuration not well suited for pull-out tests Weak spot identified! 20

21 Outline 1) Presentation of the ITA 2) Motivation 3) 3D woven spacer fabrics an introduction 4) Materials and methods 5) Results & Conclusion 6) Outlook 21

22 Outlook Production of the composites needs to be improved Combination of spacer fabric with foam core to increase stability Automation of the infusion process Shear strength can be improved by variation of pile yarn set-up Distance fabric Increased pile yarn density Additional pile yarns in 45 -direction Integration of the metal inserts needs to be improved Weakening of spacer fabric by manual insert integration Development of automated insert integration 22

23 Contact details Thank you for your attention! Dipl.-Ing. Stefan Fenske Department of Composites Phone: +49 (0) Fax: +49 (0)