1. TF 8 - Mesh tension / specifications - Summary on mesh stretching options - Fabian Kuger 1, Esther Ferrer-Ribas 2, Mauro Iodice 3 1 Julius-Maximilians-Universitä ̈ t Würzburg (Germany) / CERN, 2 IRFU/SEDI - Saclay (France), 3 Roma Tre (Italy) April 14 th 2014 MM Mechanics Meeting - CERN

2. Mesh stretching in labs or industries? (Options) Main factors to be considered: 2Mesh TF - reportApril 14, 2014 Logistics Cost Quality Stretching externally in industries Stretching ourselves on production site One centralized supplier Individual supplier per production site One or two ‘stretching sites’ Stretching in each production site  Depend strongly on logistics  Varies a lot with the supplier Example calculation will be given, not to be considered as final  Intensively discussed in the weekly meetings. Today only short summary, More detailed results in backup A logistics model for each option will be briefly discussed

3. Overview – logistics structure 3Mesh TF - reportApril 14, 2014 Logistics Stretching externally in industries One centralized supplier Individual supplier per production site Stretching ourselves on production site One or two ‘stretching sites’ Stretching in each production site Centralized stretching site ‘Drift panel’ site Assembly site ‘Drift panel’ site + in-lab stretching Assembly site centralized supplier ‘Drift panel’ site mesh delivery (2) frame return (1) local supplier ‘Drift panel’ site ‘regular’ delivery and pick-up by company Large number of frames, to be reused only one or two times to reduce logistics(-costs). (1000 – 3000 CHF per transport) Smaller number of frames in two batches, one at site and one at supplier, to be exchanged. (few 100 CHF per transport) Adds ONE extra logistic step for each (batch of) panel(s).NO extra logistics at all!

4. 4Mesh TF - reportApril 14, 2014 Overview – main cost items Costs Frames: Each stretching in industries solution requires an amount of (reusable) frames to pre-stretch and transport the meshes. Buying directly from producer saves up ≈ 50% compared to stretching companies. Exact numbers depend on logistics e.g. 2x 16 frames  8 logistic steps; 2x 8 frames  16 logistic steps Size (Module) 2.30 x 2.50 m 2 (LM1) 1.60 x 2.50 m 2 (LM2) 1.50 x 2.50 m 2 (SM1) 1.60 x 2.00 m 2 (SM2) frame (CHF/piece)220 (176€)193 (154€)188 (150€)1.23 (98€) Stretching Service: Only stretching - no mesh cleaning or frame preparation included! Huge variance dependent on company. Size (Module) 2.30 x 2.50 m 2 (LM1) 1.60 x 2.50 m 2 (LM2) 1.50 x 2.50 m 2 (SM1) 1.60 x 2.00 m 2 (SM2) Serilith (CHF/mesh)156104 Pröll (CHF/mesh)56 (45€)

5. 5Mesh TF - reportApril 14, 2014 Example – centralized industrial stretching ModuleLM1 France LM2 Italy SM1 Greece Russia SM2 Gemany Frames (kCHF / 64) 1. 14.012.412.08.0 Stretching (kCHF/128) 2. 6.8 Logistics (kCHF) 3. 56106 TOTAL 25.825.228.820.8 Mesh fabric not included! Option 1: Industrial stretching by one supplier High number of frames and less reusing will be cheaper than many transports – e.g.: -Buying half of the frames (64) and reusing them once -3 transport steps with full truck (2x company  site, 1x site  company) Costs 1. based on Hurtz offer 2. based on Pröll offer 3. Based on 3 transports, e.g. from CERN to ‘drift panel’ site Option 2: Industrial stretching by local supplier -Lower number of frames sufficient -More logistics steps, but each one much cheaper -BUT: Prices for stretching might differ significantly!

6. Summary Quality highly depends on supplier  Individual qualification and QC necessary with each supplier Time for relaxing the mesh on the stretching setup before gluing is very expensive in industries  difficult adjustment to nominal value Best Quality delivered so far ±3N/cm over 110x150cm 6Mesh TF - reportApril 14, 2014 Quality Stretching externally in industries Stretching ourselves on production site First tests have been performed with satisfying results: < ±2N/cm over 100x100cm 1 < ±1N/cm over 80x100cm 2 Improving our handling of the tools should improve this further But: Neither full size, nor gluing process have been tested! Workload is reasonably small (< 30 min per mesh) 1 Mechanical setup 2 pneumatic setup

7. company dependent ? Mesh stretching in labs or industries? (Discussion input) 7Mesh TF - reportApril 14, 2014 Costs Logistics Quality Stretching externally in industries Stretching ourselves on production site Choose & quality one supplier Individual supplier per production site Identify one or two ‘stretching sites’ Stretching in each production site + more suppliers to be qualified Quality assurance seems feasible. Doing it our self enables us to include relaxing time  improve quality 20-30 kCHF / construction site 23 – 34 kCHF/ stretching site + extra logistics ≤ 23 – 34 kCHF / construction site e.g. 2 deliveries + 1 frame return transport solutions by the local companies No logistic issues Adds one extra transport step < 20-30 kCHF/ c.s. (lower frames number, less transport)

8. Backup 8Mesh TF - reportApril 14, 2014

9. Backup - Industrial stretched meshes 9Mesh TF - reportApril 14, 2014 Quality MSW meshes - CERNPrototype meshes - LMU -7 – 21 N/cm (min-max), 10 N/cm nominal -Systematic inhomogeneity, huge difference between meshes -time stability (4 Months) proven: temperature depended deviation observed, otherwise deviation ≤ accuracy of measurement  results in backup slides -12 – 17 N/cm (min-max), 13 N/cm nominal Thanks to Elias & Ralf!

10. Backup - Self stretching - Visit @ GRÜNIG 10Mesh TF - reportApril 14, 2014

11. Backup - Self stretching - Visit @ GRÜNIG 11Mesh TF - reportApril 14, 2014

12. Backup - Self stretching @ GRÜNIG - results 12Mesh TF - reportApril 14, 2014 -± 2 N/cm (max) -‘pre-stretching’ of the mesh is important! -quality is skill dependent -larger size might increase difficulties -± 1 N/cm (max) -Individual clamp movement improves homogeneity -good repeatability -no concerns about larger size Quality Notice: Measurements done on the machine, not after gluing!

13. Self stretching - summary Stretching the meshes our self with professional tooling… … seams quiet easy to learn, … doesn’t create a huge workload, ( <15 min to install & stretch the mesh, 2 persons required) … and yields satisfying quality in terms of homogeneity … but does not come cheap! (23-34kCHF) (renting / reselling the tool tbd…) Stretching with self made setups (INFN, Class12) … … is much cheaper … seems to yield satisfying results as well … but requires more work and additional R&D With self stretching, we have the quality of the product in our hands and decrease dependence from industries! 13Mesh TF - reportMarch 3, 2014 Quality

14. Backup ‘read-to-use’ setups by Grünig 14Mesh TF - reportApril 14, 2014 offers ‘read-to-use’ setups capable to stretch up to 2500x2500 mm 2 with ≤ 50 N/cm. Mechanical tensioning setup (G-Stretch 210) -fast and continuously adoptable to smaller frame sizes -pre-tensioning of the frame -no frame-mesh contact during tensioning -clean room capable costs: 23.000 CHF Pneumatic tensioning setup (G-Stretch 215) -individual movement of the clamps  compensation of clamping uncertainties possible costs: 33.800 CHF Automatic pneumatic tensioning setup (G-Stretch 215A) -very simple to use (click here for demonstration video)(click here for demonstration video) -automatic compensation of clamping uncertainties  higher homogeneity of the mesh tensioning costs: 43.000 CHF Show-room setups can be visited and tested. (Schwarzenburg – 170km, <2h by car from CERN)

15. Backup – Tension results MSW – Seritec stretching 15Mesh TF - reportApril 14, 2014

16. Backup – Tension results MSW – Seritec – time stability 16Mesh TF - reportApril 14, 2014

17. 17 R EUSE OF T RANSFER F RAME WITHOUT GLUE Mesh Transfer: Standard technique Transfer frames rise from below Fast-Glue is applied from the top Reuse of frame: -Easy twice -More times: Cleaning glue on frame surface Mesh Transfer: Standard technique Transfer frames rise from below Fast-Glue is applied from the top Reuse of frame: -Easy twice -More times: Cleaning glue on frame surface Double-screwed transfer frame: Two coupled frames with surfaces with grooves and rubber to act as clamps One frame is placed below the stretched mesh The companion frame is positioned from the top with correponding holes for screwing Screwing in subsequent steps making one hole per step in the mesh When all screwed, cut the mesh and transport  Can be reused many times Can be built in parts -> easy to transport Double-screwed transfer frame: Two coupled frames with surfaces with grooves and rubber to act as clamps One frame is placed below the stretched mesh The companion frame is positioned from the top with correponding holes for screwing Screwing in subsequent steps making one hole per step in the mesh When all screwed, cut the mesh and transport  Can be reused many times Can be built in parts -> easy to transport stretched mesh Top frame Bottom frame Screw Tests in progress in RomaTre