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Concern/Issue |
Plyform Response |
Note |
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How does Plyform determine drawing version? |
INFN received email from SLAC and are to flow the current revision to Plyform |
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How does Plyform know it is the current version? |
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Tray Production flow plan – Where is ESPI performed? |
INFN is thinking about moving the equipment for this test to Plyform. For the first 10 trays will definitely keep the test in Pisa although the natural place for this is at Plyform. |
The main point here is the less handling and shipping of flight hardware, the better. Also, the activities performed by INFN must have travelers/test reports. |
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Where is bakeout performed? |
Done in Rome. Bakeout process – Put tray in TV chamber. Trays are inserted in rack with resistance heaters to get trays to 85 degrees C for 24 hours. (24 hours is a Tom Borden suggestion). Typically use a TQCM monitor. We will need a bakeout procedure and expect to see a TQCM monitor. Darren to check with contamination person. Nanda requests this TQCM be provide CFE. Jerry not sure of the need. Requirement came from Darren. This implies we may not need this requirement. Basic procedure is to do a surface clean at Plyform, ship to Rome where they clean with tekwipes and alcohol, place in the chamber for bakeout, clean with tekwipes and alcohol and ship to G&A. At G&A they do another cleaning. Bakeout could also be good for revealing trapped gases, (bubbles). |
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Review of Darren’s comments on the ESPI procedure and traveler. |
INFN admits this procedure is not finished. We will have to take another look when the procedure is more mature. |
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How is ESPI validated? How is the system calibrated? |
Rejection criteria will be developed with resonant frequency the main number, no damages/defects over 2 cm. This specification still needs to be developed. Minimum defect detectable is 2 cm. Already made defective panels and measured them with the ESPI setup. Ricardo showed some charts with these results. |
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Tray assembly procedure – discuss bakeout process with Ben Rodini. |
See above. Complete. |
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Plant tour and discussion of process control with Ben Rodini. |
Done. |
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Discuss adding Mandatory Inspection Points a final INFN Q/A acceptance of end-item data package. |
Darren not interested in having the end-item on the “database”. Plyform usually send the certificate of production. |
Darren does not expect to perform a detailed review of travelers. He has already done this and was very pleased by the level of process control at Plyform. |
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How are trays shipped? |
Not developed yet. Trays will be sealed in plastic bags with desiccant. Rigid box, probably wood, with foam. Will be shipped to Pisa for ESPI, inspected and then repackaged in the same basic container. |
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NCR and MRB process description. |
Sandro will have a person here at Plyform to track the production here and fill out NCRs. These will emailed directly to SLAC. Sandro proposed to start INFN level NCRs at the bare tray level. Seems like a good idea. |
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Review coupon test results |
Short beam shear and compression test results were close to COI, but tension test results are different. Plyform is getting about 55ksi where COI was getting over 80ksi. Likely to be different failure modes. Also different material lots could be a problem. Plyform has had a problem with the tension testing before. Overall thickness/fiber volume look good. |
Ben looking for material lot number. Test report to Sandro to include pictures of failed specimens. |
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Material Purchasing |
Plyform is purchasing their material from COI using a COI specification. This specification was formulated between Hytec, COI, and SLAC. The callout for it is on the sidewall drawing. This is a SLAC drawing. Currently they have no material for flight sidewalls. |
Specification problem must be solved. |
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Concern about stress in AL layer interface. |
Sandro to take existing sidewall panels back to Pisa to check and make sure they maintain integrity. Check if flatness changes or surface cracks, etc. |
Ben suggests 4 to 5 cycles with no more than 30 minutes plateaus. Less than 2 degrees C per minute. |
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Notes:
š Have this for Plyform.
š Jerry Clinton to get batch number from COI. 04 02 04.
i. Physical properties:
1. Fiber areal weight.
2. Fiber type.
3. Resin content.
4. IR scan of resin
5. Glass transition temperature
6. On-set temperature
7. Peak temperature
8. Void content.
9. Tack
10. Gel time
11. Flow
ii. Mechanical properties:
1. Tension modulus and strength (average and minimum)
2. Compression modulus and strength (average and minimum)
3. Short beam shear strength.
iii. Fabric only:
1. Number of yarns per width in warp and fill direction.
iv. Workmanship and defects part of the specification.