Plyform Response



How does Plyform determine drawing version?

INFN received email from SLAC and are to flow the current revision to Plyform



How does Plyform know it is the current version?



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.


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).


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.



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.



Tray assembly procedure – discuss bakeout process with Ben Rodini.

See above. Complete.







Plant tour and discussion of process control with Ben Rodini.




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.


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.



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.



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.


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.


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.












  1. Tom Borden sent Plyform coupons to COI for void content. We have heard that the results “were good” but have not seen any results.
  2. Need to check batch numbers of side panels at both Plyform and COI.

š    Have this for Plyform.

š    Jerry Clinton to get batch number from COI. 04 02 04.

  1. Problem is that Plyform is buying material from COI that is always good because they do not own the specification and we are not sure there is one. We all believe this is a SLAC problem. Need to get this resolved by end of February. Need to have the flight sidewalls in June. This is an engineering function. Need to turn this into actions. Who is going to COI next week?
    1. Review COI material documentation.
    2. Develop a specification for the fabric (YS90), and unidirectional material (K13D).

                                                    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.

  1. Mid-tray face sheet material specifications have been developed by Plyform. Material is in Italy for the first 10 towers. This specification is in LATDOCS or the tracker webpage.
  2. Already have the carbon-carbon material for all the trays. This was bought by SLAC. INFN only checks the “integrity of the object”. Will check weight after machining. Nothing to do about this now.
  3. Honeycomb material: Darren has Joe Cullinen is going to manufacturer to due incoming inspection in place and then will ship directly to Pisa.
  4. Kapton bias circuits: All 400 delivered to date with pads in the area Sandro asked to kept clear. Will require an additional high-voltage test after the trays are made. Will use the 39 pieces currently in Pisa this way but the rest at SLAC will be tossed and remade. This shows up on the Gerber data and not the drawings. Jerry to open an NCR. Will be made traceable to the tower by serial number. SLAC will do receiving inspection on all available bias circuits, (about 400), and ship to Pisa. An entire new lot will be made and will be inserted into the production flow when available.
  5. Sandro will receive current pieces with inserts to check them dimensionally to verify tooling. Plyform will restart insert bonding 09 02. They will also start with the closeout bonding on the sandwiches. Goal is to have 10 trays, without payload, (Tungsten and Kapton), by the end of February. Should have the first 10 trays ready to go to G&A. Counting on getting MCMs with GTRC electronics (20 units) around the middle of March. Luisella needs:
    1. Honeycomb as soon as possible.
    2. Quality form
    3. Drawings of the honeycomb with the exact position to glue to Kapton.
  6. Darren reports that he has specified the exact tracker drawings to be used by Plyform. Jeff Tice to get drawings to Sandro, Sandro to get them to Plyform.
  7. Alternative supply. Because there is no specification SLAC told INFN and thus Plyform to purchase both the K13D and YS90 from COI only. Plyform has already talked to YLA, in CA, to get the material, and is using this material for the tray face-sheets so they already have some experience, and a specification, for similar material. The COI resin system is equivalent to YLA, with the possible exception on some thermal conductive modification.
  8. Should ship honeycomb by the end of the week. If honeycomb is at Pisa on 06 02 then can be at Plyform on 11 02. Have 39 bias circuits with the rest going to SLAC for incoming inspection and then out the third week of February.
  9. To use existing facesheets for flight based on EM specifications. Should do on both 4 and 6 layer laminate.
    1. Fiber content.
    2. Void content.
    3. Existing tray-level testing.
  10. Static test fixture. Ricardo has seen the setup. May need calibration, documentation, etc. Need to get it to Pisa as soon as possible with the other bottom tray.
  11. Plyform is not ready yet for bottom production. Tool is not ready. They need drawings for the parts and the tools. Will need about 1 month to make the tools and get them adjusted.
  12. Spares are documented. Only about 11% for some of the material. The carbon-carbon bars for the sidewalls of the trays are the biggest problem with a very long, (years), procurement cycle.
  13. SLAC needs to clarify the bakeout requirement.
  14. Final trim done on milling machine.