Substrate-Paddle-Base

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Substrate-Paddle-Base

• Peter Cooke

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Substrate-Paddle-Base

• Substrate Production
• Paddle Base Feet Component Production

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LHCb Substrate Production

• Substrate Dimensions
• Materials and preparation
• Lay-up
• Inspection and Packaging
• Recommended Curing Instructions
• Summary

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Substrate Dimensions

• Carbon Fibre 177 x 123mm
• TPG 169 x 115mm with semi-circular cut-out
  (detector area)
• 4mm Carbon Fibre frame surrounding TPG

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Materials Preparation TPG

• 400um TPG board cut to 169 x 115mm
• Semi-circular area removed
• Abrade both sides with course emery paper
• Cleaned and degreased with alcohol
• Left to dry

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TPG with cut-out
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Preparation Carbon Fibre

• Supplier Amber Composites UK
• Carbon fibre Pre-preg 120 gm plain weave, epoxy
  resin impregnated
• Cut to size 177 x 123mm
• 2 Pieces weave direction 0 90 deg
• 2 Pieces weave direction /- 45 deg
• Pre-preg approximate cured thickness 0.125mm per
  layer

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Lay-up Procedure

• Release film applied to flat steel plate
• 1st layer 0 90 deg on flat plate
• 2nd layer /- 45 deg on top
• TPG placed centrally on 2nd layer
• 4mm strips of pre-preg surrounding TPG (and in
  cut-out) 3 layers with orientation of fibres
  balanced
• 3rd layer /- 45 deg placed over previous
• 4th layer 0 90 deg to complete

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Carbon Fibre and TPG
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Recommended Cure

• Amber Composites
• Fibre T300
• Resin E722.02 45 RW
• Increase temp. to 120 C _at_ 3 C/ min
• Increase pressure to 90 psi
• Hold for 1 hour
• Cool to 60 C before releasing pressure

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Inspection Packaging

• Visual Inspection - surface finish
• Inspection Micrometer/Smartscope
• Substrates have release film applied to each face
  to protect resin
• 10 substrates are sandwiched together between two
  6mm thick aluminium plates
• Surrounded in foam and packed in cardboard box
• Shipped off to Stevenage Circuits

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Summary

• Carbon Fibre remaining to produce up to 80 more
  substrates
• 39 pieces of TPG in stock (20 on order)
• Carbon Fibre stored in freezer _at_ -18 C
• TPG stored in locked cupboard
• Can produce 10 per week

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LHCb Paddle/Base Components
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Paddle/Base Assembly
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Base and Feet Manufacture

• Base Cut from solid sheet of carbon fibre and
  machined in-house.
• Invar feet CNC Wire Eroded in-house to
  guarantee accuracy. Spigot on right foot
  tolerance 0.000 to 0.008
• Feet numbered in pairs

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Paddle Fabrication

• Material Pre-preg
• ACG VTM264/CF0300-42RW 200 gram 2 x 2 Twill
  (Stored18deg C)
• Female mould tool CNC machined and hand finished
  in two halves.
• Dowelled and fastened together during lay-up
• Tool treated with PTFE release solution and
  buffed to a gloss finish

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Paddle Lay-up

• Carbon fibre cut to templates, 2 layers per face.
  1 _at_ 0/90 deg and 1_at_ /-45 deg
• Apply fibre to each face, 0/90 then /-45
• Final thickness over major area of paddle 0.5mm
• Rear face fibre flush to tool surface
• Front face overlapping tool face 6 2mm along
  length
• 3 x 12mm wide strips added to each face at the
  topmost area of the tool.

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Paddle Lay-up (cont)

• Add release film and bleed ply fabric to the
  exposed fibre
• Add a strip of breather fabric to each side
• Make vacuum bag and fit into front side of tool
• Place rear side of tool over dowels on the top
  and fasten into place
• Place assembly into large vacuum bag and seal
  inner to outer bags

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Paddle Cure

• In autoclave
• Apply vacuum
• Heat to 65 deg C at 0.5 deg C/ minute
• At 65 deg C apply 90 psi
• Hold for 16 hours
• Cool, release pressure and vacuum
• De-mould the part

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Parts Inspection

• Visual inspection Surface finish, conformity to
  mould-tool, loose fibres, resin high spots, etc.

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Summary

• 17 - Paddles ready
• We have enough carbon fibre stored in freezer to
  produce another 80 paddles
• Carbon Fibre Bases ready Total 80
• Invar Feet ready Total 80 sets
• Aluminium inserts ready Total 80 sets