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From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Receipt, inspection, and potential use of cold moulded insulation samples named Thermoplax and Pyroplax.

Identifier  WestWitteringFiles\G\August1921\  Scan44
Date  10th August 1921
  
To R & E from EFCl
c. to CJ & PN.{Mr Northey}
c. to Ry. & Rg.{Mr Rowledge}
c. to EP.{G. Eric Platford - Chief Quality Engineer} & Da.{Bernard Day - Chassis Design}
c. to R.R. of America Inc.
c. Wd.{Mr Wood/Mr Whitehead}

ORIGINAL

X.2494 - COLD MOULDED INSULATION - THERMOPLAX AND PYROPLAX.

We have recently received from the Igranic Electrical Company, Bedford, a number of samples of Thermoplax and Pyroplax moulded insulations, in different grades, and we are sending for your inspection three selected samples of each material.

Thermoplax strongly resembles Litholite or Solidite. Most of the samples have been buffed and some machined, while one sample of Thermoplax, labelled P.C.120 has been varnished.

The Pyroplax is generally rougher and more like Siluminite.

Pieces of these insulations retained by us will be put through various tests for insulation, absorbtion, etc.

Though it seems unlikely that these substances can complete with Bakelite, Pyroplax might possibly make a good mount for the nickel wire in the ballast resistance.

The Igranic Co. have sent is quite a lot of samples in all, but asked us to return the majority of these, only keeping a few for our own reference. We are attaching to your copy of this note, Publication 413 of the Cutler-Hammer Manufacturing Co., descriptive of the

Contd.
  
  


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