The Story of Courtaulds Rayon - In Photos
(First published by Courtaulds Ltd, May 1948)
Wood Pulp Manufacture, starting with Canadian Spruce trees
The logs are stored on the frozen river until spring-thaw when they flow down to the pulp mill
Log debarking an cleaning
The wood-chips are boiled in sodium bisulphite to remove non-cellulose materials
Pulp storage in Courtaulds Coventry
Batches of pulp being weighed prior to steeping in caustic soda
Caustic soda storage: "The Soda Farm"
A steeping press making a single batch of alk-cell (soda+cellulose)
Emptying the steeping press: pulp soaked in 18% caustic soda = alk-cell
A pfleiderer used to grind up the alk-cell
Alk -cell crumbs being dropped from the pfleiderer into the ageing, or Mercerising bins
The alk-cell was stored for a few days to allow the cellulose to depolymerise oxidatively so that it became easier to dissolve...
...after it had been converted to cellulose xanthate by reaction with carbon disulphide in these vacuum churns. This was one of the very smelly parts of the operation! The churns were charged with alk-cell from the mercerising bins on the floor above.
Weighing out the carbon disulphide charge for each churn.
The churns were emptied into these mixers on the floor below. Here the cellulose xanthate was dissolved in dilute caustic soda to make the viscose: "mixer viscose" at this stage.
Filter presses in the viscose cave removed any undissolved pulp fibres...
...and the viscose was then de-aerated under vacuum and "aged" ready for spinning.
Spinning viscose - a honey-like liquid in all but taste and smell!
Babcock and Wilson coal-fired boilers generated the steam and the electric power for the process
BTH turbines in the turbine room
Spinning machines at the Courtaulds Preston filament yarn factory
Preston Works spinning floor
Laboratory spinning of a single thimble
A spinning machine opened for "doffing" the acid cakes - another very smelly operation
The doffer removing an acid cake of filament yarn from the Topham box
Yarns were stretched between the lower and upper godets before being funnelled into the rapidly rotating Topham box
A viscose metering pump as used to feed each jet (1/2 inch thimble)
The viscose was pumped through these candle filter and rounder-end to the thimble.
A half-inch diameter spinnerette with 26 holes to make a 26 filament yarn - prbably at 3 denier per filament
The spinning machine godets
The spinning funnel. This took the yarn from the top godet and, by moving up and down, spread the yarn over the inside of the Topham box
Topham box and spindle motor above and below
Jet cleaning and inspection (blocked holes not allowed)
Acid cakes being wrapped in a porous paper to protect the yarns during washing - another smelly operation.
The finish end of the cake wash machine. The cakes were washed from the inside out by pressurised wash liquors fed from the central manifold
Washing needs a good supply of water
The cake wash machine: a long process where acid cakes enter on the left, pass through multiple washing stages to remove the acid and the sulphurous biproducts of regeneration prior to bleaching and finishing with lubricating oil to improve later processing.
Wet cakes were centrifuged to reduce their water content before drying
Drying was a very long process with little heat - to avoid building strain and hence shrinkage into the yarn.
Process control laboratory
Coning - transferring the yarn from the cakes to a more easily processed cone.
Winding cakes onto bobbins - again to make them easier to handle.
Pirn-winding. The pirns went inside the shuttles which inserted the weft into a woven fabric.
A twisting frame - the yarns were twisted up to 60 turns per inch for crepe fabric, or 25 turns per inch for ladies stockings (above and below)
Cones and cheeses ready for packing
Warping: winding yarns from the cones onto a swift prior to making a beam of warp yarns ready for the loom.(Courtaulds Nuneaton Mill)
Several sections of warp being wound from the swift to a beam
Sizing the beams to protect them from abrasion damage during weaving.