THE GREAT MULLARD MAGIC BLOG — CRT

Just in case you thought Sebastian and his co-workers had to heft these long and wieldy tubes to remove the supernate, actually, no, they were placed on a rotating carrel that was tilted at such a rate as not to disturb the accreted phosophor film that sat on the inner face of the tube.  Here you see a laboratory coating system, however, the full size plant used a similar principle  - such fun!

Here we have a nice photograph taken at Mullards in 1952 of Sebastian Firkle who is laying the luminescent screen in a Mullard picture tube.  The screen phosphor was suspended in a liquid carrier and introduced into the envelope. After settling, the supernatant liquid was carefully decanted off leaving an even distribution of phosphor which was then dried under a gentle stream of cold air.

Here we see a wonderful evocative photograph of operator Dabney Grimble attending to CRT bulbs at Mullard Mitcham. Pictured is the manufacturing stage where the neck tube has just been welded to the bulb.  To avoid heat induced stress at the weld junction, the bulbs are placed in an annealing furnace for 150 minutes along a graduated tunnel furnace which controlls the rate of glass cooling.   The bulbs travel by carrel to the annealing furnace whilst suspended in a vacuum chuck which is kept at the same temperature as the bulb to prevent breakage.    Placement of the vacuum...