For 100 per cent.—1lb. of size for 1lb. of warp. Similar ingredients are used, but different proportions. Flour 560lb., clay 560lb., tallow 130lb. (or other softener), chloride of magnesium 20 gallons, chloride of zinc 10 gallons, soda 10lb., and blue.
The flour is steeped alone for three weeks, at the end of which time the zinc is added to it with soda and boiled, then the other ingredients, which had been previously heated in the boiling pan, are lowered into the flour and the whole boiled together.
For 150 per cent. put still more clay and magnesium to the same quantity of other substances, adding some specially prepared softening grease, or adhesive size mixture.
The mixing of size requires constant care and supervision; for variations in the quality of materials, in the weather, or in time of storage or steepage necessitate changes in the proportions of ingredients to obtain correct and unvarying weights.
Sizing Machinery.
The slasher is the machine generally used for applying the size to the yarn; the usual name for the process is taping, a word derived from the old tape frame in use 30 years ago, and handed down to its successor, the slasher. One sizing frame is required for 300 looms, the width of the frame being adapted to the size of beam required for the loom; this is a few inches wider than the cloth. A common size is a 9/8; this makes warps 54 inches wide between the flanges, the drying cylinder face being 60 inches wide; a 6/4 is 60 inches beam and 66 inches on face; an 8/4 = 78 inches and 84 inches respectively.
A sizing frame is of great length, and in three portions—at the back the creel, in the centre the drying, and in front the headstock. (See [Plate IV].)
PLATE IV.—SLASHER SIZING MACHINE. To face p. 40.