Textile Mercury, 27.4.1889
Wool should always be carefully scoured before dyeing, since neither mordant nor dye can be properly fixed on the fibre if the scouring has been imperfectly performed. If the wool is in. sufficiently scoured, the colour ultimately obtained will not only be irregular and uneven, but it win rub off and the lustre of the fibre be seriously impaired. We purpose here to give details of recent processes for scouring wool which have proved successful.
I. - Loose Wool Scouring.
To scour 100lbs. of loose wool, dissolve in a suitable tank or washing vat, in 300 gallons of water, 12lbs. soda ash and 3lbs. carbonate of ammonia; or, instead of this, 10 gallons of lent or stale urine may be used, but the ammonia product is preferable. The wool is entered into this vat and worked for 20-30 minutes at 04°-100°F., being well raked about while in the vat. Care must be taken that the temperature should not exceed 100°F., as at higher temperatures than this the wool is deteriorated. After the operation is over, it is taken out, passed through a pair of wooden squeezing rollers, and into another vat containing 10lbs. soda ash in 300 gallons of water; in this the wool is worked for 15-20 minutes at 95°-100°F., and then, after passing through squeezing rollers, it is washed in clean cold or tepid water.
The scouring liquor in the first tank must be replaced by fresh liquor after four or five lots of wool have been passed through, since it becomes soiled by the impurities which it removes from the wool, and its efficiency decreases with each lot entered in it. It is, therefore, false economy to continue the use of the same scouring liquor too long.
II. - Scouring of Yarn.
Woollen yarn is scoured to remove the size, oil, etc., which has been added to the scoured loose wool to facilitate the spinning process.
It is most essential that the loose wool should be thoroughly scoured before it is spun, since it is almost impossible to remove the yolk from yarn, and if any of this should be left in it invariably leads to imperfect dyeing of the yarns or piece goods into which the wool is spun and woven. To enable the loose wool to spin easily it reouires to be oiled; this oiling should be done only with gallipoli oil, oleic acid or other saponifiable oil; mineral oils or mixtures of fat and mineral oils ought to be rigidly excluded.
Yarn is scoured in suitable tanks, it will be found best to have these of about 90 gallons capacity and which will hold 50lbs. of yarn. For this quantity use 4lbs. ammonia and 80 gallons of water. The yarn is worked in one tank for 20 minutes at 100°F., then it is passed through squeezing rollers into a second tank where it is again worked for 15 minutes; finally, it is washed well. The liquor in the first tank should be run off and the grease recovered from it; that in the second tank, after freshening up by addition of 2lbs. of ammonia, can be used as the first tank of a new lot of yarn.
III. - Scouring of Piece Goods.
For scouring piece goods for 100lbs. of cloth prepare a tank or vat containing 5lbs. soda and 2½lbs. carbonate of ammonia with sufficient water; this alkaline liquor is kept at 100°F. and the goods should be run through at such a rate that they will remain, in about 20 minutes; they can then pass into another vat containing fresh liquor for tee minutes, and finally through wash waters.