PAPER FROM RAGS 13
half stuiF to treatment with chlorine gas in a gas chamber, but it is better, if
possible, to remove it subsequently by mechanical means in a centrifugal machine.
In order to obtain half stuff of a good colour from such linen or flax, and
also as free as possible from shive, it will generally be found advantageous
to use more caustic soda in the boiling, and subsequently less bleach, than
vice versa, as by this means the rags are not so liable to become tender. Such
stock can rarely, if ever, be bleached to such a good white colour as cotton.
New Unbleached Cotton Cuttings, sometimes known as 'new greys' or 'yeltaw
cottons', are the waste from factories using unbleached calico, and they vary
greatly in quality and value. The best 'board cuttings' are usually excellent
material, containing little or no loading or starch, and being free from shive
and dirt. They are often nearly as expensive as new white cuttings.
On the other hand, new greys may consist of shoe cuttings or the waste
from shoe factories, consisting of inside linings of leather shoes and trimmings
from canvas shoes, and 'Swansdown'. While some of this material is ex-
cellent and equal to new board cuttings, a great deal of it is coarsely woven
and full of loading. The loading in some cases is as high as 70 per cent of the
weight of the rag. This loading is, however, by no means the greatest draw-
back to this material; leather dust and small clippings of leather, and, above all,
rubber solution, so difficult to detect in the rag room, make the use of it very
risky indeed.
Unbleached cottons are picked over by sorters, and the long strips are
either cut up by hand into suitable lengths, or the whole may be put through
the chopper and dusted prior to boiling.
Caustic soda is used for boiling, the amount varying according to the quality
of the rags, and the amount of starch and loading which they contain. From
2 to 5 per cent of caustic soda will generally be sufficient, when the pressure
employed is about 25 Ib. and the length of boil about 6 hours.
New Lace Curtain Cuttings are a valuable material, being strong, clean and
easily prepared. Their chief drawbacks are the amount of starch which they
contain, and also the small hard knots, which have to be carefully broken up.
They require to be overlooked, on account of floor sweepings from the
factories, which sometimes find their way into the bales and introduce chips
of wood, straw, etc. A small amount of soda ash (sodium carbonate) is usually
sufficient to reduce them during boiling, which may be completed in 3 or 4
hours. They require careful handling in the breakers and very little bleach.
New Unbleached and White Cotton 'Healds can sometimes be obtained, and
they form a valuable substitute for new 'greys'. These consist of cotton strings
about 6 to 12 inches long, plaited together at one end. Those from Egyptian
cotton are best, and they give a pulp of great strength and cleanliness.