DISCOVERY 



Jute-Dyeing 



This fibre is one of the most interesting, if not one of the 

 most important, that finds great and growing application 

 in the textile industry, possessing many qualities that are 

 not shared by other fibres of similar origin, and which 

 are valuable factors in directing its use for the manu- 

 facture of certain classes of fabric that are of considerable 

 commercial value. 



To many persons jute is synonymous with burlap, 

 which is used for bag manufacture ; but since processes 

 have been found that enable the fibre to be bleached 

 and dyed in a satisfactory manner, the plebeian idea of 

 the use of jute must be set aside and a more refined 

 position given it. 



A tour through any of the large department stores 

 in large cities in America, or inquiries at any interior 

 decorating establishment, will convince anyone regarding 

 the wide range of uses to which jute is put, while its popu- 

 larity from an artistic standpoint will not be overesti- 

 mated. 



Ihe jute plant has been known and raised in India 

 from the very earliest times for the valuable properties 

 of its fibre, but it has only been since the beginning of 

 the nineteenth century that the systematic treatment 

 of the plant for its fibre for use in textile manufacturing 

 received any attention. As a matter of fact, the only 

 textile manufacture that jute was consumed in for many 

 years was the manufacture of continually increasing 

 quantities of bagging for use in baling the American 

 crop of cotton. It was not until the late sixties or early 

 seventies that jute bagging became the article almost 

 exclusively used for this purpose, and consequently the 

 jute industry — not alone from the agricultural view- 

 point, but from the manufacturing viewpoint as well — 

 has increased to immense proportions, and there is a 

 prospect that it will continue to grow, for the reason 

 that we have not in sight any other fibre that is fully 

 able to take its place. 



Jute fibres are obtained from that part of the plant 

 known as the bast, which consists of that portion of the 

 stalk ne.xt to the outer crust or rind. This appears, 

 when viewed under the microscope, to be made up of 

 innumerable " bundles," wliich are actually the fibres 

 of commercial value. The scientific name is Corchorus 

 capsularia, while the common names are too numerous 

 to be given. 



The plant grows to a height of from 5 to 10 feet, the 

 average diameter of the stalk being over half an inch, 

 with few branches except near the top. While the jute 

 plant had been cultivated in many parts of the world, 

 India retains its pre-eminence in this regard, the greatest 

 crops of the fibre being raised in Bengal. 



The commercial fibre is separated from the plants 

 by treatment with cold water ; the leaves, branches, 

 and capsules are removed from the stalks. These are 

 immersed for several days in a stream of slowly moving 

 water, at the end of which time the fibre portion may be 

 removed without any difficulty, and in considerable 



purity. The dried fibre is made up into bundles, the 

 length of which varies from 6 to 8 feet. For textile 

 manufacturing purposes, not all of this length is utilised ; 

 about 12 to 14 inches from the thick end is usually cut 

 off, and finds its outlet in the manufacture of paper stock, 

 under the name of " jute butt." That portion of the fibre 

 used for textile purposes is softened with an emulsion of 

 soap and oil, and is aftenvards hackled and spun into 

 threads, and then woven into cloth, or otherwise utiUsed. 



Jute, unlike many of the vegetable fibres, though 

 used for coarse fabrics, requires considerable care, as 

 it is incapable of resisting harsh treatment. 



Wliile there are known a number of practical processes 

 for bleaching jute, the one yielding perfect results is 

 yet to be discovered. Those which follow, however, 

 are to be recommended only by the fact that they axe 

 at this date actually used in various mills where jute is 

 treated. 



For Jitte Pieces. — Pass through a J per cent, solution 

 of silicate of soda, heated to 160° F., then through a 

 second solution of sodium hypochlorite of such strength 

 that the vat does not contain more than i per cent, 

 of chlorine available for bleaching as determined by a 

 volumetric test. This hypochlorite is made bv acting 

 on a fresh solution of bleaching-powder with one of soda 

 ash, adding the latter until no further precipitation of 

 calcium carbonate is noted, let settle, and draw off the 

 clear portion for use, diluting with water until the proper 

 strength is obtained. 



After passing through this solution, the goods are well 

 washed and passed through a weak muriatic acid solution, 

 to which has been added a small quantity of sulphurous 

 acid. This treatment is to ensure the removal of certain 

 substances that tend to discolour the otherwise bleached 

 material, and also to remove the small quantity of iron 

 tliat is always found in the crude jute fibre. Finally, 

 wash well and dry, but, if it is intended to print colour 

 on the fabric, pass tlie cloth through a solution of bi- 

 sulphate of soda containing about 2 percent, of sulphurous 

 acid, squeeze the excess of liquor out of the cloth, allow it 

 to lie covered with damp burlap for three or four hours, 

 and afterwards dry over cans. This treatment leaves 

 only neutral sulpliite of soda on the fibres, which does not 

 aSect the printing colours during steaming, but preserves 

 the fibre against the oxidising action of the steam-chest 

 atmosphere. The loss in weight by this process is some- 

 times as great as 8 per cent. 



Another process is to subject the jute alternately to 

 the action of potassium permanganate and sodium bi- 

 sulphite, but the cost is against it, although the results 

 are very good when properly conducted. 



A perfect bleach is almost impossible to secure, as the 

 fibre will not stand the necessary treatment. The only 

 way to obtain passable results is to bleach with the first 

 process above indicated, and then to make use of a tinting 

 blue, for wliich purpose some of the so-called " soluble 

 blues " answer very well. 



Jute, like all the otlier fibres of similar origin, is not very 

 difficult to dye ; but unlike most fibres, unless some special 

 care is taken, uneven results will always be obtained. 



