November, 1909.] 



409 



Fibres, 



the same month of last year, India is 

 continuing to take freely and so are 

 JaTpan and Germany. 



The Problem of Over-Production. 



In considering the outlook for the in- 

 dustry, the main factor is over-produc- 

 tiou. New spinning machinery is still 

 starting in South Lancashire. Probably, 

 unremunerative trade will stop the fill- 

 ing of factories with machinery to a 

 certain extent. Then it is almost certain 

 that short time will be forced upon the 

 masters in one way or another. If, as 

 is likely, short time is generally adopted, 

 the lessened cotton consumption will 

 tend to depress the raw material. Low 

 values for cloth should attract buyers 

 abroad, and this may lead to greater 

 activity in the placing of orders for 

 distant delivery, but a good deal de- 

 pends on the clearing out of old stocks 

 bought at higher rates than to-day's 

 selling prices. 



THE SUPPLY AND MANUFACTURE 

 OP WOOD PULP. 



(Prom the Indian Trade Journal, Vol. 

 XIII. No. 157, April, I, 1909.) 



An Engineering correspondent writes 

 as follows to the Times Engineering 

 Supplement of March 10th :— 



The continually increasing demand for 

 cheap paper-making materials during 

 the last twenty years has resulted in a 

 most remarkable expansion of the wood 

 pulp industry. The general adoption of 

 this material as a substitute for rags and 

 Esparto grass in the manufacture of the 

 cheaper classes of papers is very clearly 

 shown by the Board of Trade returns, 

 which furnish an accurate index of the 

 growth of the trade. 



In 1887, the imports of wood pulp into 

 this country were for the first time 

 separately classified, and in that year 

 they amounted to 79,543 tons, valued at 

 £511,450. In 1905 these figures had risen 

 to 578,012 tons and £2,759,027 respec- 

 tively ; while during 1908 the shipments 

 were no le^s than 748,419 tons, with a 

 value of £3,625.803, or a total increase in 

 tonnage during the period under review 

 of nearly tenfold. The rapidity with 

 which the Scandinavian pulp-makers 

 have increased the capacity of their 

 mills, iu order to meet the demand, has, 

 of course, had the effect of keeping down 

 prices somewhat, but it will be seen 

 from the above figures that the total 

 value of the imports into this country 

 during last year was about seven times 

 that of the shipments for 1887. 



The best qualities of celiulose for 

 paper-making are still obtained from 

 rags and Esparto grass, and it is worthy 

 of note, as an additional indication of 

 the development of the British paper 

 trade, that although the consumption of 

 wood pulp as a raw material, or, rather, 

 as a "half-struff," has increased in such 

 a remarkable degree, the consumption 

 of rags and Esparto has not appreciably 

 decreased, although the market value 

 has inevitably fallen, as the result of 

 competition with the cheaper substi- 

 tutes. 



The various qualities of wood pulp 

 which are now available for paper- 

 making purposes are divided into two 

 distinct classes, "mechanical" pulp and 

 " chemical " pulp. In the production of 

 mechanical pulp no chemical treatment 

 is involved ; the operations, as will be 

 indicated presently, are entirely of a 

 mechanical nature, and hence the name 

 under which the material is dealt with 

 in commerce. On the other hand, 

 " chemical pulp " is a very much purer 

 form of cellulose, obtained by the treat- 

 ment of the wood with various chemicals, 

 this latter fact accounting for its tech- 

 nical description. 



Mechanical Pulp. 



In the manufacture of this material, of 

 which 432,478 tons were imported into 

 this country during 1908, the process is 

 very simple. Large blocks of wood are 

 fed into the grinders which consist 

 merely of revolving giindstones, with 

 feeding arrangements, which press the 

 blocks against the face of the stone, 

 the fibres being thus torn from the 

 blocks. As the wood is ground off, it 

 is washed away by flowing water, 

 passed through scieens, formed into 

 thick sheets from which a part of the 

 water is extracted by pressing, packed 

 into bales, and shipped as " mechanical 

 pulp." The grinding action to which 

 the wood is subjected destroys the 

 "felting power" of the fibres, and in 

 consequence machanical wood pulp is 

 not used without admixture with other 

 superior forms of celluolse in the manu- 

 facture of paper. For making what are 

 known as paper boards it can be used 

 without any addition, but if mixed with 

 a very small proportion of "chemical 

 pulp," which is longer in fibre, it forms 

 the material from which almost all 

 "news" and other inferior printing 

 papers are produced. The "felting 

 power " of mechanical pulp is improved 

 if the wood is steamed for about ten 

 hours before grinding, but even the best 

 qualities of the " hot-ground" product 



