The following notes on papermaking are condensed from Dunbar's valuable little work called the 'Practical Papermaker.' Those desiring a more exhaustive and scientific account of this industry should refer to Spoils" Encyclopaedia.'
Rags are brought to the mill in an un-sorted condition, and are called "mixed." The system of assorting and classifying rags in common use in this country, and the distinguishing mark given to each sort, cause considerable confusion.
The superiority of the Continental system is very marked. There the rag department consists of a 2-storey building; on the ground-floor the cutting and sorting is done; the upper storey is fitted up with 20 stalls or compartments, numbered from 1 to 20. The rags, cut and overhauled, are hoisted to the second flat, and deposited according to quality in the numbered compartments, and thence taken to the willows in quantities of the various sorts to make up the desired stuffs. The rags are known by number as follows: -
No. 1 rags, white linen without seams, fine clean; No. 2, white linen with seams, fine clean; No. 3, white linen with seams, second quality; No. 4, white linen with seams, third quality (the three last-mentioned qualities are easily distinguished, for as the quality deteriorates the rags become thicker, and the thicker the rags, the greater the quantity of sheive they contain); No. 5, blue linen without seams, first quality; No. 6, blue linen with seams, second quality; No. 7, blue linen with seams, third quality; No. 8, good linen, seconds; No. 9, coarse linen, seconds; No. 10, white cotton, fine, first quality; No. 11, white cotton, second quality;
No. 12, coloured cotton, third quality; No. 13, sailcloth without seams, first quality; No. 14, sailcloth with seams, second quality; No. 15, fine hemp bag-giug, good clean; No. 16, good hemp bagging; No. 17, hemp rope, fine clean; No. 18, hemp rope, good clean; No. 19, hemp rope, free from tar third quality; No. 20, broke from all the above except the rope.
The simplicity and efficiency of this method are evident; the higher the number is, the coarser the quality of the rags: No. 1 is the equivalent for S.P.F.F.F.
Blending the rags for different stuffs suitable for various qualities of paper requires great care. A paper of a certain quality is desired: the difficulty is to blend that proportion of cotton with linen rags which will produce a paper, tough, strong, well-sized, and possessing those elastic qualities which will permit it to be folded into any shape without showing signs of cracking, as is especially necessary in book papers. The most convenient and efficacious mode is to form the various rags into stuffs, composed as follows: -
No. 2 rags . .
,, 55 ,, ...
No. 4 rags . .
,, 6 ,,
,, 8 ,,
No. 1 and No. 3 stuffs are for specially strong papers.
No. 7 rags .
. 1600 lb.
,, 9 ,,
. 2800 „
„ 20 broke .
If broke accumulates, a larger proportion can be used in making coloured papers, otherwise the above quantity is sufficient. Rags Nos. 10, 11, and 12 are specially reserved for blending, for thick papers, or for printings of a high class. Nos. 13, 14, 15, and 16 supply the place of any of the numbers for which they are suited. No. 1 can be drawn upon in the event of a special paper being desired.
No. 6 rags • .
,, 8,, • •
No. 17 ropes,
. 2600 lb.
,, 18 „
. 1200 „
,, 19 „
. 200 „
The qualities of paper on the Continent are known by numbers, No. 1 being the highest quality of writings and printings. The qualities of paper that can be made from the various stuffs are -
From No. 1 stuff, extra superfine or No. 1 papers. „ 3 „ superfine and fine papers, „ 4 „ fines, fourths, and coloured papers. „ 5 „ thin papers ; also used for mixing with the rope stuff, for cigarette, copying, and tissue papers. The classification of home and foreign rags, according to the method generally adopted in this country, is: - Superfines, S.P.F.F.F., S.P.F.F., S.P.F., dark fines, grey or green linen, new pieces, sailcloth, F.F., L.F.X., C.L.F.X., C.C.L.F.X., fines, seconds, thirds, cords both dark and light, outshots, prints, and the various qualities of hemp and jute bagging Superfines consist of superfine new white shirt cuttings; S.P.F.F.F., extra superfine white linen, first quality; S.P.F.F.,- superfine white linen, second quality; S.P.F., fine white linen, third quality; dark fines, fine white cotton rags, well adapted for blotting-paper of a good quality; green linen, fine unbleached linen cuttings; new pieces, fine unbleached linen cuttings; sailcloth, canvas (worn) and new cuttings; F.F., coarse Russian linen rags, first quality; L.F.X., coarse Russian linen rags, second quality; C.L.F.X., coarse Russian linen rags, third quality; C.C.L.F.X., coarse Russian linen rags, fourth quality.
The last four sorts of rags are easily distinguished, as there is a considerable difference in the quality and appearance, the rags being thicker and sheivier as the quality deteriorates.
Fines consist of fine white cottons; seconds, soiled white cottons; thirds, extra dirty cotton linings; light and dark cords, light and dark cottons (thick); outshots, good, strong, and sound rags; prints, cotton of various grades.
Home linen rags are often mixed with jute and cotton. When jute is present in linen, the colour is not so good when manufactured. The simplest method of discovering the presence of jute in linen is to wash a sample, ana treat with diluted chlorine, when the jute will assume a red colour, and the linen bleach white. With cotton in linen, destroy the cotton with sulphuric acid, and only the linen will remain.
Boiling the raw material is most important. Neglect in this department cannot be remedied after the material has left the boilers. It is absolutely necessary to know how to bring the material to the highest state of perfection without injury to its texture, and with a proper regard to the cost. Much depends upon the facilities for boiling, and the quality of the water, whether soft or hard. All rags contain sheive, which nothing but judicious boiling will remove. Badly-boiled stuff consumes too much chlorine, and makes a poor-looking paper. Great waste of chemicals ensues when proper care is not exercised, especially with esparto, one lot boiling with 2 to 3 lb. less caustic soda to the cwt, than others; there is considerable difference in boiling summer and winter esparto: the summer requires more boiling, and turns out better - a fact attributable to the smaller amount of moisture contained in it.