5. Error due to 1)roducts of ieriiieiitation in old or spoiled samples is avoitled 1)). boiling liefore 1irccil'it:iting. 6 . l i ' i t l i the ;ivei.qc iiioisturc coiiteiit of I O - i 2 per cent. for sugars, cciit. for sirul)s, tlie lead \-dues are in each case 011 about and >,? -3,j the same a:iioiuit oi dr!. sulistaiicc. I t might be a good plan t o make a moistlire tleteriniiiatioii on w c h sample and calculate the /cui! ziiiuc to "dr!. sulistaiice." nU1:FAI.l)
~,AI',OKATOt?T.
TYPEWRITER CARBON PAPERS. BY A .
Keceived
31. 1)oYLI:. Jline 20. 190F;.
'I'ypewriter c a r l m i papers are riiucli iisetl in the departments of the go\-ernineiit and for this reason :ti1 investigation into their qualities was made liy' the Coiitwcts 1,al)oratory oi the Bureau of Chemistry. The paper fouiiclatinii \vas tested for tensile strength, length and width ; stretch iirider straiii. 1)oth lciigth ant1 \vitith; weight, inked and clean; thickncss of inked p:tper; kiii(1 of Imlp used aiid degree of beat. ?'he i n k , as distinct from the paper, \vas separated into its coiistituents of oil or \vas, t1L-e :riitl pigiiients, and iiioisture and ash were determined. ,< 1 h e lvritten matter \vas rated oil ;I scale of ten aiid was also subjected t o sunlight and solul)ilit!, tests. Of the t w e n t y eight samplcs esarnined, five were copy papers and the s black, blue, purple and green, all others record. Ci)p>. ~ ) q > e riiicluded of stantlard \\eight : record 1):tpers consisted of black, blue and purple : full-inketl arid s;ciiii-inketl: staiitlartl iveiglit, light weight and feather weight. 'I'ahlcs I , I I aii(1 111 represeiit the three classes of results. 111 lable I the p!i! sic:il t.ests Ii:i\e been arranged according to the weight of t h e paper, ;is tlescrilml I)!. the iii:tiiufac'turcr, while in Tables I 1 and 111 they :ire di\-itletl lii-st iiito record ~ i i i t l cup!. ; then according t o colbrblack, blue ant1 i)ii;pie, i i i tlic order iiaiiied ; :tiid finall!.) within each group a~cortliiig11, ivcxig-ht, ir0111 stmtlartl to feather weight. Discussion of Results. .I coiii1)arisoii oC tlie iigures for the \veig-lit of the paper per square centiiiieter iiitlicates that KO. 2 2 0 2 sliotild he classed with light weight papers. N o s . 2 2 0 0 , 2293, 2 2 9 4 , ? , ; o r a i r t l 2 , y ~with staiidard weight, ant1 S o s . 2 ~ 3 0 0 , 2 3 x 1 arid 2 , 3 8 2 \\.it11 tlic. light weight: I,ut otherwise these on tlie lahel of the papers> g r o i i p d :is iiit1ic;iLcd 1)) I lie ~iiaiiiifacturt.~.~ folIci~,\. c I ( w 1 ~c(>i.t;iiii \vc.iglit l i i i i i t y . Inkctl 1xtpers average less tlixii 2 iii;:. p r s ( 1 i i : i i ~ c~ciitiiiieterf o r fe:ttlicr \veiglit, froiii 2 . 2 -?.,I llix, i o r lig-lit \\.ctig1it :iii(1 :i little less t l i a i i ;, i i i x , ior staiidarrl \\.eight. I he cleaned pa1)ws, free oi ink, ivcigh less than I iiig. for feather weight, ,%
q1.1,
, \
1617
T Y P E W R I T E R CARBON PAPERS.
-I
: e c e c c
-a
1618
A . 11. DOYLE.
between 1.0 and 1 . 1 rng. for light weight and from 1.6-1.7 for standard weight papers . 11r. B. J . Tloward, Chief of the Microscopic 1,aborator)-, made all of t h e tests for thickness, kind of pulp and degree of beat. 1:rom the last column of the table it ma!- be seen t h a t the degree of beat of the pulp is generally coarse or medium in standard weight material and for the light and feather wcight is usually fine or medium. The kind of pulp is not uniform, being either all rag, all sulphite, mixed rag and sulphite or mixed rag lvith a kind of fiber "some\t'hat resembling esparto, though without its characteristic structure." These fibers 31r. IIoward found i t "impossible t o determine, as they were so thoroughly beaten as t o almost destroy their identity. I t \\-asfound impossible t o distinguish between linen and cotton fibers for the same reason, and both together are classified as rag," In general, those papers containing rag fibers together with t h e undetermined fiber like esparto gave the highest tests for tensile strength and stretch. The thickness of the papers nieasured i n thousandths of a millimeter showed decided average difierences for the three weights, ranging froin twenty for feather weight t o twenty-five or thirty for light \\.eight and from thirty-five to forty for standard weight. Marked difi'erences between papers of the same class were brought out Schopper paper-testing by the tensile strength anti stretch tests. machine adapted for w i g h t s from one to fifty kilograms \yas found t o be too heavy, so :i peiidulutn exercising one-fifth the strain was substituted on the same machine and all of the tensile strength tests \\;ere made with this smaller weight. The figures, as reported in the table, are, however, recalculated so ;is t u be coniparable with those obtained on the standard Schopper machine. 111 a fen. instances the tests were applied across fiber, as show1 in colunms on the table. 'l'he strip of material ernplo!.ed cin. j in width-the regulation size for the tests was 18 cm. in length and ~ . < for this machine. From the nuniber of sariiples compared and the fact t h a t their age was not known, it is difficult to trace any general rule with regard t o the relation of thickness, kind of pulp and degree of beat with the tensile strength and stretch. Seither does the weight of the paper have the direct influence that might be expected. It is certain, howe\-er, t h a t standard lveight papers of approximately I . 6 j mg. weight per sq. cni. should not be of a strength less than 18 tenth-kilograms (the unit of weight used on the table); nor have a stretch of less than 2 cm. in a n 18 cm. strip. Similarly, for light and feather weight papers averaging I mg. weight per sq. cin., the strength and stretch should not fall below 14 tenth-kilograms and I . j cm. respectively. These tests bear directly on the wearing qualities of the paper and are valuable in making a n estimate of its length of ser\.ice.
1619
T Y P E W R I T E R CARBON PAPERS.
TABLEII.-CHEMICAL TESTS. RECORD PAPERS:BLACK No.
2288 2289 2290 2377 2379 2381 2291a 2291b 2299 2300 2303 2293 2296 2297 2298
Moisture Percent.
4.03 4.08 5.25 4.42 4.41 2.98 3.73 3.94 3.46 3.86 4.16 4.84 3. I 7 3.40 3.47
Carbon. Per cent. Per cent Ash.
3.92 8.60 4.50 5.69 5.88 9.83 5.20 5.20
7,0? 7.31 6.56 0.81 4.60 4.34 4.4' 9. I1 14.36
2294 2302 2305 2378 2380 2382
5.58 3.16 3.78 4 . I9 3.79 3.57
13.76 17.39 21.87
2301 2 304
3.65 3.87
14.69 16.56
2306 2291c 2292 2295 2291d
5.40 4.34 3.45 4.83 4.16
2.73 1.53 2.26 2.64 4.50
11.28
Dye. Pigment Per cent. Per cent
0.46 2.45 0.50
5.30 12.79 6.07 8.81 8.58 14.38 8.30 7.61 8.87 IO. 24 12.85 1.40 5.93 5.47 5.38
3.31 6.65 2.59 6.81 6.28 9.89 5.53 5.63 9.00 8.58 5.76 5.10 3.58 3.58 3.50
1.90 0.82
,... ....
BLUE. 1.51 13.13 25-03 1.47 18.76 0.53
.... ....
0.72
0.83 0.77 1.20
.... 0.60 0.78
.... .... ....
0.83
.... ....
25.52
0.77 0.87
26.15 26.77
.... ....
22.66 25.50
Per cent.
Wax.
Ink. Per cent.
Paper. Per cent.
31.34 29. IO 15.18 18.86 15.77 31.27 31'87 31.44 27.42 32.85 20.95 27.60 36.88 36 * 54 34.80
44.58 55.08 29.57 39. I9 35.14 59.47 50.92 505 57 49.64 55.95 44.40 39.70 50.32 49.32 47.52
55.42 44.92 7 0 * 43 60.81 64.86 40.53 49.08 49.43 50.36 44.05 55.60 60.30 49.68 50.68 52.48
18.78 25.05 19.04 18.09 18.80 30.34
39-00 55.38 42.25 48.11 49.70 62.98
61.00 44.62 57 * 75 51-89
19.71 19.66
51.28 57.22
48.72 42 * 78
27.87 30. I5 37.07
45 * 82 43.10 63.80 46 * 05 48.11
54.18 56.90 36.20 53.95 51.89
50.20
37.02
PURPLE. 5.28 7.69
COPY PAPERS. 2.53
.... .... ....
....
6.13 4.42 6.52 11.51 6.32
3.82 3.74 6.25 4.60 2.48
25.11
34.96
The kind and relative amounts of the components of the ink are important factors in the working qualities of a typewriter carbon paper. The data obtained in Table I1 are useful in arriving a t a general idea of the various ingredients used for ink, their relative proportions and those combinations which appear to give the best results in working qualities. The influence of the kind and state of division of the carbon and other pigments used, of the kind of oil or wax, of varying kinds and amounts of dyes, etc., can be determined only by an examination of a very large number of papers, the variation being so great t h a t it is not now possible to present a formula for the composition of a standard ink. To illustrate the variation, the amount of ink in one of the best papers amounts to 63 per cent. and in another paper equally as good, so far as working qualities, there is b u t 43 per cent. of ink, while the average is between
aiid j j per cent. Of course, in deciding between two papers t h a t tlifLer so \videl!. as tliesc inentioiied, the important question is as i o which 2i:ts tlic larger aiiiount ol i d ; a\.ailxble for writing purposes. :;or the base of the ink, L)amftiii lyases oi rather high melting points are \.er!. generull!- e:iiplo!~d, although not esclusivelj- so. I'igments likc I'itlksian liluc. aiid laiiipblack aiitl tl!-cs such as methylene blue and meth;,.i \.iolet a p p w r in man!. oE the papers, while in others the sanie or 1xttt.i' rwiilts arc' c:l)tainetl 1)). other coni1~iii:ititsns. The percentage iixitrcs slioivii i l l 'i'alile I1 arc (if \.ilue iiiaiiil!. in correlation \rith the reslllts sh!i\:.tI iii '!';t:)le~ i :lilt1 111. Scp:tratioii oi' the ink froiii the paper \vas clifiicult to acconi1)liqli. Se\.cr:d inetliocls were tried. Ihiliiig- water, acids and alkalies pouretl o\-er the paper :titer i t had been cut into strips, separated the ink effectid!-, ))ut di~ititegratedthe paper. I{thyl ether or petroleum ether c,f i o \ v hoiliiig poilit \ ~ o u l dnot dissolve the was of the ink so t h a t it might he i i l t v r c l . I'etro1cu:ii ether ~ i higher ' and definite boiling point was er!. liiirtl to obtaiii, as tell gallons of 66' gasoline !.ieltIed b u t three quarts of L: product boiling tietween 7 0 3 and qo', and this was very hard to ev~lporateoff coiiipletel;; a s \vel1 as being clangerous to store and haridlc. i'ure hetizciie, h i l i n g point 81-2 ', \vas finally adopted as the solvelit. I)ut i t l i d t o iie prcparetl rrec from alcohol and Lvater, so t h a t dyes iroald i i o t I)c afi'ectetl. 'I'he benzene was therefore treated in the \vxy ordinarily i i s d ior cleaiisiiig ether, I)!. shaking repeatedly with i v a t y r an~1tiieii ailon iiig it to statid For se\-eral da\.s o\'er metallic sodium. .I \vcig::hed portioii ol thc paper, cut into narron. strips and put i i i 21 tieLtkr, I
