PAflRS THE 'DEFIBZRING OF RSOLAflIED. ROPE CABLE .. • P. 1. BairdS tad. 0. i:. Htubesk' : tntrodüotion,. • to. determine the• The purpose of this study effectiveness and the' eoononitãe 'of various 60*134' and various in 4e't' prooesaing treitments, particularly of the rod Beaterstflated. It!atf paper. fibei?iug reclaised tope ttber from the oooperator' a Si].l'oóntained a. 1*11. 'aZount atbe'. to. bundles whioh had not 'been separated sliff iaieñtly . formed into, a, ôtear sheet: of paper. A 'waterleaf 'hà$. Sheet' • from this beaten material is sho*a.as'sbeet No. MaterialS .and. Procedure.'. . . . . . . . .. . . fóllowIng equipment. was used in 'this study'%. A horizontal cylindrical steel digester,, of the zag charge of •bQiler type1' of 325 gaflons...oapaoity. A material, in 'this digeetéi is about 500 'pounds of wood 'chips oVS5O pounds of the reolaimed. oablé' paper (air—dry basis). The digester r.otateè' at 1 r.p.m. The.' charge is heated' . directly by'mea;s of steam introdnoed through one of the truTmione. At the end ct the digestion the' pressure is 'relieved and the contetti are ooted thiffioieñtiy by admission of coldwater, tG'permit the removal of the manhole oQver. 'The contents are then emptied. into, I shallow drainer provided. • with a,perforated tile bottOm, where the pulp is washed. A 2. '' photograph of the digester te shown In . sernicomrneroial rod mjtl'Shot in Figure .4 used. It is 3 feet in. diameter and 5 feet lông, 'inside measure, and can be r .tated at. speeds varying from 1? 'to 28 r.p.m. Aoharge,of pulp equivalent to '25 pounds Qven A Forebt Products LabbtatorY,MadisOn,.Wi5. %ssistant Chethist, 17.9. Forest Products Laboratory, Madison, 1Senior Chemist'1' Tie. R933' ' ' .' U.S. ' ' . ' ,. ' ' —33— . . ,. . dry anc3. at consistences ranging from 4 to 8 per cent is the proper charge for this mill. It can be run bOth COfltIflUOUSlY and batchwise, and when operated continuously the material is introduced by a screw feeding device through one trunnion of the mill- (fig. 1), the milled pulp flowing out through the Sufficient water is fed with the material opposite trunion. to form a pulp suspension of the desired consistence. When operated batchwise, the material to be milled with water sufficient to give the desired consistence is added through a side manhole. At the completion of a batcb,wise operation the manhole cover is removed and the mill contents dumped into a shallow screened drainer where the pulp can be washed. A 50—pound experimental Marx beater having a roll of 24 inches in diameter with 18 inches face, and a bed plate with 52 steel the elbow type was used. The roll is fitted fly bars, 3/8 inch thick, arranged in clusters of four. The bed plate is fitted with 14 steel fly bars each 15/32 inch thick at the base but bevelled at an angle of 25 degrees to The maximum dead an outer edge of about 1/16 inch thick. load weight of the roll, without using the counterbalancing The tub of the beater is of concrete device, is 1800 pounds. construction with a trough of special cross section designed The roll is driven at for rapid circulation of the stock. peripheral speed of 1950 which corresponds to a 300 The beater is feet per minute, by a roll settings and a power equipped with a motion recorder for 3. The beater is shown by Figure meter. Material The reclaimed paper was composed of small multicolored bundles and sheets as well as short lengths of cotton Occasionally small pieces of fine copper wire were twine. The moisture content of the paper as received was found. 8.95 per cent on the wet basis. A sample of this paper in the form of a hand sheet held together with animal glue containing a small amount of glycerin is shown as sheet No. 2. Procedure The plan of study embodied the cooking of the paper to soften it to pulp and the processing of this pulp as well as of the,raw paper in the rod mill or in the beater to determine the effectiveness of each in defibering the material. R933 —34— The first, using a chemical Three cooks were made. ratio of 3 per cent of caustic soda and a 5.6 to 1 ratio of water to fiber, was cooked for 1 hour at a temperature 126° 0.; the second, using 3 per cent o± caustic soda at a 2.23 to 1 ratio of water to fiber, was cooked-for 4 hours at a temperature of 116° 0.; and the third, without chemical but with a 5.6 to 1 ratio of water to fiber, was cooked for 1—3/4 hours at a temperature of 121° 0. The exact weights of the materials used- and the cooking conditions are shown in Table 1. Table 1.--Cooking data Materials Cook; : :Diges—: : . No. :Paper :Water Conditions : :Oaustic:Temper—: ter ature :pres— sod-a : : : : Time :Water—fiber ratio : :sure ————: : Lbs-- : : — : Los. : Lbs. : 83 : 00. : 126 : 227.5, 1267 3 227.5: 508.0: 6.83 : 116 : 4003: 227.5: 1267,0: None ; 121 : 4001: 4002: 2: Lbs.—:.dours—: . 1 : 5.6 to 20 : 4 : 2.23 to 1 25 : 1—3/4: 5.6 to 1 weight which is equivalent to 250 pounds as received. 2. —Air pressure was relieved shortly before the desired temperature was reached. the time the digester reached the desired. temperature until the pressure was relieved. relief line prevented air pressure relief. The processings in the rod mill consisted of milling both the raw paper and cook No. 4001 with plugged steel pipe pounds and with solid rods having a total weight of bronze rods having a total weight o± 3566 pounds. With the pipe rods the operation was carried. out batchwise at a consistence of o.0 per cent. At various intervals the mill was sampled, and hand- sheets were made to show the degree of deRepresentative hand, sheets as well as others mentioned form a part of this report. R933 —35— $ S A .S - - Using the heavy rods the operation was carried ouM continuously to simulate full mill—scale conditions. An attempt was made to add material at the rate of 25 pounds (oven-dry baéis) per hour but some difficulty was.enoountered at times due to the long strings of paper becoming wrapped 'arojad. the edges of the screw in the .feeditg device and ahok—, ing the feed. The consistence was held as closely as possible to 6.0 per cent but this varied somewhat due to the 'additional water required to help free the screw. At the end of '.1 hour of. continuous operation a sample of discharged pulp was taken and formed into haM sheet!. . . portion of cook No 4001 taken from the discharge at this time was passed through a 9—cut screen and formed A into hand sheets. The rod mill conditions are shown in detail in Table 2. . . The processings in the beatèi consisted of brushing 4003, each at a the raw paper, cook No. 4001 and cook consistence of 3.25 per cent with, the roll raised 0.054-inch' above the bed plate. The temperature was matntained. at about At the end of 40 minutes samples 38° 0. during the treatment. were taken for hand sheets to sho! defibering. The brushing of the raw paper and cook No. 4001 was stopped at the end of 40 minutes, but cook No. 4003 was processed for an additional just bleared. the 60 adnutes with the roll lowered 'so that bed plate. it . R933 —36— S Sheet No. 3 Sheet No. 4 Sheet No. 5 Sheet Sheet Sheet No. 8 Sheet No. 9 Sheet No. 10 No. 7 Rod Milled Cable Papers No. B conditions Table 2. Rods Rod : mill: Size Cook Kind No. : run: No. Plugged steel pipe :Inches:Inches: : : : : paper; : : 1+001 Solid . : : 3.0 bronze : 14.5 : : 23 : : 12 : 2.5 59 . . . : I : : 23 12 2021+ 151+2 25 : : 225 : . 20214. : 151+2 . 25 : . : 50 0 6.0 3—10 i.ncl 25 : 11 60 : 12 6o . —____________________ 13 ... : : : : : : : . No. : 6 : . sample ence : : : : :Consist—:Time:Sheet —25 : : : Lbs. :Per cent:Min.: : : 2.5 . . Lbs. k5 2 37 Raw Solid bronze : : : : -: 1+6 : paper:steel pipe: 2.37 : : : : : : Material added :Number: Total: :weight:Paper :Water fliam—:Length: eter : : : •.. : . . —... . : equivalent. at r.p.m. at 26 r.p.m. R933 as nearly attempt was made to hold the as possible to Gper cent but when the screw feeding device clogged, a large quantity of water had to be added to wash it free. was added at a rate of about 25 pounds per hour. Due to the strips winding around and clogging the screw feeding device, this rate varied considerably at times. I Sheet No. 11 Sheet No. 15 Sheet No. 12 Sheet No. 13 Sheet No. 16 Rod Sheet No. 17 Milled Cable Papers Sheet No.14 Sheet No. 18 The beating conditions are shown in detail in Table 3. Table .: Beater: run No. 143 144 : : : Cook: 145 : : Lbs. :Per cent: : : 4001: 50 : 50 . : 1222 : 3.25 1531 : 3.25 S : Roll : Time: Sheet :sample ature :above : : : : : : : : Consist—: Temper—: : : 4003: 50 • : : No. :Pulp: Water: ence :Raw :paper: • Materials : bed : : No. : 15 plate: :Inches:Iin,: : C. : : : 38 : : 38 : 0.054: 40 16 40 ,054 S 'z 1292 . or 38 S 054 to 0.00: 60 S S ._ - ; 1? ; 18 S .__ ._ equivalent. - a-Beater was run the spme as for runs Nos. 143 and 144 for 40 minutes; then the roll was lowered until it just cleared the decided bed plate. - From a casual examination of cook No. 4002, not to make any processing studies on it. it was Hand sheet papers were made from the variously processed materials to show the degree of defibering obtained under the different conditions. These sheets were made to thickness as possible to give sn exact comparison as of residual fiber bundles or paper pieces. Discussion of Results The pulp from cook No. 4001 proved to be superior This pulp the others processed for defibering when compared with the raw paper was very effectively de—. fibered. in the rod mill using heavy rods as shown when sheet Likewise the response No. 13 is compared with sheet No. 12. of this pulp as compared with that of. cook No, 4003 and. of the raw paper to the action of the beater is best shown by observing sheets i'Ios. 15, 16, and 17. - to R933 —37— usa, a The action of the ro& mill was studied the type of rod.. oonsistenoeof 6.0 per cent and by fibers The light pipe rods were ineffeotive in separating on the pupfoa:000k even after so minutes of millin? Nos. .5 to 10 inclusive. A. would Nb. 40Q1 as Shot by rods on the raw paper was. be expqoted the action of ..the 25 mi;utes. At. iilling.period.óf hardly notioea'b:Ie tea strips wete papet. thia time, as shown by sheet No. 11, the still contS4ned..a oonaidqrably ,reduoed. in size but the:.ptlp: . largeprQportion of the fiber bundles. . . . operating the ,mill Treatment with the heavy lore effective in defibering the continuously was. raw paper than the treatment with light. rods. With the pulp from. cook No. 4001 :however; the heavy rods qaused a very by sheet No.. 13. 4thcnjgh high degree of defibering as there was a sinaflproportion of' fiber bundles yet reaqining in the pulp,. :thtse. *erb .readfly. removed passing the mil1e4 pulp throufl:.a 9rou4 Doreen4 the .te2atin absëncO of.fiber. •howi by sh!et 116. .14.. bundles the use of rodS cast from bronzS4.. One its small pieOes of.the metal Due to their. brittle bharaoter throughout the pulp. flit were ,broken off exit deposite4 to metallic impurity would be highly the :propet slope: be reconverted into. cable paper but with would bC no tion .of milling Slement metals there H. from this source. . in this diffiotltl arose difficulty . . brushing action of the beater was very effective when the paper hadbeeü previously eoftenedby cooking with caustic soda as in cook No. 4Q01, The pulp from this. treat— ment. is shown by sheet No. 15. Paper cooked without chemioal . as in cook No. 4003 was insufficientLy, softened tO. be This.is shown by Sheet pletely difibSrized in.the beater. No. 1?. Raw paper as such would require so muoh beating 'that the fiber would be tOo greatly h*drated and cut before .pletedefibering. .. . 11933 S . . . . . . . .