\ :. 1915. 



THE INDIA RUBBER WORLD 



375 



SMOKED SHEET. 



id a'. Preventatives. 



(7) \l 



.Efficient smoking (see also under (8) ). 



oi s, 



1' A Q L'E ) 



OR 



(8) Ri - (Stretch- The sheet should be scrubbed downwith 



ing in st v, a stiff brush and plenty ..i water a few 

 hours after rolling, allowed to drip for 

 ■ me hour, and then put into the smoke- 

 house, 



It the latex is very rich, dilution with 

 « atei befon o tagulation to a pi i ipi u 

 tiou of l;i to 2 lbs. of dry rubber to 

 the galli n is recommended. 



(9) Ovi r Smokinc 

 (Dark gli 

 surface) 



(5) Cotton Fluff. 



i Kn Tin I )| posits 



This may be caused bj the 

 large a proportion of cocoanut husks, 



rubber seed or similar oily material 

 The timber used should not be wet and 

 the hits must not be allowed to burst 

 into flame. I >o not use- cocoanut oil for 

 smoking. 



.See that the roof of the smoke house 

 does not drip owing to condensation. 



il . i 

 19. — Defects. — 



CREP] 



Defects to Be Avoided. entath es. 



(1) On. streak- Se< that oil from the bearings does not 



get i m t. 1 the niMn r 



i.li i lii i iugh itsi of too much In 



cat i ng oil; 

 (hi through w i ii'n bearings. I 



should immediately he repla 



i- ■ il' fri in worn bearings con 



tains van icles i <l ippi I or 1 erdi- 



gris, which gradually eat inti 



rubber and reduce it to the . ■ u 



sistencj ol tread 

 i. ' bj taking care that the crepedoes 



in it . i .111. near the edge of the 



rolls or other part- of the ma- 

 chinery which may he oily. Trays 

 under the washing mills should 

 not protect beyond the tut]-, of 

 the rolU. 



(2) Dark streaks Vvoid oxidation and surface darkening 



of portions .if the coagulated latex by 

 the Ms, ,ii , ( little sodium bisulphite in 



the latex (for proportion, see para- 

 graph 12 abi >\ e i . Do it' 't allow the 

 rollers to grind against each other. 



i.!' ': 5 '- lxi ep tin crepe thin and do not hang it 



i ha- too closely in the -tore so that the 

 rubber dries quickly. In case of per- 

 sistent spot trouble, apply to the 

 laboratory . 



(4) Moi . ' ■■ -- Proceed as in l.h and see that the rub- 

 ber is thoroughly dry before packing. 



.Do not use cotton waste for keeping the 

 oil off the rolls. If a pad is neces- 

 sary, use one of cloth or flannel. 

 \\oid using too much oil. 

 (6) Tackiness i Heat See that rubber is not exposed to direct 

 AND STICKINESS). rays of the sun. Scrap should be 

 brought in and washed as soon as 

 possible — if there is unavoidable de- 

 lay in washing, the scrap should he 

 kept in water. 



i ARE of MACHINERV. 



20 M i..- must be well cleaned and inspected each day before commencing work. At frequent intervals i say , once a 



wceki they should be well cleansed of all trace- ot oil by means of a 5 per cent solution of caustic s. da. This must be applied 

 tinder European supervision, In means of a cloth fastened to the end of a stick. Afterwards the machines should be set in 

 motion and the water allowed to run for si, me time, say ten minutes 



21. — LUBRICATION. — The engine driver, or other responsible person, should do this work. 



22. — W' rx Parts must be replaced at once Worn bearings are often the cause of "green streaks" in crepe rubber. When 

 1 rolls have becomes worn they cease to grip the rubber thereby reducing the output of the machine and over- 

 ^ the rubber 



SORTING VND OR MUXG. 



23. — >: eat attention and careful supervision are necessary for these operations. The fewer grades the better, and the regu- 

 larity of each grade is most important. 



The perfect assortment should consist of: 



No. 1. — Fine Sheet or line (ripe Made from the tree or liquid latex. 



No. 2. — Clean light brown Crepe Made from lumps, which cannot go through tin -trainer, and skimming 



Xo. 3. — Scrap Crepe Made from trei scrap 



No. 4.— Dark Crepe Made from hark shavings and the lower quality of scrap crepe. 



:h rubber and any tacky rubber should be packed separately. 

 ir — Evenness is most desirable and any discolored or mottled pieces must not be left in the first quality. 

 In No. 2 clean brown crepe, no grit or minute pieces of bark should be left in the rubber. 

 All pie' - ' t scrap showing the slightest traces of beat must be picked out. 

 The Crepe usually known on the market as "specky brown" is often insufficiently washed: hark or other impurities left in 



the rubber reduces the value 

 No. 4, the lowest grade, naturall vine- very much and Special attention to washing is most advisable. 

 St? - .1- should "lib be of one quality \m sheets oversmoked or showing imperfections should be packed separately. 



P.m kini ' 'pinions differ as to the suitability oi cases employed, but there is no doubt that the w 1 must be planed, so that 



Splinters can get into the rubber. 



As a general rule, the three-ply « 1 cases specially made for rubber are the most desirable. Care should he taken to 



see that the inside of the p.e have is thoroughly ciean before pail 

 1 24 inches measurement and capable of holding up to about 200 lbs. is recommended for sheet. 

 21 ■ 21X24 do. do. I" about 1SS do. do crepe. 



Other cases which have proved satisfactory are the Japanese Mon i and th< ( ochin case Ordinary (local) native made chest, 

 are undesirable Rubber should never be packed in bales. 



N. B. — Consumers' worst enemy in Rubber is heat and stickiness, a very little of which will often spoil an otherwise g 1 parcel 



38, r - i 



x E. C, 

 January. 1915. 



illi Thickened edges. .Take care that the edges are not dou- 

 bled over in rolling, as this gives sheets 

 of an uneven thickness and liable to 

 cut virgin. 



