The Newtown bee., 1880-07-28

I calendering machines where it is press
 cd into smooth and regular strips or
 sheets as long or short or as thick or
 thin as may be desired for the various
 uses to which it is to be put. In this
 shape it is ready to be worked into belt ing, hose, packing, and all varieties of articles made, but while it is in this con-
 dition the ultimate shape of the fabric
 to be produced must be given it. The final operation is the yulcanizilg, or tenn pering. in immense heaters, where the
 degree of heat and time employed must be very carefully regulated In fact this
 principle has to be kept well in mind
 during all the preceding operations, the
 grinders, rollers. etc, being all hollow 1 cylinders. steam heated according to l the requirements of the special work in
 hand.
 In our illustrations the titles of the
 several views will enable the reader to
 clearly disting ish the respective opera
 tions. The washer and sheeter" as
 shown at the top ol the page. represents
 Il large vat where the rubber is cut into
 small pieces by wheel with numerous
 which at the same time knead the rubber
 something after the manner of prepar-
 ing pulp in paper making. By this pro
 cess all dirt and foreign substances are
 expelled, leaving only the pure rubber,
 which next goes to the sheeter in small fragments, loosely adherng together.
 The view shows oaly one Of the several
 powerful machines employed. which con-
 sist of large hollow cylinders of cast iron
 revolving in opposite directions, by which
 the rubber is pressed and kneaded into
 thick sheets or mats. Unlesj the rubber
 appears to be exceptionally clean, it is, previous to the washing, passed through
 another machine. not shown ill our illus trations, and known as a cracker" This machine has large, deeply grooved | iron cylinders, which revolye in pairs, slowly and heavily, grinding the tough
 rubber and driving out bark and dust,
 while they also stretch it so that other
 foreign substances drop out.
 The rubber having been thus thorou gh- ly cleaned and left in tho form of rough sheets, must be hung up for Ii colsidera-
 ble period to dry, after which it goes to the mixing machines, as shown in the adjoining picture. In this department the character of the product to be pro- duced is principally determined, for tn different varieties of rubber for particu- I.,-. l. according to what experience has demon- strated to be the best. The various sub stances here Incorporated with the rub Der include sulphur, the oxides of lead zilc, iron, etc, the proportions differ iLg for each class of goods, and each particular compound calling for trcat- ment adapted thereto in the after stages of manufacture. The value of long ex- perience i'll the business. and 8 thorough acquaintance with all that science can teach ill relation thereto, is here most signally appreciated. The workman has his box of mixture furnished him by weight, just so much for given quanti- ty of rubber, and then, taking the rough sheets as they come from the drying room, he passes them betHeen the heat- ed iron cylinders of tho mixing ma- chine, slowly feeding in, also, the mixture which is to be incorporated with the rubber. The same sheet is pspssed through many times, until the | compound has been thoroughly and even ly worked into it, the degree of heat at | which the cylinders ars kept, being all l the while closely regulated.
 After this process the rubber goes to the calcnderrng department, one of the large machines which is shown to the left at the bottom of the page. These are heavier than calendering machines generally, and the one represented is the largest ever made for this purpose. The rollers are hollow, and 80 fitted up for steam heating that the temperature can be kept as desired. The rubber is here rolled a great many times, some of it be- ing passed through ill sheets and strips, pur., and some with the rubber pressed upon web Of heavy cotton duck, pre- viously coated with rubber driven through and through it's meshes by pow ~HA'A ANAAOAJ' 1iO hooiiS doCo loi | ,his purpose is made expressly for the so as to give 1t more thar ioubie the strength of the heavy cotton luck used for sails for ships. The cot ( en fabrics thus combined with the rub ,er, give the belting aud hose thus made their great tensile strength which. in hose, where the tests eau be most accurately made by guaging the t 'xact pressure to the square Inch, has l ,een proven to be about twice that of eather.
 For belt making, the rubber-coated 1 md impregna.ed duck is taken to a arge department where this branch of he business is carried on, and uurolled pon tables one hundred feet long, whe.s he workinen cut it accurately to the re- uired width. One strip is cut so that olded, it will make the width Of belt, lad another so that the wide strip will ust fold over it's edges and meet in the niddle, which makes a three-ply belt. n this way the strips are passed between Iseries of powerful rollers. the tempera- are of which is evenly regulated, as in Il the other operations the folding yer at sides makes an even and per- ectly regular edge, and at the middle, 'here edges of the outside strip cohlci ogethec. q narrow ribbon of rubber is ed to cover exactly the line of meeting il this way the entire outside of the c cit is pressed by the heated rollers into = Il even, regular surface. h The thickness of the regular sizes of ubber belts for most machine work arc