6^6 



THE INDIA RUBBER WORLD 



Jlne 1, 1921 



The chicle and other gums to be mixed arc placed in the 

 mixing cylinder shown at the left in Fig. 4 and arc melted under 

 pressure and mixed by a geared screw. Owing to llie pressure 

 create<l a low-melting temperature is obtained which does not 

 destroy the delicate texture of the gum, which if heated in the 



Fig. 5. W. & P. Mixing Machine 



atmosphere would rapidly toughen. The correct amount of 

 moisture is controlled and a perfectly homogeneous blending of 

 the mixture obtained. With the gums to be cleaned, a certain 

 amount of clean, soft wood saw-dust is added to the charge in 

 the mixing cylinder for the purpose of forming a mat or filtering 

 surface on the wire screening in the filter press into which the 

 thoroughly melted gum mixture at the proper consistency is 

 forced by compressed air at 200 pounds pressure. The filter 

 press is heated by steam circulation supplied through flexib'.e 

 metallic hose connections to each section. 



The filtered chicle is delivered through spouts along the side 

 of the press, and the foreign matter and saw-dust separated from 



Fig. 6. G.\ng Knkader .\nd Roller 



the guin is subjected to hydraulic pressure of KX) tons before 

 removal from the press. The hot clean chicle is received from 

 the filter press in weighed amounts in suitable metal container^ 

 and transferred directly to the dough mixers for incorporation 

 of the various compounding ingredients. 



The separation of foreign matter by the filler press is abso- 

 lutely complete, all bark, sand, clay, fiber, etc., being removed 

 in the form of dry cakes and the chicle delivered jicrfectly 

 smooth and clean. All vessels and piping in which chicle is 

 blended, cleaned or filtered arc necessarily steam jacketed to 

 maintain fluidity of the gum. 



COMPOtJNDIKG 

 Following the process of blending, cleaning and sterilization 

 the filtered fluid gum is drawn into receptacles in weighed 

 amounts and transferred to a tilting steam-jacketed mixing 

 kettle or dough mixer, for mixing with selected compounding 

 ingredients. These are glucose, paste, powdered sugar and 

 flavoring extracts added to the melted gum in fixed order ; 



first, glucose and caramel paste both of which aid in the absorp- 

 tion of the dry sugar ; next, one-half the sugar. As soon as the 

 latter is absorbed in the mixing the remainder of the sugar is 

 added, followed by the flavoring material. The temperature of 

 the mass is about 250 degrees F. 



MIXING KETTLES 



Mixing kettles vary in capacity from a few gallons to 200 

 gallons per batch. Two forms much used in the chewing gum 

 industry are illustrated. Fig. 5 shows a rectangular trough 

 of special form, inside which operate two steel blades of special 

 design, carried by two horizontal shafts which pass through the 

 end walls of the trough. Stuffing boxes prevent the material 

 ■ leaking from the trough along the shafts, the bearings of which 

 are separate and distinct from the stuffing boxes. The latter 

 do not act as bearings. The trough is jacketed for cooling or 

 heating and the blades are made hollow for the same purpose. 

 The tilting of the trough is done by a lever. A straight and 

 cross-belt drive is provided by means of which the machine may 

 be run in cither direction or stopped at will. 



The second form of gum luixer shown in F'ig. 7 has a cylin- 

 drical steam-jacketed receptacle arranged for tilting. The lever 

 at the right of the machine locks the kettle in any position be- 

 tween the vertical 

 and the horizontal, 

 so that the mixer 

 can be run at any 

 angle desired. The 

 time required for 

 mixing a batch of 

 chewing gum is 

 usually less than an 

 hour. 



COOLING 



The mixed batch 

 is tilted out of the 

 mixer in small por- 

 tions into pans or 

 tanks, dusted with ciough & Win 

 powdered starch 

 and sugar to pre- 

 vent adhesion of the dough, and set aside to cool preliminary 

 to kneading into batches or loaves of convenient size. 



ROUGH ROLLING 



The stock passes next to the rough-rolling machine wdiich 

 may be either a single set of rolls or a gang roller such as that 

 shown in Fig. 6. 



The machine consists of a hopper which delivers the rough 

 stock to a pair of rollers between which a thick sheet passes 



Fig. 7. Tilting Mixer 



Fig. 8. Conditioning Room 



downward to the first pair of roughing rolls and by conveyor 

 through the succeeding rollers which finally deliver the stock 

 sheeted approximately to tlie gage of the final product. 



