May 1, ly2? 



THE INDIA RUBBER WORLD 



559 



According to the United States Commerce Reports for June, 

 1920, the total exports of chicle from Colombia for the year 1918 

 amounted to 690,496 pounds, about half of which came from the 

 Sogonioso river region of the Magdalena Valley. 



Collection and Preparation 

 The resinifcrous latex from whicli chicle is prepared occurs 

 in the bark of the tree, and is obtained by tapping in much the 

 same way as rubber or balata. Incisions are made in the bark, 

 usually in V-shaped form, a long knife known as a machete 

 being used for the purpose. The oiittii of a chicle collector, or 

 chiclero, consists of a machete, a rope for climbing the trees, and 

 receptacles for collecling the latex. 



Fig. 3. Tapping the Tree Fig. 4. Collecting the L.\tex 



A series of these V-shaped incisions are made and usually 

 connected by a vertical channel, down which the latex readily 

 flows into receptacles placed to receive it. Fig. 4 shows the 

 arrangement of tapping cuts and a canvas bag attached to the 

 tree trunk as a latex receptacle. Canvas bags are preferred for 

 this purpose because they admit of baling in large numbers, thus 

 occupying the minimum space for mule-back transportation. 



The latex is conveyed to collecting camps, where it is boiled 

 down in large vessels to a dough-like consistency, then it is 

 kneaded to remove some of the water, and pressed in wooden 

 molds for exportation. The largest quantity of the gum is pro- 

 duced in the southern states of Mexico, particularly Yucatan. 

 The gum as shipped from Mexico contains about SO per cent 

 of water. On arrival in New York it contains around 40 per cent 

 water. The latex, when fresh, resembles cow's milk, but when 

 coalesced by boiling, it assumes a grayish hue, though the color 

 may vary owing to the admixture of impurities. The latex is 

 sometimes adulterated with the milk of other trees. In Mexico, 

 the best chicle is said to be produced by trees grown in the higher 

 altitudes. The tree yielding chicle grows to a height of from 40 

 to 50 feet, with trunk from 35 to 40 inches in diameter. Each 

 tree yields, on an average, 30 to 35 pounds of chicle per year. 

 The trees are tapped throughout the year with the exception of 

 the rainy period, which lasts from three to four months. The 

 tree requires a good loamy soil and a rainfall of about 90 inches. 

 Appearance 



Crude chicle is quite hard, brittle and easily reduced to frag- 

 ments. It varies according to purity, from a light to a dark 

 brown color and melts very readily with heat, being easily softened 

 when held in the mouth. When warm it is very ductile and 

 adhesive without perceptible odor or taste, and is entirely free 

 from any injurious qualities. 



Analysis of Crude Yucatan Chicle- 



Per Cent 



Acetone soluble resins 40.0 



Gutta and hydrocarbons 17.4 



Proteins 0.6 



Sand and foreign matter 2.i 



Water 35.0 



Mineral ash 4.7 



' Dr. Frederic Dannerth, Journal of Industrial and Ensineering Chemistry, 

 1917, page 679. 



CHICLE SrrBSTITUTES 



A number of gums are regularly cleaned and blended as sub- 

 stitutes for chicle and are largely used. The ingredients of these 

 substitutes are the low-grade rubber from Borneo known as 

 Pontianak or jelutong and the inferior guttas, among them being 

 gutta siak, gutta kay, etc.; also the Pontianak resin extracted 

 from jelutong as well as waxes, resins and balsams of various 

 sorts. Several chicle substitutes have been patented and others 

 pass under special trade names. 



The aggregate tonnage of these compounded gums annually 

 employed in the manufacture of chewing gum, approximately 

 equals or perhaps exceeds that of the pure chicle used. Com- 

 paratively little chewing gum is made of a strictly chicle base 

 and much is made containing no chicle whatever. 



Methods of Making Chicle Substitutes 



There are various processes and machines fur the purilication 

 of guttas, resins and low-grade rubber for use as substitutes for 

 chicle and for chewing guin manufactme, some of which have 

 been patented. 



Cleaning Crude Pontianak 



James D. Darling, ul Philadelphia, patented the following 

 methods : 



Comminuted crude Pontianak, or jelutong, is boiled in a 

 receptacle for a considerable time in an alkaline solution con- 

 sisting of 25 pounds of caustic soda to 100 gallons of water. The 

 boiling is continued until all the impurities are precipitated, 

 while the mixture of rubber and resin, purified and changed in 

 physical characteristics, floats as a spongy mass. When freed from 

 the alkaline liquor this mass is odorless and tasteless, but still 

 somewhat tough and resilient. This product is removed and after 

 repeated washings is subjected to a pulling or kneading operation 

 liy which its physical qualities are further changed. 



During this treatment the material is maintained at a tempera- 

 ture between 200 and 300 degrees F. for a considerable time until 

 the rubber content loses its toughness and resiliency and the whole 

 mass becomes plastic, tenacious and extremely ductile, with little 

 or no resiliency, and suited to the manufacture of chewing gum. 

 Treating Pontianak Resin and Gutta 



Pontianak resin and low-grade guttas contain either an oljjec- 

 tionable taste, or odors and poisonous substances which must be 

 removed before the material can be used in making artificial 

 chicle. It has been found that these faults may be removed by 

 using sugar in solution. 



The crude materials are dried and powdered in a mill in the 

 case of tlie resin or in a hollander in the case of the gutta and the 

 finely divided materials are then boiled in a five per cent sugar 

 solution. The cleaned products are waslied and dried by suitable 

 means. Thus treated, they are sufficiently pure to be used, being 

 free from taste, odor, etc. 



Chicle substitutes are deficient in plasticity, and tougher and 

 more elastic tlian true chicle ; therefore they do not chew as easily 

 and smoothly. These features, however, are obviated in com- 

 pounding the chewing gum mixture. Practically no chewing 

 gum is now made in which chicle is not largely or even wholly 

 displaced by some combination substitute. Certain large gum 

 manufacturers prepare their own substitute, others depend on 

 purchase from concerns regularly engaged in cleaning and blend- 

 ing materials for the purpose. 



CARAMEL PASTE 



In order to obviate the naturally stiff and springy quality in- 

 herent in chicle substitutes a material known in the trade as 

 "paste" is used. In physical appearance and consistency this 

 much resembles ordinary yellow caramel candy. Oleo stock is 

 one of its principal ingredients, the effect of which is to soften 

 the chicle substitute and render it more plastic and less elastic, 

 consequently more agreeable to chew. Other functions of paste 

 are to act as a binder for the powdered sugar in the gum mixing 

 and as a preservative against aging or hardening of the finished 

 product by drying. 



