July 1, 1921 



THE INDIA RUBBER WORLD 



723 



A Glossary of Words and Terms Used in the Rubber Industry — W 



By Henry C. Pearson 



GUTTA PERCHA 



GUTTA Percha (Gum Plastic') . The more or less resinous, 

 plastic gum obtained from the concrete milk of many trees 

 of the natural order Sapotacca:, notably the Palaquixim 

 gutta and alHed genera common in the Malay Peninsula, Borneo, 

 Sumatra, the Philippines, and the Sunda Archipelago. The term 

 is said to be derived from the Malayan "gatah," "guetah," or 

 "gueutta," meaning a balsam, or a rubbery gum ; and "pertcha," 

 a tree, also a scrap, the native product looking like scraps of 

 raw rubber before being manipulated in hot water for marketing. 

 It is nearly white when pure, but is marketed as a grayish, 

 reddish, yellowish, or most generally brownish, hard, tough, dense, 

 inelastic, highly dielectric, almost inodorous substance; easily 

 molded and impressible in hot water; resistant to most acids; 

 inalterable in fresh or salt water ; and oxidizing when exposed 

 to air and light. It is a hydrocarbon mixture with a specific 

 gravity varying from .9628 to .99923. It melts at 194 degrees F. 



Few unmixed gutta perchas reach the market, most of them 

 being mixtures. The deep color is chiefly due to the steeping 

 of the gum with bark and wood particles in hot water. Besides 

 resins, it contains varying amounts of dirt, water, and even air. 

 Also called gutta. 



Assahan. a white, chalky, friable gutta percha from north- 

 east Sumatra, of inferior quality, and with about 20 per cent 

 debris. When fresh, the cakes have an odor not unlike ripe 

 cheese. 



Bagan Goolie Soondie. a hard, wine-colored, soapy-feeling, 

 good grade of gutta percha from Borneo, chiefly exported from 

 Singapore. A term also applied to gutta closely resembling balata. 



Balam-Merah, or Sambun. A Palembang high-grade gutta 

 percha. Identical with gutta-merah. See Gutta-Merah. Very 

 little reaches the market in a pure state. Reddish-gray, some- 

 times coppery when pure, very coherent, compact and hard. In 

 section it shows layers. Pear-shaped in Palembang, but in various 

 shapes on the south coast, such as cylinders, blocks and also 

 folded sheets. Bounces on stone or wood floors, and creaks 

 when two pieces are rubbed together, which characteristics dimin- 

 ish in proportion to the amount of adulteration. The mixtures 

 are commonest in southern and eastern Borneo, the adulterants 

 generally used being jelutong, hangkang, sawdust, etc. The nearly 

 pure article is commonly mixed with bringin, making a valuable 

 grade, or with sambun, also yielding a fine grade of gutta. See 

 Bringin and Sambun. 



Balata. The gum of the bully or bullet tree {Mimusops balata 

 or globosa) of the natural order Sapotacca, sometimes used as 

 an adulterant of the better grades of gutta percha or as a sub- 

 stitute for some inferior grades. The gum is usually a reddish- 

 gray or brown, often looks like dried skins, soapy to the touch, 

 more flexible and ductile than East Indian gutta percha, which 

 it resembles in the amount of resin content and in the fact that 

 it softens readily in hot water, retaining its molded shape when 

 cooled. E.xported from Colombia, Venezuela, Panama and the 

 Guianas. Comes as sheet and block, the former of which is the 

 best grade. The grades are Surinam, amber, Surinam sheet, 

 Venezuela (Ciudad Bolivar) block, Colombia block, and Panama 

 block. 



Banca Reboiled. a low grade of mixed gutta percha from 

 the island of Banca, east of Sumatra. 



Banjermassin. a producing district and point of export in 

 south Borneo for gutta percha ; a term formerly applied to an 



'Continued from The India Rubber World, May 1, 1921, pages 561-562. 



especially high grade of gutta percha, but now less expressive, 

 the gutta now usually marketed—being hard, blackish, porous- 

 looking, and containing bark debris, etc. Used also as a name 

 for jelutong rubber. 



Banjer Red. A first-grade gutta percha from the Banjermassin 

 district, Borneo, and the product of the Dichopsls gutta. 



Banjer White. A medium grade of gutta percha from the 

 Banjermassin district, Borneo. Contains often 33 per cent of 

 water and IS per cent of dirt. 



Bassia. a gutta percha from the African tree Bassia Parkii 

 and regarded by some as comparable to East Indian gutta. 



Bii.A or Red Soondi. A term sometimes applied to bagan. 

 See Bagan. 



Blitang. a Palembang, Sumatra, gray-brown, fibrous gutta 

 percha, always mixed with wood and bark, and usually com- 

 pounded of the waste of balam-merah mixtures and inferior 

 guttas. In the better grades some true balam-merah is added. 

 It is seldom coherent or resilient. It is shipped in oblong blocks, 

 sometimes with an outer layer of good gutta. 



Block Balata. See Balata. 



Book Gutta. A low-grade gutta, prepared at Siak in Sumatra 

 and exported from Singapore in sheets folded as a "book" with 

 rounded edges. It is usually firm, tough, and somewhat elastic 

 when clean. Sections show a closely-laminated, pinkish and white 

 structure. Impurities include bark, clay and water. On cleaning 

 and drying it loses 20 to 25 per cent in weight. See Gutta Siak. 



Bouhabalam. a white, chalky, friable, nerveless gutta from 

 Malacca in the Malay Peninsula. 



Bringin. Also known as suntik or sundek. A gutta percha 

 ranking second in quality to balam-merah. See Balam-Merah. 

 Seldom appears on the market pure, but is often mixed v/ith 

 balam-merah. It is usually exported to Singapore. When pure 

 it is grayish-white, very coherent, and in section shows a compact 

 mass without visible layers. Bounces and creaks like balam- 

 merah. These qualities and the color are markedly affected by 

 adulteration with inferior grades of gutta. Dujan is generally 

 used for mi-xing, and its similar color and strong cohesion make 

 detection of adulteration difficult, although expert handlers note 

 less resilience and toughness. Admixture with hangkang or 

 jelutong alters color, lessens resilience or bounce, and imparts a 

 peculiar odor. Sometimes classed with waringin. See Waringin. 



Bulongan, or Bulungan. A first grade of gutta percha from 

 a district of that name in eastern Borneo ; a hard, nervous, 

 blackish, knotty gum, white or violet in section, sometimes con- 

 taining much debris; exudes a viscous liquid which hardens on 

 contact with air. 



Bulongan, or Bulungan White. A medium grade of gutta 

 percha from the district of the same name in eastern Borneo. 



Chicle. A Central American gum containing about 17 per 

 cent of gutta, the product of the coagulated latex of certain of 

 the Sapotacece, chiefly the Achras sapota. Crude chicle comes 

 in rectangular blocks containing bark and dirt, the shrinkage 

 being from 30 to SO per cent. In cleaned chicle the blocks are 

 pulverized by machinery, the bark picked out, and the product 

 dried and bagged, the shrinkage being about 10 per cent. 



Ciudad Bolivar Block. See Balata. 



Cleaned Chicle. See Chicle. 



Colombian Block. See Balata. 



CoTi. A good gutta percha from eastern Borneo; netted on 

 the surface, reddish yellow, but little bark, hard, and nervous. 

 Compares well with bulongan. 



