562 



THE INDIA RUBBER WORLD 



Mav 1, 1921 



Speckv Scrap. A Batavia term for a low grade crepe. See 

 Crepe. 



Specky Brown Crepe. .\ New York term for a low grade 

 crepe. See Crepe. 



Spotted Rubber. Rubber stained, blemished or discolored. 



Stand.\rd Quality' Latex Crepe. New York term for first 

 grade crepe. See Crepe. 



Standard Quality Ribbed Smoked Sheet. .\ Xew York term 

 for best grade of smoked sheet. See Sheet. 



Stand.xrd Quality Smooth Smoked Sheet. A New York 

 term for best grade of smoked sheet. See Sheet. 



Standard Quality- Unsmoked Sheet. A New York term for 

 a low grade unsmoked sheet. See Sheet. 



Standardized Raw Rubbers. Referring to a plan formulated 

 for the British Rubber Growers' Association for a more accurate 

 standardization and valuation of plantation crude rubber. Assum- 

 ing 1,000 to represent the highest quality, as determined by tests 

 as to tensile properties, physical condition and stabihty, all prov- 

 ing above the index figure of 900 would be rated as first grade ; 

 above 800 as second grade ; above 700 as third grade ; above 600 

 as fourth grade, and above 50O as fifth grade. 



Scrap. Remnants of rubber obtained after tapping, which are 

 rolled into balls, made up into cakes or into lower grades of 

 crepe. Also a Java term for barky rubber. See Crepe. 

 Scrapings. Java term for scrap. See Crepe. 



Tacky Rubber. Rubber more than normally sticky or adhesive, 

 the cause being ascribed to decomposition of certain proteins by 

 acid normally in the latex. 



Thick Pall Grisly Crepe. Sec Crepe. 

 Thin Pale Crepe. See Crepe. 



Trinidad Plantation. Product of the cultivated Hevea or 

 Castilloa from Trinidad and Tobago. See Plantation Para. 



Unsmoked Sheet Standard Quality. Xew Y'ork term of 

 a high grade. See Sheet. 



Unsmoked. Rubber that has not been treated by any smoking 

 process. 



Unsorted Scraps. Java term for bark. See Crepe. 



Uganda Plantation. Para rubber from British East Africa. 

 See Plantation Para. 



Vacuum Drying. Dehydration of newly-made sheets of rub- 

 ber in a steam-heated vessel or compartment which has been 

 exhausted of air and moisture with a vacuum pump. It greatly 

 shortens drying time and helps in the making of the blocks. 

 Very efficient when handled by experts, otherwise rubber may 

 be overheated, its nerve injured and its pores opened to hannful 

 action iby the air. 



Worm Rubber. Sheets of freshly-made rubber cut into thin 

 worm-like strips with shears or machinery rolls. 



West Indies Plantation. Product of the cultivated Hevea or 

 Castilloa rubber from that district. See Plantation Para. 



Washing. Passing coagulated latex or scrap and a steam of 



water between grooved steel rolls revolving at different speeds. 



Wash-Water Rubber. The rinsings of cups, pails and other 



receptacles which contain a certain amount of latex, which is 



coagulated and thus recovered. 



The Glossary — Comments and Suggestions 



The following comments from those interested have been 

 received : 



GUAYULE-RUBBER OR SUBSTITUTE? 

 "Should not guayule be listed as a substitute and not as a true 

 rubber?" 



Guayule is a true rubber. Its source and characteristics, 

 differing as they do from other rubbers, are responsible for its 

 confusion with gums that contain no caoutchouc. 

 GUM ELASTIC 

 "Why should not the whole trade adopt 'gum elastic' as its 

 term for rubber or india rubber?" 

 Excellent. But how can it be brought about? 



ELIMINATING THE SHRINKAGE IN PARAS 

 "If all the Para sorts were washed and dried, say at Para 

 and Manaos, would it not save freight charges and get rid of 

 many meaningless names? Are there any objections to such a 

 procedure?" 



It would upset all exi,sting brands, and buyers would be sus- 

 picious of new ones. Furthermore, mixtures of good and bad, of 

 weak fine and fine would be likely to occur. Moreover, when 

 some years ago, the plan was mooted it was found that the cost 

 of washing at source w^s ten times as great as at the factory. 

 DEFINING RAW RUBBER COMPOUND 

 "In a patent suit the question uf tlie meaning of the words, 

 raw rubber compound, wants expert definition. Will you be 

 good enough to wire me your definition of raw rubber compound? 

 Our understanding being that raw or crude rubber is the base, 

 together with the necessary curing agents, .such as sulphur and 

 whatever else might be added to give the desired results. But 

 to be a raw rubber compound, nothing else but the two things, 

 rubber and sulphur, have actually to be present. Namely, these 

 two must be. 'but others may or may not be. If you speak of 

 raw rubber compound you refer to a line of uncured compounds 

 ■which are and have been well known to the rubber trade for a 

 great many years, and such compounds are based on raw crude 



rubber combined with sulphur and such things as one may, from 

 the experience of those skilled in the art, choose to combine." 



Strictly speaking, anything mixed with raw rubber for any 

 reason results in a raw rubber compound. If the product is to 

 be vulcanized, sulphur or some vulcanizing agent is employed. 

 If not, as in the case of electric tape or medicinal plasters, no 

 sulphur or vulcanizing agent is incorporated. 



WHAT IS CHICLE? 



"I am curious to know if in your listings you will refer to 

 chicle. Is it rubber, and if so, why is it taxed when other rubbers 

 are free of duty?" 



Chicle is derived from one of the Sapotads, trees that do not 

 produce rubber, but from which nearly all of the gutta percha of 

 commerce comes. It is really a Central American gutta percha. 

 .'\ccording to the last tariff law, crude india rubber and gutta 

 percha are admitted free. Nevertheless, chicle, a gutta percha, is 

 taxed. 



SYNTHETIC RUBBER NOT RUBBER 



"To my mind, synethetic rubber is not rubber. It is a substi- 

 tute." 



Nature runs one kind of laboratory, man another. When 

 the products are the same, they would seem to merit the same 

 name. 



WHERE DOES BALATA BELONG? 



"Certain of the authorities in describing balata claim that it is 

 a gum that stands midway between rubber and gutta percha. 

 Does that mean that it contains both giitta and rubber, and that 

 it is actually neither a true rubber nor a true gutta?" 



Balata contains no rubber. It does contain, however, some 39 

 per cent of true gutta. The statement that it ranks midway 

 between rubber and gutta percha is misleading, as it refers to 

 its elasticity in the crude state. East Indian gutta percha is hard 

 like wood, balata is springy like whalebone, rubber is still more 

 springy. Balata is just as truly a gutta as a lesser grade of 

 rubber is a rubber. 



