MOISTURE-PROOF MATCHES.

Dunstan Times, Issue 3130, 14 August 1922, Page 2

MOISTURE-PROOF MATCHES.

Everyone who has ever struggled to light a fire with a match which had become damp through the moisture of the air, will take much interest in a new kind recently put on the market in France, under the picturesque name of “Naiads.” They are the invention of V. Government engineer, M. Duhrisay, and the method of manufacture was recently described in a Government report .together with some general remarks upon the manufacture of matches, from which we> may select the following details :—“The paste from which the heads of matches arc made generally consists of substances of three sorts thoroughly mixed together, such as; (1) Active substances (chlorate of potash, bichromate, sesquisulphidoof phosphorous, etc.); (2) inert substances (powdered glass, zinc oxide, ochres, etc.); (3) agglutinating substances (solutions of gum glue). The last named substances arc indispensable, not only to make the paste adhere to the stick, but also to give it the desired consistency and lessen the violence of the ignition. Unfortunately, gums and glues undergo alteration when damp. In moist air they swell and soften so that friction fails to ignite the match. This is the principal cause for the deterioration of matches in the course of time;” Because of this fact the idea at once suggests itself that it would be desirable to substitute for the third ingredient substances not _ altered by moisture. This, however, is easier said than done. M. Uubrisay solved' the problem by employing as agglutinants the artificial resins called bakelites, from the name of their inventor, the American chemist, Bakeland. These substances are capable of being heated to 300 degrees centigrade without undergoing decomposition. But ordinary bakelite is manufactured .at a very high temperature, and does not harden except when heated under pressure to ICO degrees centigrade—a prohibitive temperature for the manufacture of match paste. Uubrisay got around this difficulty by devising a modified form of bakelite which is made rapidly and at a comparatively low temperature. We read further :—“There are two stages of manufacture. The first step is to mix together chlorate of potash, resorcin, and soda lye. A second mixture is made of manganese dioxide, phosphorus, and formol. These are then thoroughly mixed together by means of a. spatula. The paste thus formed will solidify at the ordinary temperature' of the, workroom if sufficient time is allowed, but the, hardening can be accomplished in half an hour by using dryers at a temperature of 10 to 50 degrees centigrade.” Very satisfactory tests have been made with these new matches, which ignite without difficulty after remaining for almost a year under a bell-jar side bv side with an evaporating dish filled with water. They will even ignite after having been placed for several moments in either fresh or salt water, provided the sticks are dried either in the air or by wiping. The striking surface of the boxes in which these ‘“Naiads” are packed is likewise unaffected by humidity. Its composition has a. base ol amorphous phosphorus identical with that on ordinary boxes, but the agglutinating substance consists of a solution of silicate of soda.