How Gramophone Records are Made

Sun (Auckland), Volume III, Issue 834, 30 November 1929, Page 27

How Gramophone Records are Made

FACTORY MYSTERIES The buying of a record is today regarded as an ordinary and every day occurrence, but it is doubtful whether one person in every thousand making such a purchase, realises the many or widely different processes which a record passes through from its inception until the hidden treasure of its music is finally discovered in some home, says a writer in ‘ The Cape Times.” The contrast between the first stages of a record in the making and the conditions under which it is eventually enjoyed would provide inspiration for an imaginative artist, especially of the modern school, to paint a canvas symbolical of life, for as with so much that is beautiful in this world, the record springs from a beginning the antithesis of its end. Let us then spend a little while in the factory of one of the great gramo-, phone companies. Leaving the bright sunshine we pass through a narrow and heavy door, and, in so doing, enter another world. A strange world this, peopled with grimed and blackened men—appearing weird and fantastical in the dim light and dust ladened atmosphere. Beating down on us the roar of great machinery, only dimly seen; driving bands moving on their endless journey; gigantic wheels turning; the clanking and clangour of laden trucks as they speed past— a veritable inferno of noise, a place of strange and fearsome shadows, the atmosphere of which smites one with a sense of oppression almost of awe. Gigantic Sieves Here, heaps of paper and materials of various descriptions are being torn and sorted, the piles of stuff as they accumulate being hurled into gigantic sieves which shape and sort the debris into some semblance of order. In one’s imagination, • the machines, which in reality are grinding mills, appear almost beast-like, as into their gaping jaws the heaps of sorted material are endlesssly shovelled by men who can never satiate these ravenous monsters of steel. So this “Food” is chewed, torn, and ground to powder which at last is spewed out io again be fed back to smaller beasts of more fastidious tastes, until finally it emerges in finer particles, and the heaps of debris are replaced by a black powder of velvety texture and indescribable smoothness. This is loaded into trucks, and/following one, we leave this inferno and enter a spacious shed where long tables of gleaming steel meet our gaze around and to the sides of these are gigantic ovens and rolling machines, the latter similar to the homely mangle hut of enormous proportions. Into these ovens goes the powder, where finally, by heat and certain processes, it is transformed into a plastic mass, known as cooked record material. This is then taken across to the rolling machines —the rollers of which are maintained at a certain temperature. It is then carefully kneaded, mixed and worked up to the requisite constituency. Finally, the molten mass is stripped from the rollers by a steel blade being pressed against them, and transferred to a receptacle at the head of the long steel tables. Here it passes through rollers which roll it out to a prescribed thickness, and, as it leaves these it passes through blade's which section the mass into oblongs measuring 6i x B.J. As it leaves these blades it is received on a canvas belt and guided by male operators to the end of the table. Here at rest —it is rapidly cooled and then becomes brittle, when the indentations made by the blades enable it to be broken by hand into sections, which are then known as “biscuits.” It is from these biscuits that the actual records are made, and they are piled on further trolleys, and so away to the record-pressing factory. The Wax Master Here we must leave them while we deviate from our course to follow what happens to the wax master record after a performance has been recorded upon it. This master or recording wax is made from superfine wax in laboratories as nearly dust-proof as human ingenuity can make them, and is carefully faced, presenting an unblemished surface of indescribable smoothness on which the recording lines have to be cut., The slightest particle of foreign matter on one of these wax masters will, of course, be fatal, and ruin not only the record but possibly a performance which cannot again be recorded. This wax is then treated with a metallised surface, and is taken to a copper plating bath, where, by an electrolytic process, copper is deposited on its surface. This copper deposit is carefully stripped from the wax, and we now have a copper master or a negative from the wax positive. Recording lines, of course, stand up above the surface of this shell. A copper “mother” is then made from the master by depositing by similar process copper on the face of the master. This is again stripped off —the recording lines now being as on the original wax. From this “mother” is taken as many pressing matrices as required. These are made by again plating the copper mother —stripping it off, and on this final metal, we, of course, have the recording lines standing up above the surface ready to leave their indentations in the “biscuits” when they meet. This pressing matrix is then faced up with nickel and carefully welded to a heavy steel bacK—tins latter being a most delicate operation. The nickelplating and steel back are necesj sary to withstand the enormous pressure which it is later subjected to in the record presses. So, in the record pressing 'rooms we meet once again the “biscuits” on the one hand, and the pressing matrix on the other. Hydraulic Press The modern record press of today is hydraulic, and, for the purpose of illustration, may be likened to a gigantic book opened in the middle, in the top and bottom half a pressing matrix is set. By the side of each press is a small steel table which is virtually a “hot plate.” On this hot plate is placed the "biscuit,” two for a lOin. record, three for a 12in. record, and these are again reduced to the plastic condition in which we saw them some, time back. The press itself is

infused by the operator with live steam or ice cold water—the latter drawn from artesian wells of great depth suuk in the actual grounds of the factory, the former supplied under terrific pressure. A label is then laid on the bottom pressing matrix and the biscuit having been made plastic by heat on the hot plate, is shaped into a nearly round mass and placed in the centre of this label. A further label is again set on top of this, and the press is closed (.the book is shut). The closing of this press exerts a presure of over 60 tons ou a record, and the molten material is evenly distributed all over the facing of the pressing'matrix, and driven into the fine indentations traced by the recording needle. After a short time the heat is cut off and ice cold water is circulated through the press which immediately cools the molten material and on the press being opened, the record, with its gleaming surface (this caused by pressure, uot by baud polishing as some people supposed) is revealed. A good operator can press from six t 9 eight hundred records in a day.

The record is quite easily removed when cold, and is then sent through to the various test departments, where one out ot every so many is tested out for various faults in its manufacture, chiefly the wear test, that is, the record is played and replayed until it is finally worn out, and also a further test by girls specially trained to listen for the slightest fault in its reproduction. If the record under test does not pass these tests and many others, the whole batch from which it was drawn is immediately scrapped. The records having been passed then go to the buffing shops, where the edges, which, of course, are rough from the press, are smoothed off and polished. This is done by means of buffing wheels revolving at some 3,000 revolutions a minute. From here the records are again taken through to a further inspection department, which checks them over for any flaw which may have occurred in their handling. They are then wiped and bagged and go through to the record reserve store. In the reserve store of the “His Master's Voice” factories at Hayes, not less than three million records are always carried. In addition to this vast stock, of course, hundreds of presses are working day and night, each press as we have previously stated, turning out six to eight hundred records a day. In this w r ay some idea may be obtained of the enormous output of a modern record factory. It may be of interest to note that the cost to manufacture a dance decord is neither less nor more than the higher priced records, but the ultimate cost to the public is determined by the fees, etc., paid to the artistes recording thereon. Quite naturally, the recording of an obscure artiste can be sold for a much lesser figure than that recorded by a Chaliapin. So from the murk, gloom and dirt of the mixing and grinding sheds, we come to the unrivalled enjoyment of the world’s best music by the world’s greatest artistes who are always at our command in our home through the medium of the gramophone record.