The Film Daily (1926)

32 THE ■^m DAILY Sunday, May 30, ig' A SERVICE TO EXHIBITORS OF WHICH LITTLE IS HEARD "KNOW YOUR OWN INDUSTRY" —No. 5 Print Preservation ELIMINATION OF OIL AND DUST ASSURES SCREEN BRILLIANCY X By TREVOR FAULKNER In Charge of the Film Depot, Eastern Studio, Famous Players IK the beginning, as an operator, then as an exhibitor, later as an exchange man, and now as a department head, of a department that has as one of its chief functions the cleaning and renovating of used positive film, I have experimented, striven, and constantly had the vision of ultimately developing, or at least helping to develop a satisfactory plant for cleaning film, and now feel that this has, to a large degree, been accomplished, for in our department we are using a plant that is satisfactorily cleaning and revitalizing used positive film. The cause and effect of both the oil and dirt on the film, and I will add, the cause and effect of cleansing film, makes that term about the only one that could rightfully be chosen as a subject for this article, regardless of any heading it might have, for in the work of cleansing film, those are the chief things to be considered. To begin, let us first consider the show case that is used to display our stock, "motion picture film" in, the operator's, or projection booth. In practically all cases this booth is in the highest and farthest back point in the entire theater, and it is seldom under the care of a janitor or porter, and in too large a percentage of cases, is hardly ever seen by the manager. This usually means a periodical house-cleaning by the operator. It is seldom that you v/ill find the floor of the booth free from dust, dirt or oil, and it is often quite necessary for film to be "spilled" out on the floor while the projection machine is in operation, in order to prevent interrupted screen presentation. Again, on account of the booth being at the highest point of a theater, and usually with an exhaust fan in it, a large percentage of dust that arises from the constant stir of patronage is drawn into the booth, and necessarily through the port holes in front of the projection machines. This all shows us that we are displaying our ware under conditions that, after a few such showings, offers a big handicap. Handling Film Now let us consider our stock or ware and its handling. When positive film is first released and placed in the hands of the operator for exhibition, as you are all familiar with, it is more sensitive to damage than when older, and consequently more care must be used in its handling. Regardless of any prior waxing the film may have had, to prevent this probable damage the operator often applies oil to the film. Then there are many cases where the film is often through a continuous bath of lubricating oil, for in one make of a projection machine when the projec Read at S. M. P. E. Mr. Faulkner's paper was read before the Spring meeting of the Society of M. P. Engineers, held in Washington recently. tor is tilted to fit the angle at which the light rays must be thrown to reach the screen, there is a receptacle created at the base of the mechanism to give a long lower loop this steady bath of oil. Another make of projection machine, the model of a year or two back, gave the film a constant spraj or sprinkle of oil through a worn intermittent bearing. It is also a usual thing for the operator to have a pan placed on the floor under the projector to catch the oil drip from the mechanism, and often this pan, with more or less oil in it, will also catch the ends of the film as the operator is either threading up the machines or is taking the film out of the lower magazine. You can rightfully place all of the blame for all oil on film to one or all of these conditions, for in no other way does film ever come in contact with oil. Oil Accumulation Motion picture film, when moving rapidly and passing through anything where any friction occurs, will generate a sufficient amount of static electircal current to attract any dust or liiit that it comes in contact with, and will so pick up such dust and lint, very much as a magnet will pick up small particles of metal. Consequently, when the doors of an enclosed projector are opened, or when film is "spilled" on the floor of the booth, the film attracts and collects a large amount of the dust and lint that is around. The oil that is already on the film holds this dirt and more or less dissolves it, and as the film is run through one projector after another, it picks up more dirt and receives more oil until it reaches a point of saturation in this respect resulting in this foreign substance forming a cataract on both the emulsion and celluloid sides of the film. There are none of you but that realize the importance of a reception of lights and shadows on the screen, unmarred by a soiled or dusty screen, dirty or sooty condenser lens, oil or dirt spots on the projection lens, or a hazy reflector in the lamp house. All of these are under the control of the operator and can be totally absent through his efforts, but he is not equipped to remove dirt and oil from the film, and as a result the screen presentation is marred in practically all instances w^here the film used has had five or six prior bookings. You can visualize looking at some beautiful scene through a window, or through eye glasses which are covered with a film of oil and dirt, then magnify that condition by the ratio of the motion picture frame to the screen results and you can see the handicap that the operator attempts to overcome through higher lamp amperage, etc. I have tried briefly here to outline the cause and effect of dirt and oil on film, and all of it does outline most positively the cause or necessity of cleaning that film. Wash Solution In helping to build a proper wash solution, we found first that we wanted one that would remove all oil and dirt fast enough to offer any vehicle using it a sufficient capacity. Next we must have a non-inflammable fluid, throwing off no inflammable or explosive gasses. It must be free from all salts and alkalis that would attack the emulsion in any manner. It must oft'er off no gas that would impair the health of the cleaning operator and its cost must com within a reasonable figure, and above all of these things, it must revitalize the celluloid stock instead of devitalizing it. We have been able to secure such a solution and are using it to day in our department, with satisfactory results in all of these features. After our problems were solved in securing a satisfactory wash solution, we then had its application to consider and were fortunate in getting the manufacturer of the most acceptable machine then on the market, to agree to go through a period of trials and experimentations with us, we agreeing to any changes in his machine that he and we found would make it more applicable. From this period of experiments we have a machine that does the work satisfactorily, quickly and inexpensively. Cleaning Unit To describe the operation of the machine used, the film is passed first through a bath of the wash solution, about eight inches being submerged at a time. There are felt brushes submerged in the liquid that brush both sides of the film. The film then travels up through the rubber wipers, suspended on a spring suspension at the same angle, and very much in the same manner as a window cleaner uses his "sqeege" in drying the water from a freshly washed window pane. The film then passes through or between flannel strips, slowly driven in an opposite direction to "that which the film is traveling. The points of contact with these strips are arrnged at offsetting points so that the tension of the film is sufficient to thoroughly polish it on both sides. It then passes through two rubber rollers, wringer-like, which is the only driving povyer o rdraught the film has in the entire operation, and is then wound on a reel by an automatic takeup of the same principle as the takeup on the lower magazine. 1 The solution tank holds app mately one quart of the cleaning and is drained off into a filter every seventh or eighth reel has cleaned. After the fluid p; through the filter, it can be use)a often as it is thoroughly filtered freed from the oil and dirt th carries after it has cleaned the s or eight reels. By actual mea: ments this filter, from a day's | of 100 of film, has caught fou{ cubic inches of dirt and oil. ( In analyzing a machine, it is j essary to take into consideratiorjh following pertinent factors: — I First, the capacity of the mac'' In developing capacity, you must stantlv bear in mind the greater s of your operation, the greater the possibilities of your damagin] film. We have overcome thii using large aluminum rollers wide flanges to guide the film, film is pulled through the mai by two wide rubber rollers, arra: similar to a wringer. A gri switch controls the motor so should the film break, the e plant is stopped immediately, are no buffs or fast rotating poli^i to heat the film, should it bei stationary and ther are no sprl teeth to injure it. or idler rollej crease or mark it. Results These results can be summei as follows: — We are now cle film, regardless of the amount and dirt that there is on it, ai rate of 1000 ft. reel, in practicall: minutes. Every inch of the l,( reel is entirely free from all oil dirf there has been no strain oi| perforations in any manner; sides of the film is polished; thi ver salts in the emulsion havi been attacked in any manner, tinting of either the film stock ( the emulsion is totally unaffected is as safe against future attacks the acids ni the different lubrii the operators use, as it was b cleaning; the film stock is not si or warped in any manner, and all, every inch of that 1,000 ft.| has had a bat hin a chemical tha| a tendency to soften it and r its elasticity. Film that has had this treat for rightfully it can be called is so entirely fre€ from anythin] fering any foreign resistance _ smooth passage through a proji machine, and is so entirely and oughly polished and lubricat every corner and all the surfac] every perforation, that even the corners of them may be ed, the film is much less liab] probable damage than it was its treatment. Thus, aside froi clear, unobstructed screen recej of the picture, its passage throug| machine is freer and the life o film stock is, therefore, much gni' mL