Device and method for cleaning an elongated record medium

Abstract

The device sprays a mist of cleaning fluid onto the record medium—e.g., motion picture film—and wipes it off, preferably with a soft material such as velvet. Then, the film is dried with air, including thin air jets to spread the liquid evenly, and heated, ionized air. The device has a closed housing and air in the housing is evacuated and sent to a still to recover much of the cleaning liquid and prevent its escape into the atmosphere.

What is claimed is:  
     
         1 . A device for cleaning a thin elongated flexible record medium, said device comprising, in combination: 
 a sprayer for spraying a liquid solvent onto a moving elongated flexible record medium at a first location, 
 a wiping device for wiping said medium at a second location, and  
   drive means for driving said record medium sequentially past said first and second locations.    
     
     
         2 . A device as in  claim 1  including a blower for blowing heated air onto said record medium at a third location.  
     
     
         3 . A device as in  claim 1  in which said record medium is motion picture film.  
     
     
         4 . A device as in  claim 1  in which said sprayer produces a mist and produces minimal wetting of the surface of said film.  
     
     
         5 . A device as in  claim 1  including a device for blowing ionized air onto said record medium at a third location.  
     
     
         6 . A device as in  claim 1  including a device for blowing heated ionized air onto said record medium at a third location.  
     
     
         7 . A device as in  claim 1  in which said wiping device comprises a wheel having a soft, absorbent surface, and drive means for rotating said wheel against said record medium to move its surface in a direction opposite to the direction of movement of said record medium.  
     
     
         8 . A device as in  claim 7  in which said wheel comprises a reel with a hub and an easily replaceable velvet cover on said hub forming said soft, absorbent surface.  
     
     
         9 . A device as in  claim 8  including a layer of sponge material between the outer surface of said hub and said cover.  
     
     
         10 . A device as in  claim 8  in which said cover comprises a sleeve with elastic borders at opposite ends.  
     
     
         11 . A device as in  claim 1 , said record medium being motion picture film having two opposed sides and including at least two of said sprayers, one for spraying solvent onto each of said sides of said film, and at least two of said wiping devices, each one being located adjacent one of said sprayers and contacting said film after one of said sprayers.  
     
     
         12 . A device as in  claim 1  including air flow means for directing at least one thin stream of air against at least one surface of said record medium onto which solvent has been sprayed and which has been buffed by said buffing device.  
     
     
         13 . A device as in  claim 11  including at least four of said sprayers and buffing devices, two acting upon one of said film surfaces and two on the other of said film surfaces.  
     
     
         14 . A device as in  claim 1  in which said solvent is perchloroethylene.  
     
     
         15 . A device as in  claim 1  including a substantially air-tight housing in which said sprayer and wiping device are located, and solvent recovery means including a recovery still and exhaust means for removing solvent-containing air from said housing and sending said air to said recovery still.  
     
     
         16 . A device as in  claim 1  in which said sprayer is an airbrush supplied with said solvent and with compressed air.  
     
     
         17 . A motion picture film cleaning device comprising, in combination: 
 a first sprayer for spraying solvent onto a first surface of said film,    a first buffer located adjacent said first sprayer for buffing said first surface of said film upon which said first sprayer has sprayed solvent,    a second sprayer for spraying solvent onto the opposite side of said film,    a second buffer adjacent said second sprayer to buff said opposite side of said film upon which said second sprayer has sprayed solvent,    a heated air blower for blowing heated air against said film after said sprayers and buffers have acted upon said film, and    a drive device for moving said film past said sprayers, buffers and said blower.    
     
     
         18 . A device as in  claim 17  including air stream producing means located ahead of said blower in the path of movement of said film for directing a thin stream of air against said film at an acute angle opposite the direction of movement of said film.  
     
     
         19 . A device as in  claim 18  in which said air stream producing means produces two air streams directed against opposite sides of said film.  
     
     
         20 . A device as in  claim 17  in which said blower is an ionizing air amplifier and including an electrical heating element in the air stream output from said air amplifier, and including a drying enclosure positioned to pass said film therethrough, with an air distribution structure for directing air from said blower against said film in multiple streams flowing opposite the direction of movement of said film.  
     
     
         21 . A device as in  claim 20  including means for directing said film through said drying enclosure a plurality of times.  
     
     
         22 . A method of cleaning an elongated, thin flat record medium, said method comprising the steps of: 
 (a) continuously spraying a solvent on at least one surface of said record medium at a first location,    (b) wiping said one surface to remove dirt and solvent therefrom at a second location adjacent said first location,    (c) drying said one surface at a third location, and    (d) moving said medium continuously past said first, second and third locations.    
     
     
         23 . A method as in  claim 22  in which said drying step includes directing against said medium streams of heated air flowing counter to the flow direction of said medium.  
     
     
         24 . A method as in  claim 22  including the step of removing static electricity from said medium.  
     
     
         25 . A method as in  claim 22  in which said wiping step comprises buffing said surface of said medium with a buffing wheel.  
     
     
         26 . A method as in  claim 22  in which said medium is motion picture film and said spraying and wiping steps are performed on both sides of said film.  
     
     
         27 . A method as in  claim 22  including the step of capturing fumes from said spraying step, and sending them to a recovery station for recovery of solvent therefrom.  
     
     
         28 . A device for cleaning a thin elongated flexible record medium, said device comprising, combination: 
 means for cleaning said record medium with a solvent, and an air stream ionizing device for sending a stream of ionized air for reducing static electricity on the surface of said medium and thus reducing electrostatic attraction of particles to the medium.    
     
     
         29 . A device as in  claim 28 , said means for cleaning including, 
 a sprayer for spraying a liquid solvent onto a moving elongated flexible record medium at a first location, 
 a wiping device for wiping said medium at a second location, and  
 drive means for driving said record medium past said locations.  
   
     
     
         30 . A device as in  claim 28  in which said deionizing device comprises an air stream creation device, an ionization device for ionizing air in said air stream, a heating device for heating the air in said stream, and means for directing said air stream against said record medium.  
     
     
         31 . A method of cleaning an elongated thin, flat record medium, said method comprising the steps of: 
 (a) spraying a solvent mist onto at least one surface of said medium while moving said medium past a first station,    (b) wiping said surface with a soft wiper at a second station closely adjacent said first station, while said medium is moving,    (c) drying said surface at a third station, and    (d) moving said medium successively past said first, second and third stations.    
     
     
         32 . A method as in  claim 31  in which the quantity of said solvent sprayed onto said surface is just sufficient to lubricate said surface against scratching by said wiping step, but insufficient to run, said wiper being a replaceable velvet wiper, and including the step of replacing said velvet wiper when it becomes dirty.  
     
     
         33 . A method as in  claim 31  in which said wiper is a sleeve on a rotary drum, and including the step of rotating the drum to move the outer surface of said wiper in a direction opposite the movement of said medium.  
     
     
         34 . A method as in  claim 31  in which said drying step includes directing heated ionized air against said surface at said third station.  
     
     
         35 . A method as in  claim 31  including the step of spraying a solvent mist onto the opposite surface of said medium and subsequently wiping said opposite surface with a soft wiper, said drying step including directing at least one air jet against each surface of said medium to spread any solvent accumulations on said medium, and directing heated, ionized air against each of said surfaces, said air being directed against said surfaces at an acute angle in a direction counter to the direction of movement of said medium, and 
 applying a vacuum source to one surface of said medium and directing another air stream against the opposite surface, said air stream being directed towards said vacuum source.  
 
     
     
         36 . A method as in  claim 31  in which said record medium is motion picture film and said solvent is perchloroethylene.