The particle transfer roller, often abbreviated to PTR, is a device for cleaning

motion picture film Film stock is an analog device, analog medium that is used for recording film, motion pictures or animation. It is recorded on by a movie camera, film developing, developed, film editing, edited, and projected onto a screen using a movie proj ...

. It consists of a cylindrical roller coated with urethane, over which the surface of the film passes.

History

The particle transfer roller was developed by

Eastman Kodak The Eastman Kodak Company, referred to simply as Kodak (), is an American public company that produces various products related to its historic basis in film photography. The company is headquartered in Rochester, New York, and is incorporated i ...

and launched in 1989. It was intended to replace the

organic solvent A solvent (from the Latin '' solvō'', "loosen, untie, solve") is a substance that dissolves a solute, resulting in a solution. A solvent is usually a liquid but can also be a solid, a gas, or a supercritical fluid. Water is a solvent for p ...

s that were the main method of film cleaning before that point. Although their effectiveness is not usually considered sufficient for lab operations, where

ultrasonic cleaning Ultrasonic cleaning is a process that uses ultrasound (usually from 20 to 40 kHz) to agitate a fluid, with a cleaning effect. Ultrasonic cleaners come in a variety of sizes, from small desktop units with an internal volume of less than , to large ...

with a solvent solution remains the standard, the PTR sold widely for use in projection booths and transfer houses.

Use

At least two PTRs are needed in the film path – one for the base side and one for the emulsion side – though four are frequently used. A set of PTRs is frequently placed in the film paths of

projectors A projector or image projector is an optical device that projects an image (or moving images) onto a surface, commonly a projection screen. Most projectors create an image by shining a light through a small transparent lens, but some newer typ ...

telecine Telecine ( or ), or TK, is the process of transferring film into video and is performed in a color suite. The term is also used to refer to the equipment used in this post-production process. Telecine enables a motion picture, captured origi ...

machines,

scanners ''Scanners'' is a 1981 Canadian science fiction horror film written and directed by David Cronenberg and starring Stephen Lack, Jennifer O'Neill, Michael Ironside, and Patrick McGoohan. In the film, "scanners" are psychics with unusual telep ...

and

printers Printer may refer to: Technology * Printer (publishing), a person * Printer (computing), a hardware device * Optical printer for motion picture films People * Nariman Printer (fl. c. 1940), Indian journalist and activist * James Printer (1 ...

in order to remove dust and contaminants from the surface of the film before projection, transfer or duplication. PTRs are also used in some dedicated film cleaning machines, or mounted between rewind heads and used for manual cleaning. The contaminants are lifted from the film and adhere to the roller as the film passes in contact with it. The rollers themselves are then cleaned, usually in soapy water, and dried before the next use.

References

External links

Page on PTRs
on the

National Film and Sound Archive The National Film and Sound Archive of Australia (NFSA), known as ScreenSound Australia from 1999 to 2004, is Australia's audiovisual archive, responsible for developing, preserving, maintaining, promoting, and providing access to a national c ...

of Australia's site. Film and video technology Film and video terminology Film production {{film-tech-stub