1963 to 1993
In 1963 when I was first introduced to the X-ray business, film processors were really in their infancy. When I talk about "X-ray film processors", I mean those devices that were automated in some fashion, and the processing of film was taken out of the hands of the X-ray technician.
The first Hospital that I walked into with the man that was assigned to train me, had probably one of the first X-ray film processors in the St. Paul, Minneapolis, Minnesota area. It was a Kodak M1 or M2 processor. It was more than 8 feet long, and took 10 to 15 minutes to process a film from "dry to dry". The roller racks in the processor were so large that a "traveling" crane was attached to the ceiling to lift the racks out of the processing fluid tanks. The crane was designed to move up and down the line of travel in order to lift one or another of the racks out of the tanks. It could then be moved to lower the rack at the side of the processor where the rack could be cleaned. These roller racks allowed the film to travel in a somewhat vertical fashion, down and up, through the chemistries. The film would be fed into the rack and follow a "turn-around" which would direct the film down into the bath, traveling through the rollers. Than the film would be directed through a turn around at the bottom of the rack and brought back up to be sent over to the next rack. This was the beginning of automated film processing. I would say that the Kodak company was the father of the automated processor. There could have been others that were there 1st, but I didn't know about them.
Other companies came on line soon after, but Kodak (I think) still dominates the market with its processor line.
I think a step back in time, is in order to look at what the X-ray technician had to do before the automated processor became popular.
The dark room consisted of 2 or 3 tanks that were filled with chemistry. The tanks were than contained in a massive tank filled with tempered water. The water was constantly circulating and replaced as it drained out, at a controlled temperature, usually 68 degrees F. This arrangement kept the chemistry at the required temperature, so that the films could come out with very little variation in density, contrast, fog, (Etc.). The tanks were arranged so that the developer chemistry was at one end, with a "Stop" bath (sometimes) next, than the fixer chemistry, and sometimes a tank was used for the wash bath. Fixer chemistries were later changed to contain the "stop" action needed to stop development. This did away with the stop bath portion of the system. Usually the wash was done in the master water tank where the circulating water would aid in washing the film.
In this system, the film in a special holder, would be placed in the developer tank for a specified time (5 minutes more or less). Than the film was moved to the stop bath, if the system used one, or moved into the fixer tank for 10 or more minutes. Then the film was moved into the wash where it could be left for up to 20 minutes. After that the film was moved into a tall heated drying rack which looked like a large clothes locker. Depending on temperature the film would be dry in 15 to 20 minutes.
Can you imagine? Some thing had to be done in order to speed up the process, because if you looked at the total system, the developing part of the chain was slower than pouring honey out of a bottle. That's where Kodak came to the rescue with the Kodak M1 and M2 processors which even though they were Hugh, did speed up the process. They did one other thing, they took the X-ray technician out of the dark room where his or her time could be used more efficiently. It allowed one person to be assigned to the dark room in order to process the films as they were passed through special dark room "pass boxes" that were mounted in the dark room wall.
Along came the competition! Several companies took up the challenge to get into the processor market, one of them being Picker X-ray Corporation. Here we go again with one of those people who didn't know anything about the industry, and didn't know that it couldn't be done. I don't remember his name, but he was an engineer in a Picker production plant near Toronto, Canada. Even though he knew absolutely nothing about the processor industry, he designed a new processor that was about 1/3 or less in size from the processors than on the market. He called it a "mini" processor. It revolutionized the industry. It caught Kodak, Dupont, and many other companies by total surprise. It developed the film in about 6 minutes but was eventually sped up to 2 minutes and 40 seconds, from "dry to dry". He just upped the developer temperature in order to speed the processing time. It worked!
3M got into the automated film developer business by producing a film processor in it's 3M Italy plant at Ferrania, Italy. The 1st processors were not bad, but because of patents held by Kodak, they along with other companies could not always run film through the processor roller system with a "scratch free" surface. Kodak held a patent that allowed them to be the only one who could use a "non-opposed" roller system. In this system, no roller touched another in those areas where the film was the most sensitive to scratches or emulsion damage. The other manufactures had to wait until the patent ran out before they could use this system to help avoid the critical roller marks that sometimes made a patient diagnosis difficult.
Kodak and others by this time, had upped the speed of the processors to 90 seconds "dry to dry". Many companies than went to 45 seconds in order to further speed the process. This speed would have been almost impossible if it had not been for the introduction of Solid State or Microprocessor control of the systems and improvements in developer and fixer chemistry. Even plus or minus 1/2 to 1 degree temperature change in the Developer could throw the film consistency off far enough to make the film almost non-readable.
3M went one step further, it developed a "dry film" technology, in which no processing chemicals are used. It was called Dry Silver! The system uses Heat to developed the film in less than 10 seconds. This technology is discussed in the Related film portion of this article.
Stop and think about what I wrote in this article. When processing was done by hand, you could count on the film taking 40 or more minutes "dry to dry". I must say that Radiologists of Old were innovative and would rush into the dark room and read wet films out of the developer tank by placing them against the Red Safety light just to try and save time. As evolution took place, we advanced to 15 minutes, then 2 minutes and 40 seconds. From there we went to 90 seconds, 45 seconds, and now 3M is doing it in around 10 seconds with a system that no longer uses any chemicals. Not only is the system used by 3M ecologically sound but it is less contaminating. But look at the speed with which we now do things.
Some where along the line the industry may leave "Hard Copy" or films entirely and go to a computerized system that no longer requires a film archive. What a future!
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Last updated on 14 January 2006