What Are The Layers Of X-ray Film?
The x-ray film or radiographic film consists of following layers.
A) Super coating.
B) Emulsion
C) Adhesive layer.
D) Base.
A) Super coating:- The super coating layer is also called protective layer. It is made of gelatin material. It protect the emulsion from scratching, pressure, handling and processing.
B) Emulsion:- The emulsion is important part is the x-ray film. The emulsion is covered by the super coating layer. The emulsion is consists of gelatin and silver halide. The gelatin is transparent of light and it gives support for silver halide by holding them properly. The silver halide is light sensitive material in emulsion. In silver halide, the silver bromide is about 90 to 99% and about 1 to 10% of silver iodide.
When the film is exposed with the x-ray. The energy photons interact with the silver bromide and the silver bromide is produce the secondary electrons. The electrons migrate to the sensitive center and get trapped. The silver atoms are attracted to sensitivity centers, where they combine with electron and become metallic silver and the metallic silver atoms give latent images.
C) Adhesive layer:- The adhesive layer present between the emulsion and base of x-ray film. The adhesive layer bind the emulsion and base. It help to maintain proper contact between emulsion and base.
D) Base:- The function of base of the film is to support the emulsion. The base is rigid structure. The base is flexible, fracture resistance and easy to hold. Initially the base is made up of glass and cellulose nitrate. In 1920, the base made up of cellulose triacetate. and polyester are Add in 1960.
The film base is always added in dye, so the films looks like blue. This film are called blue sensitive.