1. Each type of PET film (including color PET film) consists of two basic components: a single or multi-layer emulsion layer, and a support for the emulsion layer-based. Emulsions are made of light-sensitive fine particles suspended in a gelatin medium. Gelatin on PET film is similar to gelatin used in some foods.
2, the photosensitive material suspended in the gelatin is silver halide grains. The particles are so fine that they can only be observed under high magnification. Of the nearly 1-in. Square of sensitive photopolymer-based PET film emulsions, about 40 billion silver halide crystals contain poly (silver halide) crystals that change in structure upon exposure. The mechanism of this change in chemical properties is not important to us, and the end effect of change is paramount. How did this change happen? As you shoot, the light hits the emulsion layer of the PET film through the lens of the camera. When the light reaches the silver halide crystals, the clumps formed by the coalescence of silver halide crystals are still extremely subtle. The amount of light received by the emulsion layer changes and coalesces more. This means that light of different intensities impinges on the PET film, and different amounts of crystals undergo structural changes and coalesce in the microscopic field of the PET film emulsion layer.
3, PET film exposure, immediately produce a latent image - an invisible image. The PET film must be developed to convert the latent image into a visible solid image. When the PET film is developed, the silver halide crystals whose structure has been changed are transformed into aggregates of black metallic silver particles, resulting in image-negative images. Those on PET film that are not sensitive, that is, those that have not undergone structural changes, are washed away by a chemical called a fixative to render the portions light gray or transparent. The result is that the darker (thicker) part is the more exposed part; the bright (thinner) part is the less exposed part; the fully transparent part is the part that is not exposed to light. This is the basic process of black and white PET film recording images. The company is located in:
4, the color PET film has three layers of emulsion, in these emulsion layers also contain different organic compounds can generate dyes, called color coupler (coupler). They are inherently colorless, but can couple with the color developing agent's oxide as a colored dye during color development. For negative PET films, the coupling agent contained in the upper blinding emulsion forms a yellow color during color development, a magenta color in the middle layer, and a cyan color in the lower layer. This is the rinsed, colorized PET film that we obtained. By printing or enlarging the image onto a photographic paper or reversal rinse, the upper yellow color of the PET film changes to its complementary color blue, the middle one to green, and the lower to red Get the same natural color photos or transparent reversal film. This is the basic process of recording images on a color PET film.