Imaging Plates Information
Imaging plates, imaging films and imaging chemicals include offset printer plates, photographic or image setter film, developers, fixers and other supplies for printing, graphics, radiographic and IR imaging. Offset printing plates transfer an inked image to a rubber blanket, avoiding direct contact with the printing surface. Photographic films and image setter films are also used in printing, graphics, and pre-press applications. Typically, photographic films are used in conjunction with chemicals called developers, stop baths, and fixers. In the processing of light-sensitive materials, a developer detects changes in the film’s silver salt emulsion and turns areas exposed to light into metallic silver. The stop bath halts the action of the developer, and the fixer (usually sodium thiosulphate) arrests the film’s sensitivity to light. In addition to printing and photographic applications, imaging plates, films and chemicals are also used in infrared (IR) and radiographic imaging.
Selecting imaging plates, imaging films and imaging chemicals may require an analysis of products for offset printing. Imaging plates for offset lithography differ by substrate, plate-end type, and graining. Substrate materials include cellulose-based paper, plastic or aluminum-coated paper, polyester, acetate, and plastic or copper-coated steel. Plate-end styles are defined as straight edge, pinbar, slotted, and serrated. There are four graining methods for imaging plates: ball, brush, sandblast, and chemicals. Photopolymer offset plates require the use of an organic solvent and ultraviolet (UV) light. Pre-sensitized diazo plates are also exposed to UV light, but are treated with lacquer and a gum-etch solution. Photo-direct plates do not require imaging films or imaging chemicals. By contrast, bimetal plates require electro-chemical treatment while deep-etch plate use both etching and chemical treatment. Imaging plates, films and chemicals also include aqueous and waterless offset plates, helium film and infrared film for image setters, manual fixers and concentrated developers, and single-side and double-sided plate processors.
Imaging plates, imaging films and imaging chemicals is a product area that includes medical films for use with X-ray equipment. Medical X-ray films may be categorized as either green-sensitive or blue-sensitive. Green-sensitive X-ray film is designed for use with green-emitting rare earth screens. This orthochromatic, high-contrast medical film can be used for general radiography or serial radiography, and may be developed manually or automatically. Blue-sensitive medical X-ray film is designed for use with calcium tungstate and blue-emitting rare earth screens. This high-contrast, medium speed film is available in a variety of sizes and is specified in sheet per box or boxes per case. Typically, suppliers of radiography films provide medical accessories such X-ray film cassettes and X-ray grids. Some provide imaging plates, films and chemicals for mammography machines and nuclear medicine.