摘要:
A method for controlling the width of a polyester film support comprising, in order, the steps of: (a) extruding a polyester resin using one or more extruders; (b) casting the resin on a casting wheel to form a polyester sheet; (c) stretching the polyester sheet along the machine direction by ratios of 3 to 5 times at temperatures ranging from above the glass transition temperature to below the thermal crystallization temperature, wherein the machine contains extended edge rollers (14) in the drafter at the point where stretching occurs; (d) stretching the polyester sheet along the transverse direction by ratios of 3 to 5 times at temperatures ranging from above the glass transition temperature to below the thermal crystallization temperature; and (e) heat setting the polyester sheet at temperatures ranging from 180 to 250° C.
摘要:
A process for controlling curl in polyester film is disclosed in which a cost sheet is heated assymetrically across its thickness during longitudinal stretching to product positive, negative or zero curl, as required for subsequent uses or treatments of the film formed by such stretching.
摘要:
A radiographic element comprises a polyester support having double sided silver halide emulsion layers. An ultraviolet light absorbing methine compound is copolymerized with the support and is present in an amount sufficient to reduce the average percent transmission of ultraviolet light over the range of wavelength of from about 350 nm to about 395 nm to less than about 25 percent, and whereby the percent transmittance of said element is at least about 55 percent at a wavelength of about 410 nm for an element thickness of about 0.007 inches.
摘要:
An intensifying screen for imagewise exposing a radiographic element is disclosed comprised of a fluorescent layer capable of absorbing X-radiation and emitting longer wavelength electromagnetic radiation to which the radiographic element is responsive and a support capable of redirecting incident longer wavelength radiation back toward the radiographic element. The support includes in at least one portion reflective lenslets.
摘要:
A silver halide light sensitive photographic element is disclosed comprising a polyethylene terephthalate film base, at least one light sensitive silver halide-containing emulsion layer, an antihalation undercoat layer, and a process-surviving antistatic backcoat, wherein the polyethylene terephthalate film base has been formed by drafting a cast resin at a stretch ratio of at least 3.4, tentering at a stretch ratio of at least 3.4, and heat-setting at an actual heat-set temperature of at least 216° C. In accordance with preferred embodiments of the invention, the polyethylene terephthalate film base of the photographic element is formed by: (a) casting a molten polyethylene terephthalate resin in a machine direction onto a casting surface to form a continuous sheet, (b) drafting the sheet by stretching in the machine direction at a stretch ratio of from 3.4 to 4, and at a temperature ranging from 70 to 130° C., (c) tentering the sheet in the transverse direction by stretching at a stretch ratio of from 3.4 to 4, and at a temperature ranging from 70 to 130 C., (d) heat-setting the tentered sheet at an actual temperature sensed by the sheet of at least 216° C., and (e) cooling the heat-set sheet without substantial detentering to obtain a stretched, heat-set polyethylene terephthalate film.
摘要:
In the manufacture of a paint-coated stretchable film which is useful as a covering for automobile panels and other articles, a stretchable carrier film is formed by extruding a thermoplastic polymer composition onto a heat resistant temporary carrier film. The extruded layer is coated with paint or other layers and dried initially at a moderate temperature and finally at a high temperature which exceeds the heat deformation temperature of the stretchable carrier film but not of the heat resistant temporary carrier film. This shortens drying time and/or reduces residual solvents in the dried layers. The temporary carrier film, which is later stripped away, resists deformation of the laminate as it is drawn under tensile stress through the coating and high temperature drying stages.