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System Performance | System Description | Case Study |
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System Performance
Due to the configuration of the film and its prismatic surface, 3M BEF is a very reflective material that also permits the redirection and diffusion of light. This film can form part of a double glass insulating unit. The system works by utilizing the principles of refraction and total internal reflection by refracting usable light towards the viewer and reflecting most of the remaining light back into the display. In other words, BEF films increase on-axis perceived brightness by focusing light into a narrower viewing angle. A single sheet of BEF film can be used to increase perceived brightness by up to 60% or two sheets crossed at 90 degrees to each other can be used to increase brightness by up to 120%.
The film is mounted with the prisms running either vertically or horizontally. The narrow viewing angle will be primarily along the plane that is 90 degrees away from the prisms’ main direction: if the prisms are running vertically, resp. horizontally, the viewing angle will mostly be narrowed down along the horizontal, resp. vertical, plane, and slightly along the vertical, resp. horizontal, plane. |
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Performance data for all systems in the same category. Comparison to systems in other categories, selected through the matrix filtering process.
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System Description
Made out of an acrylic resin coated on a polyester substrate, 3M BEF is a thin flexible film with an array of prisms on one face and a smooth finish on the other. For different performances, the prismatic surface is manufactured so that it follows ordered patterns, like arrangements of 90º prisms, or randomized prism patterns to more effectively prevent wet-out and reflective moiré effects. Its prismatic surface has been made using a microreplication technology, a process that allows the generation of precisely designed microsurfaces to achieve specific optical properties. The film’s thickness ranges from 62 microns to 160 microns., and is sold in rolls that are 0.95m (37”) wide and are between 30m and 150m (99 feet and 480160yd) long. When used in flat double glazings, the film should be placed inside the cavity with the smooth side next to the inner glass pane and the prisms facing outwards, to protect the delicate prismatic surface from dust and mechanical alterations. If a second sheet of BEF film is used, it should be mounted with its prism direction perpendicular to the first sheet’s prism direction. 3M only commercializes the film for electronic displays; hence using the film in flat glazings is a customized solution. A variety of different Vikuiti BEF films are available in kit format to match specific applications. |
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