A correction fluid is an opaque, white fluid applied to paper to mask errors in text. Once dried, it can be written over. Earlier It is typically packaged in small bottles, and the lid has an attached brush (or a triangular piece of foam) which dips into the bottle, but now both are mixed together and filled in pen that’s why we now a days, call it as correction pen. The pen is spring-loaded and, when dabbed onto the paper, releases a small amount of fluid. If the pen does dry out, a few vigorous shakes usually get the fluid to flow again. Compared to the bottled form, the pen allows a more even and thin application, and is less prone to drying out (since only a tiny surface is exposed during application) or clogging.
History:
Before the invention of word processors, correction fluid greatly facilitated the production of typewritten documents. One of the first forms of correction fluid was invented in 1951 by the secretary Bette Nesmith Graham, founder of Liquid Paper.
Chemical composition:
It contains volatile organic compounds; like thinner, which originally contained toluene, which was banned due to its toxicity. Later, it contained 1,1,1-trichloroethane, a skin irritant now widely banned under the Montreal Protocol on Substances that deplete the Ozone Layer, and then the slightly safer trichloroethylene. Thinners currently used with correction fluid include bromopropane.
To avoid the inconveniences of organic solvents (safety and availability), some brands of fluid are water-based. However, those have the disadvantages of a longer drying time, and incompatibility with some inks (which will soak through them).
Harmful
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