Abstract:
Holographic labels are used on a variety of articles of manufacture for security, authenticity, or aesthetic appeal. Manufacturing a holographic label or sticker typically entails microembossing, that is, imprinting or cutting, microscopic grooves into a clear plastic sheet with a shiny aluminum coating. The grooves diffract light and form a three-dimensional image, such as the dove commonly found on Visanull brand credit cards. Unfortunately, conventional microembossing machines, or microembossers, suffer from a number of problems. For example, these microembossers include two large base rollers that move back and forth in sequence to contact a shimroller. The clumsy back and forth movement not only limits how fast embossing can occur but also causes misalignment of embossed images. To address this and other problems, the inventors devised an exemplary microembosser which includes a single base roller and a shimroller which one or more unique features. Among these features are magnetic members that assist in holding a shim; an internal temperature sensor that aids control of shimroller temperature; and one or more shimcollars or shimclamps that spans across a gap between the leading and trailing edges of a shim. Other features of the exemplary embosser include an automatic mechanism for separating the base roller and shimroller during shutdown.