What is security printing holographic printing

With the development of optical holographic technology, a new printing process capable of clearly and massively reproducing three-dimensional images on a two-dimensional carrier emerged in the printing industry in the 1980s. This new printing process is holographic printing technology.

Holographic Printing was developed based on holographic photography. In 1948 the British physicist Denis Gabor invented holography, a photographic method that can record and reproduce 3D stereoscopic information of objects. Because there was no ideal light source at the time, the development of holographic technology was basically in a state of stagnation.

Until the laser came out in 1960, the world’s first hologram made by the United States’s E.N. Leith and J.V. Pahieta in 1963, using a laser as the light source, confirmed the theory of Gabriel’s theory before making the hologram. Research and development of technology have developed rapidly. The technologies of rainbow holography, true color three-dimensional rainbow holography and holographic embossing, which have been developed successively in the late 1960s and the mid 1970s to observe reconstructed images under natural lighting conditions, have laid the foundation for holographic printing technology.

Holography is different from ordinary photography. Ordinary photography records light reflected by various points on the scene through a camera lens or a camera lens on the photosensitive film. Only the light intensity (ie the amplitude of light) is recorded on the photo film. Since the ordinary camera records only the amplitude of the scattered light of the scene, a two-dimensional image with a large difference from the real object is obtained. The hologram uses optical interference to record the amplitude and phase of the scattered light wave of the object to be recorded in the form of interference fringes, that is, to record all the information of the object (such as the shape of characters, patterns, or three-dimensional objects) in a kind. On the carrier. In simple terms, the hologram obtained by the hologram is a thin sheet that is covered with a complex inter-phase striped structure that is indistinguishable by the naked eye. Such a striped structure is often referred to as a grating. When the light beam strikes the grating at a certain angle on the hologram, the object information will be released from the hologram in the form of a certain light. The human eye faces the light to watch, just as you would look through the window to the scene outside the window. A realistic stereoscopic image or a variable color image can be viewed from multiple sides around the hologram, which is essentially different from the planar image of an ordinary photograph.

There are many methods for replicating holograms, of which the copying method and the embossing method are the main copying methods for holographic printing. In particular, the embossing hologram uses a hologram with an embossed grating as a stamper to emboss an embossed grating on the surface of a plastic film with strong plasticity, thereby realizing a printing technique for mass-producing a hologram.

The holographic printing process can be represented by the following block diagram:

Film hologram → copy and copy → coating conductive layer electroformed nickel plate → peeling → stamping copy → vacuum aluminizing → coating compound → slitting