Common three-dimensional printing technology comparison

Among the three-dimensional printing technologies currently used, the most common three-dimensional printing technologies are ordinary three-dimensional printing, dynamic three-dimensional printing, and holographic three-dimensional printing. Here, we will use a comparative method to elaborate these three-dimensional printing technologies.

Ordinary three-dimensional printing stereography mainly uses the arc movement shooting method, that is, the center point of the object is set as the center, the center point to the radius of the photosensitive film radius to do circular motion, cylindrical lens plate directly installed in the photosensitive film In front, and moving synchronously and randomly, each exposure will focus one pixel below each half cylinder of the reticle, eventually covering the entire grid. Rinse to get a three-dimensional picture. As with other printing methods, the three-dimensional printing process also includes separation, screening, and printing.

It is worth noting that in the separation of three-dimensional printing, the number of scanning lines is generally more than 400 lines/cm, and due to the fineness of the pixels in the stereoscopic image and the magnifying effect of the cylindrical lens grating, etc. Fine meshes are screened. In the three-dimensional printing, the angle of the screen should not be selected to be 0°. In addition, the screen angles of the C and K versions in the three-dimensional printing should be the same, and the density of the color ink in the field should be high.

Ordinary three-dimensional printing overprinting accuracy is very high, generally using the PS version. The three-dimensional printing can be printed in different layouts, and the finished printed product can have a three-dimensional effect after being covered with a cylindrical lens grid plate. Currently used cylindrical lens grids are hard plastic and soft plastic. The former mainly consists of polystyrene, and the latter mainly consists of polyvinyl chloride. Prior to the compounding of the cylindrical lens, a cylindrical lens negative template needs to be manufactured according to relevant parameters, and then formed by edge pressing. Commonly used methods include flat pressing, legal sticking, and sticking.

Dynamic three-dimensional printing is an extension of ordinary three-dimensional printing, that is, printing a dynamic picture on the basis of printing a three-dimensional picture, as long as the change of viewing angle can produce a dynamic product. The principles and methods of producing dynamic three-dimensional prints are the same as ordinary three-dimensional prints.

Dynamic three-dimensional printing also requires stereoscopic photography of the original document first, but unlike ordinary stereoscopic printing, it is necessary to determine the number of motions to design the original; each motion has a screen, and the number of motions determines how many negative films are used.

Dynamic three-dimensional printing manuscripts are now generally used desktop printing system for color separation, get multiple sets of separation film (female), the resulting film after the copy of the action of the screen together on a film, which requires step-by-step exposure, and finally Through the display and fixing, the positive picture corresponding to the action picture is obtained and then the printing, printing, and composite cylindrical lens plate are obtained to obtain the dynamic three-dimensional print.

Holographic three-dimensional printing is a new three-dimensional printing technology that transforms interference fringes formed by laser photography into three-dimensional images and appears on a specific substrate. It is based on holography.

In the 1980s, holographic three-dimensional printing technology entered the stage of promotion and application, and holographic three-dimensional printed materials began to become popular and gradually realize commercialization. Holographic three-dimensional printing process as shown below. Holographic three-dimensional printing is not printed with inks, and the printing is similar to conventional printing methods and processes. Holographic three-dimensional printing first takes a holographic image. Before the holographic image is taken, it is necessary to select an appropriate theme and the best layout of its space, pay attention to the influence of light, and when the hologram is not properly illuminated, it does not show any feature of the recorded scene.

Rainbow holograms are based on the diffraction properties of light. Its production is obtained by placing a photo resist plate through exposure, development, fixing, and the like. In the holographic three-dimensional printing, a softer photoresist material will be used, but it is not suitable for direct imprinting. Therefore, it is necessary to make an imprint template. The metal template is often used to transfer rainbow holographic image information, and then Stamping on the press.

The purpose of imprinting is to transfer the image information on the imprint template to a transparent film or a vacuum aluminized film at a certain temperature. Commonly used films for imprinting are PVC, PET, PS, PP, etc. The embossing process is performed according to a hot press-cooling-peeling process. After embossing, vacuum aluminum plating is performed. This is mainly for the purpose of directly viewing the holographic image under white light. It is the process of atomizing and depositing the aluminum wire on the embossed film under high vacuum conditions.

At present, it is also possible to directly use an aluminum-plated film for imprinting. After that, it is necessary to apply a glue and a film to facilitate the transfer of stereoscopic image information. The process mainly includes two types of holograms: paste type and hot stamp type. Processing. Holographic three-dimensional printing quality is still not ideal, and needs to be further improved. With the popularization and development of computer technology, many manufacturers have used computer to produce three-dimensional images, making the three-dimensional printing technology has been a good development.