Process principle Analysis of Imaging Mechanism of Laser Holographic Image on Paper Substrate The imaging mechanism of the paper substrate laser hologram is basically similar to other traditional substrates (plastic film, aluminized film). Holograms are obtained by holography, then the hologram is turned into a holographic metal plate and then passed through the heat. The molding process copies holograms onto paper prints. However, the surface properties of paper prints are significantly different from plastic films or aluminized films. The film that can be used for making holographic products has thermoplastic deformation properties, and the surface is smooth, and can directly perform holographic text imprinting. Especially after aluminum plating, due to the reflection effect of the metallic aluminum layer, the hologram can be greatly enhanced. Depending on the effect. However, paper-based prints are not the same. It is not possible to imprint holograms directly on inks, and it is impossible to apply aluminum-plating on prints. Therefore, to print holographic effects on paper prints requires a special printing medium. This medium should have excellent thermoplastic deformation properties and be able to obtain stable fine holographic grating stripes after deformation. At the same time, this medium must have sufficient transparency to ensure the visibility of the original printing graphics and colors. This particular hologram media is called a holographic coating. In order to obtain a good hologram visual effect on the holographic coating, the smooth and smooth surface quality of the coating is a key factor, which requires the holographic coating to have high gloss and good leveling. In addition, other physical and chemical properties of the coating, such as folding resistance, abrasion resistance, and post processing suitability, are also very important. From the optical point of view, the hologram recorded on the holographic coating is to use the diffraction effect of light to reproduce the holographic effect, while the original ink printing graphic is to use the reflection effect of light to express the printing effect, due to the use of light Different ways, hologram text does not interfere with the original ink printing effect, on the contrary, a transparent holographic coating allows two kinds of printing effects can be expressed at the same time, and form a special decorative effect. (1) Transparent holographic printing process: Under the premise of not affecting the original printing effect, a process method for directly printing holographic text on paper substrate prints is studied. Transparent holographic printing process On the premise of not affecting the original printing effect, a method for directly printing holographic text on paper substrate prints was developed. This process does not affect the normal printing process, can make full use of existing post-printing processing equipment, and meet the requirements of industrial production. The process flow is as follows: In the coating process, the holographic paint is uniformly applied to the surface of the printing ink of the paper substrate by a coating device, and the coating quality directly affects the holographic effect. The coating method adopts the three-roller coating method, which has the advantages of making full use of the existing post-printing coating coater, and coating and drying one machine for two purposes with low cost. Drying of the paint is dried by infrared radiation heating. After the holographic coating is leveled and dried, it is then calendered by a continuous rolling calender. The smoothness and gloss of the holographic coating can be greatly improved and improved so that an ideal holographic text effect can be obtained in the holographic molding process. . Holographic coating The main role of holographic coating is two: smooth and clean paper surface and printing hologram. For different application conditions, we developed two types of paper holographic special coatings: QXC alcohol-soluble holographic coatings and QXS water-soluble holographic coatings. (1) Alcohol-soluble holographic coating technology features Select the refractive index and transparency of AB, C, D comonomer, and hard monomer, soft monomer, reactive monomer reasonable match, select E, F initiator and co-solvent. Strictly control the reaction conditions, keep the temperature, initiator concentration, monomer concentration, solvent concentration in the polymerization process as much as possible, and fill with inert gas protection. The average molecular weight of the obtained copolymer is about 90,000. The colorless transparent resin is made of a blended resin I (flexibility at high speed), additives, and solvents to make a paper substrate with high refractive index, high gloss, abrasion resistance, flexibility, etc. Analysis of Imaging Mechanism of Laser Holographic Image on Paper Substrate The imaging mechanism of the paper substrate laser hologram is basically similar to other traditional substrates (plastic film, aluminized film). Holograms are obtained by holography, then the hologram is turned into a holographic metal plate and then passed through the heat. The molding process copies holograms onto paper prints. In order to obtain a good hologram visual effect on the holographic coating, the smooth and smooth surface quality of the coating is a key factor, which requires the holographic coating to have high gloss and good leveling. In addition, other physical and chemical properties of the coating, such as folding resistance, abrasion resistance, and post processing suitability, are also very important. From the optical point of view, the hologram recorded on the holographic coating is to use the diffraction effect of light to reproduce the holographic effect, while the original ink printing graphic is to use the reflection effect of light to express the printing effect, due to the use of light Different ways, hologram text does not interfere with the original ink printing effect, on the contrary, a transparent holographic coating allows two kinds of printing effects can be expressed at the same time, and form a special decorative effect. According to the imaging mechanism of paper substrate laser hologram, the basic principle of “printing†a hologram on a paper substrate is that a layer of thermoplastic holographic coating is first applied to the paper or paperboard that has been printed with ink, and is dried. After the calendering process, a layer of bright and smooth coating is obtained as a memory layer of the hologram, and then holographic molding is performed on a special holographic paper molding machine. Finally, a transparent diffractive hologram is formed on the surface of the printed matter. Therefore, the main content of this study has the following three aspects: (3) Holographic replication technology: A general-purpose holographic press-molding device, a flatbed paper holographic press, is developed for general offset sheet or paperboard. Transparent holographic printing process On the premise of not affecting the original printing effect, a method for directly printing holographic text on paper substrate prints was developed. This process does not affect the normal printing process, can make full use of existing post-printing processing equipment, and meet the requirements of industrial production. The process flow is as follows: In the coating process, the holographic paint is uniformly applied to the surface of the printing ink of the paper substrate by a coating device, and the coating quality directly affects the holographic effect. The coating method adopts the three-roller coating method, which has the advantages of making full use of the existing post-printing coating coater, and coating and drying one machine for two purposes with low cost. Drying of the paint is dried by infrared radiation heating. After the holographic coating is leveled and dried, it is then calendered by a continuous rolling calender. The smoothness and gloss of the holographic coating can be greatly improved and improved so that an ideal holographic text effect can be obtained in the holographic molding process. . The main role of holographic coating is two: smooth and clean paper surface and printing hologram. The quality of the coating directly affects the holographic effect. The main technical requirements for the coating are: sufficient adhesive fastness to paper, excellent plastic deformation characteristics, and excellent physical and chemical properties and post processing suitability. For different application conditions, we developed two types of paper holographic special coatings: QXC alcohol-soluble holographic coatings and QXS water-soluble holographic coatings. (1) Alcohol-soluble holographic coating technology features The water-based resin II has a high refractive index and can well print a hologram, but the film is relatively brittle and has poor water resistance. For this reason, we synthesized a water-based emulsion with high solids content, low scale, good flexibility, and excellent water resistance. The organic combination of the two, supplemented by additives, to produce a high refractive index, high gloss, wear resistance, flexibility, water resistance and other comprehensive performance, suitable for paper security, environmental protection type holographic coating. Whether the hologram can play a role in economy, culture, art, anti-counterfeit and daily production, one of the most critical issues is to be able to replicate in large quantities in order to achieve industrial production. Due to the fact that except for gravure printing, the general lithographic prints are plain sheets. The traditional film web presses cannot be used for holographic stamping of flat sheets or cardboard. To this end, we integrated the advantages of existing wide-format soft presses and hard presses, and designed and manufactured a platform-type holographic paper press. Its outstanding features are: (1) can be used for hologram copying of post-press sheetfed copying; (2) automatic overprinting device; (3) peeling mechanism with anti-sticking plate; (4) automatic feeding , paper collection and points function.
According to the imaging mechanism of paper substrate laser hologram, the basic principle of “printing†a hologram on a paper substrate is that a layer of thermoplastic holographic coating is first applied to the paper or paperboard that has been printed with ink, and is dried. After the calendering process, a layer of bright and smooth coating is obtained as a memory layer of the hologram, and then holographic molding is performed on a special holographic paper molding machine. Finally, a transparent diffractive hologram is formed on the surface of the printed matter.
Therefore, the main content of this study has the following three aspects:
(2) Development of holographic coatings: Development of a solvent-based, water-soluble, environmentally friendly paper substrate holographic printing coating formulation suitable for different application conditions and its preparation method.
(3) Holographic replication technology: A general-purpose holographic press-molding device, a flatbed paper holographic press, is developed for general offset sheet or paperboard.
The quality of the coating directly affects the holographic effect. The main technical requirements for the coating are: sufficient adhesive fastness to paper, excellent plastic deformation characteristics, and excellent physical and chemical properties and post processing suitability.
However, the surface properties of paper prints are significantly different from plastic films or aluminized films. The film that can be used for making holographic products has thermoplastic deformation properties, and the surface is smooth, and can directly perform holographic text imprinting. Especially after aluminum plating, due to the reflection effect of the metallic aluminum layer, the hologram can be greatly enhanced. Depending on the effect. However, paper-based prints are not the same. It is not possible to imprint holograms directly on inks, and it is impossible to apply aluminum-plating on prints.
Therefore, to print holographic effects on paper prints requires a special printing medium. This medium should have excellent thermoplastic deformation properties and be able to obtain stable fine holographic grating stripes after deformation. At the same time, this medium must have sufficient transparency to ensure the visibility of the original printing graphics and colors. This particular hologram media is called a holographic coating.
(1) Transparent holographic printing process: Under the premise of not affecting the original printing effect, a process method for directly printing holographic text on paper substrate prints is studied.
(2) Development of holographic coatings: Development of a solvent-based, water-soluble, environmentally friendly paper substrate holographic printing coating formulation suitable for different application conditions and its preparation method.
Holographic coating
Select the refractive index and transparency of AB, C, D comonomer, and hard monomer, soft monomer, reactive monomer reasonable match, select E, F initiator and co-solvent. Strictly control the reaction conditions, keep the temperature, initiator concentration, monomer concentration, solvent concentration in the polymerization process as much as possible, and fill with inert gas protection. The average molecular weight of the obtained copolymer is about 90,000. Colorless transparent resin in addition to mixed resin
Holographic paint.
(2) Technical Features of Water-Soluble Holographic Coatings
Flatbed holographic paper press
The platform-type holographic paper mold press consists of four parts: the main unit, the oil heating system, the hydraulic system, and the electrical control system. The basic working principle is that the high-temperature heat-conducting oil is heated in the oil tank and pumped by the oil to the hollow molded holographic roll. Pass the heat to the hologram roller so that the roller maintains a certain temperature. The hologram roller forms a pair of rotary pressure pairs with the rubber roller directly below it. At the beginning of the molding operation, the hydraulic system lifts the rubber roller up and presses against the holographic roller to apply a certain pressure to the hologram roller. Send a single sheet of cardboard one by one to the two rollers, and the two rollers rotate to move the cardboard forward.
Post-print paper transparent hologram printing technology