Author: Site Editor Publish Time: 2021-04-26 Origin: Site
The focus of water transfer operation characteristics is the control of force and time parameters. Water transfer paper or water transfer film products. Water transfer printing is mainly used in food packaging, food labeling (label), food surface decoration water transfer printing, especially food labeling (label) water transfer printing. The current practice is Use adhesives to stick printed plastic labels and paper labels on the food surface. The second layer is a water-soluble material that acts as a printing material (graphic carrier) and water-soluble peeling and bonding products; the third layer is Ink (printing ink), printed graphics. The fourth layer is cover oil, its function is to protect the printed graphics from damage and improve reflectivity to produce a three-dimensional effect. Water transfer printing is sometimes made into a five-layer or six-layer structure. The five-layer structure adds a protective film to the surface of the cover oil. The six-layer structure is a water-soluble material that is a combination of water-soluble glue and plastic film, and there is no volatilization of the adhesive solvent. When it is soaked in water, it is peeled off and pressed to complete the water transfer. Therefore, the water immersion treatment should be carried out at the prescribed time.
Then, without damaging the material and graphics, peel off or drag off the transfer base paper. The water transfer structure is also called water transfer paper or water transfer film structure. Its structure is shown in Figure 1. The structure is generally composed of 4 layers, that is, the transfer base paper (or film) is used to support water-soluble materials and facilitate printing; this method is because the adhesive and ink may migrate and penetrate into the food, so over time Extension and temperature rise will inevitably lead to food safety problems. Water transfer printing has good safety for food labels (labels). Analyzing the principles and characteristics of water transfer printing, water transfer printing applied to food has the following advantages. Water transfer can be done with only water, without heating or applying chemical substances such as adhesives.
Therefore, there is no high-temperature decomposition of chemical components, and it has good safety components and prevents migration and penetration. Research experiments show that the dissolved products of the water-soluble plastic film are hydrogen atoms, oxygen atoms and carbon atoms, which have no side effects on the environment and the human body (see Table 2) The core of water transfer printing—water-soluble materials have good safety. The key material for water transfer printing is water-soluble material, that is, water-soluble plastic film. Its basic ingredient is polyvinyl alcohol. Generally, it is first printed and made into special water transfer products. In addition, the water-soluble plastic film has good barrier properties below 70°C, which can prevent various chemical components and harmful gases from entering the food. Migration and penetration. It can be seen that water transfer printing has no side effects on food safety.