The rapid development of the packaging and printing industry requires that both the level of packaging and printing machinery manufacturing and the quality of packaging processes in China must be significantly improved. Although there are a large number of packaging and printing machinery manufacturers in China, there are fewer mechanical manufacturing companies with higher technological content. Many small companies do not even have real mechanical designers. However, the manufacture of some coating composite equipments requires single-piece manufacturing, and it is particularly necessary for machinery manufacturing companies with high mechanical design technology to produce. At present, the coating types and squeegee methods used by many companies for coating composite equipment are relatively simple. This article will introduce several coating methods and methods for using different squeegee scrapers for designers' reference.
Types of Coater The coater can be divided into three types: light roll sizing, anilox roll sizing, and hot melt squeezing.
1. The light roller is coated with a high-precision light roller for sizing coating. The coating effect is good. The coating amount can be flexibly controlled by the micro-motion adjustment of the coating blade, and the coating accuracy is high. At present, light roller coating is most widely used in coating composite devices.
2. The anilox roller coating is coated with anilox roller and coated uniformly, but the coating amount is difficult to adjust. The amount of coating is mainly related to the depth of the cell of the anilox roller and the viscosity of the glue. The deeper the anilox roll is, the more glue is transferred from the mesh to the substrate. Conversely, the lighter the anilox roll is, the more the amount transferred to the substrate is. The shallower the anilox roll net, the amount of glue transferred to the substrate is also reduced accordingly. Adhesive viscosity is too large and too small are not conducive to the normal transfer of glue, glue is too easy to transfer, too thin is easy to flow, so that uneven glue, easy to produce vertical or horizontal flow patterns. Therefore, once the type of anilox roll and glue is set, it is difficult to adjust the amount of coating, which is also the main reason for the limited application of anilox roll coating.
3. Hot-melt adhesive spray coating The coating apparatus adopting this coating method mainly causes the solid-state glue to be heated and melted, and the glue is directly sprayed on the substrate by the hydraulic device through the coating die head. This kind of coating method can use 100% solid state glue without the need of thinner, and has no pollution to the environment. It is a green environment-friendly coating method and is favored by more and more users.