It is suitable for manufacturing hot stamping film, laser film, gold and silver paperboard which need coating and laminating.
Advances in coating technology
Advances in coating technology require the continuous development of pigments, adhesives and auxiliaries, and coating auxiliaries are becoming more and more important.
As the solids content increases, the viscoelastic properties of the coating become more and more important. The interaction between the various components in the coating results in the structuring of the wet coating and exhibits significant viscoelastic characteristics. It would be beneficial if such a structure of the coating could be effectively broken under shear and recovered quickly after metering. On the one hand, it exhibits good runningability, on the other hand, it has less migration of coating adhesive and good coating coverage. However, at very high solids, the viscoelastic structure does not eliminate to the desired level. As a result, problems that may occur with the above-described blade coating and metering size press coating are produced.
With theoretical breakthroughs and technological breakthroughs, WRRM, which can significantly reduce the viscoelastic properties of coatings, has begun to emerge. The addition of this WRRM not only allows the Coating to exhibit lower viscoelastic characteristics, but also helps to quickly eliminate viscoelastic properties under shear and renders the coating viscoplastic at high shear rates. Such a coating can achieve better blade and metering size press coating runability, and can increase the solids content by 2 to 3%, while the high shear viscosity is the same or lower.
Spray coating and curtain coating require a new coating aid to achieve good runnability. For example, a wetting agent is required in the coating to allow the spray coated coating to drip and stabilize the curtain coated coating curtain. More importantly, spray coating requires a low coating viscosity, and curtain coating requires a suitable coating elongation viscosity and other properties may also require suitable additives to match.
In addition, coating auxiliaries also show a trend of versatility. Rheology and water retention modifiers have some of the functions of lubricants, and even some companies claim to function as water repellents; new lubricants show many of the characteristics of rheology modifiers.
Micro gravure coating advantages:
1. A very thin coating can be applied to very thin materials. Since there is no back pressure roller, there are no defects such as offset printing and wrinkles on the coated surface.
2. Since there is no back pressure roller, the edge of the film can be coated with glue without worrying that the glue is applied to the back pressure roller to affect the coating.
3. Due to the light contact of the doctor blade with the anilox roller, the scraper and the web roller are very worn.
4. The micro-concave roller has small diameter and light weight, and different coating amounts are applied, and it is convenient to replace the micro-concave roller. 5. Reverse coating can obtain relatively flat coating, and the coating amount is evenly distributed.
Miniature gravure coating disadvantages:
1. The micro gravure coated glue storage tank needs to remain full when the coating liquid is applied, and the micro concave roller is only in contact with the overflowed liquid phase, so that the glue in the plastic storage tank cannot be fully utilized, and It can't be recycled, so it causes a certain amount of waste, and the amount of glue waste is about 10KG.
2. If the micro-concave roller is not clean after use, it will easily cause the micro-concave roller to rust and it is difficult to remove rust.
3. Since the glue in the glue storage tank is exposed to the air during coating, dust and particles in the air are easily dropped into the glue storage tank during coating, which has a certain influence on the quality of the coating.
4. The micro gravure coating system is more complicated, and it is difficult to clean and disassemble. It often takes 1-2 hours.
Zhengzhou EAST IMPORT AND EXPORT co., ltd . ( a goulian group of company) a manufacturer and exporter for all kind of packaging machinery , like bopp tape coating machines, bopp tape slitting machines. Bopp tape core cutter, bopp tape core loader etc