- PVC Tarpaulin
- PVC Film ( PVC Sheet )
How to improve the phenomenon of PVC calendering film printing adhesion?
PVC calendering film is a product printed on pvc calendering film by gravure printing machine. The film pattern is clear, colorful and varied, it has strong decorative effect and is applied in daily life, military and industry. However, if the film is stuck after printing, it will greatly affect the decorative effect of the product and reduce the quality of the product. This is a big problem that often plagues the production of PVC calendering printing film.
How to improve the phenomenon of PVC calendering film printing adhesion
The improvement method of PVC calendering film printing adhesion:
1. The quality control of the bottom film
The performance of the bottom film is directly related to whether the printing film has adhesion. Therefore, it is very important to strictly control the quality of PVC calendering film. If the film is found to be soft, attention should be paid to controlling the amount and type of plasticizer in the bottom film, and the amount of lubricant should not be too much. At the same time, observe whether the temperature of calendering roller is too high; If the bottom film is tight and the belly is often caused by uneven shrinkage of the film, first check whether the film exists. Three highs and two bottoms' Phenomenon, whether the roller temperature is uniform and whether the cross angle of the shaft is too large; Secondly, check whether the cooling is uniform, whether the coiling tension is appropriate and stable, and whether the calendering speed ratio is reasonable. And the bottom film should be treated with cold trimming as much as possible. Only by reasonably determining the formula of the calendering film and the calendering process conditions can the quality performance of the bottom film be ensured to be stable, thus bringing convenience to the subsequent printing process, ensuring the printing quality and avoiding adhesion.
2. Reasonably determine the ink composition and formula
PVC printing ink is made by mixing transparent puree and color paste in a certain proportion, when in use, dilute with mixed solvent to the required viscosity. The amount and type of plasticizer and solvent used in ink composition have an important influence on the adhesion phenomenon of printing film. Generally, the influence of the selected materials on the dissolving ability of chlorine vinegar resin, the wetting and permeation ability of the bottom film, the viscosity adjustment ability, the drying speed and other factors should be comprehensively considered. Usually plasticizer is better to choose DBP. DBP has high plasticizing efficiency, strong volatility and easy drying; Solvents are generally cyclohexanone, butyl acetate, acetone and ethyl acetate, which are often mixed with solvents.
from the actual production point of view, PVC calendering film printing ink preparation as shown in Table 1. It is worth noting that the proportions in the table should be revised according to the climate and the specific conditions in production. For example, in summer, the temperature is high and the solvation ability is strong, and the dosage of cyclohexanone in the puree can be appropriately reduced; However, the temperature in winter is low and the solvation effect is weakened, and the dosage of Cyclohexanone can be appropriately increased. At this time, the dosage of acetone can be increased in the mixed solvent, and ethyl acetate can be used instead of some butyl acetate to accelerate the volatilization rate of the solvent, avoid the adhesion of the printed film.
3. Improving the fineness of color paste and the uniformity of solid-liquid dispersion
The fineness of ink has a very important influence on printing adhesion, the fineness of ink depends on the fineness of color paste. In the process of color matching paste, all components must be fully and evenly mixed and ground to a certain fineness by Colloid mill, and the color paste particles are usually controlled at 30μBelow m.
attention should be paid in the grinding process: ① Colloid mill must be cooled by water; (2) the flow rate of circulating pumps I and II should be adjusted in accordance with the fineness of Colloid mill; (3) the fineness of Colloid mill can be adjusted according to the production needs and different varieties of raw materials. A can of color paste needs to be subjected to Colloid mill for 3 times (That is, thick, medium, thin)Can be used for production.
The color paste is ground by this method, the fineness and dispersion degree are greatly improved, and the pigment ratio in the color paste can be reduced, thus not only reducing the cost, but also improving the fluidity of the color paste, easy to produce, avoid slurry and paste. At the same time, the engraving depth of the printing plate roller can be reduced, the network cable can be increased, and the slurry consumption per ton of film can be reduced. In this way, the tinting strength and color fastness of the product are improved, the ink is full, the color is delicate and bright, easy to dry, and the phenomenon that the product cannot be opened after being rolled up is completely avoided, thus greatly improving the quality of PVC printing film.