In order to meet the demand for high-quality, long-term and large-quantity packaging of Yunnan cigarette labels, many Yunnan printing companies have put gravure printing equipment into the cigarette labels on the occasion of the 90th generation, forming an upsurge in the history of printing in Yunnan. In the past few years, we have experienced a process from infatuation to familiarity with the gravure printing process and quality control. Here we only take the company's part of the process improvement projects and quality control procedures as examples to illustrate the quality of the gravure printing of gravure labels. Control talking about rough.
(-) Reasonable process design and technical improvement are prerequisites for quality control.
At the beginning of gravure printing, ink and ink flying were the most common quality problems, leading to high scrap rates. The main causes of the phenomenon of ink-pulling caused by the analysis are the material issues of the ink knife itself; the flatness of the surface of the printing plate; impurities in the ink such as coarse particles, foreign substances, etc. raise the part of the tool upwards, aiming at the most common third For some reason, we added a filter to the ink circulation system to filter the ink before it was filtered and filter it in circulation to effectively control the pull-ink phenomenon. Solving the problem of flying ink starts from prepress. First of all, the typographic layout should not be over-filled, accounting for 75-85% of the maximum printing width. The second is to improve the chamfering accuracy at both ends of the plate roll, reduce the concentricity deviation, and also reduce the phenomenon of flying ink. The third plate is equipped with a hard ink plate at both ends to prevent ink splashing.
The Honghe cigarette markings printed by our company have strict requirements for hue, and the depth of the printing plate directly affects the hue index. In order to ensure that the hue indicators are qualified, the plates are required to have a certain depth. The darker plate has a poor smoothness. Although the number of lines and the angle of the engraving needle are adjusted several times, there has been no substantial breakthrough in the smoothness of the printed product. Last year, our company put into use a high-shear emulsifier, the ink insisted on emulsified after the machine. During the emulsification process, the ink particles are fully ground. The ink after grinding is delicate, uniform, and smooth. After the machine is used, the level of twist is significantly improved, and the phenomenon of pulling ink is also significantly reduced. In the hue adjustment process, the ink needs to be added with different color types. Due to insufficient mixing, the phenomenon of uneven ink transfer during printing tends to occur. The white strip is commonly known as the high shear emulsifier to solve the problem of the color ink preparation process.
(2) The establishment of acceptance criteria for key accessories is one of the keys to quality control.
Paper surface scratches, moisture levels, dust degree; original ink viscosity, hue L, a, b value range, printability; solvent water content, dryness, residual odor; printing plate proofs are listed as me The company's most basic accessories inspection project.
(3) Strengthening process supervision and improving statistical records are the intermediate links in quality control.
If the reference printing index specified by the printing plate is 1 million revolutions, the printing plate that is still printing more than the prescribed number will be monitored by the process control department for preventive measures, so that not only the potential quality influencing factors are controlled but also the production is saved. cost. The company has also implemented a system in which the quality management department periodically evaluates the supplier's capabilities through statistical data of process supervision, and selects suppliers based on the statistical qualification rate of accessories.
(4) Quality consciousness is the fundamental of quality control.
My company has a leadership team that attaches great importance to quality and has formulated a quality policy of “people-oriented, advanced technology-led, advanced management methods for control, and ensuring quality first”. Formulated and implemented the series of documents such as Gravure Process System Documents, Process Discipline Documents, Process Quality Control System Documents, and Quality Awards and Punishment Regulations to enable employees to tighten string quality from top to bottom. Quality workers do "have laws to follow."
In a word, staff's quality consciousness, skill quality, reasonable printing process design, equipment performance, auxiliary material performance and so on are all related to gravure printing quality. Along with the development of the gravure printing industry, gravure quality control will remain a long-term issue. We still need to do a lot. Only by constantly exploring and summarizing can we better grasp the quality of gravure printing and make quality truly become a competitive enterprise. Powerful guarantee.
