印刷廠在印刷過程中會遇到的一個問題就是實地印刷墨色不勻,這個是常見的一個問題,那么怎么避免和呢?我們要知道一般印品墨色不勻表現為水紋狀不勻和橘皮狀不勻兩種。
One of the problems that printers will encounter in the process of printing is the uneven ink color in the field printing. This is a common problem, so how to avoid and solve it? First of all, we need to know that the ink color unevenness of general printing products is manifested by two kinds of unevenness, i.e. water pattern unevenness and orange peel unevenness.
造成這兩種現象的原因:1.水紋狀色不勻主要是由于凹版雕得太深,而油墨的黏度偏低所造成的。2.橘皮狀墨色不勻產生的主要原因一是油墨中加入了過量的極性溶劑如丁酮等;二是油墨的黏度過高導致流平性不好;三是壓印膠輥質量,導致印刷時壓印膠輥對印版滾筒的不同部位壓力不均勻。
The reasons for these two phenomena are as follows: 1. The uneven color of the water pattern is mainly caused by the deep gravure carving and the low viscosity of the ink. 2. The main reasons for the unevenness of orange peel ink are the addition of excessive polar solvents such as butanone in the ink; the high viscosity of the ink leads to poor leveling; and the quality of the embossing cots, which results in uneven pressure on different parts of the printing cylinder.
原因找到了,那么的辦法有哪些呢?
The reason has been found, so what are the solutions?
(1)與制版企業聯系,通過測試找出印版滾筒、油墨、印刷條件的匹配結果。制版企業以此為基礎確定適宜的雕版工藝參數。經過此過程制程的凹版在實地專色版印刷不勻上具有較強的適應性。
(1) Contact with plate-making enterprises and find out the matching results of plate drum, ink and printing conditions by testing. On this basis, plate-making enterprises determine appropriate engraving process parameters. Gravure plate produced by this process has strong adaptability in solving uneven spot printing.
(2)在接到新活件時,及時和客戶溝通,盡量避免將專色版雕得太深。如果凹版雕得較深時,可在保證油墨流平性的基礎上適當提高油墨的工作黏度。
(2) When receiving new live parts, communicate with customers in time and try to avoid engraving the spot-color plate too deeply. If the Gravure Engraving is deeper, the working viscosity of the ink can be improved properly on the basis of guaranteeing the leveling of the ink.
(3)對于專色橘皮不勻現象,一顆適當降低油墨黏度,第二課適當降低壓印膠輥的壓力,第三盡量提高印刷速度。
(3) For spot orange peel irregularity, the first one is to reduce the ink viscosity properly, the second one is to reduce the pressure of the embossing roller properly, and the third one is to increase the printing speed as far as possible.
(4)合理調配溶劑配比和油墨的工作黏度。在印刷速度超過100m/min,油墨的黏度一般控制在20~26s左右,在溶劑配比上可適當增加快干溶劑。
(4) Rational mixing of solvent and working viscosity of ink. When the printing speed is over 100 m/min, the ink viscosity is generally controlled at about 20-26 s, and the fast-drying solvent can be properly increased in the solvent ratio.
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