1. The influence of ink viscosity

濟(jì)南印刷廠油墨黏度應(yīng)與印刷速度相匹配，高速印刷時(shí)，油墨的黏度控制在12～15秒(3#察恩杯)之間；中速印刷時(shí)，油墨的黏度應(yīng)控制在16～18秒(3#察恩杯)之間。油墨黏度過(guò)高，對(duì)印版滾筒的黏附性過(guò)強(qiáng)，不利于刮墨刀將版面多余的油墨刮干凈，印刷品出現(xiàn)刀線的幾率就高。印刷過(guò)程中要定時(shí)測(cè)量和控制好油墨黏度，一般隔20—30分鐘測(cè)量一次。

The viscosity of ink in Jinan printing plant should match the printing speed. When printing at high speed, the viscosity of the ink should be controlled between 12 and 15 seconds (3 × chaen cup); in medium speed printing, the viscosity of ink should be controlled between 16 and 18 seconds (3 × chaen cup). The viscosity of the ink is too high, and the adhesion to the printing plate cylinder is too strong, which is not conducive to the scraping knife to clean the redundant ink in the layout, and the probability of knife line in printed matter is high. During the printing process, the ink viscosity should be measured and controlled regularly, usually every 20-30 minutes.

2．油墨干燥性的影響

2. The influence of ink dryness

油墨干燥過(guò)快，容易出現(xiàn)結(jié)皮現(xiàn)象，如果結(jié)皮在油墨循環(huán)過(guò)程中未被溶解，一旦接觸到刮墨刀就會(huì)黏附在刀口或刀底，產(chǎn)生印刷品刀線。如果油墨循環(huán)系統(tǒng)采用的是敞口墨槽，更容易發(fā)生油墨結(jié)皮、結(jié)塊現(xiàn)象。為了減少此類刀線故障的發(fā)生幾率，要經(jīng)常攪拌墨槽中的油墨；根據(jù)需要加入適量慢干劑；如有條件，還可加裝密封蓋，能夠有效地控制和減少印刷品刀線故障。

If the ink dries too fast, it is easy to skin. If the crust is not dissolved in the process of ink circulation, once it contacts the doctor blade, it will adhere to the edge or the bottom of the knife, resulting in printed product knife line. If the ink circulation system is open ink tank, it is more likely to occur ink crust, caking phenomenon. In order to reduce the occurrence of such knife line failure, the ink in the ink tank should be stirred frequently; appropriate amount of slow drying agent should be added as required; if possible, a sealing cover can be added to effectively control and reduce the knife line fault of printed matter.

3．油墨細(xì)度的影響

3. The influence of ink fineness

凹印油墨主要由顏料，連結(jié)料、助劑等成分組成。如果顏料研磨不充分，顆粒較粗，且不溶于連結(jié)料和溶劑中，印刷時(shí)停留在刮墨刀口，就會(huì)導(dǎo)致印刷品出現(xiàn)細(xì)小，不規(guī)則的刀線。顏料顆粒的細(xì)度對(duì)刀線的出現(xiàn)頻率有直接影響，例如藍(lán)墨中所使用的顏料顆粒硬度高，即使經(jīng)過(guò)充分研磨也很難達(dá)到很細(xì)的顆粒度，在印刷過(guò)程中就容易損傷刮墨刀或影響刮墨效果，印刷藍(lán)墨時(shí)經(jīng)常出現(xiàn)刀線故障。

Gravure ink is mainly composed of pigments, binders and additives. If the pigment is not fully grinded, the particles are coarse and insoluble in the binder and solvent, and stay at the edge of the squeegee during printing, it will lead to small and irregular knife lines. The fineness of pigment particles has a direct impact on the frequency of knife line. For example, the pigment particles used in blue ink have high hardness, and it is difficult to achieve a very fine particle size even after full grinding. In the printing process, it is easy to damage the doctor blade or affect the scraping effect. When printing blue ink, knife line failure often occurs.

4．油墨活性的影響

4. The influence of ink activity

在油墨生產(chǎn)過(guò)程中，一般都加入一定量的活性劑。印版滾筒鍍鉻后也有一定的活性，如果油墨和印版滾筒的活性太高，在印刷時(shí)，活性物質(zhì)就會(huì)牢固地黏附在滾筒上，刮墨刀也很難將其刮干凈，從而形成刀線。此時(shí)先對(duì)印版滾筒進(jìn)行清洗，其表面的活性物質(zhì)，同時(shí)在油墨中加入活性減緩劑刀線。

In the ink production process, generally add a certain amount of active agent. The plate cylinder also has a certain activity after chromium plating. If the activity of the ink and plate cylinder is too high, the active substance will adhere firmly to the cylinder during printing, and it is difficult for the scraper to clean it, thus forming a knife line. At this time, the plate cylinder is cleaned to remove the active substances on its surface, and the active retarder is added to the ink to eliminate the knife line.

5．油墨質(zhì)量的影響

5. The influence of ink quality

油墨儲(chǔ)存時(shí)間過(guò)長(zhǎng)，溶劑平衡發(fā)生變化，引起油墨溶解力降低；或者油墨調(diào)配、使用不當(dāng)，引起化學(xué)反應(yīng)，都會(huì)使油墨產(chǎn)生沉淀。在印刷過(guò)程中，油墨中的沉淀物容易積聚在刮墨刀口引起刀線，需要更換油墨。

Ink storage time is too long, solvent balance changes, resulting in ink solubility reduction; or ink deployment, improper use, causing chemical reactions, will make ink precipitation. In the printing process, the deposit in the ink is easy to accumulate on the blade edge, causing knife line, so the ink needs to be replaced.