Understanding Capillary Diameter Of Newsprint And Ink Pigment

It takes three elements for maintaining an overall output of quality print and ink consumption in newspaper printing—newsprint, ink and fount solution. In this respect, Nilay Patel, Technical Director, OneVision Software AG, explains about efficiency in newspaper printing and ink consumption with a focus on newsprint capillary diameter and ink pigment size.

When it comes to composition of ink, it usually is made of pigment, oil (vehicle), resin and additives (dryers, waxes, etc). According to The Print Ink Manual by Robert Leach, newspaper printing ink is composed of chlorinated para red (CI pigment red 4), extender pigment, resin varnish, mineral oils, long-oil length alkyd resin, wetting agent, anti-oxidant, etc, as shown in the table ‘Newspaper ink composition’.

Printing Process

Newsprint is of low cost and usually not for longer storage type. Wood pulp is used as a main material to make newsprint. Newsprint and ink are two key materials that play important role in cost optimisation in newspaper printing. When printing newspaper on a web offset press (blanket-to-blanket printing method), newsprint is passing between two blankets. Dampening and inking units (roller train) are connected to plate cylinder where the printing plates are loaded. Plate cylinder is connected to blanket cylinder, so that image area from plate is transferred to blanket and non-image area is wiped out by fount solution. When newsprint is moving between both sides of blankets, ink is transferred to the newsprint, printing on both sides. Ink has to work with both fount solution and newsprint during the printing process, as shown in the figure ‘Blanket-to-blanket printing.’

Newsprint Capillary

If newsprint capillary diameter is small, only oil penetrates in the newsprint. Then, ink pigment and rest of the vehicle remain on the surface of the newsprint. That would help to achieve print quality better with low consumption of ink. In this scenario, ink lay down is low on newsprint. As a result fount solution will also become low. This becomes the best condition for press operators. They can sustain good print quality for longer time without playing much more on ink and fount solution nozzles as chances of scrumming and solid ink density variance are the least. This will help in faster drying of substrate with better ink lay down and trapping.

On other hand, if capillary diameter is large, pigment and vehicle will also penetrate, leading to reduced colour strength of newsprint, which in turn leads to higher ink lay down and higher consumption of fount solution. This will make printing cycle vicious and printer has to engage himself to play often on ink and fount solution nozzles to print without scrumming/toning as well as to maintain standard ink density on printed newspaper. This affects the drying process. Newsprint may be wet and chances of set off and doubling will be high as first lay down ink will be back split on other inking unit blankets.

Optimisation Of Ink Pigment

Ink pigment particle size is important and should be optimum with capillary diameter of paper. If pigment particle is of 0.1 µm, capillary diameter should be less than 0.1 µm, to ensure that pigment remains on top of the newsprint. This consideration will help printer to complete print cycle with better condition with advantage of low ink and fount solution consumption. It is called yield in printing ink consumption, with the same amount of ink getting more mileage—which is nothing but cost optimisation with better print quality

(Appendix: The Printing Ink Manual; Print Media Technology and Huber Group)

Dainik Jagran on top spot in Hindi readership and The Times of India in English

According to the India Readership Survey report (Q3 IRS 2019), Dainik Jagran occupies the number one spot in Hindi readership, while The Times of India leads the league of English dailies. The survey also reveals that the data for the top magazine where India Today (Hindi and English editions), took the number one spot. The survey found that dailies have managed to hold on to their loyal readers. As per the report Dainik Jagran has garnered Total Readership (TR) of 72,559,000 in Q2 IRS 2019 compared to TR 70,430,000 in Q3. Dainik Jagran Average Issue Readership (AIR) stood at 17496000, a marginal drop from 18146000 in Q2. The Times of India was amongst the most read daily with their TR saw a hike from 16126000 (IRS Q2 2019) to 16986000.

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