Qualified water-based inks How can you sure it is a qualified water based ink? And what are Benefits? By ecat experts You can make a quality control sheet to compare between two water-based ink suppliers and to ensure the quality of your ordinary supplier as following: pH: it is the main important parameter in water-based ink and you can use pH-Meter to test Solid content: you simply can use oven and balance to compare at least three samples to get the best result. Viscosity: it can be measured by ford cup 4 or Brookfield. Gloss: you can compare it by using Gloss-Meter Fineness: as it affects the cylinder and Doctor Blade and it can be detected by Hegman Gauge Color Strength, transparency, and different shades: can be compared by using X-Rite. Heat and Cold resistance, water, soap and alkali resistance, scratch: they can be measured by making a drawdown and comparing both samples. Foam ratio: foam is major in a water-based system with ink movement (especially during color mixing, printing process) and it affects the quality of your final printing so you should be aware how to control or prevent foam generation. Benefits of using qualified water-based inks: You can save money especially by using less quantity of ink to get the best printing Makes sure that, your final product is permanent qualified and obtaining a consistent quality To make sure it is a more stable qualified final product. To provide the cleanliness of image with no haloing areas Obtaining the optimum press operating speeds To save your viscosity and drying stability especially against bad effect of different pH changes. As you know standard pH range is 8-9 and if you have a higher pH it will cause lower viscosity and lower drying time. To minimize waste products during first printing trials
How to evaluate the quality of printing by using water-based flexo ink? Printing by using water-based flexo ink is easy to evaluate quality of printing if you know well the character of water-based flexo ink which you selected you to use in printing The main idea The main idea of Water-based flexo ink printing technology depending on transferring the ink from the machine parts, Anilox with a doctor blade to substrate with an image of printing, so the formulation of water-based ink should have some component to have good Image also Anilox roller cells number is important in a printing process. First, you should select suitable substrate suitable for the application which you will use as end product, like Kraft, white or brown, tissue, coated or uncoated paper also absorption of substrate must be considered an important factor when you select the suitable type of water-based flexo ink and anilox no, also is very important to have well-printed substrate Kraft paper is the main type of substrate which uses for producing this type of boxes, thickness and weight also absorption are main factors which detect the type and quality of Kraft substrate. Viscosity of water based flexo ink is very important to have good performance on printing machine which is controlled by ink manufacturer easily by using suitable material in formulation to match with type of printing machine and it is easily measuring by lab equipment by seconds or centipoise sometime the ink needs to dilute, after dilute water based ink by water sometimes causes foam that why users of water based flexo ink complain from that foam but this type of problem is easy to solve by adding some of Antifoam additive, some drops of antifoam can kill this foam in seconds especially during printing process. due to flexo, water-based ink is water soluble user can dilute water-based ink with normal water.
How can I achieve optimum flexo printing quality? For achieving optimum flexo printing quality, there are major steps that should be followed. pH control: Proper pH is critical to achieving sharp and defined printing image. Ph that is not properly adjusting from color to color on the printing machine will cause a number of printing defects. pH is acidity, neutrality or alkalinity of a liquid ranging from 1 to 14 on a pH meter. Below 7 is acid and above 7 is alkaline and 7 is neutral. Flexographic ink should be on the alkaline side of the scale, so pH should never be below 8 or higher than 9.5 in flexo ink pH reading should be taken and adjustment made when viscosity readings and adjustment are made. pH adjuster, supplied by the same ink supplier. The challenge is in keeping pH up, not down, and to achieve the stepping of pH, it is important to use measuring cup amounts for this purpose, hot humid condition and evaporation accelerate downward movement in pH. Viscosity control: Ink viscosity determines the rate of flow and is measured in seconds by using a No.2 Zahn cup, the device that allows liquid to through an opening at the bottom of the cup, and which is the adopted instrument of the corrugated board industry. The proper viscosity is that which achieve suitable coverage and color density matching a costumer color sample. Two vehicles are used to reduce the viscosity, water, and extender varnish. As with pH adjuster, a measuring cup of either water to extender varnish should be used to avoid reducing viscosity to a point where desire coverage and density are no longer achieved. Often it is better to use extender varnish that has the same properties as ink, except pigment. This vehicle will have less effect in reducing the solid content of the ink. In the next article, we will talk about setting impression and cleaning printing plate.