Application control of water-based varnish
- 2019-10-24-

  01 Viscosity control

In the application of water-based varnish, the viscosity of varnish should be regularly checked. The excellent viscosity range of offset printing is between 35 seconds-60 seconds. It affects the normal operation of the oil pump, causing problems such as oil cut-off, rough leveling and drying.

  02 Avoid cracking

Application of water-based glazing should be printed with high concentration and fast drying ink, and pay attention to the difference between the thickness of the varnish coating and the thickness of the ink coating to avoid cracking caused by thick ink layer, thin oil layer or slow drying of ink.

  03 Avoid pinholes

The oil suction pipe in the oil pumping system should be placed at the bottom of the varnish barrel, and the oil return pipe should be placed on the upper surface of the water-based varnish and lean against the barrel wall, so that the recovered varnish flows slowly down to avoid impact caused by varnish There are a lot of micro-bubbles inside the liquid, causing pinholes or film formation problems.

  04 Prevent back sticking

After the water-based varnished printing film is dried, it becomes soft and sticky at higher temperature and humidity, which leads to the adhesion of the printed product. Therefore, the temperature of the stack should be controlled below 36 as much as possible during printing. In the case of high temperature or humidity, especially in the rainy and rainy season in summer, the storage and transportation of varnished products should pay attention to the control of temperature and humidity.