Paste plate also is known as blocking, refers to the inability of printing ink to transfer to the substrate. The causes of paste plate phenomenon in mesh screen printing are complicated. It can be analyzed from the following aspects.
(1) Substrate reason. Screen printing substrate is diverse, and the substrate is one of the reasons paste plate. For example paper class, wood class. Fabric substrate surface smoothness is low, the surface strength is poor, in the printing process is relatively easy to produce powder, picking, resulting in paste plate.
(2) Workshop temperature, humidity and ink properties, screen printing workshop requirements to maintain a certain temperature and relative humidity. If the temperature is high, low relative humidity, the ink in the volatile solvent will quickly evaporate, ink viscosity, thus blocking the mesh hole. Another point to note is that, if the downtime is too long, will also produce paste version phenomenon, The longer the time is more serious. Secondly, if the environment temperature is low, the ink fluidity is also easy to produce a paste.
(3) Screen printing plate. Make the screen printing plate to be washed with water before use and placed dry. If the plate is not used for a long time, in the preservation process more or less will adhere to dust, printing if not clean, will cause paste plate.
(4) The cause of printing pressure. In the printing process, the pressure is too large, will make the scraper bending, scraper and screen printing plate and the substrate are not line contact, but surface contact, so each time scraping can not clean the ink, leaving residual ink, after a certain period of time will conjunctiva paste version.
(5) Screen printing plate and substrate gap improper reasons. Screen printing plate and the gap between the substrate should not be too small, too small gap will cause screen printing plate cannot be separated from the substrate, printing plate rise, printing plate bottom will adhere to a certain amount of ink, so it is easy to paste.
(6) The reason for the printing ink. Screen printing ink pigment and other solid particles when large, it is easy to plug the mesh. In addition, the selection of screen specifications and the through-hole area is suitable for the smaller size of the ink, so that the larger ink particles are difficult to pass through the mesh. On this account, you can control ink fineness to solve.
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