What are the causes and solutions of paste edition?

What are the causes and solutions of paste edition?

Paste plate, also known as block plate, refers to the screen plate image hole part of the printing ink can not be transferred to the substrate.The appearance of this phenomenon will affect the printing quality, or even the normal printing.

The causes of the paste phenomenon during screen printing are complex.Paste version of the reasons can be analyzed from the following aspects.

(1) Substrate reason.Screen printing substrate is a variety of substrate texture characteristics is also produced paste plate phenomenon a factor.For example: paper, wood class.Fabric substrate surface smoothness is low, the surface strength is poor, in the printing process is more prone to drop powder, hair phenomenon, resulting in paste plate.

(2) workshop temperature, humidity and ink properties of the reason, screen printing workshop to maintain a certain temperature and relative humidity.If the temperature is high, low relative humidity, ink in the volatile solvent will quickly volatilize, ink viscosity becomes high, thereby blocking the mesh.Another point to note is that if the downtime is too long, will also produce paste version of the phenomenon, the longer the paste version of the more serious.Secondly, if the ambient temperature is low, ink fluidity is also easy to produce paste version.

The reason of screen printing plate.The finished screen printing plate should be washed with water and dried before use.If the finished version is left too long and not printed in time, it will stick to the dust more or less in the preservation process. If the printing is not cleaned, the paste version will be caused.

The reason of printing pressure.In the printing process, too much imprinting force will make the scraper bend. The scraper is not in line contact with the screen plate and substrate, but in surface contact. In this way, each scraping can not clean the ink, leaving residual ink, after a certain period of time will cause the conjunctiva paste plate.

(5) Screen plate and substrate clearance is not appropriate reasons.Screen plate and substrate between the gap should not be too small, the gap is too small after scraping the screen plate can not be separated from the substrate, screen plate lifting, printing plate at the bottom adhere to a certain amount of ink, which is also easy to cause paste version.

The reason for ink.In screen printing ink pigment and other solid particles of larger, it is easy to plug the phenomenon of mesh.In addition, the selection of mesh mesh and hole area and ink particle size compared to some small, so that the coarser particles of ink is not easy to pass through the mesh and the phenomenon is one of the reasons.For larger ink particles caused by the paste version, can be started from the manufacturing of ink, the main method is to strictly control the ink fineness.

Ink drying in the printing process too fast, easy to cause paste plate fault.Especially in the use of volatile drying ink when this phenomenon is more prominent, so the printing must choose the appropriate solvent control drying rate.In the selection of ink to consider the impact of the climate, generally in the winter use of fast drying ink, summer should be added in the ink late dry, if the use of late dry agent also paste version of the phenomenon, you must change to other types of ink.

The use of oxidation drying ink, paste version of the phenomenon is not a lot, but in the summer if excessive use of desiccant, will also occur paste version of the phenomenon, the general summer to control the use of desiccant.

The use of two-liquid reactive ink, because the ink itself drying speed is slow, so almost no paste version of the phenomenon, but occasionally there are paste version of the phenomenon.

In the printing process, the ink viscosity increase resulting in paste version, the main reason is: on the version of the ink solvent evaporation, resulting in increased ink viscosity, and the phenomenon of closure.If the printing image and text area is relatively large, screen printing ink consumption, paste version less.If the picture and text area is small, screen printing ink consumption is less, it is easy to cause paste version, its countermeasures often replace with new ink.Ink fluidity is poor, will make ink in the screen will not produce paste version, this situation can be solved by reducing ink viscosity to improve ink fluidity.

Paste version of the fault, can be based on the nature of the ink, using the appropriate solvent to scrub.The main point of the scrub is to start from the printing surface and gently wipe from the middle to the periphery.After wiping, check the printing plate, if there is a defect should be timely repair, repair can start printing again.It should be noted that each time the film is swabbed, will become thinner, such as wipe caused by a major defect in the film, then had to change the new printing.