Adjustment method for screen distance discomfort in screen printing

- Apr 08, 2019-

In screen printing, in order to avoid screen plate stuck to the substrate, screen printing plate and substrate must keep a certain distance.Screen once adhered to the substrate, it will seriously affect the printing quality, the role of the screen distance is to effectively overcome this problem, so that the screen only in the scraper scraping contact substrate, once the scraper scraping, screen rebound, screen and substrate instantly off, to avoid the phenomenon of dragging and smudging.It is well known that the quality of screen printing is affected by many variable factors, among which the screen distance is one of the most important factors.In most cases, printing quality and registration problems are largely attributed to improper screen spacing or adjustments made to compensate for it.In addition, it is necessary to correctly understand the concept of "rebound distance", in screen printing it is closely related to the screen distance, but different from the screen distance."Rebound distance" refers to the blade after the ink after the screen slowly rebound distance, it occurs at the beginning of the printing, and only in the process of scraper scraping, it ensures that the screen can quickly rebound, out of the substrate.Screen printing in the general screen distance of 9.5-12.7mm, but more reasonable and use more is 1.5-3.0mm.Too much screen spacing can cause problems with print quality and registration, so it should be kept as small as possible.When printing some high precision products, screen deformation tolerance directly determines the size of the screen.In the printing of electronic products, stainless steel screen version of the screen distance is often smaller, about 0.1-0.2mm.Therefore, whether it is printing graphics or textiles, the screen distance is a parameter worthy of special attention.Once the screen distance is not appropriate or inconsistent, will bring unnecessary losses to the printing, need to be carefully controlled.In multicolor and four-color screen printing, the problem of color registration must be well handled, and the screen distance plays a crucial role in the registration.In a strict sense, the existence of screen spacing is not possible to make the printed matter and the original, which is due to the screen in the printing process due to the expansion and deformation.The larger the screen distance, the scraper pressure will be greater, the larger the screen is stretched, resulting in a pattern on the substrate offset.Small spacing can improve the situation to a certain extent.Therefore, in order to reduce the image offset, it is required to choose the smallest distance possible.For some printed materials with high requirements for registration accuracy, it is suggested that the screen distance should be 1.5mm, and the maximum should not exceed 3mm.As the distance increases, many problems arise.First of all, in order to ensure the screen and substrate contact, ink transfer, scraper pressure is bound to increase, the force on both ends of the scraper is bound to be greater.Relative to the screen frame, the longer the scraper, the more prominent this phenomenon.This not only increases the distortion of the pattern, but also seriously affects the printing quality.In addition, sometimes the printed pattern is drawn and elongated, part of the reason for this situation is the network distance problem, but also with the pattern position, the length of the scraper and the direction of the scraper operation.In screen printing, it is very important to keep the screen distance uniform.If the screen before, after, left and right around the net distance is not consistent, the image in the corresponding position will appear offset.In this case, the second color will never align with the first, no matter how hard the operator tries.Obviously, if the various colors in the printing can not be aligned, the whole live parts will be scrapped.It is worth mentioning that in electronic circuit printing, some pattern deformation can be calculated in advance when there is no pattern.In addition, some manufacturers have introduced devices that can overcome these problems.

SP302-C 五色五面气球印刷机 9