Single-panel ink problem and countermeasures

Black oil, oxidation, tin foam, and green oil are common defects in single and double panel plants. It is generally considered to be caused by a bad process section of the green oil front plate. However, in the actual work, it will be found that the post-etching process has a great influence on the later stage. There is a small sample that can be made by a manufacturer with poor process before green oil. After the normal production of etching, take several types of circuit board and several kinds of sheet molding products into the water to pick up (non-absorbent) upright for 3 to 7 days, generally can see the post-etching process problems (single-sided look at the reverse grease stain Case). At the same time, after the normal production of green oil printing plate before grinding to take several models and several kinds of two plates, one of which is placed in the water to pick up and put upright for 1 to 3 days can also find the problem of green oil before the grinding board.

For example: the green bottom is black (the finished board is finished, packed and warehousing, about 1~3 months later, there will be 1 strip of black or dark under the green oil, and it will fall off with a piece of tape.) In the text. The blackening or darkening phenomenon of a strip, if it is formed from the end of the plate to the end, and is the direction of brushing, can indicate the problem of brushing. One is that the poor quality of its own performance in the abrasive, need to increase the pressure to see the brushing effect, brushing water cooling and cooling is not satisfied to form a brush to stain the dragon, after grinding the plate can be found with a magnifying glass, dark black Smooth stripes. Larger strips should be left after the etching of the process oil left on the panel, or used to scrub the grease reworked board and the pressure grinding green oil rework board caused by grease stains caused by the brush. Check the production board can be seen without roughening, and when the pressure is serious, it does not have much effect. The post-grinding inspection is not obviously visible with green oil. If the stripe is not linear, it should be regarded as a problem in the post-etching process to remove the ink. The grease on the surface of the board causes difficulty in polishing, and it cannot be completely removed by a normal grinding. Normally, the ground is severely wiped with electronic water, and it can only be solved by batch grinding twice or even three times.

For the poor de-inking process or grease stained sheet after etching, the deinking section of the equipment should have sufficient length and potion pressure. Usually pay attention to maintaining a uniform mouth, so as to ensure that the concentration of the drug remains as low as possible. The process should pay attention to the ink alkali tablets do not directly join the drug tank, but should be placed in another barrel, add water to dissolve the drug tank. The first one can not be added, and then it is added once every 1-2 hours to maintain a relatively low stable concentration, which is beneficial to control the addition of defoamer (because the oil produced is mainly derived from defoamer). The quality of the base sheet and defoamer should be controlled. There is such a phenomenon that if the ink is not completely removed for the first time in production, it is difficult to completely remove the rework the second time or the third time. It can be difficult to brush. Therefore, it is very important to solve the post-etching process problem, which is beneficial to the cost reduction and quality improvement.

For green oil mill plate process section. Mainly in the selection of equipment, the usual equipment maintenance. The first chemical cleaning section, also known as chemical roughening section, is usually used, oxalic acid, hydrochloric acid, and flow acid. There is a saying that oxalic acid removes grease, roughens hydrochloric acid, and deoxidizes the acid. Therefore, in some plants, oxalic acid is used to grind the plate before the black oil line, hydrochloric acid is used to grind the plate before the green oil, and acid is used to grind the plate before the rosin. Before the green oil commonly used hydrochloric acid: should control the concentration and stability is generally 3%, if the concentration is high enough after flushing there will be a little hole to the surrounding flower-like oxidation, after grinding the board can not find a short time screen printing.

The middle section is a brush scrub section, also known as a mechanical roughening section. The use of abrasive brushes is mainly based on the quality of the abrasive material. Generally, the first brush is selected by No. 500, and the second brush is selected by No. 320. Due to the recent decline in the quality of brushing caused by price competition, some plants use 320 before and after. It should be noted that changing brushes should not be changed at the same time. If 3 months are 1 cycle, change it 1 month and a half. Usually pay attention to the grease stains, once the stain is difficult to wash. Perform leveling and maintenance on a periodic basis. Usually pay attention to maintenance can increase the use of time and improve quality.

In the middle and back of the water wash, the general brushing section with recycled water. After brushing, use high-pressure circulating water and clean the tap water. The flow of water is after the washing with water → high-pressure circulating water after grinding → grinding and circulating water → outside the row. Some plate mills do not have high-pressure circulating water after flushing (which is one of the causes of the defects). This machine should control the concentration of hydrochloric acid before chemical cleaning. Usually pay attention to water pressure, do not plug the nozzle. After the sponge absorbent shaft should pay attention to cleaning and cleaning. Generally do not use detergent to clean, if necessary, there should be enough time and water to completely clean, or else use a magnifying glass inspection will find spot-like white mist, sometimes very obvious, some off the green oil and tin green oil from Bubbles are the reason for this. Regular periodic cleaning and replacement can control batch oxidation due to poor water absorption. Check the cleanliness of the sponge suction axis. Take the board behind the sponge suction shaft and use a magnifying glass to see the drying process. You will see a large piece drying to a point, forming a bead of water and then drying to the midpoint. The white spray-like point is formed when the dirty water accumulates as the water drops dry.

The last is the hot drying section. There are two general types: furnace type, test type. The furnace wire is directly on the surface of the board, which we call the test furnace type. This type of furnace is prone to have a high thermal efficiency. In fact, the heat loss efficiency is rather poor, and the effect of the former cold air knife is easy to produce water droplets to generate flower-like oxidation. The hearth furnace is ideal, and there should be a strong cold knife on the front to remove the water droplets formed on the board surface. The middle hot air knife section heater heating wire does not directly face the board but uses circulating hot air to blow the board so that the efficiency is high and the temperature is stable and the temperature is lower than the test type (the board surface temperature is low to control the bending board). This type of furnace preferably has an open cold air blow plate to allow the hot gas on the plate surface to blow away and cool the plate. If there is such a situation, if silkscreens are dried after drying, it is found that there is a flower-like oxidation. If the cold plate silk screen oxidation plug-in loss, it should pay attention to open the cold plate after grinding. Timely and stable control of the etching and plate-milling processes will not result in cyclical and batchy failures of green oil defects.