Possible Problems and Solutions of Plates (Part 2)

Fourth, the ink caused by the dirty version, flower version, paste version

1, the ink viscosity is too large and produce a flower version

Ink viscosity is too large, in addition to making the printing difficult, but also will break the middle of the ink layer fracture conditions, so that the layout of the remaining ink layer is insufficient, due to the graphics part of the exposed wear caused by the flower version.

Treatment method: Add a certain amount of detackifying agent to reduce the viscosity of the ink without increasing the fluidity of the ink too much. For printing fine products, lowering the viscosity of the ink is preferable to using a release agent because it does not increase the flowability of the ink while lowering the viscosity, and it is advantageous for drying the ink. However, the dosage should be appropriate. Excessive usage will affect the gloss of the imprint. Generally, the amount of yellow ink added is 1% to 1.5%, and the other color ink is about 2%.

2, the ink viscosity is too small easy to paste version

Small-viscosity inks are easily emulsified, causing turbidity and rendering the inks unable to transfer properly, causing pigment particles to accumulate on the rollers, plates, and blankets. When the pigment particles accumulate to a certain thickness on the plate, it will cause a paste plate. Sometimes the layout is not enough due to insufficient ink on the layout.

Treatment method: Add some concentrate ink properly, but not too much, to avoid affecting other properties.

3, ink flow is too large to make the network point of deformation, the lack of ink fluidity produce flower version

Ink flow is too large to spread the ink layer, so that the geometric size of the print is enlarged, and the print cannot be correctly reproduced. Insufficient ink fluidity tends to result in uneven distribution of the ink, resulting in a lack of ink for the printing plate.

Treatment method: The ink flowability is not fully adaptable to all printers, and high speed machines have greater fluidity than low speed machines. Materials that regulate the fluidity of the ink are generally No. 6 varnish and high-boiling point kerosene. But be careful not to add oil or other non-dry mineral oil to the ink.

4, thick ink particles and produce flower version

The ink particles are coarse and act as abrasives on the printing surface. In the thousands of times of rolling, the graphic and textual basis are destroyed and the pattern is created.

Treatment method: When printing, use ink made of pigment with small specific gravity as much as possible. For dilute color inks, clear dip or bright paste should be used as diluting agent instead of white ink.

5, dry oil in the ink and paste version

In the printing, some operators add a desiccant to the drying performance of the ink for fast drying of the printing material, which promotes the aging of the ink roller and causes the ink to become thick and emulsify, so that the ink layer on the printing plate cannot be Breaking from the middle, most stay on the plate, causing a stack. Under the effect of printing pressure, the ink layer on the outlet gradually expands to cause paste.

Treatment method: For stencils caused by too much dry oil, can not be solved by increasing the method of surface moisture, the old ink on the ink roller should be washed out and replaced with new ink. In the printing needs to add a suitable amount of dry oil ink, when the downtime is short, you can apply some anti-drying agent on the roller, when the downtime is long, you should clean the ink on the roller. $Page break $

Fifth, the causes of ink-induced printing failure and treatment methods

Ink is a colorant for printing and is the main raw material for printing. The ink has a great relationship with the quality of the printing, especially when the ink properties are not suitable for printing, it will cause a series of failures in the process, seriously affecting the normal production and the quality of the product. The printer must change the ink. Certain properties are suitable for printing needs, but some process failures are not only caused by ink, but also related to other factors, so the printing operator must carefully analyze and properly handle. This article first discusses the problems caused by the ink during the printing process and how to deal with it. Hopefully, it will help.

1. Ink pile

Phenomenon and reason: In the printing process, the ink from the ink fountain cannot be balanced and transferred to the paper through the ink roller, printing plate and blanket, but piled up and lost good transmission. This happens, in addition to the pressure of the machine is not appropriate and the rubber blanket and other factors, the common are the following reasons:

(1) The viscosity of the binder is not suitable, and there is insufficient adhesion to transfer the pigment, so that some pigment particles are accumulated on the ink roller, plate, and blanket.

(2) The thicker or specific gravity of the pigment particles, the poorer the transfer ability of the linking material, and the less ability to transfer it, so that the ink is deposited on the ink roller, plate, and blanket. This situation is common when printing yellow ink. Due to the large proportion of yellow pigment in the ink, it can account for 75%. The heavier the pigment, the more important the connection force of the binder.

Yellow ink printing is prone to stacking

(3) The amount of oil in the ink is too small and the pigment particles do not have enough binder to accumulate.

(4) The viscosity of the ink is too high or too hard, its fluidity is small, and the ink in the printing ink fountain is not easy to get down to the ink roller. If the ink adhesion strength is greater than the printing plate, blanket, and the paper's ink absorption force, The ink will still accumulate on the rollers, plates, and blankets.

(5) Adding too much dry oil in the ink will make the ink dry on the ink roller or make the ink sticky, especially in the summer or when the downtime is too long, once the ink is dry on the ink roller, it will lose its transmission performance. The ink from the ink fountain accumulates on the ink roller.

(6) The paper texture is loose or "powder removal", resulting in the mixing of paper wool and silt into the ink, as well as stacking and stacking blankets. Approach:

(1) Due to the poor adhesion of the binder or the coarseness and specific gravity of the pigment particles, an additive varnish or oil can be added to increase the viscosity and transfer performance.

(2) As the viscosity of the ink is too high and too hard, the texture of the paper is loose, the powder is removed, or the oil content is insufficient, and No. 6 varnish, Cambon, Vaseline, Willy oil, etc. can be used to change the ink viscosity and increase the wetting property.

(3) reduce the amount of dry oil (plus new ink) or add some non-dry accessories.

(4) Ink pigment particles are coarse, with a large specific gravity, and it is still not possible to increase the viscosity. The ink can be rolled before being used in the ink mill.

(5) If certain properties are changed, the phenomenon of stacking ink cannot be thoroughly solved. It can be processed in combination with multiple washing rollers, printing plates, and blankets.

2. Flower board

Phenomenon and reason: The flower pattern is gradually getting smaller and falling off. The printing plate loses its good fat-sensing ability, which reduces the level of printed matter and reduces the ink color. There are many reasons for floral patterns. For example, the pressure of rollers, water rollers, and ink rollers is too high. The water of the bucket is too large or the water is too large. There are too many paper sands or the blanket is too hard. Commonly caused by the ink The following reasons:

(1) The ink pigment particles are too thick and too hard, and the friction on the plate surface is large. Especially for the fine dots, the scratches damage the pattern ink-absorbing foundation and cause a flower pattern. Some pigments have slight corrosion to the layout, and the ink-absorbing foundation that damages the pattern of the layout will also cause floral patterns.

(2) Insufficient oiliness of the ink, weak ability to resist the acidic liquid, and the ink layer on the basis of the layout pattern is invaded by the acidic liquid to cause a flower pattern.

(3) The viscosity of the ink is not suitable, and the viscosity of the ink is too large. The cohesion of the ink is also large. During the transfer process, the ink layer is not easily broken, resulting in insufficient ink layer on the basis of the layout pattern and the flower pattern; the viscosity is too small, the ink is on the layout The adhesion is not strong, the layout of the layout of the foundation can not be protected by the remaining ink layer, the pattern of the foundation is directly invaded and friction caused by the acidic version of the flower.

Approach:

(1) The ink has low oiliness, low viscosity, low adhesion, common in black ink and 915 dilute ink, can add some 05-90 or 05--93 bright light to improve performance (black ink should not exceed 10%) .

(2) The viscosity of the ink is too large, resulting in the lack of residual ink layer on the plate and the flower pattern. Adding No. 6 varnish or Kangbang can be used to improve.

(3) Ink pigment particles are too coarse and corrosive (eg chrome yellow ink). Replace the ink or grind the ink before use.

3 paste version

Phenomenon and reason: When the paste version is unclear, the dot lines are enlarged, and the neighboring dots are merged with each other, so that the printed ink is dark and thick and the layers are reduced. The reasons for stencil are: In addition to the fact that the syrup is too hot, the pressure of the roller is too large, and the blanket is too loose, the following reasons are commonly caused by the ink:

(1) The ink is adjusted too thinly and the texture is too loose. The cohesion is small, and it is easy to spread outwards, resulting in the expansion of dots and lines.

(2) When the amount of ink under the ink is large, and it exceeds the amount of ink that can be accommodated in the layout pattern, it spreads out to cause a paste.

Fine network printing must strictly control the ink quality, otherwise it is easy to paste

(3) Ink pigments are too thick or too heavy, and the transfer properties of the linking material are reduced, resulting in deposits blocking the dots on the plate. On the other hand, because the particles are too thick, the fine mesh can not accommodate and expand outwards, and at the same time, the friction on the plate increases, destroying the hydrophilic properties of the blank parts and making them feel fat, causing the adjacent dots to merge and paste.

(4) The weight of the ink makes the blank part of the plate feel fat and produces a paste plate. If too much auxiliary material is added to the ink, the viscosity of the ink may be reduced, the ink may become loose, and the oiliness of the ink may increase.

(5) The ink accumulates on the plate, blocking the gaps in the dots, expanding the lines, and causing stencils.

Approach:

(1) Paste of ink occurs frequently in gold and red ink, and some gum arabic may be properly added in the water bucket. Can also be diluted with 915 Wei Li oil and 05-93 light pulp half, the use of better results. Most of the ink is too thin, resulting in the paste is too thin and the resulting paste, replace the new ink or add some concentrated ink.

(2) When the ink is large, the color of the ink can be adjusted to reduce the amount of ink.

(3) Reduce the use of accessories such as Kangbang to control the paste.

(4) The stencils caused by the stack are to be resolved from the root cause of the heap. $Page break $

4. Deinking

Reason for deinking: Deinking refers to that the ink does not rotate with the ink fountain in the ink fountain, but separates from the ink fountain shaft so that the ink string roller and the uniform ink roller do not ink. Saying that ink will affect the normal ink transfer roller, so that the printing plate can not get the desired ink and fade, resulting in different shades of ink. Common deinking has the following reasons:

(1) Insufficient oiliness and low viscosity of the ink cannot drive the ink to move with the rotation of the ink fountain shaft, causing deinking.

(2) The ink has poor fluidity and does not easily flow between the ink cutter shaft and the blade, affecting the ink under the ink.

(3) The ink is gelled into a jelly state, which reduces the viscosity and fluidity and loses the printing performance, while the stationary ink causes deinking on the ink fountain.

(4) The ink contains too little oil, too much fines, and does not transfer pigment particles well and stays in the ink fountain to form deinking.

(5) The ink dries too fast, which causes the ink fountain shaft to dry and solidify, loses ink transmission performance, and blocks the gap between the ink fountain roller and the blade to form deinking.

(6) Too much impurities such as ink, residue, etc. in the ink block the gap between the ink fountain and the blade, affecting the formation of deinking under the ink.

(7) The water bucket syrup is too acidic or the gum arabic ink is too much ink.

(8) The layout is too watery.

Approach:

(1) Ink roll deinking caused by ink problems, black ink is more common. The ink produced from the soot lime has a large oiliness and does not cause deinking. The black ink with carbon powder as the raw material is poor in oil and deinking phenomenon may occur. It is possible to dilute some thin inks. If the image contrast of the product is large, when the ink cannot be thinned, some oleic acid can be added to the ink. .

(2) The ink has low viscosity and short ink. It is commonly used in light-colored inks formulated with a lighter. This type of ink is easily emulsified. The acid in the water bucket invades the ink, corrodes the surface of the ink roller, and causes the surface of the ink roller to pro The water layer can be used to remove oil from the ink. In this case, thicken ink can be added to the ink to increase the viscosity.

(3) After the occurrence of deinking of the ink roller, the moisture of the plate should be reduced as much as possible and the acidity of the water bucket should be reduced to remove the gum arabic.

(4) The ink is too thick and too hard, add No. 6 varnish to increase its fluidity.

(5) Intensively agitate the ink fountain and remove the inner skin and impurities from the ink fountain to prevent the ink from drying or gelling and prevent deinking.

5. Ink emulsion

Phenomenon and Cause: The separation of water into tiny droplets dispersed in the ink is called emulsification. In the printing process, the oil and water are not absolutely incoherent, due to the constant contact of ink and moisture, and the role of mechanical forces and other factors. Participation