Two ink-making experience

1. Copying Method to Eliminate Screen Printing Defects

In the practice of screen printing, it is often encountered that the ink drafts are of different shades, black and white contrast is not strong, and hand-painted inks have defects similar to pinholes. Inconvenience to the printing. Our emergency method is to use a copying machine to copy the ink draft method, eliminate and improve the quality of ink drafts, and the effect is very good.

Most of the copier's operation panel is equipped with an auto density key, a manual density key, and a photo key. The manual concentration key and photo key can further adjust the concentration in five different values ​​of 1, 2, 3, 4, and 5. “Auto Density” is a function key that the machine performs automatic detection and other processing according to the condition of the original to obtain the best copying effect. “Manual Density” can be used by the operator to make thicker or lighter adjustments of function keys according to the text and the form of the original document. “Portrait” is a function key for adjusting the shade effect of copy pictures and photo originals.

In actual work, we adjusted the automatic density key to the range of original copying effect that can meet the normal blackness, and there is no adjustment value; the concentration adjustment value of the manual density key is adjusted to a slightly deeper effect than the automatic concentration; the photo key will be The intermediate adjustment value of the concentration is adjusted to be slightly lighter than the automatic concentration. This assigns the three copy keys as normal, slightly dark, and slightly shallow.
The following ink defects can be solved or improved by copying:

1) The black and white contrast of the ink draft is poor.

2) Hand-painted ink residue is not evenly etched, ink is unevenly painted, and defects such as pinholes are transmitted by light and sunlight.

3) Due to the aging of the drum of the laser printer or lack of toner, the output of the ink draft is particularly dark and light and dark.

Solution:

1) First copy the ink draft in automatic density to see if the defect is eliminated.

2) If the defect has not been eliminated, depending on the printed sample, a determination should be made as to whether the copy density should be adjusted darker or lighter. To adjust the depth, copy the ink in the manual density 3 state. When copying in this state, it still appears darker, then it is adjusted to manual density 1; if it is copied in the manual density 3 state, it still appears shallow, and it is adjusted to manual concentration 5; if it is still dark, the ink draft is in the photo 3 Copy under state. Also deep, choose photo 1, still shallow, choose photo 5 copy.

3) When the black and white contrast of the ink draft is not obvious, and the color is severely shallow, the graphic and text may be unclear. A) First copy the ink in the darkest state. At this time, the picture is deepened, but at the same time there is a serious bottom ash in the ink draft; B) The copy of the ink with a bottom ash is placed in the lighter density of the photo key. At this time, the ink draft The text on the map has become darker, but the bottom ash has basically been eliminated. This copy can be used for printing.

2. The experience of anti-crease of sulfuric acid paper ink draft by laser printer

The use of a laser printer with a resolution of 600 dpi to output sulfuric paper (tracing paper) for screen Printing Plate making is effective, and has a lower cost compared to the output film. In practice, often due to the thin paper of sulfuric acid used, resulting in ink draft wrinkles to bring a lot of inconvenience to the printing version, how can we avoid the sulphuric acid paper wrinkle it?

Our experience is: Select slightly larger than the sulfuric acid paper area of ​​the business card paper (not more than A4 format, 70g copy paper can also be used instead), folded in the lower part of the business card paper 1cm width, in the collapsed part of the cut into sulfuric acid paper. With the business card paper affixed together, the folded bottom is put into the laser printer feed slot, and the computer and the laser printer are connected online so that the sulfuric acid paper and the business card paper sandwiched in the business card paper can be synchronized and output.

Causes of wrinkling: Sulfuric acid paper is thin. After being heated by a laser printer, it is prone to deformation, causing wrinkling, curling, and influencing the printing. The use of a business card paper as a backing pad to achieve simultaneous output, one is to improve the degree of sulphuric acid paper, and the other is to avoid overheating of sulfuric acid paper.

This method is more suitable for business card offset sulfuric acid paper ink output, after the output of the draft, the printing version can be printed on the machine, but it should be noted that the selected business card paper should not be too thick, and to ensure that after folding, folding The actual thickness of the double-decker business card is not more than the thickness of the thick card business card, so as not to affect the service life of the laser printer.

We recommend that the use of business card paper be as basic as possible with the maximum output width of the laser printer. Such as HP6L laser printer maximum output format for A4 business card paper. The sulfuric acid paper used is slightly smaller than the business card paper, so as to ensure the use of the laser printer laser drum in the largest range, to avoid frequent use of a certain section of the drum for a long time, and to excessively wear the section.

Some friends carry cuts of sulfuric acid paper mostly 64K. The business card paper that is cushioned is only a little larger than the sulfuric acid paper. This results in long-term and frequent use of the middle part of the laser printer's light drum. At the time of the manuscript, two ink lines appeared, actually damaging the drum.