Pad printing is the use of the principle of imaging, the first to be printed on the steel plate etching patterns, and then in the printing machine using a soft pad (silicone rubber head) to transfer the ink printed on the object.
Pad printing can be applied to a variety of workpiece, the shape of the location of printing, and adjust the printing position is very convenient, and the effect of printing decorative patterns than the fuel injection, silk screen, hot stamping is more refined and beautiful.
Pad printing machine is the core of printing production, it is the use of compressed air as the driving force, the electric signal control plastic head movement and printing action (such as the number of printing) program to print monochrome or multicolor pattern. Can be one to three times the scroll Printing, 1-2 color turntable printing and 2-6 color pusher printing. (Note pad printing large pattern area need to be sub-printed, but need to pay attention to print misplaced issue)
Two printing operation basic principle:
1. Open the valve -------- open the power -------- press the scraper action button -------- then press the start button --------- - press the automatic cycle printing button ------- printing machine to work.
2. According to the requirements of the printing pattern, adjust the air before and after the action and scraper landing system, if it is multi-color printing, you can adjust the function of the need to print the number of cycles.
3. According to the environment and climate, ink, open water, the depth of the plate pattern, pressure size, etc. to adjust the front and rear movement of plastic printing head, delay data.
Three parts of the printing machine Description:
1. Pad printer host: Select the appropriate printing machine, to consider the size of printed objects and size, according to the need to choose monochrome, two-color or rolling printing and other functions.According to the machine << Operating Manual >> to select and Use the dial, keys, determine the response function and set the process parameters.
2. Printing plate: The size of the plate is determined by the size of the printed pattern, usually the plate area does not need too much, different sizes of steel to match the size of the ink plate, knife holder and oil sweep.
3. Pad printing plastic head:
(1) the relevant requirements:
Generally divided into three kinds of hardness printing head: soft (30 degrees A), moderate (35 degrees A), hard (40 degrees A). Fine patterns should be harder plastic head, if the workpiece surface uneven , The best choice of softer plastic head.Printing plastic head size to compare the printing pattern may be, just enough for good.Plastic head shape according to the rough and choose the workpiece trim, plastic head should be trimmed to fit the workpiece The arc, corner and bump bit.
(2) plastic head production:
Plastic head from the three kinds of raw rubber, silicone oil, driers made.
The three kinds of materials mixed mortar into the selected shape of the plastic cover mold or copper mold, and then in the adhesive surface with a piece of wood (for fastening on the machine positioning), then about 12 hours Curable silicone oil to join the more soft plastic head, and vice versa, the plastic head harder drier amount of just adjust the plastic molding head speed, the hardness of the plastic head has no effect.
(3) plastic head cleaning:
Production, the plastic head may stick to the dirt, grease.At the time available amount of water that day to clean and wipe, and then the plastic head printed on white paper, suck the plastic surface of the excess water that day, if necessary Combined with talcum powder, keep plastic head clean and dry.
4. Oil scraping system:
By the ink tray, knife holder, scraper and oil sweep three parts.
Ink plate used to hold ink and fixed printing plate.
Scrapers must be parallel with the steel, scraping the surface of the board when the ink fell.
Oil brush used to mix ink.
5 printing bottom mold:
Bottom mold requirements can make the workpiece accurate positioning, and to facilitate the release.
Bottom mold available Bakelite, bakelite, metal materials, plastics, plaster epoxy resin and other materials to produce, in order to be practical principle.
Bottom mold with screws and plate fixed on the machine, the bottom mold installation must ensure accurate positioning, solid.
Four printing plate production process:
1. Clean the plate: use that day to wipe off the oil stains on the plate and dust (steel plate commonly used oil)
2. Sensitive oil / drying
Photosensitive oil should be evenly on the steel plate with electromagnetic force to fix the plate and the turntable, by centrifugal force to make the photosensitive film thin coating.
3 exposure: spotlights from the plate about 18 inches, exposure time 1-3 minutes,
4> Development / Rinse: Wash the pattern with the developer after exposure, hand pressure pump to develop into the oven for about 5-10 minutes, remove the heat and rinse with water
1 pattern part of the plate.
2. Etching: With 20% -50% dilute nitric acid brush pattern position in the steel, the general corrosion twice.