A, pad printing is a concave rubber head of intermediates, should transfer to the design of sheet metal objects on the printing technology.
Second, pad printing, the depth of the steel plate, plastic head of the characteristics of hard and soft, size, shape, printing ink, volatile speed, the printing surface characteristics (smooth or rough, the arc size, etc.), working environment control (temperature, for example, color, moisture, dust, etc.).Must deal with the change of the related parameters, and to adjust, to be successful pad printing.
Third, the depth of the steel determine whether appropriate.In depth gauge measurement, the conventional pad printing plate depth at about 2.4 microns.Such as small text, line 2 microns.Entity graphic, is also suitable for 3 micron, node may have dark 1.6 microns.Concrete plate depth difference.2. According to the actual design and the requirements of the ink layer.If again as a graphic, printing work surface roughness, pits or smooth, required plate depth and the printing effect.For example: if the oil return, by fuzzy, larger possibility for steel plate was too deep, such as a bubble back (blister), may be too shallow.If the pad printing rubber head not printed onto the object, ink has to dry glue head, steel plate is too shallow.If the ink appear uneven glue head (orange peel lines), the steel plate is too deep.Due to the rubber head can only touch the area of a small number of ink plate design, so the etching depth is too large will not have any benefits.Etching depth is 25 micron, glue head can only touch up 12 micron ink film, the rest on the sheet metal.Because of the ink film contains at least 40% of the diluent, this part of the diluent in the ink transfer and dry completely evaporate, so finally stay was printed on the ink layer is about 7 microns.
Fourth, the selection of rubber head.1. The elastic.2. Have radian.3. Not infinite.Meaning that pad printing can't print the design of large area, but the irregular shape, uneven artifacts that printing is very applicable.The rubber head diversified colors (red, white, yellow, blue) is mainly due to the system of rubber head raw materials of color.From the standpoint of pad printing, plastic head, color does not transfer function on the rubber head (with ink and deinking is completely), and adhesive materials and technology of the head, is the most important thing.
Art can be produced more than 100 of rubber head all adopt the crystal mold, vacuum suction.Not only appearance is bright and clean level off, even and fine figure line text can also clear.And no bubble of the rubber head, trachoma, more durable.The hardness of rubber head affect the quality of the print design and durability of the rubber head itself.Hard rubber head transfer can be a very good design and good durability, but was printed content arc is large, using soft rubber head, because it is easier to come into contact with the curved parts of the rubber head must be bigger than design some, because such plastic head, the smaller the deformation, the printing pattern is more precise, clear.New rubber head with ink effect is not ideal, can testing-run first try many times or wipe with alcohol or neutral solvent surface can solve this problem.With high ink solvents such as thinner, mop, although will soon make rubber ink, but the effect will be poor transfer pattern, and accelerate the aging rubber head.Rubber head of the printing quality will gradually decline, because silicone oil was scrubbing away slowly, so the surface becomes rough and has absorbent.
Five, the characteristics of the ink: pad printing requirements drive oil and fast dry, avoid glue head can well realize transfer ink, screen printing requirements slow dry, avoid screen plugging.This is the difference between screen printing and pad printing thinner.But under certain conditions, such as high temperature drying screen printing on the oil and water can be used for pad printing.
One-component ink, glue head durability is better.While a two-component inks are usually less corrosive prone to bubble, can make the rubber head silicone oil consumption faster, so could the rubber head to shorten.Rubber head without printed onto the printed material, and the ink dry solid glue head, is thinner, fast dry.When, after the completion of printing was printed on graphic fluff, wiredrawing phenomenon, fast dry.Oil return vague;Is too dry, already into pieces, no adhesion force, fast dry;Printing, fast dry.
Six, why the printing into often appear bubbles (trachoma) phenomenon.Mainly rubber head, plate, ink three aspects.
1. The rubber head shape is not appropriate, peace or radian is wrong.2. The glue head center (highest) on the design, form the air out, produce bubbles.3. Rubber aging is tacky, breakage, oil engine-grease cause gum head bad printing.4. The steel plate etching, reservoir are thick enough.6. Dry ink is too thin or too slow.7. The ink is too dry or too dry.
Seven, pad printing work environment: room turbidity (best for 18 to 20 ° C).Humidity is (best is 60% - 070%).Dust.Light white wall ground, etc.Can art bear with a beginner, start with monochrome machine, small design, using with pointed round rubber head, choose easily printed materials, such as PVC, PS.Light color or white background introduction, the effect is not ideal, it can be adjusted by respectively or replace glue head, steel plate or ink.