A printing method, keyboard
General keyboard use material is given priority to with ABS engineering plastics, and sales, etc.Keyboard printing commonly used method is laser etching printing, screen printing and transfer printing.
1, laser etching printed keyboard
Laser engraving printing is to use laser etching technique keys on black grooves burn out.Is because etching out the trace of the current, so the common laser printing the arrow on the keyboard, etc are all hollow.The laser printing of low cost, strong, although its production line equipment is expensive, but its production speed is unmatched by other printing way.In addition, because the etching is writing, do not need any other measures can have a very clear and firm's handwriting.
Laser lithography printing method used in the mainstream on the keyboard in addition to the cost factors, there is another important reason is that environmental protection.Compared with the ink printing, laser engraving printing has much less pollution to the environment.Pollution in the process of laser lithography printing only burn in etching trace amounts of plastic, in addition to light plastic burning smell in the air almost no longer have any harmful products.In addition, the laser etching print some fatal flaws, it also determines its can not be used in the production of high-grade keyboard.Laser lithography printing, for example, USES is etching method, so can only print a single black font, font drab not beautiful also can't print color, in the high-end keyboard often the multi-color overprint design will not be able to do,High-grade keyboard in the need for design and durability, mostly USES the white is the color of the design, and the key cap material added the abrasion resistance of packing, but as a result of laser etching printed their own characteristics, making it in the white system and add the other packing on the keyboard do not etched with ideal clear handwriting.
2, the keyboard screen printing
The principle of which is to a special silk screen cover on the blank of the keyboard, which have their own place to be hollow out, after scraping in the hollow part will be printed on the handwriting.Screen printing in the printing of a low cost, fast, are usually used in ultra-thin keyboard printing, such as laptop keyboard.Characterized by a font is beautiful, but the print is not strong enough, but after the printing with a special screen brush on a layer of plastic, can form a layer of plastic protective film after dry, to prevent wear and tear, this also is called keyboard film coating technology.Compared with laser printing, screen printing can be more than net version of the repeated overprint free printing a variety of color, and there is no requirement for the keyboard material restrictions.But because of the limitation of the way of printing can't print too complex keyboard shape.
3, the transfer printing method
, three methods of traditional keyboard printing transfer printing method is the most complex kind of printing technology, is also one of the oldest traditional keyboard printing method.So-called transfer printing, which USES a set of letters type as the original font, through the automatic after the printing ink on the above, then a set of soft rubber piece of pressure in the above, this took up the rubber piece, writing ink will be transferred to the rubber block, and then the rubber piece will be moved to the blank on the keyboard, to press the rubber piece, ink is printed on the keyboard.Before phototypesetting technology appeared, such as books, newspapers and magazines are printed.Compared with laser printing and screen printing, transfer printing method without any limitations, can be used to print any kind of keyboard.But the transfer printing method shortcomings, obviously, the printing speed is very slow, printed a keyboard can make almost the same time more than 10 laser printing the keyboard down the line.Secondly because of the effect of the printing process, coated in transfer printing method of keyboard is much more difficult than screen printing.Transfer printing method flexibly, fonts, good-looking, but being the worst.
Today and packing technology, laser heat sublimation printing, hollow out text three new keyboard printing method.Compared with the traditional way of keyboard printing, new methods of printing process is more complicated, the cost is more expensive.
Second, the keyboard screen printing technology
Keyboard characters of screen printing process is commonly: silk screen preparation, plate making, plastic workpiece prepress processing - printing - test - drying - inspection.
1, silk screen preparation.Generally choose 240 mesh screen, stretch mesh machine tension net, cleaning and drying.
2, plate-making.Commonly used plate making method has sensitive glue plate method and capillary photosensitive diaphragm plate making method.The screen photosensitive plastic plate with a thickness can grasp;Sensitive time have mastered;Burr less after mapping, graphics is not easy to damage, etc.Capillary photosensitive diaphragm plate making method is to use photosensitive diaphragm plate making, its advantages are simple technology, silk screen can be repeated use.Drawback is that organic solvent resistance and resistance to such as sensitive glue plate making, printing force and scrubbing graphic easily damaged.
3, the prepress processing of plastic workpiece.Mainly washed up on the surface of the grease and stolen goods, available cleaning CK - 821 to oil at low temperature, temperature at 50 degrees Celsius, put up in to get oil oil soaked in 5 minutes, and then with dilute acid neutralization, rinse and dry.
4, printing.First select the appropriate printing ink, in terms of printed material, due to the poor plastic ink brightness and color, easy plugging, ordinary ink adhesion and not ideal, therefore, the choice brightness is good, not easy plugging, for ABS plastic adhesion of printed materials, is the key to printing.When printing, printing ink viscosity shoulds not be too big.After another ink dry, spray a layer of thin the paint coat again (nitrocellulose lacquer) can obviously improve the brightness of the surface of parts, and can protect the printing ink layer.When printing, plastic parts with special fixture first place, with a special ink screen printing, if the material is too dry, available ST diluent dilution.
5, early screening.Check printing products, discovered in the printing of the unqualified product can be used after alcohol clean printing again.
6, dry.Use 0.5 minutes 60 degrees centigrade oven to dry, or dry at room temperature for 2 hours, to ensure that the ink completely dry.
7, inspection.Test, after the completion of the printing products to all, the main content of the test has the following several aspects:
A. binding force.After printing dry, delimit gently with nails, writing out is qualified.
B. wear resistance.Adopt cathode mobile devices, with sponge friction, friction pressure 100000 times, writing off for qualified.
C. high and low temperature experiment.30 minutes at 70 degrees Celsius in the heat - 10 minutes - 20 degrees Celsius under normal temperature low temperature for 30 minutes for a cycle, a total of three loop, the handwriting no discoloration, fall off phenomenon for qualified.
D. hand sweat resistant.The available filter paper, absorb formula is: the sodium chloride 7 g / 1, lactic acid, urea 1 g / 4 g / 1 artificial sweat, covering the keys, after 2 hours to wipe, hard writing off for qualified.
E. water resistance.Soak in the water the key cap after 4 hours to wipe, forcibly handwriting without falling off as a qualified.
F. solvent resistance.Will keycap were soaked in alcohol and gasoline, 4 hours to wipe, forcibly submerged in some loss of alcohol, soaked in gasoline in the keyboard writing no falls off phenomenon is qualified.
(note: the Wright technology, only supplies the reference!)