High hardness of the pad printing with steel plate after the "plane grinding", if not for grinding, plate-making printing, easy cause graph edge roughness and a lot of ink.By hand grinding is a chore.
The author embarks from the electrolytic grinding principle, combining site solutions for polishing technology, solves this problem.
Electrolytic grinding principle is: the iron and steel in the specific electrolyte, electricity, its surface generation thin oxide film, immediately drop table carbon hardness, it can be easily grinding, grinding, and then oxidized to synchronize the oxidation and grinding, until satisfied.
As a professional processing enterprises, don't spend large sum of money to buy the electrolytic grinding machine.But used alone why grinding wheels, but because of the bowl is not suitable for manual grinding flat steel plate, therefore to make your own.Manufacturing method has the following three types:
1, mix resin adhesive with emery 1:1 (volume), add hardener, cast in thickness is 5 mm, 150 mm * 300 mm plate.After solidification, with a diamond cutter according to certain geometric shape groove regularly, see the bottom of the iron, in order to achieve some solution and the purpose of conducting fluid circulation.With a surface grinder leveling.
2, what will continous oilstone article rectangular or trapezoidal with epoxy adhesive, regularly intervals to stick in the 300 mm * 150 mm, thickness is 5 mm plate, with a thick plate glass pin, set aside.
3, use graphite plate as a point solution, because of its dual role of electrolytic grinding and edm grinding, so its extremely fast.But also easy to wear, so often should trim.
Grinding electrolyte formula:
NaNO2 9.6%
NaNO3 0.3%
Na2HPO4 0.3%
K2Cr2O7 0.1%
Current density for 5 to 10 a/cm ^ 2, anti-corrosion equipment the solution at room temperature.
Operation: the module face up in a basin composed of PVC sheet welding, connect the cathode rectifier.Import the electrolyte, let the liquid level and module parallel to the surface and higher than 1 cm.Adjust the grinding block parallel to the four corners in order to achieve.To be sharpened in steel plate made of PVC plate fixture, connect the positive pole of the rectifier, facing the grinding block contact.Open rectifier, in the case of steel plate moves back and forth, gradually increase the voltage, the appreciation of the current is scheduled, do random moving steel plate, the generated oxide film and ground to a simultaneous oxidation film.Then, gradually reduce the voltage again, stop the power supply.Grinding again a few times, then take out.If do not meet the requirements, repeat the above steps, until satisfied.Ideal as a result, the surface of gray, meticulous silking, feel is exquisite, flat grinding mechanical scratches disappear.
Electrolytic polishing, or the principle of electrochemical anodic dissolution is: will work (anode) in the very thick liquid electrolyte, between the poles because the resistance is different, in concave and convex convex of low resistance and large current density, the priority to dissolve.This process is ongoing, until the surface is flattening, to achieve the effect of light.
Formula:
70% H3PO4
- H2SO4 20%
The rest is water
Temperature is 60-70 ℃;Current density is 60 a/dm ^ 2;Time for 1-2 min.The cathode lead plate.
Operation will measure good water in tank first, then stir in two acid, and its proportion, normal should be in 1.69 to 1.70, from the adjustment.Heat up to 60 ℃.The grinding good steel plate into made of PVC board and fixture.Access to the anode, hanging into the slot.Facing the cathode lead plate, electricity.
Note:
1, the electrolytic process, liquid temperature will rise automatically.
2, do not easily into the sink, the weight of solution must be in 1.69 to 1.7, there is no effect.
3, the hanging, the steel plate surface should be with fixture surface on the same plane.Don't lower than fixture surface steel plate surface, or edge is not bright.Steel plate surface is not higher than the fixture surface, or edge effect seriously.
More than 4, the interelectrode distance 30 mm, electrolysis, do not move, let its static electricity.
The last effect is that the workpiece is silver grey half light, under a microscope, small grain size.The entire surface without any mechanical scratch, feel is smooth.