[教程]模具拋光的技術(shù)和技巧

1、教程模具拋光的技術(shù)和技巧with the widespread use of plastic products, such as daily necessities and beverage packaging containers, the appearance of plastic mold cavities often requires the mirror surface to be polished and the production of optical lenses, laser discs and other molds on the surface roughness re

2、quirements extremely high, so the polishing requirements are also very high polishing not only increases the beauty of the workpiece, but also can improve the corrosion resistance of the material surface, wear resistance, but also make the mold has other advantages, such as plastic products easy to

3、release, reduce the production cycle of injection molding therefore, polishing is a very important process in the manufacture of plastic moulds1 polishing methodat present, the commonly used polishing methods are as follows:1.1 mechanical polishingmechanical polishing by cutting, surface plastic def

4、ormation was removed after polishing and convex smooth surface polishing method, the general use of oilstone, wool wheel, sand paper, mainly manual, special parts such as rotary table surface, can use auxiliary tools such as high surface quality requirements can be used method ultra precision polish

5、ing super precision lapping is made of special abrasive tools, which are tightly pressed on the machined surface of the workpiece and rotate at high speed with this technique, the surface roughness of rao. 008 mu m can be achieved, which is the highest among various polishing methods optical lens mo

6、lds are often used in this way.1.2 chemical polishingchemical polishing is to make the material in the chemical medium surface micro protruding part, concave part of priority dissolved, so as to obtain smooth surface the main advantage of this method is that the complex parts can be polished without

7、 complicated equipment, and many workpieces can be polished at the same time, and the efficiency is high the key problem of chemical polishing is the preparation of polishing liquid the surface roughness obtained by chemical polishing is usually 10 mu m.1.3 electrolytic polishingthe basic principle

8、of electropolishing is the same as that of chemical polishing, ie., the surface of the material is smoothed by selective dissolution of the surface of the materia1. compared with chemical polishing, the effect of cathodic reaction can be eliminated, and the effect is better the electrochemical polis

9、hing process is divided into two steps:(1) macro leveling dissolves the product diffusion into electrolyte, and the surface roughness of material decreases, ra > 1 mu in.(2) micro - smooth anode polarization, the surface brightness increased, ra < 1 m.1.4 ultrasonic polishingthe workpiece is p

10、laced in an abrasive suspension and is placed together in an ultrasonic field, depending on the oscillating action of an ultrasonic wave to grind the abrasive on the surface of the workpiece ultrasonic machining has little macro force and will not cause workpiece deformation, but it is difficult to

11、make and install tooling ultrasonic machining can be combined with chemical or electrochemical methods based on the solution of corrosion, electrolysis, and ultrasonic vibration mixing solution, dissolving the product from the surface of the workpiece, near the surface of the electrolyte corrosion o

12、r uniform; ultrasonic cavitation in the liquid can also inhibit the corrosion process for surface light lighting1.5 fluid polishingfluid polishing is based on high-speed flow of liquid and its abrasive particles, scouring the surface of the workpiece to achieve the purpose of polishing commonly used

13、 methods are: abrasive jet machining, liquid jet machining, fluid power grinding, etc fluid power grinding is driven by hydraulic pressure,the liquid medium carrying abrasive particles flows back and forth to the surface of the workpiece at high speed. the medium is mainly made of special compound (

14、polymeric substance) flowing under low pressure and mixed with abrasives, and the abrasive can be made of sic powder1.6 magnetic abrasive finishingmagnetic abrasive finishing is the use of magnetic abrasive in the formation of abrasive brush under the magnetic field, grinding of the workpiece the me

15、thod has the advantages of high processing efficiency, good quality, easy control of processing conditions and good working conditions with proper abrasive, the surface roughness can reach rao. 1 mu m.2 basic methods of mechanical polishingin the plastic mold processing, said polishing and other ind

16、ustries in the required surface polishing is very di f fere nt, strictly speaking, the mold polishing should be called mirror processing it not only has a high demand for polishing itself, but also has a high standard of surface smoothness, smoothness and geometric accuracy. surface polishing usuall

17、y requires only bright surfaces mirror processing standards are divided into four levels: ao=rao.008 m, al=rao.016 m, a3=rao.032 m, a4二rd0. 063 m, the geometric accuracy of electrolytic polishing, polishing fluid is very difficult to precisely control parts, chemical polishing, ultrasonic polishing,

18、 grinding and polishing methods such as magnetic surface quality is not up to the requirements so the precision mold processing or in the mirror based mechanical polishing2. 1 basic program of mechanical polishingin order to achieve high quality polishing results, the most important thing is to have

19、 high quality whetstone, sandpaper and diamond polishing paste and other polishing tools and accessories the choice of polishing procedures depends on the surface conditions after the initial processing, such as mechanical processing, edm, grinding and so on. the general process of mechanical polish

20、ing is as follows:(1) after rough polishing, the surface of milling, edm, grinding and so on can be selected to rotate at 35000 - 40000 rpm rotating surface polishing machine or ultrasonic grinding machine for polishing the commonly used method has the diameter of 3mm, wa # 400 wheels removing white

21、 electric spark layer then, hand whetstone is used to grind, strip whetstone and kerosene as lubricant or coolant the general order of use is #180 、 #240 #320 #400 #600 ' #800 #1000 many die makers choose to start with #400 in order to save time(2) half fine, half cast, half polished, mainly san

22、d paper and kerosene the number of paper are as follows: #400 #600 #800 #1000 #1200 #1500. in fact, only suitable for #1500 sandpaper hardened die steel (above 52hrc), and is not suitable for pre hardened steel, because it may cause burns of surface pre hardened steel parts(3) fine throwing, polishi

23、ng and polishing mainly using diamond grinding paste if the buffing wheel and diamond grinding powder or mixed grinding paste grinding, grinding sequence usually is 9 m (#1800) 6 m (#3000) 3 m (#8000). 9 m diamond grinding paste and polishing cloth can be used to remove hair worn #1200 and #1500 san

24、dpaper left next, they are polished with sticky felt and diamond abrasive paste, in order of 1 mu m (#14000) 1/2 mu m (#60000) l/4 mu m (#100000).the accuracy required in 1 m or more (including 1 m) polishing process, in the mold processing workshop in a clean polishing room can be carried out for m

25、ore precise polishing, a clean space is required dust, smog, dandruff, and saliva foam can all be scrapped for several hours to obtain a highly polished finish2. 2 attention should be paid to mechanical polishingwith sandpaper polishing, you should pay attention to the following points:(1) polishing

26、 with sandpaper requires the use of a soft wooden stick or bamboo stick when polishing round surface or spherical surface, using cork bar can better match the radian of spherical surface and spherical surface the harder wood, like cherry wood, is more suitable for smooth surface polishing. trim the

27、ends of the wood so that it fits well with the surface of the steel so that the sharp angle of the wood (or bamboo bar) is avoided, causing deeper scratches on the surface of the steel.(2) when using different types of sandpaper, the polishing direction should be changed 45 degrees 90 degrees, so th

28、at the previous model of sandpaper polished left stripes shadow can be identified before the change of different types of sandpaper, must use 100% pure cotton dipped in the cleaning liquid from alcohol, on the polished surface carefully wipe, because a very small gravel on the surface will destroy t

29、he next whole polishing work the process of cleaning is also important when it is changed from sandpaper to diamond paste before polishing continues, all particles and kerosene must be completely cleaned(3) in order to avoid scuffing and burn, the workpiece surface must be treated with special care

30、when polishing with # 1200 and # 1500 sandpaper therefore, it is necessary to load a light load and polish the surface by two steps polishing method polishing with each type of abrasive paper should be done two times in two different directions, each turning about 45 degrees to 90 degrees each time

31、between two directionsdiamond grinding and polishing should pay attention to the following points:(1) the polishing must as far as possible in the light under the pressure of pre hardened steel parts and especially polishing with a fine abrasive polishing paste when polishing with #8000 abrasive, th

32、e load is usually 100200g/cm2, but it is difficult to keep the accuracy of this load to make it easier to do this, you can do a thin and narrow handle in the wood, such as adding a copper: or in bamboo on the cut part and make it more flexible this helps to control the polishing pressure to ensure t

33、hat the die surface pressure is not too high(2) when using diamond grinding and polishing, not only the surface of the work is required to be clean, but also the hands of the workers must be carefully cleaned.(3) each polishing time should not be too long, the shorter the time, the better if the pol

34、ishing process is too long, it will11丄丄cause orange peel and pitting .(4) in order to obtain high quality polishing effect, the polishing methods and tools which are easy to be heated should be avoided. for example: polishing wheel polishing, polishing wheel generated heat will easily lead to "

35、orange pee1.(5) when the polishing process is stopped, it is very important to ensure that the surface of the workpiece is clean and to remove all the abrasives and lubricants carefully, and then spray a layer of antirust coating on the surface3 factors affecting the quality of mold polishingmechani

36、cal polishing is mainly done by hand,therefore, polishing technology is still the main reason affecting the quality of polishing in addition, it also relates to the mould material, the surface condition before the polishing and the heat treatment process high quality steel is a prerequisite for good polishing quality if the surface hardness of the steel is uneven or different in quality, it will often cause polishing difficulties all kinds of inclusions and pore