This paper lists 6 polishing styles, matters to pay attention during the polishing process and the main factors affecting the polishing quality.
6 types of mould polishing ways
When polishing, generally use rough honing gravestone for rough polishing to the face of the depression of the crafted mould, remove the cutter marks, and also use the fine fortitude earth polishing monuments, and also use fine- fortitude sandpaper for polishing the face. Eventually, the diamond pad is used to finish the final polishing of the depression face of the mould, achieving the glass effect.
mould polishing monuments
Mechanical mould polishing
Mechanical polishing is a polishing system that obtains a smooth face by cutting and plastic distortion of the material face to remove the polished projections. Generally, monuments, hair bus, sandpaper,etc. are applied and substantially for homemade operation. Special corridor similar as the face of the rotating body can be polished by supplementary tools similar as turntables with anultra-precise polishing system for high face quality conditions. Theultra-precise grinding polishing adopts a special grinding tool and pressed against the face of the workpiece for high- speed gyration in the polishing liquid containing abrasives. It can achieve the face roughness of Ra0.008 μm by the technology. Optic lens molds frequently applied this system.
Chemical polishing
Chemical polishing is to make the face of the material microscopically convex in the chemical medium dissolve preferentially, carrying the smooth face. The main advantage of this system is that it doesn't bear complex outfit, can polish workpieces with complex shapes, and can polish numerous workpieces at the same time with high effectiveness. The core problem of chemical polishing is the medication of polishing liquid. The face roughness attained by chemical polishing is generally 10μm.
Electropolishing
The introductory principle of electropolishing is the same as chemical polishing, that is, the face is smooth by widely dissolving the bitsy projections on the face of the material. Compared with chemical polishing, it can exclude the effect of cathode response, and the effect is better.
The electropolishing process is divided into 2 way
Macro leveling, the dissolved product diffuses into the electrolyte, and the face roughness of the material decreases and Ra> 1 μm.
Micro leveling, anodization, face brilliance is bettered, Ra< 1μm.
Ultrasonic polishing
Put the workpiece in the abrasive suspense and together put in the ultrasonic field, and make the abrasive polished on the face of the workpiece by the ultrasonic vibration. Ultrasonic machining has a small macro force and doesn't beget distortion of the workpiece, but the product and installation of the institution is delicate. Ultrasonic machining can be combined with chemical or electrochemical styles. On the base of result erosion and electrolysis, ultrasonic vibration is applied to stir the result to dissolve the dissolved products on the face of the workpiece, and the erosion or electrolyte near the face is invariant. The cavitation of ultrasonic swells in the liquid can also suppress the erosion process and grease the face cheering.
Fluid mould polishing
Fluid polishing relies on high speed flowing liquid and abrasive grains to wash the face of the workpiece to achieve the purpose of polishing. Common styles are abrasive spurt processing, liquid spurt processing, hydrodynamic grinding andetc.
Hydrodynamic grinding is driven by hydraulic pressure so that the liquid medium carrying abrasive grains flows back and forth across the workpiece face at high speed. The medium is substantially made of special composites (polymer-suchlike substances) that flow through under low pressure and mixed with abrasives. The abrasives can be silicon carbide greasepaint.
6 ） Glamorous grinding and polishing
Glamorous grinding and polishing are that forming abrasive skirmishes under the action of a glamorous field by glamorous abrasives for grinding workpieces. This system features high processing effectiveness, good quality, easy control of processing conditions and good working conditions. The face roughness can reach Ra0.1 μm with suitable abrasives.
Notes during the polishing process
Pay attention to the following points when polishing with sandpaper
The soft rustic stick or bamboo stick is used for sandpaper polishing. When polishing round or globular shells, the soft stick can more match the bow of the round and globular shells. The harder stick that's like cherry wood is more suitable for the polishing flat shells. Trimming the ends of the rustic stick can keep in line with the shape of the sword face. This can avoid the sharp angle of the rustic strip (or bamboo strip) from reaching the sword face, causing deep scrapes.
When changing to different types of sandpaper, the polishing direction should be changed into 45 ° to 90 °, so that the murk left by the polishing of the former sandpaper can be distinguished.
Before changing the different types of sandpaper, should wipe the polishing face with a cleaning result similar as 100 cotton and alcohol, because a small grain left on the face will destroy the entire polishing process. The cleaning process is inversely important when changing from sandpaper polishing to diamond pad polishing. All grains and kerosene should be fully gutted before polishing continues.
In order to avoid scratching and burning the face of the workpiece, you should be careful when polishing with 1200# and 1500# sandpaper. When polishing with each type of sandpaper, polishing should be performed doubly in two different directions, with each gyration between 45 ° and 90 °.
Pay attention to the following points when grinding and polishing by diamond pad
Pay attention to the following points when grinding and polishing by diamond pad.
This polishing should be performed under light pressure as much as possible, especially when polishingpre-hardened sword corridor and polishing with fine diamond pad. When polishing with 800# abrasive pad, the cargo is 100 ～ 200g/ cm2, but it's delicate to maintain the delicacy of this cargo.
To make this easier, a thin and narrow handle can be made on the rustic stick, similar as adding a bobby piece or cut a part of the bamboo stick to make it softer. This can help to control the polishing pressure to insure that the mould face pressure isn't too high.
When grinding and polishing with diamond pad, not only the work face needs to be clean, but also the workers’ hands are clean.
Each polishing time shouldn't be too long, the shorter the time, the better the effectis.However, it'll beget orange peel and pitting, If the polishing process is performed too long.
In order to gain high- quality polishing results, polishing styles and tools that are easy to toast should be avoided. For illustration, the heat from the polishing wheel can fluently beget orange peel.
When stopping the polishing process, it's veritably important to insure that the workpiece face is clean and precisely remove all grinding complements and lubricant, and also spot a subcaste of antirust coating on the face.
Pay attention to the following points when grinding and polishing by diamond pad.
3 factors affecting the quality of mould polishing
Because mechanical mould polishing is substantially done manually, polishing technology is still the main reason that affects the quality of polishing. In addition, it's also related to the earth accoutrements, the face condition before polishing, and the heat treatment process. High- quality sword is a prerequisite for carrying good polishingquality.However, it's delicate for polishing, If the face hardness of the sword is uneven or the features are different. It isn't good for polishing if there are colorful eliminations and pores in the sword.
The effect of different hardness on the polishing technology ： High hardness makes the grinding delicate, but the roughness after polishing is reduced. Due to the adding hardness, the polishing time needed to achieve the lower roughness is similarly increased. At the same time, the hardness is increased, and the possibility of inordinate polishing is similarly reduced.
The effect of the workpiece face condition on the polishing technology During the crushing process of the slice sword, the face subcaste will be damaged because of heat, internal stress or other factors. Indecorous slice parameters will affect the polishing effect.
It's more delicate to grind for the face after EDM than face after ordinary machining or heat treatment, so EDM dressing should be done before the EDM, else the face will form a hardened subcaste.
Still, the depth of the heat-affected subcaste can be over to 0, If the EDM dressing rules aren't chosen duly.4 mm. The hardness of the hardened thin subcaste is advanced than that of the matrix and must be removed. Thus, it's stylish to add a rough grinding process to fully remove the damaged face subcaste to form an average rough essence face, which provides a good base for polishing.
In conclusion, in the factual mould polishing process, we should choose an applicable polishing system, and ameliorate the driver’s specialized position, and successfully complete the polishing operation.
