Enterprise name: Zongsheng Precision Mould Co., Ltd.
Contact: Mr. Nie 13923298099 (Wechat same number).
Miss Jia 15820657628 (Wechat same number).
Tel: 0757 2226 9630.
0757 color 22269276.
Fax: 0757 2226 9631 22269276.
Web site: en.fszongsheng.com.
Add: no. 1, Rongye 6 road, Fengxiang industrial zone, Daliang, Shunde district, Foshan city, Guangdong province
(1) polishing with sandpaper requires the use of a soft mallet or bamboo stick.
When polishing a circle or sphere, the use of a soft mallet can better match the Radian of the circle and the sphere.
Harder strips, like cherry wood, are more suitable for polishing flat surfaces.
Trim the end of the wood bar so that it can adhere to the shape of the steel surface, so as to prevent the sharp angle of the wood (or bamboo) from touching the steel surface and form deep scratches.
(2) when different types of sandpaper are used, the polishing direction should be changed from 45 °to 90 °, so that the stripes and shadows left after polishing the former type of sandpaper can be distinguished.
Before changing different types of sandpaper, it is necessary to carefully wipe the polished surface with a cleaning solution such as 100% pure cotton stained with alcohol, because a small piece of gravel left on the surface will destroy the rest of the polishing operation. This cleaning process is equally important when changing from sandpaper polishing to diamond grinding paste polishing. All particles and hot oil must be thoroughly cleaned before polishing continues.
(3) in order to avoid scratches and burns on the workpiece surface, special care should be taken when polishing with # 1200 and # 1500 sandpaper.
Therefore, it is necessary to load a light load and choose a two-step polishing method to polish the surface.
When polishing with each type of sandpaper, it should be polished twice in two different directions, rolling 45 °~ 90 °each time between the two directions.
(1) it is necessary for this kind of polishing to be carried out under light pressure as far as possible, especially when polishing pre-hardened steel parts and polishing with fine grinding paste.
When polishing with # 8000 grinding paste, the commonly used load is 100g / 200g / cm ~ 2, but it is difficult to maintain the accuracy of this load.
To make this easier, you can make a thin and narrow handle on the stick, such as adding a piece of copper, or cut off part of the bamboo to make it softer.
This can help control the polishing pressure to ensure that the surface pressure of the mold is not too high.
(2) when using diamond grinding and polishing, not only the working surface is required to be clean, but also the operator's hands need to be carefully cleaned.
(3) each polishing time should not be too long, the shorter the time, the better the effect.
If the polishing process is too long, it will form "orange peel" and "pitting".
(4) in order to achieve high-quality polishing effect, simple hot polishing methods and things should be avoided.
For example: polishing wheel polishing, the heat of the polishing wheel will be very simple to form "orange peel".
(5) when the polishing process is terminated, it is important to ensure that the workpiece surface is clean and that all abrasives and lubricants are carefully removed, followed by spraying a mold antirust coating on the surface.
3 factors affecting the polishing quality of moulds.
As the mechanical polishing is mainly completed manually, so the hot runner mold polishing technology is still the primary reason to affect the polishing quality.
In addition, it is also related to mold material, surface condition before polishing, heat treatment process and so on.
High-quality steel is a prerequisite for good polishing quality. if the surface hardness of steel is uneven or there are differences in characteristics, polishing difficulties often occur.
All kinds of inclusions and pores in steel are not good for polishing.
3.1 effect of different hardness on polishing process.
The increase of hardness increases the difficulty of grinding, but the roughness decreases after polishing.
Due to the increase in hardness, the polishing time required to reach a lower roughness increases accordingly.
With the increase in hardness, the possibility of excessive polishing is reduced accordingly.
The relationship between part hardness and grinding function and polishing function is shown in figure 2.
Fig. 2 the relationship between the hardness of parts and the functions of grinding and polishing.
3.2 influence of workpiece surface condition on polishing process.
In the crushing process of cutting machining, the surface layer of steel will be damaged due to heat, internal stress or other factors, and improper cutting parameters will affect the polishing effect.
The surface after EDM is more difficult to grind than the surface after general machining or heat treatment, so precise EDM dressing should be selected before the end of EDM, otherwise the surface will form a hardened thin layer.
If the electric spark precision repair specification is not selected properly, the maximum depth of the heat affected layer can reach 0.4mm. The hardness of the hardened thin layer is higher than that of the matrix, so it is necessary to remove it.
Therefore, it is best to add a rough grinding process to thoroughly remove the damaged surface layer to form an average rough metal surface, which provides a good foundation for polishing.
Foshan Shunde Zongsheng Precision Mould Co., Ltd.
Tel: 0757 Tel: 22269630 / 13923298099 (Mr. Nie).
Web site: www.fszongsheng.com.
Add: no. 1, Rongye 6 road, Fengxiang industrial zone, Daliang, Shunde district, Foshan, Guangdong
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