Fundamental procedures for polishing plastic molds To a […]
Fundamental procedures for polishing plastic molds To achieve high-quality polishing, the most important thing is to have high-quality polishing tools and accessories such as whetstone, sandpaper, and diamond abrasive paste for plastic molds.
The general process of plastic mold polishing is as follows:
1. Fine polishing
Fine polishing mainly uses diamond abrasive paste. If you use a polishing cloth wheel to mix diamond abrasive powder or abrasive paste for grinding, the usual grinding sequence is 9 μm (# 1800) to 6 μm (# 3000) to 3 μm (# 8000). The 9μm diamond abrasive paste and polishing cloth wheel can be used to remove hairline marks left by # 1200 and # 1500 sandpaper. Followed by polishing with sticky felt and diamond abrasive paste, the order is 1μm (# 14000) ~ 1 / 2μm (# 60000) ~ 1 / 4μm (# 100000). The polishing process with an accuracy of more than 1 μm (including 1 μm) can be performed in a clean polishing room in the mold processing workshop. For more fine polishing, a surely clean space is required. Dust, smoke, dandruff and drool are all high-precision polished surfaces that may be obtained after working for hours.
2. Rough throw
After milling, EDM, grinding and other processes, the surface can be polished by rotating surface polishing machine or ultrasonic grinding machine with a rotation speed of 35 000-40 000 rpm. A common method is to remove the white electric spark layer by using a wheel with a diameter of 3mm and a WA # 400. This is followed by manual whetstone grinding, with strips of whetstone plus fire oil as a lubricant or coolant. The general application sequence is # 180 ~ # 240 ~ # 320 ~ # 400 ~ # 600 ~ # 800 ~ # 1000. Many mold makers choose to start with # 400 to save time.
Semi-fine polishing mainly uses sandpaper and kerosene. The order of the sandpaper is: # 400 ~ # 600 ~ # 800 ~ # 1000 ~ # 1200 ~ # 1500. In fact, # 1500 sandpaper is only suitable for hardened mold steel (above 52HRC), not for pre-hardened steel, because it may cause burns on the surface of pre-hardened steel.
Fine polishing with abrasive paste, 8000, 10000 will reach the mirror surface.