Polishing Process of Plastic Molds

The production of plastic molds generally requires a polishing process to improve their surface smoothness. Below, we will briefly introduce the polishing process of plastic molds:

1. Fine throwing

Fine polishing mainly uses diamond grinding paste. If diamond grinding powder or paste is mixed with a polishing cloth wheel for grinding, the usual grinding sequence is 9 μ m (# 1800)~6 μ m (# 3000)~3 μ m (# 8000). A 9 μ m diamond grinding paste and polishing cloth wheel can be used to remove the hairline marks left by # 1200 and # 1500 sandpaper. Next, polish with adhesive felt and diamond grinding paste in the order of 1 μ m (# 14000)~1/2 μ m (# 60000)~1/4 μ m (# 100000). The polishing process with an accuracy requirement of 1 μ m or above (including 1 μ m) can be carried out in a clean polishing room in the mold processing workshop. If more precise polishing is to be carried out, a sufficiently clean space is necessary. Dust, smoke, dandruff, and saliva can all potentially render the high-precision polished surface obtained after several hours of work unusable.

2. Rough throwing

The surface after milling, electric discharge, grinding and other processes can be polished using a rotating surface polishing machine or ultrasonic polishing machine with a speed of 35000 to 40000 rpm. The commonly used method is to remove the white spark layer using wheels with a diameter of Φ 3mm and WA # 400. Then there is manual oilstone grinding, with strip-shaped oilstones mixed with kerosene as a lubricant or coolant. The general usage order is # 180~# 240~# 320~# 400~# 600~# 800~# 1000. Many mold manufacturers choose to start from # 400 in order to save time.

3. Semi precision throwing

Semi precision polishing mainly uses sandpaper and kerosene. The numbers of sandpaper are: # 400~# 600~# 800~# 1000~# 1200~# 1500. In fact, # 1500 sandpaper is only suitable for hardened mold steel (above 52HRC) and not for pre hardened steel, as this may cause surface burns on the pre hardened steel parts.

4. Fine throwing

Using grinding paste for precision polishing, 8000-100000 will achieve a mirror finish.

Qingdao Xueyu Molding Products Co., Ltd. is mainly engaged in the design and manufacturing of injection molds, injection molding and secondary processing (spraying, pad printing, ultrasonic welding, stamping), etc. For more information about plastic mold, please contact us.

Website: www.xyzmould.com

Address: No.18 Henan Head Road, Henan Head Community, Jihongtan Street, Qingdao Industrial Park, Shandong Province, China

Email: wangmiaotian8@163.com