In the process of NC machining, there are various problems, such as NC machining defects, color balance, cracks and so on. Today, I'd like to talk about the factors that cause color irregularity in the process of CNC hand board processing, as well as other problems of CNC hand board, which will be mentioned in the next article.

　　之前生產的手板很正常，但是突然出現手板的顏色，是不能接受的，所以造成CNC手板顏色的因素，可以從以下幾個原因開始:

　　The handboards produced before are normal, but the color of the handboards suddenly appears, which is unacceptable. Therefore, the factors that cause the color of CNC handboards can start from the following reasons:

　　一、模具原因

　　I. die reason

　　1. 模具不干凈，灰塵或其他灰塵沉積在材料上，導致材料被污染和變色。

　　1. The mold is not clean, and dust or other dust is deposited on the material, causing the material to be polluted and discolored.

　　2. 熱電偶、溫度控制器或加熱系統不平衡導致溫度控制失靈，溫度過高導致塑料或顏料成分發生化學變化，分解變色，特別是PVC，對溫度非常敏感。

　　2. Imbalance of thermocouple, temperature controller or heating system leads to temperature control failure, high temperature leads to chemical change of plastic or pigment composition, decomposition and discoloration, especially PVC, which is very sensitive to temperature.

　　3.氣缸內有障礙物，容易促進塑料降解;氣缸或螺旋槽內卡有金屬異物，塑料變色是由于不斷的磨削造成的。

　　3. There are obstacles in the cylinder, which is easy to promote plastic degradation; there are metal foreign matters stuck in the cylinder or spiral groove, and the plastic discoloration is caused by continuous grinding.

　　二世。流程的原因

　　II. Reasons for the process

　　1.數控車床螺桿轉速過高，螺桿剪切力過大，預成型背壓過大，塑料熔煉過程和筒體摩擦溫度造成變色。

　　1. The screw speed of CNC lathe is too high, the screw shear force is too large, the back pressure of preform is too large, and the plastic melting process and the cylinder friction temperature cause discoloration.

　　2. 鋼瓶和噴嘴的溫度過高，特別是對溫度敏感的物料。

　　2. The temperature of cylinder and nozzle is too high, especially for materials sensitive to temperature.

　　3.注射壓力過高，儲存時間過長，停機時間過長。塑料原料會分解變色。

　　3. The injection pressure is too high, the storage time is too long, and the shutdown time is too long. Plastic materials will decompose and change color.

　　三、原材料原因

　　III. reasons for raw materials

　　1. 材料被污染，與其他顏色混合或與混合材料混合。

　　1. The material is contaminated, mixed with other colors or mixed with mixed materials.

　　2. 原料水分和揮發性高，應按要求烘干。

　　2. Raw materials with high moisture and volatility shall be dried as required.

　　3.著色劑和添加劑選擇不當，顏料耐高溫分解導致變色，應選擇合理的顏料配方進行調整。

　　3. If the colorant and additive are not properly selected, and the pigment is resistant to high temperature decomposition, resulting in discoloration, a reasonable pigment formula shall be selected for adjustment.