In the manufacturing process of plastic products, the flatness and smoothness of the appearance are often important criteria for measuring product quality, especially for those products that do not allow obvious gate marks. In order to meet this demand, the point gate, a special and delicate gate design, came into being, and is also vividly called the needle gate. With its needle-like small size, it leaves only a tiny trace on the surface of the part, perfectly maintaining the appearance of the part.
The reason why the point gate is so popular is mainly due to its unique advantages:
Good mold filling effect: The design of the point gate is conducive to the smooth filling of the plastic melt, ensuring uniform filling of all parts of the part.
Controllable solidification time: By accurately adjusting the size and shape of the point gate, the solidification time of the gate can be effectively controlled, thereby optimizing the molding process of the part.
Convenient automated production: The perfect fit between the point gate and the automated production line makes the production process of plastic parts more efficient and convenient.
Easy to trim the gate marks: The small gate marks make subsequent trimming work easy and simple, further improving the appearance quality of the part.
However, when using the point gate design, special attention should be paid to the following issues:
The gate length needs to be moderate: Due to the extremely small diameter of the point gate, the pressure loss during the injection process is large, which is easy to cause the shrinkage rate to increase and the internal stress concentration near the gate, resulting in defects such as warping and deformation of the product. Therefore, the length of the gate should be shortened as much as possible to reduce these adverse effects.
Careful selection of molded plastic parts: Point gates are not suitable for all types of plastic parts. For flat and thin plastic parts or plastic parts that are not allowed to deform, a single point gate may cause problems such as low material temperature at the weld and weak welding due to the long process, forming obvious welding marks, affecting the appearance and strength of the plastic part. At the same time, the difference in material temperature may also cause the distortion and deformation of the plastic part. Therefore, in the molding process of such plastic parts, a multi-point feeding method should be adopted to ensure the quality and stability of the parts.
In summary, as an important gate design in the double-parting surface injection mold, the point gate plays an important role in the manufacture of plastic products with its unique advantages. However, in practical applications, we also need to carefully select and design according to specific circumstances to give full play to its advantages and avoid potential problems.
