The needle valve hot runner technology with its unique process control technology can improve the reliability of the parts to a higher degree, make the melt flow in the three-dimensional cavity faster and smoother, and bring faster to the parts. The cycle cycle plays a particularly important role in improving the quality of parts. By controlling the gate opening time, the cavity is filled smoothly and the melt flow is balanced, and the weld marks are eliminated.
Injection molding of large injection molded parts usually requires two or more hot gates to fill. For ordinary hot runner systems, the gate opens at the same time when the injection starts. This kind of melt feeding method inevitably has fusion defects, that is, when the two melt fronts merge, because the two melts cannot be completely melted into one body, a fusion mark is formed, and the reaction on the surface of the product is the so-called weld mark. . Although it can be improved by increasing the melt temperature, increasing the holding pressure and adjusting the injection molding process parameters, the actual improvement effect is limited.
The needle valve hot runner technology is used to construct the gating system, which can realize the program control of the opening and closing of each valve gate, and it can also control the valve needle to open when the first stream of melt just flows through the second valve gate. Open the second gate. At this time, you can open or close the first gate as needed. Continue until all gates are opened and the cavity is filled, so that the melt is completely fused and a product without weld marks is obtained. And a balanced flow state can be obtained by switching the valve gate.