Needle valve hot runnerControl gate opening time of

1. Needle valve hot runner, by controlling the gate opening time, ensures smooth filling of the mold cavity and balanced melt flow, and eliminates welding marks.

The injection molding manufacturing of large injection molded parts usually requires two or more hot gates to fill. For ordinary hot pouring systems, the gate opens simultaneously at the beginning of injection. This glue feeding method inevitably has fusion defects, that is, when two strands of molten material converge at the front, fusion marks are formed due to the inability of the two strands of molten material to completely melt into one, and react on the surface of the product, which is commonly known as fusion marks. Although improvements can be made by increasing the melt temperature, increasing the holding pressure, and adjusting injection molding process parameters, the actual improvement effect is limited. By using needle valve hot runner technology to construct a pouring system, program control can be achieved for the opening and closing of each valve gate. It can also control the opening of the valve needle and the opening of the second gate when the first melt just flows through the second gate. At this time, the first gate can be opened or closed as needed, and continue until all gates are opened and the mold cavity is filled, allowing the melt to fully fuse and obtain products without fusion marks.

2. The product obtained by using this technology will not have any residual gate marks, so it is suitable for processing injection molded parts with high surface quality requirements.

Sometimes the reason for using a valve gate is because the marks on the workpiece are smooth, equivalent to the marks left by an ejector pin, so it is much smaller than the end marks of latent gates and other types of hot runners.

3. More effective control of holding and forming cycles.

The needle valve hot runner can use larger diameter gates, which can accelerate the flow of melt in the mold cavity, shorten the forming cycle of the workpiece, and better maintain pressure.

4. Effectively reduce the internal stress of the product and improve the stability of the product.