The primary function of standard sprue bushing is to guide the plastic melt ejected from the nozzle of the injection molding machine to smoothly enter the runner system of the mold and then flow to the cavity. It provides an accurate channel for the plastic melt to ensure that the melt can flow according to the designed path and avoid splashing, turbulence and other phenomena when the melt enters the mold. This function ensures the stability of the injection molding process and the quality of plastic parts, which is the most basic and important role of standard sprue bushing.
During the injection molding process, the plastic melt is injected into the mold at a high pressure and speed. As a direct contact part between the melt and the mold, standard sprue bushing can effectively prevent the melt from causing damage and wear to the mold. This not only protects the integrity of the mold, extends the service life of the mold, but also reduces the cost of mold maintenance and replacement.
Standard sprue bushing can make the injection plastic enter the mold cavity more smoothly and reduce runner resistance. This helps to increase the injection speed and pressure transmission efficiency of the injection molding machine, thereby improving production efficiency while ensuring the quality of the molded product. At the same time, due to the precise guidance of the sprue bushing, the plastic melt can fully fill the mold cavity, avoid defects and bubbles, and further improve the molding quality of the plastic part.
A good sealing structure needs to be formed between the standard sprue bushing and the injection molding machine nozzle to prevent the plastic melt from leaking from the connection between the two during the injection molding process. This sealing effect is crucial to maintaining the injection molding pressure, improving the injection molding efficiency, and avoiding the waste of plastic melt. If the seal is poor, it will not only cause melt leakage, but also may affect the molding quality of the plastic part, such as defects such as lack of material and bubbles.
During the injection molding process, the plastic melt is injected into the mold at a higher pressure. The standard sprue bushing needs to withstand this high pressure and effectively transfer the pressure to the runner and cavity of the mold. Therefore, the sprue bushing must have sufficient strength and rigidity to ensure that it will not be deformed or damaged under high pressure. This feature ensures the smooth progress of the injection molding process and the stable molding of plastic parts.
During the flow of plastic melt, some impurities or incompletely melted plastic particles may be mixed in. The structural design of standard sprue bushing can collect and filter these impurities to a certain extent, preventing them from entering the mold cavity. This helps to avoid defects on the surface of plastic parts or affect the performance of plastic parts, further improving the molding quality and reliability of plastic parts.
Standard sprue bushing is usually used in conjunction with the mold's positioning ring and other components to determine the relative position of the mold and the injection molding machine. This positioning and centering function ensures the accurate centering of the injection molding machine nozzle and the mold gate, avoiding problems such as gate blockage and poor molding of plastic parts caused by centering deviation. At the same time, accurate positioning and centering also help improve the stability of the injection molding process and the molding accuracy of plastic parts.
Standard sprue bushing plays a vital role in plastic molds. It not only guides the injection plastic into the mold cavity, prevents mold damage and wear, and improves production efficiency and molding quality, but also has multiple functions such as sealing to prevent leakage, bearing injection pressure, collecting and filtering impurities, and positioning and centering. These key functions make standard sprue bushing an indispensable and important component in plastic molds.
