Development of High Pressure Injection Technology for Normal Hydraulic Injection Molding Machines

Abstract

Abstract Previous studies have shown that enhancing injection pressure can help improve the precision and mechanical properties of molding products, and reduce their shrinkage. But for now the ordinary hydraulic injection molding machine cannot generally meet the requirements of high pressure injection. To improve the injection pressure, the pressurizing module and the hydraulic circuit were designed, and their influence on the product quality was explored via molding experiments. The relationship between the system pressure of injection molding machine and the injection pressure was demonstrated. The experimental results showed that the maximum injection pressure of the injection molding machine with the pressurizing module was improved from 204 MPa to 320 MPa, up 56.86 %. The lack of materials, bubbles, sags of products were gradually weakened until finally disappeared with increasing the injection pressure. The pressurizing module was convenient to be assembled into or removed from the injection molding machine without damaging the original structure, and the state of pressurizing or no pressurizing could be transformed easily during the injection molding process. These results indicated that this technology was easy to be popularized and applied.