Correlation between runner pressure and cavity pressure within injection mold

Abstract

Cavity pressure in the injection molding process is closely related to the quality of the molded products and is used for process monitoring and control to upgrade the quality of molded products. However, the sensor installed inside the cavity makes the molded product of the cavity defective, reducing productivity. In view of this, this study investigates the correlation between melt pressure and cavity pressure in different runner positions and determines the appropriate runner position, where the runner pressure can represent the cavity pressure, in order to increase productivity. First, the Taguchi method is used to obtain the optimal parameter combination of injection molding, and then, the experiment is conducted based on this condition in order to discuss the difference between runner and cavity pressure history profiles. According to the experimental results, the quality of molded products can be monitored and controlled by installing sensors at different runner positions, and the maximum value of the cavity pressure profile varies with the runner position. When the distance between the top of the pressure sensor mounted in the secondary runner and the outside diameter of the runner is greater than the maximum thickness of the molded product, the obtained pressure history profile approximates to that inside the cavity. In other words, the runner pressure can represent the cavity pressure. Mold temperature significantly influences the runner pressure history profile and form accuracy (contour precision) of the lens during the injection molding process, which can be used as a process monitoring and control parameter. In addition, the cavity pressure profile at the cooling stage is closely related to the form accuracy of the lens and is the key to determining process monitoring and control parameter.

Injection Mould Design and Analysis of the Telephone Base Based on Pro/E

“…Its structure is shown in Figure 6, the disc clamping slide block is installed in the T guide chute, so it can glide smoothly in the direction of the pull. The inclined guide pillar installed obliquely with the moving direction of opening mould, the inclined guide pillar fitted with slide block corresponding hole, and the inclined guide pillar moving relatively against the slide block when opening mould, which generates the lateral force component on the slider and forces the slider to finish the core-pulling motions [4] . The angle of the inclined guide pillar is 20°.…”

“…03010-p. 4 of the plastic will be arranged uniformly, so that it can make sure the requirements of the push rod. Based on the stiffness and strength of the push rod itself, and after putting into the mold, the face also should be with the cavity bottom level or higher cavity 0.05 -0.1 mm [7] .…”

The Influence of Processing Conditions on the Polypropylene Apparent Viscosity Measured Directly in the Mold Cavity

“…Friesenbichler has showed that the viscosity measured by a capillary rheometer differs by 10% from the value determined during injection molding . In‐line measurements, in addition to determining the material rheological characteristics under processing conditions, allow process control and its optimization …”

“…[8] In-line measurements, in addition to determining the material rheological characteristics under processing conditions, allow process control and its optimization. [9][10][11][12] There are several original solutions that allow rheological measurements under actual injection molding conditions. One of them is placing temperature and pressure sensors between the injection molding plasticizing unit and the segment nozzle.…”

Multiobjective Optimization of Injection Molding Process Parameters for the Precision Manufacturing of Plastic Optical Lens

“…They established an inverse model of injection molding for form accuracy of optical lens by combining the artificial neural network (ANN) with a genetic algorithm (GA) [9]. They also investigated the correlation between melt pressure and cavity pressure in different runner positions [10]. Other researchers, taking the optical and mechanical performance of the optical lens as the optimization objectives, proposed different methods to adjust the IMPP, reducing the birefringence and stress of the optical lens effectively.…”