The Research Of Distribution Of Cavity Pressure Based On Cavity Pressure Monitor

Injection molding process is one of the important ways to produce plastic products and the adjustment of process parameters is mainly depending on the experience of engineers who lack reliable scientific theory.The change of the melt in mold cavity can be observed more directly by using cavity pressure sensor during the injection molding process.This provides the basis for the determination of process parameters.Moldflow software was used for simulation and experiments were made in this paper,studying the relationship among injection molding process parameters,the distribution of cavity pressure and the quality of products based on the coincidence rate of cavity pressure curve.This helped providing theoretical and practical support for the determination of injection molding process parameters.The main work contents and results are as follows:First,the simulation experiment was carried out with Moldflow software.The coincidence rate of cavity pressure curve of three points in the cavity was used to characterize the distribution of cavity pressure and the quality of products was characterized by its warping deformation.By setting different process conditions,the pressure curves of three points in the cavity and the warping deformation of the products were simulated.The relationship between the distribution of cavity pressure and the warping deformation of the products was analyzed.At the same time,the influence of mold temperature,melt temperature,holding pressure and holding time on the distribution of cavity pressure was studied by single factor method.On this basis,the influence extent of these four process parameters toward the distribution of cavity pressure was studied by orthogonal experiment.Secondly,the experimental platform was established.The cavity template of mold was designed by Solidworks software,and the injection molding experiment was carried out after machining the template.On this basis,data acquisition system was built by Labview and cavity pressure data was collected by Kistler pressure sensor.Finally,the experiment was conducted by self-built experiment platform.The correctness of the conclusions obtained from the Moldflow software simulation experiment was verified.The experimental results showed that the more uniform the cavity pressure distribution,the higher the coincidence rate of cavity pressure curve and the smaller the warping deformation of the products.At the same time,single-factor method to control the variables was used.Under the circumstance that other process parameters remained unchanged and all the parameters were within the reasonable parameter range,the coincidence rate of cavity pressure curve got higher and the distribution of cavity pressure became more uniform as the temperature of the mold increasing,the melt temperature decreasing,the holding pressure and holding time increasing.The influence extent of these four process parameters toward the distribution of cavity pressure was listed in the following order:melt temperature>holding time>mold temperature>holding pressure.