关键词: 模具表面温度, 注塑温度, 注射压力, 保压压力, 正交试验, 极差分析

Abstract:

Taking the rear trim strip of a certain type of car skin as the research object， feature point A on the strip was selected as the warpage observation point， and an “overflow loop” was added along the direction of the material flow at the buckle feature. Mold surface temperature， injection temperature， injection pressure， and pressure holding pressure were selected as the research objects to construct a four⁃factor four⁃level L₁₆ orthogonal experiment. The range analysis was carried out upon 16 groups of data to obtain the most sensitive factors and levels as well as the optimal combination of process parameters. With the optimal combination of parameters， the warpage quantity at the point A reached 5 mm under all effects， which was 30 % lower than that under the tenth group of parameters. The optimal parameters were verified by experiments. The main injection parameters were determined to be a mold surface temperature of 128 ℃， an injection temperature of 330 ℃， an injection pressure of 48 MPa， and a holding pressure of 95 % of the injection pressure. After molding， the appearance of the product was uniform. There was no silver grain， wire drawing， and white injection defects. The feature point A looks smooth over the all transition of the product， meeting the test expectations. After molding， the product can meet the requirement of application. The results verified the accuracy of the Moldflow⁃2023 analysis software and the scientificalness of range analysis.

Key words: mold surface temperature, injection molding temperature, injection pressure, holding pressure, orthogonal test, range analysis