*Article* **Transfer Learning Applied to Characteristic Prediction of Injection Molded Products**

**Yan-Mao Huang, Wen-Ren Jong \* and Shia-Chung Chen**

Department of Mechanical Engineering, Chung Yuan Cristian University, Taoyuan City 320314, Taiwan; H05850207@hotmail.com (Y.-M.H.); shiachun@cycu.edu.tw (S.-C.C.)

**\*** Correspondence: wenren@cycu.edu.tw

**Abstract:** This study addresses some issues regarding the problems of applying CAE to the injection molding production process where quite complex factors inhibit its effective utilization. In this study, an artificial neural network, namely a backpropagation neural network (BPNN), is utilized to render results predictions for the injection molding process. By inputting the plastic temperature, mold temperature, injection speed, holding pressure, and holding time in the molding parameters, these five results are more accurately predicted: EOF pressure, maximum cooling time, warpage along the *Z*-axis, shrinkage along the *X*-axis, and shrinkage along the *Y*-axis. This study first uses CAE analysis data as training data and reduces the error value to less than 5% through the Taguchi method and the random shuffle method, which we introduce herein, and then successfully transfers the network, which CAE data analysis has predicted to the actual machine for verification with the use of transfer learning. This study uses a backpropagation neural network (BPNN) to train a dedicated prediction network using different, large amounts of data for training the network, which has proved fast and can predict results accurately using our optimized model.

**Keywords:** injection molding; CAE; machine learning; transfer learning
