Abstract: Provided by the present disclosure is an ultrasonic phased array-based in-situ imaging method for melt flow in injection molding. The ultrasonic phased array is used for the detection of an injection molding process for the first time, and an effective dynamic monitoring imaging method for a melt front position is developed. A melt flow process in a mold cavity is dynamically monitored by collecting an FMC (Full matrix capture) dataset online. A mapping relationship between an incident angle and a target pixel point is established to rapidly determine time delay of each point in a measurement target region, and a melt bottom image is acquired using TFM (Total focusing method) imaging conditions, from which the melt front can be localized. The provided method is high in measurement accuracy, short in imaging time, and capable of effectively improving imaging efficiency of online measurement.

Abstract: An optimization method for a layering scheme of multilayer injection molding, including: solving a heat transfer equation by using a finite difference method to obtain a cooling time for injection of each layer under different layering schemes, and obtaining a relationship model of a cooling time of a single layer and a layering scheme by fitting; and finally, with an objective of minimizing cooling times of all injection layers and a constraint condition of a total thickness of a product, optimizing a particular layering scheme by using a Lagrange multiplier method. Through optimization by the method, an optimized layering scheme can be obtained, allowing for an effectively shortened injection molding cycle, a reduced production cost, and improved product quality.

Abstract: The present disclosure discloses an ultrasonic online nondestructive measurement method for a melt density in injection molding, which solves the problems of difficult installation, high cost, influence on product surface quality, and the like existing in an existing density measurement method. According to the present disclosure, an ultrasonic velocity is obtained from a time domain signal with reference to time domain and frequency domain signal analysis of ultrasonic echo signals, an acoustic impedance is calculated by full spectrum analysis of a frequency domain signal, and the melt density is calculated from a correlation of the ultrasonic velocity, the acoustic impedance, and the density. The method has the advantages of having high measurement accuracy and being nondestructive, online and low in cost, and has a great application value in the injection molding industry.