Injection molding machines are widely used to fabricate plastic products with complex geometries and structures. They consist of an injection unit and a clamping unit. To withstand the pressure of the mold cavity, the clamping unit needs a high clamping force to hold the mold halves. Unfortunately, the clamping force is among the overlooked parameters of the injection molding parameters. Setting the clamping force at max is needed in practice to avoid flash defects for most operators. However, excessive clamping force creates problems for the machine. This study proposes a verification method for determining optimal clamping force based on the clamping force change ΔCF. When ΔCF becomes zero, the current set value of the clamping force is appropriate. A positive and negative ΔCF corresponds to an excessive and insufficient set value of the clamping force, respectively. Verification experiments are implemented on an electric injection molding machine with polypropylene (PP). The experimental results show that the novel strategy can basically calculate and identify the optimal clamping force with iteration method. The optimal clamping force value for current working conditions (620kN) is acquired after several automatic molding trials, which provides a direction for further research.

Injection molding (IM) is one of the essential forming methods for thermoplastic polymers, which is widely used in modern industries such as automobiles, electronics, and medical industries. At present, the machine parameters of the IM machine (IMM) have achieved sufficient high control accuracy and repeatability. However, the viscosity of thermoplastic melt is still easily influenced by the external environment, such as the fluctuations in batches, the compounding in recycled materials, and so on. Conventional IM equipment cannot sense and conduct adjustments correctly, which leads to the production of rejects. A real-time monitoring and controlling model employed for viscosity compensation was established in this article, which could monitor viscosity fluctuations and implement self-adjustment in the IM process. Three kinds of polypropylenes (PP) with different viscosity and materials with different percentages of recycled pellets were randomly added into the barrel for comparison. The results revealed that the pressure integral relative to time is able to monitor the melt viscosity and illustrate the IMM to optimize the V/P switchover and packing pressure in the current molding cycle. The part weight could achieve a higher stability and the model could bring about a decrease in weight fluctuations of 50% to 70%.

Injection molding (IM) is one of the most essential forming methods for plastics. However, some potential risks which influence part quality may occur in the molding process. A non-return valve (NRV) is a major component on the screw head whose function is to seal during the injection process to prevent the backflow of the melt. The NRV will wear in this process and cause fluctuations in parameters and quality but the wear states of NRVs cannot be monitored without the disassembly of the injection barrel. In this study, we proposed an optimization method to compensate for the wear damage of the NRVs. The V/P switchover point in each molding cycle was recalculated and output to stabilize the part quality. As a result, the wear damage of the NRV on the current machine was able to be predicted and the part quality could be initially optimized in the condition that the NRV had a degree of wear. The experimental results reveal that our proposed compensation algorithm can monitor the type of wear of NRV online, and at the same time, it can compensate the axial wear of NRV and finally improve the consistency of product weight, which established a fundamental for further research in the future.

Reactive materials have mechanical properties comparable to metal materials and also have the reaction‐release energy characteristics of energetic materials. The calorific value of reactive materials is even higher than that of explosives. They can react under high pressure/high temperature and release a large amount of chemical energy. Therefore, reactive materials have a wide range of potential applications in aviation and national defense fields. This study examines the energy release characteristics of the metal reactive material casing (MRMC) under thermobaric explosives and compares them to traditional steel casing. The test specimens had the same casing‐charge mass ratio and size, with the only difference being the casing material: reactive material (with reactive elements Zr and Al) and AISI 1020 steel. The physical and chemical properties of the reactive materials were tested and analyzed using ICP‐MS, oxygen bomb calorimeter, and SHPB. Through explosion tests, the characteristic parameters of explosion fireball and ground shock wave overpressure were measured. And the reactive fragments recovered from the experiment were subjected to XRD testing. The results show that MRMC can significantly increase the diameter, duration, and temperature of the explosion fireball compared to steel casing data. The maximum fireball diameter of the MRMC specimen increased by 31.9 %, while the duration before attenuation increased by 47.3 %. MRMC can increase the area ratio of high‐temperature areas (greater than 1300 °C) in the fireball. MRMC increases the overall temperature of the fireball, not just in specific local areas. Additionally, MRMC significantly enhances far‐field shock waves. At a scaled distance of 2.54, the peak overpressure and positive impulse of the MRMC specimen were 50 % and 52 % higher than those of the steel specimen, respectively. This study provides new insights into the application, design, and energy release research of MRMC.