Cavity pressure-based holding pressure adjustment for enhancing the consistency of injection molding quality

Cavity pressure is one of the best indicators of injection molding conditions and thus has been used for quality prediction in the injection molding process. Also, the repeatability of the cavity pressure profile at each shot indicates the consistency of the part quality, which is easily affected by environmental changes, such as barrel temperature. To maintain quality consistency (such as part weight and geometrical dimensions) during mass production, this study proposed a novel method of the holding pressure adjustment to control the deviation in the cavity pressure distribution during each shot. Injection molding of a thin-walled dumbbell-shaped sample was performed to verify the proposed process, which proved the feasibility of this method for suppressing the influence of the barrel temperature changes on part quality.     

FAK in Cancer: From Mechanisms to Therapeutic Strategies

Focal adhesion kinase (FAK), a non-receptor tyrosine kinase, is overexpressed and activated in many cancer types. FAK regulates diverse cellular processes, including growth factor signaling, cell cycle progression, cell survival, cell motility, angiogenesis, and the establishment of immunosuppressive tumor microenvironments through kinase-dependent and kinase-independent scaffolding functions in the cytoplasm and nucleus. Mounting evidence has indicated that targeting FAK, either alone or in combination with other agents, may represent a promising therapeutic strategy for various cancers. In this review, we summarize the mechanisms underlying FAK-mediated signaling networks during tumor development. We also summarize the recent progress of FAK-targeted small-molecule compounds for anticancer activity from preclinical and clinical evidence.     

Speed control of brushless DC motor by adaptive network-based fuzzy inference

Microsystem Technologies - Brushless dc (BLDC) motor provides many advantages such as less power consumption, small volume, good stability, larger torque and simple control. As a result, the...     

Maximum torque per ampere control of IPMSM drive by fuzzy logic

Microsystem Technologies - This paper mainly focuses on studying the torque control with maximum torque per ampere (MTPA) technique based on fuzzy theory and without dealing with complex...     

Applying Kansei engineering to industrial machinery trade show booth design

Trade shows are considered an important marketing channel for companies since they provide manufacturers and purchasers with a vital commercial platform. Traditionally, plastics and rubber industry trade shows have been ineffective due to poor booth planning. Nevertheless, few studies have examined trade show booth design and planning. Actually, most companies lack distinct goals, and their decisions regarding trade show participation may influence decisions regarding which products should be demonstrated, size of trade booth, and level of advertising. Such a decision-making is a problem involving multi-criteria decisions, and requires a logical and objective operating procedure. This work thus devises an objective procedure for trade show. This investigation focuses on booth design for plastics and rubber industry trade shows and comprises three parts: (1) selecting appropriate assessment criteria for trade show design using the Delphi method and Kansei engineering. (2) Establishing suitable booth design principles and procedures for plastics and rubber industry trade show using fuzzy product positioning. (3) Further employing the proposed method to design trade show booths and verify their performance. The results demonstrate the feasibility of the proposed method.

Relevance to industry

This study was conducted to support machinery vendors as a systematic design flow chart and related criteria to provide an objective approach to trade show booth planning.     

Eye to hand calibration using ANFIS for stereo vision-based object manipulation system

Microsystem Technologies - Standard industrial robot manipulator has possibility to manipulate the objects accurately in arbitrary position by using additional vision sensor. This applies in...     

Visual optimization and decision making system for android robot soccer

Microsystem Technologies - The paper developed a visual optimization algorithm to ameliorate the problems encountered by androids on the soccer field involving a visual prediction path that can...     

Influence of V/P switchover point,injection speed,and holding pressure on quality consistency of injection-molded parts

During the injection molding of molten polymers, the control strategy is switched from speed control to pressure control at the filling-to-packing (V/P) switchover point. V/P switchover influences part quality and process stability. V/P switchover timing traditionally depends on the degree of volumetric filling of molten polymer in the cavity and is limited to obtain a smooth and repeatable pressure curve for each injection, indicating consistent part quality. Repeatability is affected by the V/P switchover point, injection speed, holding pressure, and holding time. This study clarifies the effect of the injection speed, V/P switchover point, and first-stage holding pressure setting on cavity pressure curves and injection molding quality. These factors were optimized and verified through the injection molding of integrated circuit trays. The experimental results indicate that adjusting the rear speed of filling stage, V/P switchover point, and first-stage holding pressure, can yield the ideal pressure curve and improve process stability. Compared with the initial process parameter setting, part warpage was reduced by 40% from 0.042 to 0.025 mm, deviation of part width at the end of the filling pattern was reduced by 54% from 0.024 to 0.011 mm, and width range was reduced by 50% from 0.006 to 0.003 mm.     

Calibration of cavity pressure simulation using autoencoder and multilayer perceptron neural networks

Numerical simulations of polymer melt flow behavior in cavities help predict and optimize injection molding process parameters. However, simulation and actual results may differ because of simplified mathematical models, inaccurate processing conditions, material property settings, and machine aging, among other factors. Therefore, simulated optimal process parameters cannot be directly applied in practice. This study applied machine learning to generate a virtual–actual correction model to improve the accuracy of simulation results, especially the cavity pressure profile, a key indicator of injection-molding quality for identifying ideal process parameter settings such as filling-to-packing switchover time and holding pressure. This method does not require big data for model training to enhance its practicality. Therefore, the correction model is only suitable for specific settings. A set of injection molding machines, molds, and processed materials were used for experimental verification. An autoencoder model was used to extract the features of simulation and actual cavity pressure curves. Then, a multilayer perceptron model was used to determine a relationship between simulation and actual features. The autoencoder was used to decode simulated features into cavity pressure curves. The proposed method was verified with dumbbell-shaped specimens; the correlation between simulated and actual cavity pressures was greatly improved from 81% to 98%.     

Multilayer injection molding of high-profile convex lens

The use of injection molding to produce a convex lens of a high thickness and a high proportion of the component thickness requires not only a long cooling time but also results in a low production efficiency and a low yield. In particular, the heat concentration in thick regions can create high shrinkage and create poor surface geometry in these lenses. Multilayer injection molding (MIM) has reduced the cycle time and also improved the geometrical accuracy of thick parts, and thus it has drawn attention in recent years. This study evaluated the feasibility of MIM to produce a convex lens having a high thickness and a high thickness ratio, in which a thick optical lens would be made of a plurality of thin layers. In this study, conventional injection molding (CIM), two-layer IM, and three-layer IM were evaluated empirically to explore the effects of various molding combinations on surface contours accuracy, cycle time, residual stress, and lens transmittance. In the comparison, the three-layer IM significantly reduced the surface profile error to 0.015 mm (CIM was 0.1 mm) and reduced the surface profile error to 30%. Moreover, uniformity of the shrinkage distribution and good surface profile accuracy can be obtained. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48600.