Development of a Reliable Vibration Based Health Indicator for Monitoring the Lubricating Condition of the Toggle Clamping System of a Plastic Injection Molding Machine

Plastic injection molding has become one of the most widely used polymer processing methods due to its ability to viably produce large volumes of complex parts in a short time frame. Most of the plastic injection molding machines currently used in industry possess a toggle clamping mechanism that undergoes a repeated clamping and unclamping cycle during operation. This toggle must therefore be properly lubricated to avoid catastrophic failure and eventual machine downtime. To overcome this limitation, the industry currently relies on the experience of a skilled operator, paired with a fixed empirical value, to determine the timing for re-lubrication. This method often leads to the machine operator either wasting lubricant by over-lubricating the toggle, or damaging the toggle by failing to re-lubricate when needed. Herein, we explore the use of vibration analysis to perform real-time condition monitoring of the lubrication condition of the toggle clamping system. In this study, our novel structural response analysis out performed both traditional time domain and frequency domain analyses in isolating the vibrational signatures indicative of lubricant degradation. Additionally, this study confirms that the vibration generated during the unclamping period of the toggle, proved to contain more valuable information relevant to the instantaneous lubricant quality than provided by its corresponding clamping period.

DESIGN AND PRODUCTION OPTIMIZATION OF PP 20% TALC ADDITIVE FILTER WITH PLASTIC INJECTION MOLDING MACHINE

In the paper, the design optimization of the food-contact water tank filter used in industrial kitchen products was made and produced in plastic injection molding machine with different parameters. The effects of production parameters on product weight, fabric filter strength (tearing), production time and surface quality (burrs and gas gap) were investigated experimentally and statistically. The design of the experiments was prepared with the Taguchi L[Formula: see text] orthogonal array. Experiment parameters are determined as injection speed (A), holding press (B), holding speed (C), mold temperature (D), melting temperature (E) and compression waiting time (F). As a result, 154% improvement was achieved in the fabric strength as a result of design optimization. As a result of the optimization of the injection parameters of the product, when the response tables were examined, it is determined that the greatest value of filter fabric strength is 298[Formula: see text]N in A2B2C2D1E1F3 parameters. When ANOVA results are analyzed, the most effective parameter for fabric strength and surface quality was determined as mold temperature with 36.38% and compression waiting time with the lowest effective parameter as 0.08%.

Optimal design on Watt-chain double-toggle mold clamping mechanism for injection molding machine

Introduction The mode clamping mechanism is the most important part of forming section for the plastic injection molding machine. If this mechanism has double-toggle effects at the close position, it will get a larger clamping force and have higher safety. This study focuses on the optimal design of the Watt-chain mechanism with double-toggle effects at the close position. Methods The Watt-chain double-toggle mechanism is chosen to be the mold clamping mechanism by referring to the existing patents. Then, the kinematic characteristics of the Watt-chain double-toggle mechanism are analyzed by the vector loop method. Finally, based on the kinematic requirements and the proposed optimal design process according to the objective function, the optimal design on Watt-chain double-toggle mechanism is accomplished in this study. Results This study proposes an optimal design process on Watt-chain double-toggle mold clamping mechanism. By following the optimal design process, the optimal Watt-chain double-toggle mold clamping mechanism has a maximum acceleration 3418 mm/s2 ( amax = 3418 mm/s2) and a force ratio is 2.24 ( Fin/ Fout = 2.24). Discussion According to the studies on the optimal designs of mechanisms, the optimal Watt-chain double-toggle mechanism, which is better than the multiple-joint double-toggle mold clamping mechanism in the existing patent by reducing 19.5% of acceleration and 30% of a driving force, is proposed. The results of this study could be the design reference in engineering when designing mold clamping mechanisms for plastic injection molding machines.