Views:1 Author:Site Editor Publish Time: 2020-11-10 Origin:Site
The control of ordinary plastic machinery is relatively simple, and most of the machines are single-machine operation, which is limited by the level of mechanical reliability. Plastic machinery does not have high requirements on the reliability of the control system. Therefore, the special controller developed by embedded products can meet the needs of most The demand of most users has a great advantage in price, so it is widely used in this industry, especially in injection molding machines, and the application ratio in blow molding equipment is also relatively high. In extrusion equipment, due to the high reliability of PLC, short development cycle and mature application, the application of PLC occupies a dominant position. The PLC brands that are currently used more in this industry include Siemens, Omron, Mitsubishi, NAIS, LG, etc. Siemens provides a series of PLC-based plastic machinery controllers.
With the development of plastic machinery technology, the controller is no longer a simple action control, but a comprehensive control of various parameters including melt temperature, injection pressure, injection speed, pressure holding time, cooling process and hydraulic circuit. Most of them used open-loop control in the past, and are currently developing towards closed-loop control. New equipment has further requirements on the control ability and response speed of the controller. Traditional controllers based on embedded products cannot meet these requirements. Therefore, PLC is the mainstay for new equipment and large-scale equipment. The use of PLCs on high-end and large-scale equipment and special controllers on low-end equipment will not change in the plastics machinery industry in the next three years. Competitive prices are the prerequisite for entering the largest number of general plastic machinery controller markets.
The characteristics of the production process of plastic machinery have great energy-saving potential. Take the injection molding machine as an example. The process of the injection molding machine is generally divided into several stages such as clamping, injection, melting, holding pressure, cooling, and mold opening. Different pressures and flows are required. For the oil pump motor, the injection process is in a changing load state. In the hydraulic system of a fixed pump, the oil pump motor provides a constant flow rate at a constant speed, and the excess hydraulic oil flows back through the overflow valve. This process is called high pressure section. Flow, this backflow will cause energy loss. The use of frequency converters can solve this problem. By adjusting the speed of the oil pump, the oil pump can provide appropriate oil pressure at various stages of injection molding machine production, and reduce energy loss to the greatest extent. Some end users were the first to use frequency converters on plastic machinery. System integrators provided them with frequency conversion energy-saving transformation schemes for plastic machinery. The results were remarkable. As a result, more and more plastic machinery users used frequency converters to transform their equipment. In response to this demand, plastic machinery manufacturers have also begun to use frequency converters on plastic machinery, and users of plastic machinery can choose models with frequency converters. In order to reduce the one-time investment, most users still choose plastic machinery without frequency converters, and they can carry out frequency conversion energy-saving transformation in the subsequent use process.
The main purpose of using frequency converters in plastic machinery is to save energy, and the requirements for frequency converters are relatively low. At present, major suppliers on the market can provide frequency converter products that meet the use of plastic machinery. Therefore, price has become a key factor in entering the market. Domestic manufacturers have Certain advantages, they perform best in the plastic machinery industry.
Servo and motion control products are mainly used in all-electric plastic machinery to replace traditional hydraulic systems. Compared with the hydraulic system, the servo system has the advantages of high control accuracy, low maintenance, good production environment, high production efficiency and power saving. It is increasingly used in occasions with high product accuracy requirements, such as mobile phones, automobiles and Medical equipment and other industries.
Due to the development and progress of hydraulic plastic machinery, it can currently meet almost all requirements. Therefore, although the all-electric plastic machinery has higher technical indicators, the excessively high cost limits its rapid development in the market and only a small amount of production , And mainly face foreign markets. Although the price of servo products is decreasing, the technology of hydraulic injection molding machines has also been greatly improved. Therefore, in recent years, the application status of servo products in China's plastic machinery industry will not change much, only high-end models. Use sparingly. Due to the characteristics of servo products, plastic machinery manufacturers need external technical force to provide them with solutions.