Source: Golden Eagle Press
Due to the common plastic machinery control is relatively simple, but most machines are stand-alone operation, subject to the conditions of mechanical reliability level, plastic machinery to the reliability of the control system request is not too high, so the embedded product development special controller can meet the needs of the vast majority of users, has great advantage in price, and thus in widely used in the industry, especially in injection molding machine is widely used, application in blow molding equipment has a high proportion. In the extrusion equipment, PLC is dominant because of its high reliability, short development cycle and mature application. Currently, there are more PLC brands in this industry, including Siemens, Omron, Mitsubishi, NAIS, LG, etc. Siemens provides a series of plastic mechanical controllers based on PLC.
With the development of plastics machinery technology, the controller is not a simple movement control, but including melt temperature, injection pressure, injection rate, holding time, cooling process and various parameters of the hydraulic circuit of integrated control. Most of the past use of open loop control, is now in the closed loop control direction development. New equipment to the controller's control ability and response speed have the further requirements, the traditional controller based on embedded products is difficult to meet these requirements, so the new type of equipment and large equipment is given priority to with PLC. The use of PLC in high-end and large equipment and the use of dedicated controllers on medium and low-end devices will not change in the plastics machinery industry in the next three years. Competitive prices are the precondition for entering the largest market for general plastic machinery controllers.
Production process characteristics of plastic machinery with very large energy saving potential, injection molding machine, for example, general component is the process of injection molding machine clamping, rubber, plastic, pressure maintaining and cooling, mould and so on several stages, each stage need different pressure and flow rate. For the oil pump motor, injection molding process is in the change of load state, quantitative pump in hydraulic system, the oil pump motor at a constant speed to provide a constant flow of redundant hydraulic oil backflow through the overflow valve, this process is called high pressure throttle, this return will cause energy loss. The use of frequency converter can solve this problem, by adjusting the pump rotation speed, the oil pump can in the different stages of injection molding machine production to provide the proper oil pressure, the greatest degree of reduce the energy loss. The earliest use of frequency converter in plastic machinery are some end users, systems integrators to provide them with the plastic machinery of frequency conversion energy-saving retrofit scheme, fruitful, so more and more plastic machinery users adopt inverter transformed their equipment. To cope with this demand, plastic machinery manufacturers are also starting to use inverters on plastic machinery, and users of plastic machinery can choose a model with a converter. In order to reduce the one-time investment, most users still choose the plastic machinery with no frequency converter, and they can modify the frequency conversion energy during the subsequent use.
Plastic machinery using frequency converter is the main purpose of energy saving, the demands of frequency converter is relatively low, currently on the market can provide meet the major suppliers of plastic machinery using inverter products, thus becoming the key factor of entering the market price, domestic manufacturers have a certain advantage, their table is the best in the plastics machinery industry.
Servo and motion control products are mainly used in the whole electro plastic machinery to replace the traditional hydraulic system. Relative to the hydraulic system, servo system has high control precision, small amount of maintenance, good production environment, the advantages of high production efficiency and save energy, more and more used in product requiring higher precision, such as mobile phones, cars and medical equipment and other industries.
Due to hydraulic plastic machinery development and progress, is able to meet the requirements of almost all, therefore, although electrical plastic machinery has higher technical index, but the higher cost of limiting the rapid development of it in the market, only a small amount of production, and mainly in the face of overseas markets. Although servo products prices are lower, but the hydraulic injection molding machine technology also got great improvement, therefore, servo products in recent years the application of plastics machinery industry in China will not have too big change, only a small amount of use in the high-end models. Due to the characteristics of the servo product itself, plastic machinery manufacturers need external technical force to provide solutions for them.
The melt temperature is very important, and the temperature of the cylinder used is only guidance.The melt temperature can be measured at the nozzle or by air injection.The temperature setting of the ejection cylinderdepends on the melt temperature, screw speed, back pressure, injection...details >>
The melt temperature is very important, and the temperaturedetails >>