Precision injection molding technology

With the “3C” product development, precision injection molding machine as a precision injection molding of a key basic equipment, the size of the molding products, repeatability, precision and the intrinsic quality and repeat all three forming efficiency has been greatly improved. Equipment compared to traditional injection molding, precision injection molding machines for products actually implement the accurate control and precise production. Then, precision injection molding technology “precision” are reflected in where?Precision injection molding of plastics plant Precision injection molding of plastics unit to improve the quality of plastics, injection repeatability and product quality within the three key components. Currently, the device mainly to high-speed, high pressure and rapid response of the target development. 1, high-speed injection molding plastics plant High-speed precision injection molding plastics injection molding machine is an important feature. General, high injection speed can reach 300 ~ 1000mm / s, injection molding equipment and even meet some of 2000mm / s. The injection speed of not more than 500mm / s of the injection molding process can be used coaxial line device simultaneously injection molding and plastics, and when the injection rate of more than 500mm / s, the use of first-line coaxial devices are difficult to achieve the required injection accuracy and quality of plastics, mainly due to the kind of device is easy to have high-speed injection molding plastics melt when the material back, resulting in measurement of molten materials are not allowed and the deterioration of quality. To address this problem, according to the characteristics of precision high-speed injection molding, can be used “IMC”-style plastics injection molding device, the coaxial line to the traditional injection molding and plastics unit was split into two interrelated and function separate equipment, plastics in part by the extrusion screw to complete, while the plastic part by injection plunger to complete, such as injection plunger and the injection molding machine with the gap between the cylinder wall is far less than injection molding machine screw and cylinder wall / stop the space between loop and effectively avoid the high-speed injection molding plunger may cause back flow of molten material, and independent plastics molding cycle completely free from the restrictions, which greatly improved the quality and plasticizer plasticizing capacity. 2, precision all-electric mould plastic molding  plant All electrical equipment used in precision plastics injection molding plastics injection molding device, it can significantly improve the plastics injection molding equipment, displacement, speed plastics, plastics back pressure, stroke and packing injection molding plastics injection molding parameters such as control precision, therefore, in precision injection molding machine has been widely used. 3, Precision Injection Screw Compared with the conventional screw injection molding, precision injection with compression screw is relatively small and large aspect ratio and high wear resistance and other features to aspect ratio, for example, common injection screw is 20 to 23, while the Precision Injection Screw was 24 to 30. General, the materials used for precision injection screw has high stiffness and strength, precision injection molding screw obtained under the processing of materials will also differ. To improve the flow of longer than injection, and to minimize shrinkage forming products, precision injection molding machine injection pressure up to 216 ~ 243MPa, while the high pressure injection molding machines pressure can reach 243 ~ 392MPa. In this case, the screw must have sufficient stiffness and strength, can not occur when the high-pressure injection is broken, such as bending and failure phenomena. Precision clamping device Clamping device is to protect the precision mold and assuring quality of major components. Clamping device and ordinary compared to the stiffness of precision clamping device is 10% to 15%, and the move, given the parallelism between the standard template should be high 30% to 40%, the general control of 0.05 ~ 0.08mm in order to achieve low-voltage protection for the mold clamping force and the precise control. 1, precision toggle clamping device unit The traditional toggle clamping device unit, and the dynamic, will not have access to long-term stability between the template parallel degree, while difficult to achieve low-voltage protection for precision molds.To overcome this shortcoming, precision toggle device to do the following improvements: high-precision ball bearing guideways to guide the operation of moving the template to ensure the accuracy of the stability of the dynamic template operation; applied with speed and closed loop control of the dual pressure function of servo valve, to achieve a low-voltage protection for precision molds; pin and the steel sleeve with a high wear resistance of friction pairs, and further stabilized the move, given the parallelism between the template; precision adjustment model agency application implementation a high precision adjustment mode, thus ensuring the dynamic template in any position to achieve a stable parallel.2, precision hydraulic clamping device Precision injection molding mold device is the main hydraulic clamping device. Clamping devices traditional devices of its toggle clamping force is usually the role of the upper and lower (or left and right) sides of the central place will result in moving the template deformation, thus affecting the parallelism of the template, and this hydraulic mold clamping cylinder piston unit acting on the central position of moving the template to ensure the move, set the template parallelism between the long-term stability. As application requirements increase, precision hydraulic clamping device has been engaged in transformation, moving the template run-oriented high-precision ball bearing guideways is one of the most significant progress achieved to further enhance its move, set the template for parallelism between the stability requirements. 3, no rod clamping apparatus No rod clamping device is not used as bar, rod deflection to eliminate the parallelism of the template. In recent years, the deformation of the vulnerability of the “C” shaped frame to improve and enhance the action, set the template parallel between the degree of accuracy and precision stability. For example, the Freedom Series Milacron injection molding machine without tie clamping device was its U-structure, and just under 2 bar, has a higher rigidity. By configuring the balance tank structure patent, making the parallelism between the fixed mold is more stable. 4, block Siamese head board General, there are rod clamping device of its first board molding machines are based on block structure, and design of such structures are often the first board as a result of excessive force overall deformation. Precision injection molding machine through the use of sub-block piece head board, which effectively improved the stiffness of the first plate, so as to achieve power while reducing the template due to the deformation of the mold deflection. This piece first board to block the first force plate functions and features to install separate molds were borne by the respective block, and remain connected with the center circle of acceptance and installation of block mold block. To withstand the process of clamping force, due to the force center ring body block area less than the force area, the force generated by the first deflection plate, only the center circle of the central body of the premises pass deflection deformation resulting mold block installation This shows that, due to force installation of mold block deflection caused by the deformation zone center ring only in the central body, will not block the installation of the overall production mold deflection, so as to achieve the purpose of improving the precision clamping. Precision hydraulic control technology Development of high-speed response of integrated components and systems are precision hydraulic control technology development, and to achieve high-speed response capability, not only to improve the response speed of valve itself, but also to improve control performance in the premise of streamlining the number of valves in order to achieve loop response speed requirements. To achieve this requirement, precision injection molding machine hydraulic control technology is speeding up their own Di technical Fazhan, the most obvious Tedian that will Shuzi electronic hydraulic technology of electronic computing technology to integrate He formed “intelligent” control system that no Jiezhuwaibu Kongzhiqiji independently complete a variety of operating functions, to realize the major parameters such as flow, speed, position and pressure of the precise closed loop control, the system can achieve better Gaosu response control effect. Highly integrated multi-function hydraulic components is the ratio of precision injection molding machine hydraulic components development, an important feature. Different from the application of different functions that previously required valve control loop, the current precision injection molding equipment, these multi-function control valve into a loop, greatly improving the dynamic performance of the equipment. For example, Atos has developed for injection molding plastics loop digital servo proportional valve plug compound. The device integrates a P / Q digital amplifier with an external pressure through the sensor, a valve in the injection only needs to complete the original 3 to 5 control valve to complete the task. The device can also implement speed control and pressure control, back pressure in the packing and the plasticizing phase high dynamic, accurate conversion. Precision Control System To further improve the accuracy of rapid response, the application of advanced control systems to further enhance the precision injection molding machine precision level of the key, is also a precision injection molding machine to complement and enhance the performance. At present, the Japanese refined the company through the use of the new TACT control system, effectively improve the device response speed and stability, and security with the new pressure control system, its products, changes in the weight range from the 0.022g reduced to 0.006g, significantly improve the product quality stability. Hong information technology Co., Ltd. took the lead in developing a fully electric precision control system, the CPU speed can be common 40MHz upgrade to 400MHz, and the temperature accuracy of ± 10, effectively upgrading the entire electrical position of Precision Injection Molding Machine and running accuracy. JSW in Japan’s J-E Ⅱ-P Series hydraulic injection molding machine has a six-block speed control, packing six-block loop control, three retaining screw speed control and three closed-loop control block back pressure, and equipped with a flexible high-speed low-voltage The high sensitivity of servo loop controller, hydraulic accumulator with high-performance loop and closed loop control servo valve comprising the combination of accuracy ensures oil temperature, resin temperature and die temperature settings and random changes in the measured values effective agreement in order to achieve high-speed precision injection molding process, high response, high stability. In addition, the system can set the high-speed high-pressure molding and high-speed low-pressure molding, in a stable within a wide range of the best pressure injection molding, significantly improved the stability of product quality. Application Analysis For complex, thin wall injection molding production of workpieces, using precision injection molding has great application and performance advantages. To Ningbohaida Plastic Machinery Co., Ltd. developed HDJM-100 all-electric injection molding machine precision (as shown), for example, all the equipment powered by AC servo motor closed-loop control, can achieve the required precision high-speed injection molding machine response and accurate positioning of the moving parts of the purpose. Unlike other precision injection molding equipment, which has applied the advanced precision injection molding machine control system of dialogue and the use of advanced methods of high precision pressure control, can significantly improve the stability of product weight. HDJM-100 all-electric injection mold molding machine precision The device features high-speed high-pressure injection molding, injection speed of its standard configuration for the high-speed 300mm / s, ultra-high injection speeds of up to 500mm / s, injection pressure 235.2MPa, keeping pressure up to 196MPa, can be precisely controlled micro-oriented products contraction, contraction and micro-micro-compression elastic reset. The use of PID barrel temperature control, temperature control accuracy up to ± 10. The main technical parameters of the screw through the optimization, the device can significantly increase the melting material density repeatability, and Ji Liang density increased from 3% to 5% decrease to 0.5% to 0.6%. Through the use of small inertia servo motor, the device can reduce the time to accelerate and slow down more than 60%, making products with superior quality plastics. The clamping device template using mobile devices for axial positioning ball guideways to mold clamping system with high enough precision. Increased by thickening the first plate and rod diameter, clamping system with a sufficiently large rigidity, may well prevent the “arch-shaped” deformation. In addition, the device configuration the precision of displacement sensors up to 0.05mm, with the combination of the control system of the closed loop can be measured accurately control the stroke, injection schedule, more than the thickness of pad material (injection control point), to improve product repeatability.