1、IIIPrecision injection molding technology of progress Abstract: The polymer precision injection molding technology, impact on precision injection molding of factors, including the precision molds, injection molding machine control accuracy, precision injection process control and other computer cont
2、rol technology. These factors were discussed, and give the relevant solutions, finally introduces some advanced molding technology. Key words: precision injection; injection molding machine precision injection technology; Precision Injection Mold In recent years, as electronics, telecommunications,
3、medical, automotive, and other industries of the rapid development of the high-precision plastic products, and high-performance requirements of growing precision molding technology to continue to progress, new technologies continue to emerge. Precision injection molding products not only require hig
4、h dimensional accuracy, and low warpage, to write good, but there should also be excellent optical properties. Injection molding is the most important one of the plastic molding methods, including plastics plastics, injection, packing, cooling, and some of the basic process, thus affecting the preci
5、sion injection molding of many factors. 1, precision molds To produce sophisticated products, precision molds is essential. Die Die in general, the accuracy of the temperature control, mold and die design precision manufacturing, use of plastic shrinkage rate impacts. 1.1 Precision Mold temperature
6、control In general precision injection molding of parts, control mold temperature is to increase productivity. However mold temperature control for precision injection molding of great impact, it affects parts of the contraction, shape, crystallization, such as stress, hot and cold circuit design mo
7、ld temperature distribution at the request reasonable, precise control accuracy, a die temperature of the best and Lengshuiji control. Mold temperature control and cooling time on the products and their impact on performance of the following factors: (1) melt plastic injection molds and a two-cycle
8、time will be produced in the mold temperature difference fluctuations, and should therefore be to minimize the volatility differential peak. (2) the heat transfer Die Die Die heat through the concrete and die in the transfer out of the media, mold is changed, the media control is the key, the genera
9、l import and export of its cooling water temperature difference is less than 1 Application of theory to calculate the average temperature, which can guarantee the stability of heat transfer. Media flow and heat transfer are interlinked, mould surface temperature can be used to control the media flow
10、 sensor to compensate for environmental temperature changes caused by mold temperature changes. (3) To enable stable Die Die by the heat absorption and dissemination of balance, the injection molding machine to melt injection to strictly maintain a stable temperature. Die surrounding temperature on
11、the mold had a great impact on the general will be affected to die within the melt convection coefficient of change, so the best set up in the mold surface temperature sensor, die at any time observation of the surface temperature, and keep it stable. (4) changes in the efficiency of heat exchange w
12、ith mold after a long time in the cooling water pipes and Youban appears in the scale, then the interface to reduce the thermal conductivity should furring timely clearance. 1.2 Precision Die Design and Manufacture Die design is good or bad is to ensure the dimensional accuracy of plastic parts prem
13、ise, in order to enhance the accuracy of precision injection mold, in the process of designing a computer-aided analysis is necessary, especially for gating system and the flow of heat-conditioning systems mold temperature distribution the analysis. Applications should be as much as possible the use
14、 of simulation software and close to the actual loading conditions to melt in the mold simulation analysis in the pouring, cooling, and other non-steady-state process. Die manufacturing quality assurance plastic parts Size is the key to accuracy, precision die is the main characteristic of the manuf
15、acturing and assembly operations in addition to polishing, are no manual processing. Die general machining and manual processing ratio is about 6:4 to 7:3, and the machining precision molds and manual processing ratio of 9:1. Die materials and heat treatment is the protection of precision molds in t
16、he molding process, the die temperature in the state, which even the mould parts tempered by low temperature, high temperature melt production and will repeat parts tempering而使lower hardness, Consideration should also be given retained austenite caused by the volume expansion. Therefore general tempering temperature should be at least molding processing, more than double the die temperature and low-temperature processing is carried out properly in order to elimi
