Foamed plastics reaction injection molding equipment
DATE：2022/4/13 8:43:36 / READ： / SOURCE：This station
Foamed plastics reaction injection molding equipment
1. control system foam plastic reaction injection molding equipment should be able to accurately control the following four elements: materials; handle; Measurement; Proportioning and mixing. Figure 9-16 shows Milacron liquid reactive injection molding (LRM) system, which uses the following devices when controlling the above four elements.(1) Electronic control electronic control adopts program and whole system logic control, and uses service process controller to maintain constant flow rate and mixing ratio throughout the metering cycle. The controller uses the continuous feedback of the injection process to maintain the input set value, in addition to providing the molds that can be injected by the above process control. In addition to the control function, the pin controller can also pin the action program of the lead machine and select the next one
(2) Hydraulic system
(3) The sensitivity of the chemical reaction device in the monomer treatment tank should be avoided. The hydraulic iron system is an independent pressure detectable power system, which is very important for the development device and mixing mechanism, as well as the liquid level grab pin device and automatic feeder. The single sale processor contains units B and B, with temperature control
(4) The piston cylinder pressure group can provide stable and accurate propulsion flow control, and can also eliminate or reduce the pulsation in the form of "front warping" or "back thinning". The increase of these cylinders in the whole injection cycle is 1% higher than that of the metering precision bowl
Within.
(5) Sexual lubricant system sexual lubricant system sends the sexual lubricant to the distributor, and then the distributor distributes it to each lubrication point; Ensure that all parts with relative motion work smoothly. Due to the use of inert lubricants, there is no harm of chemical pollution or oxidative degradation.
(6) Distribution main channel the distribution main channel can direct the material flow of each reaction monomer to each mold locking device according to the injection requirements (the LRM system shown in Figure 9-16 includes four mold locking devices).
(7) The mold locking device is composed of four mold locking devices. The four decomposition actions of each mold locking platform in one cycle of the complete liquid reaction injection system are as follows.
① The mold locking mechanism fixes the two half molds together, rotates 90 and deflates through the parting surface. Then turn to the operator to take out the parts and provide space for cleaning and removing the mold (see the action of mold locking Table 1 in Figure 9-16).
② After the upper and lower dies are turned to the parallel position, prepare to close the die (see the action of die locking Table 2 in Figure 9-16).
③ The long stroke hydraulic cylinder raises the lower mold and the upper mold to close the mold and lock the mold. Constant clamping force can ensure that the parting surface fits evenly and closely (see die locking Table 3 in Figure 9-16)
Action).
④ The whole C-shaped frame rotates to a certain direction to discharge the air in the mold cavity. When the material is full, the C-shaped frame returns to the upper right position, Fully solidify the workpiece (see Fig. 9-16 action of mold locking Table 4). The lower half of the mold drops and the template turns to the predetermined position to take out the workpiece (that is, the action of mold locking Table 1 in Fig. 9-16 is ready for the next cycle) 。 There are two basic types of rim devices. One is to use metering pump to measure multienzyme and isocarboxylate. The other uses the piston to measure the reactant, which uses the displacement of the piston to complete a feeding pulse. Both machines use high pressure to force the reaction object into a small mixing chamber through the nozzle hole. Due to the high speed of the sprayed material, the two components are strongly impacted and mixed in the mixing chamber. The current M mixing head is equipped with a cleaning plunger, which can discharge the material in the mixing chamber at one time at the end of injection, so there is no need to purge the mixing head with air or agent.
Compared with the corresponding thermoplastic injection molding, the temperature and pressure of rim are very low, so the equipment cost and operation cost of the parts formed by rim are low, which can be reflected by the comparison of the energy spent in producing the same parts. Figure 9-18 is a comparison of the energy required per unit volume of different raw materials in the production of similar molded parts. It can be seen from the figure that the energy consumption for refining and manufacturing metal parts is quite high. The polymer in the picture has already included the energy consumption value of the raw material. Obviously, the energy consumption of RIM polyurethane elastomer foam is the lowest.
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