Wuhan Handern raw materials and molding technology
日期：2021/1/8 8:51:17 / 阅读： / 来源：本站
Wuhan Handern raw materials and molding technology1. Raw materials
Almost all thermosetting plastics can be injection molded, but the larger one is phenolic plastics.
(1) Most of the phenolic plastics used for injection molding are filled with wood powder or cellulose, which have good flow properties. And the allowable heating time range is wider than that of Baolong and wangjuyin adhesives (as shown in Fig. 7-23). Therefore, it is easy to control the product quality and the operation safety is good. Because of the face. PF is one of the main permitted thermal cycle fertilizers. There are several jin products in China. Hollow board www.handern.com
(2) The amino plastic is shown in Fig. 7-23. The heating time of amino plastics is short, so high injection speed is required. But if the construction degree is too high, the residual internal stress in the product will cause color cracking. The curing conditions of amino plastics are better than those shown in Fig. 7-24, and the core and material temperature should be well set. Due to the sensitive transformation of teaching materials, it is reasonable. The western use of time (ambft) is not to change the time from the smell of mipuding. In addition, the heating temperature of the molten resin is about 30 ℃. So as not to round the heart, which is not enough. 1t (no powder filling)
(3) It is not common for beiwen to use glass fiber, huitangqiang's DMC or SMC, which is in accordance with the requirements of moving beads. The performance of Tongjie Xuanhang press meter is better than that of other components. Due to the increase of mixed sand shear force, the distribution of glass fiber length is destroyed, which makes the products have a strong impact on the market. The bending strength is not affected. Hollow board www.handern.com
For the runner system of the casting tool, it is better to shorten the nozzle in the zone) 2) the runner section should be more than 46mm in shape; for the non limited runner with large taphole, the mechanical strength can be improved by increasing the depth of the runner, but it has nothing to do with the width of the runner.
(4) The curing time of epoxy resin is determined by mbft. The wall thickness has little effect on the curing time, and the molding shrinkage is only about 0,1%, but the difference between the flow direction and the vertical direction is about 3%. So injection pressure
5) The melting viscosity of the resin is low, and the torque is only 500-650g at 120-140c. The process conditions are as follows: barrel temperature (back) 120 ℃ and (front) 120 ℃; nozzle temperature 120 ℃, mold temperature 215-240 ℃, injection pressure 5-7npa (00kgi / C)
2. Molding process hollow plate www.handern.com
Temperature control is the key to injection of thermosetting plastics. Because it affects the change of plastic flow and hardening rate. The changes of temperature and viscosity of phenolic plastic during injection molding are shown in Figure 7-27. It can be seen from the figure that the temperature of the plastic in the barrel rises to about 20-95 ℃ C after the process of top plastic and material accumulation. At this time, the plastic is mainly biophysical and chemical. During the injection, because of the high flow rate of the material at the injection site, the temperature of the plastic rises rapidly due to the shear friction, and the temperature of the injection is controlled at 120 ~ 130 ℃