Views:5 Author:Site Editor Publish Time: 2019-10-17 Origin:Site
The types of materials that can be made by twin-screw granulators are:
1) Glass fiber, the temperature is too low, the resin is semi-melted, and the glass fiber is poorly coated in the latter stage; the temperature is too high, the resin flow is increased, the tempering and shearing action is small, and even high temperature degradation occurs, and the setting principle is as follows:
1. According to different base materials and different glass fiber content;
2. The heat input from the screw shearing is deducted, which is slightly higher than the melting point of the base material;
3. Melt flow condition in the latter part of the melting section (ie, glass fiber inlet).
2) Filling system, (providing strong shear to make the filler fully dispersed), the melting section is 10~20 °C higher than the melting point of the base material (as much as possible), so that the material is fully melted and evenly distributed.
3) Flame retardant system (protective flame retardant), its temperature should be low, especially white material, as low as possible.
4) Glass fiber reinforced flame retardant system, the set temperature is between the former two, based on the basic melting point of the material.
5) The alloy system is based on the melting temperature of the two groups, and the temperature is appropriately adjusted according to the ratio of the components and the heat sensitivity of the components.
For example, PC/ABS (6:4), PC: melting point of about 230 degrees, decomposition point of about 350 degrees; ABS: melting point of 180 ~ 190 degrees, decomposition point of 245-290 degrees - so PC / ABS processing temperature 230-250 Degree - taking into account other additives such as compatibilizers, thermal stability of lubricants, etc.