Usually barrel temperature, nozzle temperature and material melting temperature are shown in Table 1.
Considering service life of screw, temperature difference between rear, middle and front can be reduced. In order to prevent nozzle drooling, nozzle temperature can be 10℃ lower than temperature shown in the table. If fluidity is to be improved, temperature can be set 20℃ higher than temperature shown in table, but following conditions must be noted.
When reducing temperature of barrel: residence time is too long, which will not cause aging of pellets in barrel, and will not produce corrosive gas, so long residence time generally does not cause any major problems. However, if molding is interrupted for a long time, please reduce temperature of barrel, and it is better to throw away a few molds when molding again.
Barrel temperature during molding of each grade (℃)

Mold temperature that LCP can form is between 30℃ and 150℃. But we generally set mold temperature at around 70℃-110℃. In order to shorten molding cycle, prevent flash and deformation, a low mold temperature should be selected; if product is required to be dimensionally stable (especially for products under high temperature conditions), reduce generation of weld seams and solve problems such as insufficient filling, a high mold temperature should be selected.
Barrel temperature: 300℃
Residence time of 0 points refers to molding under normal cycle

 

Fig.1 Relationship between residence time in barrel and retention of tensile strength
Residence time in barrel (min)
Barrel temperature: 300℃
Residence time of 0 points refers to molding under normal cycle

 

Fig. 2 Relationship between residence time in barrel and retention rate of elongation
Residence time in barrel (min)
Barrel temperature: 300℃
Residence time of 0 points refers to molding under normal cycle

 

Fig.3 Residence time and discoloration (△E) in barrel

 

Figure 4 Thermal Decomposition Curve
When temperature of barrel is set to 300℃, effect of residence time of material in barrel on mechanical properties and color is shown in Figure 1--Figure 2. Unpacked stage was left in barrel for 15 minutes with a slight decrease in its mechanical properties. While GF grade stays in barrel for 60 minutes, its mechanical properties remain basically unchanged.
Either one has a little change in color (△E).
Weight loss obtained by thermobalance is shown in Figure 4. Temperature at which decomposition begins gradually is about 460℃, which is much higher than usual molding temperature.

Rotational speed of screw is generally 100 rpm. If it is a material containing glass fiber or carbon glass fiber (for example: A130, A230, etc.), in order to prevent glass fiber from being broken, we must choose a relatively low speed. Also, keep back pressure as low as possible

The most suitable pressure must depend on material, product shape, mold design (especially sprue, runner, gate) and other molding conditions. However, melt viscosity of LCP without any grade is very low, so pressure is lower than that of general thermoplastic resins.
It is a good method to use low pressure at beginning of molding and then gradually increase pressure. Most molded products can be molded under pressure of 15MPa-45MPa. In addition, curing time of LCP is relatively fast, so it is easy to obtain good results if speed is fast.

Molding cycle depends on size, shape, thickness, mold structure and molding conditions of molded product. As mentioned above, LCP has good fluidity, so its filling time is relatively short, and curing speed is relatively fast, so we can get a short molding cycle. A typical molding cycle is 10 seconds to 30 seconds.