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Five elements of injection molding process


1. Temperature
A. Oil temperature: for hydraulic press, it is the heat energy generated by the movement and friction of hydraulic oil due to the non-stop operation of the plastic molding machine. It is controlled by cooling water. When starting up, confirm that the oil temperature is about 45 ℃. If the oil temperature is too high or too low, it will affect the transmission of pressure.
B. Material temperature: that is, the barrel temperature. This temperature should be set according to the shape and function of materials and products. If there are documents, it should be set according to the documents.
C. Mold temperature: this temperature is also an important parameter. Its level has a great impact on the performance of the product. Therefore, when setting, we must consider the function and structure of the product, as well as the material and cycle.

2. Speed
A. The speed setting of opening and closing mold is generally based on the principle of slow fast slow. This setting mainly considers the injection molding machine, mold and cycle.
B. Ejection setting: it can be set according to the product structure. Some forbidden words with complex structure can be ejected slowly, and then demoulded quickly to shorten the cycle.
C. Shooting speed: set according to the size and structure of the product. If the structure is complex, the thin wall can be fast. If the structure is simple, the wall thickness can be slow. Set from slow to fast according to the performance of the material.

3. Pressure
A. Glue injection pressure: according to the size of the product and the thickness of the wall, from low to high, other factors shall be considered during commissioning.
B. Holding pressure: the holding pressure is mainly to ensure the finalization and stable size of the product, and its setting should also be set according to the structure and shape of the product.
C. Low pressure protection pressure: this pressure is mainly used to protect the mold and minimize the damage of the mold.
D. Clamping force: it refers to the force required for high pressure during mold closing. Some machines can adjust the clamping force, while others cannot.

4. Time
A. Glue injection time: this time setting must be longer than the actual time, and can also play the role of glue injection protection. The set value of glue injection time is about 0.2 seconds larger than the actual value. The coordination with pressure, speed and temperature should be considered during setting.
B. Low voltage protection time: when this time is in manual mode, first set the time to 2 seconds, and then add about 0.02 seconds according to the actual time.
C. Cooling time: this time is generally set according to the size and thickness of the product, but the glue melting time should not be greater than the cooling time, so that the product can be fully shaped.
D. Pressure holding time: this time is the time to cool the gate before the melt flows back under the pressure of pressure holding to ensure the size of the product after the injection. It can be set according to the size of the gate.

5. Location
A. The injection molding machine mold opening and closing position can be set according to the mold opening and closing speed. The key is to set the starting position of low-pressure protection, that is, the starting position of low-pressure protection should be the point most likely to protect the mold without affecting the cycle, and the ending position should be the position contacted by the front and rear molds of the mold during slow mold closing.
B. Ejection position: this position can meet the complete demoulding of the product. First, set it from small to large. Pay attention to set the fallback position to "0" during mold loading, otherwise the mold is easy to be damaged.
C. Glue melting position: calculate the material quantity according to the product size and screw size, and then set the corresponding position.
D. The V-P position should be found by the large to small short short method (V-P switching point).