What uncertain factors will be generated by the blow molding machine in the production

Usually in the production of automatic blow molding machine, the weight of the product is often unstable, and the weight of the product exceeds the specified deviation. The characteristic of weight instability is that the length of the nozzle material at the bottom of the bottle is different. In severe cases, the length of the material tube is not enough, so that the product cannot be blown. The reasons for the weight instability are mainly as follows:

1. The temperature control of the blow molding machine is inaccurate or the temperature deviation is large during production, and the installation position of the temperature measuring point (thermocouple) is unreasonable, which causes periodic deviation of the temperature. As the temperature deviation increases, the deviation affecting the weight also increases. big. When the temperature rises, the stretching of the extrusion barrel increases. In the same operation cycle, the nozzle material at the bottom of the bottle increases, and the weight of the product is reduced. When the temperature is low, the weight of the product increases.

When the thermocouple has poor contact, there is a similar failure. If the thermocouple is bad, the extrusion volume will decrease, and when the temperature is lower than the melting point of the plastic, the motor current will increase. It cannot be extruded below the melting point of the plastic. Whether the installation position of the thermocouple is reasonable and the size of the temperature control area of ​​the thermocouple measuring point will directly affect the extrusion stability.

2. The running time of the two mold bases is inconsistent (the difference is too large). If the downward flow of the material pipe is at a constant speed, when the time difference between the left and right mold bases is large, the weight of both sides will be unstable. The mold base that runs faster is heavier, and the mold base that runs slower is lighter due to stretching. The solution is to adjust the die set on both sides to make the run time close.

3. The extrusion volume is unstable, and the extrusion volume is unstable due to the unstable rotation speed of the motor and the unsuitable lightness of the belt.

4. The reason for the plastic raw materials is that the output is different due to the change of different plastic raw materials or the mixing ratio. The amount (percent) of the nozzle material added often affects the extrusion volume.