Under what circumstances will the pet plastic bottle blowing process have excellent products
1. Auxiliary machine and mould
Auxiliary equipment mainly refers to the equipment to maintain the constant temperature of the mold. Mold constant temperature plays an important role in maintaining product stability. Generally, the body temperature is high and the bottom temperature is low. For the cold bottle, the cooling effect at the bottom determines the degree of molecular orientation, so it is better to control the temperature at 5-8 ℃, while the temperature at the bottom of the hot bottle is much higher.
The mold is an important factor affecting the blow molding process of PET bottle. The shape of the mold will reduce or increase the difficulty of process adjustment, such as the stiffener, the radian of the transition area and the heat dissipation at the bottom.
The quality of production environment also has a great influence on process adjustment. Constant temperature conditions can maintain process stability and product stability. PET bottle blow molding is generally better at room temperature and low humidity.
3. Other requirements
The pressure bottle shall meet the requirements of stress test and pressure test at the same time. Stress test is an internal quality control to prevent the cracking and leakage caused by the degradation of molecular chain in the process of contact between the bottle bottom and lubricant (alkaline) during the filling of PET bottle; pressure test is a quality control to prevent the bottle from bursting after being filled with certain pressure gas. In order to meet these two needs, the thickness of the center point should be controlled within a certain range. Generally, the center point is thin, the stress test is good, and the withstand voltage is poor; the center point is thick, the withstand voltage test is good, and the stress test is poor. Of course, the results of stress test also have a great relationship with the accumulation of materials in the transition area around the center point, which should be adjusted according to practical experience.
The adjustment of PET bottle blow molding process is based on the corresponding materials. If the materials are not good, the process requirements are very strict, and even it is difficult to blow molding qualified bottles.