Nine problems most likely to occur in the quality of blow-molded plastic bottles

Problem 1: If the top is thick and the bottom is thin, it is necessary to delay the pre-blowing time, or reduce the pre-blowing pressure and air flow.

Problem 2: The bottom is thick and the top is thin, which is the opposite of the problem that has been solved.

Problem 3: There will be wrinkles under the bottleneck, the pre-blowing is too late or the pre-blowing pressure is too low, or the billet cooling here is not good.

Problem 4: The bottom is white, the main reason is that the preform is too cold; at the same time, it is stretched too much; the pre-blowing time is too early or the pre-blowing pressure is too high.

Question 5: There is a magnifying glass phenomenon at the bottom of the bottle, and there is too much material at the bottom of the bottle; the pre-blowing is too late, and the pre-blowing pressure is too low.

Problem 6: There are wrinkles in the bottom of the bottle, the bottom temperature is too high (the cooling at the gate is not good); the pre-blowing is too late, the pre-blowing pressure is too low, and the flow rate is too small.

Question 7: The whole bottle looks turbid and less transparent, and the cooling is not enough.

Problem 8: Partial whitening: excessive stretching, the temperature here is too low, or the pre-blowing is too early, or the stretching rod is touched.

Question 9: The eccentricity of the PET plastic bottle bottom may be related to the preform temperature, stretching, pre-blowing, high-pressure blowing, etc. The solution is to first reduce the temperature of the preform; at the same time, speed up the stretching speed; check the gap between the tie rod head and the bottom mold; delay the pre-blowing and reduce the pre-blowing pressure; delay the high-pressure blowing; check after processing Whether there will be eccentricity of the preform.