Collapsing the bottle neck finish will have major production issues. When the neck is distorted, the cap pick off setting is compromised causing the cap to bottle engagement to be miss-applied resulting in a poor cap to be applied correctly. This issue can stem from the bottle leak detector hitting the bottle too hard, the filler bowl being too low, because the wrong valves are used, and the springs or diaphragms are too heavy which distort the neck finish.

The leak detector can also be an issue. If bottles are very warm on the cooling bed, when the leak detector tests the bottles, the leak detector may be hitting the bottle too hard, which will distort the neck finish. This problem can be corrected by checking on the air pressure setting. Backing off the air pressure just enough for the leak detector, may resolve this problem. Check the leak detector manual for the correct setting.

The filler bowl being will also collapse the bottle neck the actual bowl can be too low. The reasons can be from two different diaphragms may be mixed on the filler, different length valves may have been installed etc. A couple of items: there may be two different length valves on the filler which the valve will not activate the smaller valve until it is in the correct position; the longer feed tube began distorting the neck finish for some time. The rubber diaphragms are on the wrong filler (gallon vs. half gallon) or the springs may be too heavy.