Because the weight and thickness of tube blank is different, the shape of bottle is different, and the temperature of production place is different, it's hard to provide a settled and accurate process parameters to customer. The best bottle blowing parameters could only be found in actual operation by customers. Here we only recommend the general process range:
Preheat part: It could test by put tube blank inside. Generally, only if the hardness of up, middle and down segments of tube blank are proper, and the tube blank with elasticity, then it suits for blowing. But it also need to adjust the heating voltage of 10 segments in preheat area according to the shape of bottle, and heating time for soften tube blank in every segment (about 5～10 minutes), so not to be impatient. After preheat and trial blowing succeeded, record the voltage of every segment immediately as the heating reference data for blowing and forming the same kind of tube blank next time.
In tube blank blowing process, it's a period that mold closing-gate closing-seal-stretching-minor blowing-blowing-air releasing-mold opening. The setting of every single action should according to the production situation.
(1) Period Time
The period time includes stretching delay (0.0～0.3s), minor blowing delay (0.1～0.5s), minor blowing time (0.1～0.5s), blowing time (0.5～3.0s), air release time (0.1～1s), etc. Generally, a period time is set as 3～6s.
(2) Delay Stretching Time
When blowing tube blank, the stretching and blowing are working synchronously. For ensuring a reasonable ratio between stretching length ways and blowing laterally to raise the strength of bottle, it's a must that blowing after the tube blank been stretched a certain length ways, that means the blowing time has a little delay than stretching time. That time is delay stretching time. Delay stretching time is subject to the length of tube blank and shape of bottle, no longer or shorter. Stretching too long: lines of upper part of the bottle not obvious or the bottle is thin after formed (If the delay is longer, then the upper part will be more thin, and below part will heap up); If the delay is too short: the upper part of bottle will be very thick, below part of bottle will be very thin. If serious, the bottle bottom will be blew broken, upper part will heap up. Generally, the time setting is 0.0～0.3s.
(3) Minor Blowing Time
Minor blowing time is subject to the shape of bottle. If the bottleneck need to be thin, then longer minor blowing time. In contrary, shorten minor blowing time. The minor blowing time is often set between 0.1～0.5s, pressure about 0.3～0.8MPa.
(4) Blowing Time
The blowing time is subject to the volume of bottle body. Generally, for bottles of volume less than 1L, the time is 0.5～1.2s, For 1～6L, it's 1.2～3.0s. The larger the volume, the longer the blowing time.
(5) How to judge whether the bottle blank reached the temperature needed for blowing?
Turn on the infrared lamp corresponding with tube blank, and to have the machine under position shifting status. After heated for 5～10 minutes, output 1 group of tube blanks. At this time, the bottle blank move from the input side to output side of heating source area. After the bottle blank come out, If it feels elasticity by hand, and without becoming white, that means the bottle blank almost reached the temperature needed. When bottle blank is rigid, that means the bottle blank not reached the temperature needed yet. Once blowing, it will explode in the mold, so it need proper temperature adjusting, so as to reach the best ratio between temperature and heating time.
