In the high end market of bottle, generally made by two step bottle blowing method, That means it is divided into two steps, also called the injection stretch blow moulding. It needs to inject the bottle preform firstly, then blow the bottle preform into bottles.
Because it is to process the blowing bottle with the bottle preform, so the quality of the preform is very important. "One can't make bricks without straw", If there is no good meters, that is not easy to make a good meal, SO the bottle preform is not good, it is hard to blow a good bottle.
Usually some problems easily occur in the process of blowing bottle. Such as blow a broken bottle, All raw materials are gathering at the bottom of the bottle, the bottle bottom is not straight, the bottle wall is too thin, bottle turn white etc. How to distinguish the problem is from blowing bottle step or bottle preform. Now we are analyzing from different status of blowed bottle.
一, Reasons of blowing broken bottle:
1, germ tube heating is not enough, no roast;
2, stretching rod didn't pull in place (end);
3, stretching rod speed is too slow;
4,In the circumstance of the temperature protection but temperature limit is set too high.
Solution:
1, To increase the voltage under the stable yield. To reduce output when voltage is unchanged, that means lengthen the time of two time blowing.
2, Put the air out while closing the mold, hand stretching rod to die bottom and touch the die bottom, tightening the limiting nut. (limited to mechanical limit cylinder regulation).
3, The throttle on the drawing cylinder to maximum.
4, To lower floor limited temperature, generally PET preform is set to 85~95, upper limit can be set to 125~130.
二, The accumulation of material, that is many material gathering together at the bottom.
1, Generally delayed blowing time is too long, or one time blowing is too long;
2, The bottle bottom is not baked soft,large temperature difference with other placement.
The solution:
1, Reducing the delayed blowing time, general dosage is 0.3 seconds, according to the situation to increase or decrease.
2, Pinch the preform by hand, to see if the bottom is also very hard, If yes, heighten the corresponding light.
三, The bottle bottom is not straight:
1, The stretching rod speed too slow;
2, The delayed time is not enough;
3, the preform serious eccentricity.
Solution:
1, Put the throttle on stretching cylinder to maximum;
2, Lengthen delayed blowing time;
3, Test the eccentricity of the bottle preform. (Eccentricity is too large, to a certain extent, the preform will become bent);
4, Including the temperature protection.
四, The bottle wall is too thin
1, If the bottle bottom nozzle is in the middle placement, It may be the preform problem, or the injection mold cooling water.
2, in some places there is no rotation.
The solution:
1, Test by other cavity perform, modify injection molding or injection molding process.
2, To see which perform seat do not rotate, If found, fix the autorotation chain, and make all the heating area of the perform in a good performance.
五,Bottle turn into white
Reasons:
1, The voltage is too high, the bottle body or local placement is ceramic white.
2, the voltage is not enough, resulting in no roast, the bottle body or the local placement is pearl white.
Solution:
The voltage is too high and decrease Voltage, the voltage is too low and heighten voltage.
